vulkan: add an overlay layer
authorLionel Landwerlin <lionel.g.landwerlin@intel.com>
Sat, 19 Jan 2019 21:26:12 +0000 (21:26 +0000)
committerLionel Landwerlin <lionel.g.landwerlin@intel.com>
Thu, 21 Feb 2019 18:06:05 +0000 (18:06 +0000)
Just a starting point to display frame timings & drawcalls/submissions
per frame.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Acked-by: Jason Ekstrand <jason@jlekstrand.net>
+1-by: Mike Lothian <mike@fireburn.co.uk>
+1-by: Tapani Pälli <tapani.palli@intel.com>
+1-by: Eric Engestrom <eric.engestrom@intel.com>
+1-by: Yurii Kolesnykov <root@yurikoles.com>
+1-by: myfreeweb <greg@unrelenting.technology>
+1-by: Kenneth Graunke <kenneth@whitecape.org>

meson_options.txt
src/vulkan/Makefile.am
src/vulkan/meson.build
src/vulkan/overlay-layer/README [new file with mode: 0644]
src/vulkan/overlay-layer/VkLayer_MESA_overlay.json.in [new file with mode: 0644]
src/vulkan/overlay-layer/meson.build [new file with mode: 0644]
src/vulkan/overlay-layer/overlay.cpp [new file with mode: 0644]
src/vulkan/overlay-layer/overlay.frag [new file with mode: 0644]
src/vulkan/overlay-layer/overlay.vert [new file with mode: 0644]
src/vulkan/overlay-layer/vk_layer_table.cpp [new file with mode: 0644]
src/vulkan/overlay-layer/vk_layer_table.h [new file with mode: 0644]

index d0ab500..4983cb6 100644 (file)
@@ -168,6 +168,12 @@ option(
   description : 'Location relative to prefix to put vulkan icds on install. Default: $datadir/vulkan/icd.d'
 )
 option(
+  'vulkan-overlay-layer',
+  type : 'boolean',
+  value : false,
+  description : 'Whether to build the vulkan overlay layer'
+)
+option(
   'shared-glapi',
   type : 'boolean',
   value : true,
index cc738d5..fbd9e30 100644 (file)
@@ -9,6 +9,14 @@ MKDIR_GEN = $(AM_V_at)$(MKDIR_P) $(@D)
 PYTHON_GEN = $(AM_V_GEN)$(PYTHON) $(PYTHON_FLAGS)
 
 EXTRA_DIST = \
+       overlay-layer/README \
+       overlay-layer/meson.build \
+       overlay-layer/overlay.cpp \
+       overlay-layer/overlay.frag \
+       overlay-layer/overlay.vert \
+       overlay-layer/VkLayer_MESA_overlay.json.in \
+       overlay-layer/vk_layer_table.cpp \
+       overlay-layer/vk_layer_table.h \
        util/gen_enum_to_str.py \
        util/meson.build \
        wsi/meson.build \
index 59e1fd1..35d7e5e 100644 (file)
@@ -25,3 +25,6 @@ inc_vulkan_wsi = include_directories('wsi')
 
 subdir('util')
 subdir('wsi')
+if get_option('vulkan-overlay-layer')
+  subdir('overlay-layer')
+endif
diff --git a/src/vulkan/overlay-layer/README b/src/vulkan/overlay-layer/README
new file mode 100644 (file)
index 0000000..d3fb03a
--- /dev/null
@@ -0,0 +1,22 @@
+A Vulkan layer to display information about the running application
+using an overlay.
+
+To turn on the layer run :
+```
+VK_INSTANCE_LAYERS=VK_LAYER_MESA_overlay /path/to/my_vulkan_app
+```
+
+List the available statistics :
+```
+VK_INSTANCE_LAYERS=VK_LAYER_MESA_overlay VK_LAYER_MESA_OVERLAY_STATS=help /path/to/my_vulkan_app
+```
+
+Turn on some statistics :
+```
+VK_INSTANCE_LAYERS=VK_LAYER_MESA_overlay VK_LAYER_MESA_OVERLAY_STATS=submit,draw,pipeline-graphics /path/to/my_vulkan_app
+```
+
+Position the layer :
+```
+VK_INSTANCE_LAYERS=VK_LAYER_MESA_overlay VK_LAYER_MESA_OVERLAY_STATS=submit,draw,pipeline-graphics VK_LAYER_MESA_OVERLAY_POSITION=top-right /path/to/my_vulkan_app
+```
diff --git a/src/vulkan/overlay-layer/VkLayer_MESA_overlay.json.in b/src/vulkan/overlay-layer/VkLayer_MESA_overlay.json.in
new file mode 100644 (file)
index 0000000..5a9a88a
--- /dev/null
@@ -0,0 +1,11 @@
+{
+    "file_format_version" : "1.0.0",
+    "layer" : {
+        "name": "VK_LAYER_MESA_overlay",
+        "type": "GLOBAL",
+        "library_path": "@install_dir@/libVkLayer_MESA_overlay.so",
+        "api_version": "1.1.73",
+        "implementation_version": "1",
+        "description": "Mesa Overlay layer"
+    }
+}
diff --git a/src/vulkan/overlay-layer/meson.build b/src/vulkan/overlay-layer/meson.build
new file mode 100644 (file)
index 0000000..573983e
--- /dev/null
@@ -0,0 +1,62 @@
+# Copyright © 2019 Intel Corporation
+
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+vklayer_install_dir = join_paths(get_option('prefix'), 'share', 'vulkan', 'explicit_layer.d')
+
+glslang = find_program('glslangValidator')
+
+overlay_shaders = [
+  'overlay.frag',
+  'overlay.vert',
+]
+overlay_spv = []
+foreach s : ['overlay.frag', 'overlay.vert']
+  overlay_spv += custom_target(
+    s + '.spv.h', input : s, output : s + '.spv.h',
+    command : [glslang, '-V', '-x', '-o', '@OUTPUT@', '@INPUT@'])
+endforeach
+
+vklayer_files = files(
+  'overlay.cpp',
+  'vk_layer_table.cpp',
+)
+
+vklayer_mesa_overlay = shared_library(
+  'VkLayer_MESA_overlay',
+  vklayer_files, overlay_spv,
+  c_args : [c_vis_args, no_override_init_args],
+  cpp_args : [cpp_vis_args],
+  dependencies : [libimgui_core_dep, dep_dl],
+  include_directories : [inc_common, inc_vulkan_util],
+  link_args : cc.get_supported_link_arguments(['-Wl,-Bsymbolic-functions', '-Wl,-z,relro']),
+  link_with : [libmesa_util, libvulkan_util],
+  install_dir : vklayer_install_dir,
+)
+
+sdata = configuration_data()
+sdata.set('install_dir', vklayer_install_dir)
+
+configure_file(
+  input : 'VkLayer_MESA_overlay.json.in',
+  output : '@BASENAME@',
+  configuration : sdata,
+  install_dir : vklayer_install_dir,
+  install : true
+)
diff --git a/src/vulkan/overlay-layer/overlay.cpp b/src/vulkan/overlay-layer/overlay.cpp
new file mode 100644 (file)
index 0000000..f367819
--- /dev/null
@@ -0,0 +1,1843 @@
+/*
+ * Copyright © 2019 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <string.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#include <vk_loader_platform.h>
+#include <vulkan/vulkan.h>
+#include <vk_dispatch_table_helper.h>
+#include <vulkan/vk_layer.h>
+#include "vk_layer_data.h"
+#include "vk_layer_table.h"
+#include "vk_layer_extension_utils.h"
+
+#include "imgui.h"
+
+#include "util/debug.h"
+#include "util/hash_table.h"
+#include "util/ralloc.h"
+#include "util/os_time.h"
+#include "util/simple_mtx.h"
+
+#include "vk_enum_to_str.h"
+
+enum layer_position {
+   LAYER_POSITION_TOP_LEFT,
+   LAYER_POSITION_TOP_RIGHT,
+   LAYER_POSITION_BOTTOM_LEFT,
+   LAYER_POSITION_BOTTOM_RIGHT,
+};
+
+static enum layer_position
+parse_layer_position(const char *str)
+{
+   if (!str || !strcmp(str, "top-left"))
+      return LAYER_POSITION_TOP_LEFT;
+   if (!strcmp(str, "top-right"))
+      return LAYER_POSITION_TOP_RIGHT;
+   if (!strcmp(str, "bottom-left"))
+      return LAYER_POSITION_BOTTOM_LEFT;
+   if (!strcmp(str, "bottom-right"))
+      return LAYER_POSITION_BOTTOM_RIGHT;
+   return LAYER_POSITION_TOP_LEFT;
+}
+
+/* Mapped from VkInstace/VkPhysicalDevice */
+struct instance_data {
+   VkLayerInstanceDispatchTable vtable;
+   VkInstance instance;
+
+   enum layer_position position;
+   uint64_t enabled_stats;
+};
+
+enum frame_stat_type {
+   FRAME_STAT_SUBMIT,
+   FRAME_STAT_DRAW,
+   FRAME_STAT_DRAW_INDEXED,
+   FRAME_STAT_DRAW_INDIRECT,
+   FRAME_STAT_DRAW_INDEXED_INDIRECT,
+   FRAME_STAT_DRAW_INDIRECT_COUNT,
+   FRAME_STAT_DRAW_INDEXED_INDIRECT_COUNT,
+   FRAME_STAT_DISPATCH,
+   FRAME_STAT_DISPATCH_INDIRECT,
+   FRAME_STAT_PIPELINE_GRAPHICS,
+   FRAME_STAT_PIPELINE_COMPUTE,
+   FRAME_STAT_PIPELINE_RAYTRACING,
+
+   FRAME_STAT_COUNT,
+
+   FRAME_STAT_ACQUIRE_TIMING = FRAME_STAT_COUNT,
+   FRAME_STAT_HELP,
+};
+
+#define FRAME_STAT_ENABLED(id) (1ULL << (FRAME_STAT_ ## id))
+
+static struct debug_control enable_flags[] = {
+   { "submit",                      FRAME_STAT_ENABLED(SUBMIT) },
+   { "draw",                        FRAME_STAT_ENABLED(DRAW) },
+   { "draw-indexed",                FRAME_STAT_ENABLED(DRAW_INDEXED) },
+   { "draw-indirect",               FRAME_STAT_ENABLED(DRAW_INDIRECT) },
+   { "draw-indexed-indirect",       FRAME_STAT_ENABLED(DRAW_INDEXED_INDIRECT) },
+   { "draw-indirect-count",         FRAME_STAT_ENABLED(DRAW_INDIRECT_COUNT) },
+   { "draw-indexed-indirect-count", FRAME_STAT_ENABLED(DRAW_INDEXED_INDIRECT_COUNT) },
+   { "dispatch",                    FRAME_STAT_ENABLED(DISPATCH) },
+   { "dispatch-indirect",           FRAME_STAT_ENABLED(DISPATCH_INDIRECT) },
+   { "pipeline-graphics",           FRAME_STAT_ENABLED(PIPELINE_GRAPHICS) },
+   { "pipeline-compute",            FRAME_STAT_ENABLED(PIPELINE_COMPUTE) },
+   { "pipeline-raytracing",         FRAME_STAT_ENABLED(PIPELINE_RAYTRACING) },
+   { "acquire-timing",              FRAME_STAT_ENABLED(ACQUIRE_TIMING) },
+   { "help",                        FRAME_STAT_ENABLED(HELP) },
+   { NULL,                          0 },
+};
+
+struct frame_stat {
+   uint32_t stats[FRAME_STAT_COUNT];
+};
+
+/* Mapped from VkDevice/VkCommandBuffer */
+struct queue_data;
+struct device_data {
+   struct instance_data *instance;
+
+   VkLayerDispatchTable vtable;
+   VkPhysicalDevice physical_device;
+   VkDevice device;
+
+   VkPhysicalDeviceProperties properties;
+
+   struct queue_data *graphic_queue;
+
+   struct queue_data **queues;
+   uint32_t n_queues;
+
+   struct frame_stat stats;
+};
+
+/* Mapped from VkQueue */
+struct queue_data {
+   struct device_data *device;
+
+   VkQueue queue;
+   VkQueueFlags flags;
+   uint32_t family_index;
+};
+
+/* Mapped from VkSwapchainKHR */
+struct swapchain_data {
+   struct device_data *device;
+
+   VkSwapchainKHR swapchain;
+   unsigned width, height;
+   VkFormat format;
+
+   uint32_t n_images;
+   VkImage *images;
+   VkImageView *image_views;
+   VkFramebuffer *framebuffers;
+
+   VkRenderPass render_pass;
+
+   VkDescriptorPool descriptor_pool;
+   VkDescriptorSetLayout descriptor_layout;
+   VkDescriptorSet descriptor_set;
+
+   VkSampler font_sampler;
+
+   VkPipelineLayout pipeline_layout;
+   VkPipeline pipeline;
+
+   VkCommandPool command_pool;
+
+   struct {
+      VkCommandBuffer command_buffer;
+
+      VkBuffer vertex_buffer;
+      VkDeviceMemory vertex_buffer_mem;
+      VkDeviceSize vertex_buffer_size;
+
+      VkBuffer index_buffer;
+      VkDeviceMemory index_buffer_mem;
+      VkDeviceSize index_buffer_size;
+   } frame_data[2];
+
+   bool font_uploaded;
+   VkImage font_image;
+   VkImageView font_image_view;
+   VkDeviceMemory font_mem;
+   VkBuffer upload_font_buffer;
+   VkDeviceMemory upload_font_buffer_mem;
+
+   VkFence fence;
+   VkSemaphore submission_semaphore;
+
+   /**/
+   ImGuiContext* imgui_context;
+   ImVec2 window_size;
+
+   /**/
+   uint64_t n_frames;
+   uint64_t last_present_time;
+
+   double frame_times[200];
+
+   double acquire_times[200];
+   uint64_t n_acquire;
+
+   enum frame_stat_type stat_selector;
+   struct frame_stat stats_min, stats_max;
+   struct frame_stat stats[200];
+};
+
+static struct hash_table *vk_object_to_data = NULL;
+static simple_mtx_t vk_object_to_data_mutex = _SIMPLE_MTX_INITIALIZER_NP;
+
+thread_local ImGuiContext* __MesaImGui;
+
+static inline void ensure_vk_object_map(void)
+{
+   if (!vk_object_to_data) {
+      vk_object_to_data = _mesa_hash_table_create(NULL,
+                                                  _mesa_hash_pointer,
+                                                  _mesa_key_pointer_equal);
+   }
+}
+
+#define FIND_SWAPCHAIN_DATA(obj) ((struct swapchain_data *)find_object_data((void *) obj))
+#define FIND_DEVICE_DATA(obj) ((struct device_data *)find_object_data((void *) obj))
+#define FIND_QUEUE_DATA(obj) ((struct queue_data *)find_object_data((void *) obj))
+#define FIND_PHYSICAL_DEVICE_DATA(obj) ((struct instance_data *)find_object_data((void *) obj))
+#define FIND_INSTANCE_DATA(obj) ((struct instance_data *)find_object_data((void *) obj))
+static void *find_object_data(void *obj)
+{
+   simple_mtx_lock(&vk_object_to_data_mutex);
+   ensure_vk_object_map();
+   struct hash_entry *entry = _mesa_hash_table_search(vk_object_to_data, obj);
+   void *data = entry ? entry->data : NULL;
+   simple_mtx_unlock(&vk_object_to_data_mutex);
+   return data;
+}
+
+static void map_object(void *obj, void *data)
+{
+   simple_mtx_lock(&vk_object_to_data_mutex);
+   ensure_vk_object_map();
+   _mesa_hash_table_insert(vk_object_to_data, obj, data);
+   simple_mtx_unlock(&vk_object_to_data_mutex);
+}
+
+static void unmap_object(void *obj)
+{
+   simple_mtx_lock(&vk_object_to_data_mutex);
+   struct hash_entry *entry = _mesa_hash_table_search(vk_object_to_data, obj);
+   _mesa_hash_table_remove(vk_object_to_data, entry);
+   simple_mtx_unlock(&vk_object_to_data_mutex);
+}
+
+/**/
+static struct instance_data *new_instance_data(VkInstance instance)
+{
+   struct instance_data *data = rzalloc(NULL, struct instance_data);
+   data->instance = instance;
+   map_object(data->instance, data);
+   return data;
+}
+
+static void destroy_instance_data(struct instance_data *data)
+{
+   unmap_object(data->instance);
+   ralloc_free(data);
+}
+
+static void instance_data_map_physical_devices(struct instance_data *instance_data,
+                                               bool map)
+{
+   uint32_t physicalDeviceCount = 0;
+   instance_data->vtable.EnumeratePhysicalDevices(instance_data->instance,
+                                                  &physicalDeviceCount,
+                                                  NULL);
+
+   VkPhysicalDevice *physicalDevices = (VkPhysicalDevice *) malloc(sizeof(VkPhysicalDevice) * physicalDeviceCount);
+   instance_data->vtable.EnumeratePhysicalDevices(instance_data->instance,
+                                                  &physicalDeviceCount,
+                                                  physicalDevices);
+
+   for (uint32_t i = 0; i < physicalDeviceCount; i++) {
+      if (map)
+         map_object(physicalDevices[i], instance_data);
+      else
+         unmap_object(physicalDevices[i]);
+   }
+
+   free(physicalDevices);
+}
+
+/**/
+static struct device_data *new_device_data(VkDevice device, struct instance_data *instance)
+{
+   struct device_data *data = rzalloc(NULL, struct device_data);
+   data->instance = instance;
+   data->device = device;
+   map_object(data->device, data);
+   return data;
+}
+
+static struct queue_data *new_queue_data(VkQueue queue,
+                                         const VkQueueFamilyProperties *family_props,
+                                         uint32_t family_index,
+                                         struct device_data *device_data)
+{
+   struct queue_data *data = rzalloc(device_data, struct queue_data);
+   data->device = device_data;
+   data->queue = queue;
+   data->flags = family_props->queueFlags;
+   data->family_index = family_index;
+   map_object(data->queue, data);
+
+   if (data->flags & VK_QUEUE_GRAPHICS_BIT)
+      device_data->graphic_queue = data;
+
+   return data;
+}
+
+static void device_map_queues(struct device_data *data,
+                              const VkDeviceCreateInfo *pCreateInfo)
+{
+   for (uint32_t i = 0; i < pCreateInfo->queueCreateInfoCount; i++)
+      data->n_queues += pCreateInfo->pQueueCreateInfos[i].queueCount;
+   data->queues = ralloc_array(data, struct queue_data *, data->n_queues);
+
+   struct instance_data *instance_data = data->instance;
+   uint32_t n_family_props;
+   instance_data->vtable.GetPhysicalDeviceQueueFamilyProperties(data->physical_device,
+                                                                &n_family_props,
+                                                                NULL);
+   VkQueueFamilyProperties *family_props =
+      (VkQueueFamilyProperties *)malloc(sizeof(VkQueueFamilyProperties) * n_family_props);
+   instance_data->vtable.GetPhysicalDeviceQueueFamilyProperties(data->physical_device,
+                                                                &n_family_props,
+                                                                family_props);
+
+   uint32_t queue_index = 0;
+   for (uint32_t i = 0; i < pCreateInfo->queueCreateInfoCount; i++) {
+      for (uint32_t j = 0; j < pCreateInfo->pQueueCreateInfos[i].queueCount; j++) {
+         VkQueue queue;
+         data->vtable.GetDeviceQueue(data->device,
+                                     pCreateInfo->pQueueCreateInfos[i].queueFamilyIndex,
+                                     j, &queue);
+         data->queues[queue_index++] =
+            new_queue_data(queue, &family_props[pCreateInfo->pQueueCreateInfos[i].queueFamilyIndex],
+                           pCreateInfo->pQueueCreateInfos[i].queueFamilyIndex, data);
+      }
+   }
+
+   free(family_props);
+}
+
+static void device_unmap_queues(struct device_data *data)
+{
+   for (uint32_t i = 0; i < data->n_queues; i++)
+      unmap_object(data->queues[i]->queue);
+}
+
+static void destroy_device_data(struct device_data *data)
+{
+   unmap_object(data->device);
+   ralloc_free(data);
+}
+
+static void check_vk_result(VkResult err)
+{
+   if (err != VK_SUCCESS)
+      printf("ERROR!\n");
+}
+
+/**/
+static struct swapchain_data *new_swapchain_data(VkSwapchainKHR swapchain,
+                                                 struct device_data *device_data)
+{
+   struct swapchain_data *data = rzalloc(NULL, struct swapchain_data);
+   data->device = device_data;
+   data->swapchain = swapchain;
+   data->window_size = ImVec2(300, 300);
+   map_object(data->swapchain, data);
+   return data;
+}
+
+static void destroy_swapchain_data(struct swapchain_data *data)
+{
+   unmap_object(data->swapchain);
+   ralloc_free(data);
+}
+
+static void snapshot_swapchain_frame(struct swapchain_data *data)
+{
+   uint64_t now = os_time_get();
+
+   if (data->last_present_time) {
+      data->frame_times[(data->n_frames - 1) % ARRAY_SIZE(data->frame_times)] =
+         ((double)now - (double)data->last_present_time) / 1000.0;
+   }
+
+   struct device_data *device_data = data->device;
+   data->stats[data->n_frames % ARRAY_SIZE(data->frame_times)] = device_data->stats;
+   memset(&device_data->stats, 0, sizeof(device_data->stats));
+
+   data->last_present_time = now;
+   data->n_frames++;
+}
+
+static float get_frame_timing(void *_data, int _idx)
+{
+   struct swapchain_data *data = (struct swapchain_data *) _data;
+   if ((ARRAY_SIZE(data->frame_times) - _idx) > (data->n_frames - 2))
+      return 0.0f;
+   int idx = ARRAY_SIZE(data->frame_times) +
+      (data->n_frames - 2) < ARRAY_SIZE(data->frame_times) ?
+      _idx - (data->n_frames - 2) :
+      _idx + (data->n_frames - 2);
+   idx %= ARRAY_SIZE(data->frame_times);
+   return data->frame_times[idx];
+}
+
+static float get_acquire_timing(void *_data, int _idx)
+{
+   struct swapchain_data *data = (struct swapchain_data *) _data;
+   if ((ARRAY_SIZE(data->acquire_times) - _idx) > data->n_acquire)
+      return 0.0f;
+   int idx = ARRAY_SIZE(data->acquire_times) +
+      data->n_acquire < ARRAY_SIZE(data->acquire_times) ?
+      _idx - data->n_acquire :
+      _idx + data->n_acquire;
+   idx %= ARRAY_SIZE(data->acquire_times);
+   return data->acquire_times[idx];
+}
+
+static float get_stat(void *_data, int _idx)
+{
+   struct swapchain_data *data = (struct swapchain_data *) _data;
+   if ((ARRAY_SIZE(data->stats) - _idx) > data->n_frames)
+      return 0.0f;
+   int idx = ARRAY_SIZE(data->stats) +
+      data->n_frames < ARRAY_SIZE(data->stats) ?
+      _idx - data->n_frames :
+      _idx + data->n_frames;
+   idx %= ARRAY_SIZE(data->stats);
+   return data->stats[idx].stats[data->stat_selector];
+}
+
+static void position_layer(struct swapchain_data *data)
+
+{
+   struct device_data *device_data = data->device;
+   struct instance_data *instance_data = device_data->instance;
+
+   ImGui::SetNextWindowBgAlpha(0.5);
+   ImGui::SetNextWindowSize(data->window_size, ImGuiCond_Always);
+   switch (instance_data->position) {
+   case LAYER_POSITION_TOP_LEFT:
+      ImGui::SetNextWindowPos(ImVec2(0, 0), ImGuiCond_Always);
+      break;
+   case LAYER_POSITION_TOP_RIGHT:
+      ImGui::SetNextWindowPos(ImVec2(data->width - data->window_size.x, 0),
+                              ImGuiCond_Always);
+      break;
+   case LAYER_POSITION_BOTTOM_LEFT:
+      ImGui::SetNextWindowPos(ImVec2(0, data->height - data->window_size.y),
+                              ImGuiCond_Always);
+      break;
+   case LAYER_POSITION_BOTTOM_RIGHT:
+      ImGui::SetNextWindowPos(ImVec2(data->width - data->window_size.x,
+                                     data->height - data->window_size.y),
+                              ImGuiCond_Always);
+      break;
+   }
+}
+
+static void compute_swapchain_display(struct swapchain_data *data)
+{
+   struct device_data *device_data = data->device;
+   struct instance_data *instance_data = device_data->instance;
+
+   ImGui::SetCurrentContext(data->imgui_context);
+   ImGui::NewFrame();
+   position_layer(data);
+   ImGui::Begin("Mesa overlay");
+   ImGui::Text("Device: %s", device_data->properties.deviceName);
+
+   const char *format_name = vk_Format_to_str(data->format);
+   format_name = format_name ? (format_name + strlen("VK_FORMAT_")) : "unknown";
+   ImGui::Text("Swapchain format: %s", format_name);
+   ImGui::Text("Frames: %lu", data->n_frames);
+
+   {
+      double min_time = FLT_MAX, max_time = 0.0f;
+      for (uint32_t i = 0; i < MIN2(data->n_frames - 2, ARRAY_SIZE(data->frame_times)); i++) {
+         min_time = MIN2(min_time, data->frame_times[i]);
+         max_time = MAX2(max_time, data->frame_times[i]);
+      }
+      ImGui::PlotHistogram("##Frame timings", get_frame_timing, data,
+                           ARRAY_SIZE(data->frame_times), 0,
+                           NULL, min_time, max_time,
+                           ImVec2(ImGui::GetContentRegionAvailWidth(), 30));
+      ImGui::Text("Frame timing: %.3fms [%.3f, %.3f]",
+                  get_frame_timing(data, ARRAY_SIZE(data->frame_times) - 1),
+                  min_time, max_time);
+   }
+
+   if (instance_data->enabled_stats & FRAME_STAT_ENABLED(ACQUIRE_TIMING)) {
+      double min_time = FLT_MAX, max_time = 0.0f;
+      for (uint32_t i = 0; i < MIN2(data->n_acquire - 2, ARRAY_SIZE(data->acquire_times)); i++) {
+         min_time = MIN2(min_time, data->acquire_times[i]);
+      max_time = MAX2(max_time, data->acquire_times[i]);
+      }
+      ImGui::PlotHistogram("##Acquire timings", get_acquire_timing, data,
+                           ARRAY_SIZE(data->acquire_times), 0,
+                           NULL, min_time, max_time,
+                           ImVec2(ImGui::GetContentRegionAvailWidth(), 30));
+      ImGui::Text("Acquire timing: %.3fms [%.3f, %.3f]",
+                  get_acquire_timing(data, ARRAY_SIZE(data->acquire_times) - 1),
+                  min_time, max_time);
+
+      for (uint32_t i = 0; i < ARRAY_SIZE(data->stats_min.stats); i++) {
+         data->stats_min.stats[i] = UINT32_MAX;
+         data->stats_max.stats[i] = 0;
+      }
+      for (uint32_t i = 0; i < MIN2(data->n_frames - 1, ARRAY_SIZE(data->stats)); i++) {
+         for (uint32_t j = 0; j < ARRAY_SIZE(data->stats[0].stats); j++) {
+            data->stats_min.stats[j] = MIN2(data->stats[i].stats[j],
+                                            data->stats_min.stats[j]);
+            data->stats_max.stats[j] = MAX2(data->stats[i].stats[j],
+                                            data->stats_max.stats[j]);
+         }
+      }
+   }
+
+   for (uint32_t i = 0; i < ARRAY_SIZE(device_data->stats.stats); i++) {
+      if (!(instance_data->enabled_stats & (1ULL << i)))
+         continue;
+
+      char hash[40];
+      snprintf(hash, sizeof(hash), "##%s", enable_flags[i].string);
+      data->stat_selector = (enum frame_stat_type) i;
+
+      ImGui::PlotHistogram(hash, get_stat, data,
+                           ARRAY_SIZE(data->stats), 0,
+                           NULL,
+                           data->stats_min.stats[i],
+                           data->stats_max.stats[i],
+                           ImVec2(ImGui::GetContentRegionAvailWidth(), 30));
+      ImGui::Text("%s: %.0f [%u, %u]", enable_flags[i].string,
+                  get_stat(data, ARRAY_SIZE(data->stats) - 1),
+                  data->stats_min.stats[i], data->stats_max.stats[i]);
+   }
+   data->window_size = ImVec2(data->window_size.x, ImGui::GetCursorPosY() + 10.0f);
+   ImGui::End();
+   ImGui::EndFrame();
+   ImGui::Render();
+}
+
+static uint32_t vk_memory_type(struct device_data *data,
+                               VkMemoryPropertyFlags properties,
+                               uint32_t type_bits)
+{
+    VkPhysicalDeviceMemoryProperties prop;
+    data->instance->vtable.GetPhysicalDeviceMemoryProperties(data->physical_device, &prop);
+    for (uint32_t i = 0; i < prop.memoryTypeCount; i++)
+        if ((prop.memoryTypes[i].propertyFlags & properties) == properties && type_bits & (1<<i))
+            return i;
+    return 0xFFFFFFFF; // Unable to find memoryType
+}
+
+static void ensure_swapchain_fonts(struct swapchain_data *data,
+                                   VkCommandBuffer command_buffer)
+{
+   if (data->font_uploaded)
+      return;
+
+   data->font_uploaded = true;
+
+   struct device_data *device_data = data->device;
+   VkResult err;
+   ImGuiIO& io = ImGui::GetIO();
+   unsigned char* pixels;
+   int width, height;
+   io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);
+   size_t upload_size = width * height * 4 * sizeof(char);
+
+   /* Upload buffer */
+   VkBufferCreateInfo buffer_info = {};
+   buffer_info.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
+   buffer_info.size = upload_size;
+   buffer_info.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;
+   buffer_info.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
+   err = device_data->vtable.CreateBuffer(device_data->device, &buffer_info,
+                                          NULL, &data->upload_font_buffer);
+   check_vk_result(err);
+   VkMemoryRequirements upload_buffer_req;
+   device_data->vtable.GetBufferMemoryRequirements(device_data->device,
+                                                   data->upload_font_buffer,
+                                                   &upload_buffer_req);
+   VkMemoryAllocateInfo upload_alloc_info = {};
+   upload_alloc_info.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
+   upload_alloc_info.allocationSize = upload_buffer_req.size;
+   upload_alloc_info.memoryTypeIndex = vk_memory_type(device_data,
+                                                      VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT,
+                                                      upload_buffer_req.memoryTypeBits);
+   err = device_data->vtable.AllocateMemory(device_data->device,
+                                            &upload_alloc_info,
+                                            NULL,
+                                            &data->upload_font_buffer_mem);
+   check_vk_result(err);
+   err = device_data->vtable.BindBufferMemory(device_data->device,
+                                              data->upload_font_buffer,
+                                              data->upload_font_buffer_mem, 0);
+   check_vk_result(err);
+
+   /* Upload to Buffer */
+   char* map = NULL;
+   err = device_data->vtable.MapMemory(device_data->device,
+                                       data->upload_font_buffer_mem,
+                                       0, upload_size, 0, (void**)(&map));
+   check_vk_result(err);
+   memcpy(map, pixels, upload_size);
+   VkMappedMemoryRange range[1] = {};
+   range[0].sType = VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE;
+   range[0].memory = data->upload_font_buffer_mem;
+   range[0].size = upload_size;
+   err = device_data->vtable.FlushMappedMemoryRanges(device_data->device, 1, range);
+   check_vk_result(err);
+   device_data->vtable.UnmapMemory(device_data->device,
+                                   data->upload_font_buffer_mem);
+
+   /* Copy buffer to image */
+   VkImageMemoryBarrier copy_barrier[1] = {};
+   copy_barrier[0].sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
+   copy_barrier[0].dstAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
+   copy_barrier[0].oldLayout = VK_IMAGE_LAYOUT_UNDEFINED;
+   copy_barrier[0].newLayout = VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL;
+   copy_barrier[0].srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
+   copy_barrier[0].dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
+   copy_barrier[0].image = data->font_image;
+   copy_barrier[0].subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
+   copy_barrier[0].subresourceRange.levelCount = 1;
+   copy_barrier[0].subresourceRange.layerCount = 1;
+   device_data->vtable.CmdPipelineBarrier(command_buffer,
+                                          VK_PIPELINE_STAGE_HOST_BIT,
+                                          VK_PIPELINE_STAGE_TRANSFER_BIT,
+                                          0, 0, NULL, 0, NULL,
+                                          1, copy_barrier);
+
+   VkBufferImageCopy region = {};
+   region.imageSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
+   region.imageSubresource.layerCount = 1;
+   region.imageExtent.width = width;
+   region.imageExtent.height = height;
+   region.imageExtent.depth = 1;
+   device_data->vtable.CmdCopyBufferToImage(command_buffer,
+                                            data->upload_font_buffer,
+                                            data->font_image,
+                                            VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
+                                            1, &region);
+
+   VkImageMemoryBarrier use_barrier[1] = {};
+   use_barrier[0].sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
+   use_barrier[0].srcAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
+   use_barrier[0].dstAccessMask = VK_ACCESS_SHADER_READ_BIT;
+   use_barrier[0].oldLayout = VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL;
+   use_barrier[0].newLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
+   use_barrier[0].srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
+   use_barrier[0].dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
+   use_barrier[0].image = data->font_image;
+   use_barrier[0].subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
+   use_barrier[0].subresourceRange.levelCount = 1;
+   use_barrier[0].subresourceRange.layerCount = 1;
+   device_data->vtable.CmdPipelineBarrier(command_buffer,
+                                          VK_PIPELINE_STAGE_TRANSFER_BIT,
+                                          VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT,
+                                          0,
+                                          0, NULL,
+                                          0, NULL,
+                                          1, use_barrier);
+
+   /* Store our identifier */
+   io.Fonts->TexID = (ImTextureID)(intptr_t)data->font_image;
+}
+
+static void CreateOrResizeBuffer(struct device_data *data,
+                                 VkBuffer *buffer,
+                                 VkDeviceMemory *buffer_memory,
+                                 VkDeviceSize *buffer_size,
+                                 size_t new_size, VkBufferUsageFlagBits usage)
+{
+    VkResult err;
+    if (*buffer != VK_NULL_HANDLE)
+        data->vtable.DestroyBuffer(data->device, *buffer, NULL);
+    if (*buffer_memory)
+        data->vtable.FreeMemory(data->device, *buffer_memory, NULL);
+
+    VkBufferCreateInfo buffer_info = {};
+    buffer_info.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
+    buffer_info.size = new_size;
+    buffer_info.usage = usage;
+    buffer_info.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
+    err = data->vtable.CreateBuffer(data->device, &buffer_info, NULL, buffer);
+    check_vk_result(err);
+
+    VkMemoryRequirements req;
+    data->vtable.GetBufferMemoryRequirements(data->device, *buffer, &req);
+    VkMemoryAllocateInfo alloc_info = {};
+    alloc_info.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
+    alloc_info.allocationSize = req.size;
+    alloc_info.memoryTypeIndex =
+       vk_memory_type(data, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT, req.memoryTypeBits);
+    err = data->vtable.AllocateMemory(data->device, &alloc_info, NULL, buffer_memory);
+    check_vk_result(err);
+
+    err = data->vtable.BindBufferMemory(data->device, *buffer, *buffer_memory, 0);
+    check_vk_result(err);
+    *buffer_size = new_size;
+}
+
+static void render_swapchain_display(struct swapchain_data *data, unsigned image_index)
+{
+   ImDrawData* draw_data = ImGui::GetDrawData();
+   if (draw_data->TotalVtxCount == 0)
+      return;
+
+   struct device_data *device_data = data->device;
+   uint32_t idx = data->n_frames % ARRAY_SIZE(data->frame_data);
+   VkCommandBuffer command_buffer = data->frame_data[idx].command_buffer;
+   VkResult err;
+
+   device_data->vtable.ResetCommandBuffer(command_buffer, 0);
+
+   VkRenderPassBeginInfo render_pass_info = {};
+   render_pass_info.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
+   render_pass_info.renderPass = data->render_pass;
+   render_pass_info.framebuffer = data->framebuffers[image_index];
+   render_pass_info.renderArea.extent.width = data->width;
+   render_pass_info.renderArea.extent.height = data->height;
+
+   VkCommandBufferBeginInfo buffer_begin_info = {};
+   buffer_begin_info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
+
+   device_data->vtable.BeginCommandBuffer(command_buffer, &buffer_begin_info);
+
+   ensure_swapchain_fonts(data, command_buffer);
+
+   /* Bounce the image to display back to color attachment layout for
+    * rendering on top of it.
+    */
+   VkImageMemoryBarrier imb;
+   imb.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
+   imb.pNext = nullptr;
+   imb.dstAccessMask = VK_ACCESS_MEMORY_READ_BIT;
+   imb.srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
+   imb.oldLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
+   imb.newLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
+   imb.image = data->images[image_index];
+   imb.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
+   imb.subresourceRange.baseMipLevel = 0;
+   imb.subresourceRange.levelCount = 1;
+   imb.subresourceRange.baseArrayLayer = 0;
+   imb.subresourceRange.layerCount = 1;
+   imb.srcQueueFamilyIndex = device_data->graphic_queue->family_index;
+   imb.dstQueueFamilyIndex = device_data->graphic_queue->family_index;
+   device_data->vtable.CmdPipelineBarrier(command_buffer,
+                                          VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT,
+                                          VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT,
+                                          0,          /* dependency flags */
+                                          0, nullptr, /* memory barriers */
+                                          0, nullptr, /* buffer memory barriers */
+                                          1, &imb);   /* image memory barriers */
+
+   device_data->vtable.CmdBeginRenderPass(command_buffer, &render_pass_info,
+                                          VK_SUBPASS_CONTENTS_INLINE);
+
+   /* Create/Resize vertex & index buffers */
+   size_t vertex_size = draw_data->TotalVtxCount * sizeof(ImDrawVert);
+   size_t index_size = draw_data->TotalIdxCount * sizeof(ImDrawIdx);
+   if (data->frame_data[idx].vertex_buffer_size < vertex_size) {
+      CreateOrResizeBuffer(device_data,
+                           &data->frame_data[idx].vertex_buffer,
+                           &data->frame_data[idx].vertex_buffer_mem,
+                           &data->frame_data[idx].vertex_buffer_size,
+                           vertex_size, VK_BUFFER_USAGE_VERTEX_BUFFER_BIT);
+   }
+   if (data->frame_data[idx].index_buffer_size < index_size) {
+      CreateOrResizeBuffer(device_data,
+                           &data->frame_data[idx].index_buffer,
+                           &data->frame_data[idx].index_buffer_mem,
+                           &data->frame_data[idx].index_buffer_size,
+                           index_size, VK_BUFFER_USAGE_INDEX_BUFFER_BIT);
+   }
+
+    /* Upload vertex & index data */
+    VkBuffer vertex_buffer = data->frame_data[idx].vertex_buffer;
+    VkDeviceMemory vertex_mem = data->frame_data[idx].vertex_buffer_mem;
+    VkBuffer index_buffer = data->frame_data[idx].index_buffer;
+    VkDeviceMemory index_mem = data->frame_data[idx].index_buffer_mem;
+    ImDrawVert* vtx_dst = NULL;
+    ImDrawIdx* idx_dst = NULL;
+    err = device_data->vtable.MapMemory(device_data->device, vertex_mem,
+                                        0, vertex_size, 0, (void**)(&vtx_dst));
+    check_vk_result(err);
+    err = device_data->vtable.MapMemory(device_data->device, index_mem,
+                                        0, index_size, 0, (void**)(&idx_dst));
+    check_vk_result(err);
+    for (int n = 0; n < draw_data->CmdListsCount; n++)
+        {
+           const ImDrawList* cmd_list = draw_data->CmdLists[n];
+           memcpy(vtx_dst, cmd_list->VtxBuffer.Data, cmd_list->VtxBuffer.Size * sizeof(ImDrawVert));
+           memcpy(idx_dst, cmd_list->IdxBuffer.Data, cmd_list->IdxBuffer.Size * sizeof(ImDrawIdx));
+           vtx_dst += cmd_list->VtxBuffer.Size;
+           idx_dst += cmd_list->IdxBuffer.Size;
+        }
+    VkMappedMemoryRange range[2] = {};
+    range[0].sType = VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE;
+    range[0].memory = vertex_mem;
+    range[0].size = VK_WHOLE_SIZE;
+    range[1].sType = VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE;
+    range[1].memory = index_mem;
+    range[1].size = VK_WHOLE_SIZE;
+    err = device_data->vtable.FlushMappedMemoryRanges(device_data->device, 2, range);
+    check_vk_result(err);
+    device_data->vtable.UnmapMemory(device_data->device, vertex_mem);
+    device_data->vtable.UnmapMemory(device_data->device, index_mem);
+
+    /* Bind pipeline and descriptor sets */
+    device_data->vtable.CmdBindPipeline(command_buffer, VK_PIPELINE_BIND_POINT_GRAPHICS, data->pipeline);
+    VkDescriptorSet desc_set[1] = { data->descriptor_set };
+    device_data->vtable.CmdBindDescriptorSets(command_buffer, VK_PIPELINE_BIND_POINT_GRAPHICS,
+                                              data->pipeline_layout, 0, 1, desc_set, 0, NULL);
+
+    /* Bind vertex & index buffers */
+    VkBuffer vertex_buffers[1] = { vertex_buffer };
+    VkDeviceSize vertex_offset[1] = { 0 };
+    device_data->vtable.CmdBindVertexBuffers(command_buffer, 0, 1, vertex_buffers, vertex_offset);
+    device_data->vtable.CmdBindIndexBuffer(command_buffer, index_buffer, 0, VK_INDEX_TYPE_UINT16);
+
+    /* Setup viewport */
+    VkViewport viewport;
+    viewport.x = 0;
+    viewport.y = 0;
+    viewport.width = draw_data->DisplaySize.x;
+    viewport.height = draw_data->DisplaySize.y;
+    viewport.minDepth = 0.0f;
+    viewport.maxDepth = 1.0f;
+    device_data->vtable.CmdSetViewport(command_buffer, 0, 1, &viewport);
+
+
+    /* Setup scale and translation through push constants :
+     *
+     * Our visible imgui space lies from draw_data->DisplayPos (top left) to
+     * draw_data->DisplayPos+data_data->DisplaySize (bottom right). DisplayMin
+     * is typically (0,0) for single viewport apps.
+     */
+    float scale[2];
+    scale[0] = 2.0f / draw_data->DisplaySize.x;
+    scale[1] = 2.0f / draw_data->DisplaySize.y;
+    float translate[2];
+    translate[0] = -1.0f - draw_data->DisplayPos.x * scale[0];
+    translate[1] = -1.0f - draw_data->DisplayPos.y * scale[1];
+    device_data->vtable.CmdPushConstants(command_buffer, data->pipeline_layout,
+                                         VK_SHADER_STAGE_VERTEX_BIT,
+                                         sizeof(float) * 0, sizeof(float) * 2, scale);
+    device_data->vtable.CmdPushConstants(command_buffer, data->pipeline_layout,
+                                         VK_SHADER_STAGE_VERTEX_BIT,
+                                         sizeof(float) * 2, sizeof(float) * 2, translate);
+
+    // Render the command lists:
+    int vtx_offset = 0;
+    int idx_offset = 0;
+    ImVec2 display_pos = draw_data->DisplayPos;
+    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    {
+        const ImDrawList* cmd_list = draw_data->CmdLists[n];
+        for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
+        {
+            const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
+            // Apply scissor/clipping rectangle
+            // FIXME: We could clamp width/height based on clamped min/max values.
+            VkRect2D scissor;
+            scissor.offset.x = (int32_t)(pcmd->ClipRect.x - display_pos.x) > 0 ? (int32_t)(pcmd->ClipRect.x - display_pos.x) : 0;
+            scissor.offset.y = (int32_t)(pcmd->ClipRect.y - display_pos.y) > 0 ? (int32_t)(pcmd->ClipRect.y - display_pos.y) : 0;
+            scissor.extent.width = (uint32_t)(pcmd->ClipRect.z - pcmd->ClipRect.x);
+            scissor.extent.height = (uint32_t)(pcmd->ClipRect.w - pcmd->ClipRect.y + 1); // FIXME: Why +1 here?
+            device_data->vtable.CmdSetScissor(command_buffer, 0, 1, &scissor);
+
+            // Draw
+            device_data->vtable.CmdDrawIndexed(command_buffer, pcmd->ElemCount, 1, idx_offset, vtx_offset, 0);
+
+            idx_offset += pcmd->ElemCount;
+        }
+        vtx_offset += cmd_list->VtxBuffer.Size;
+    }
+
+   device_data->vtable.CmdEndRenderPass(command_buffer);
+   device_data->vtable.EndCommandBuffer(command_buffer);
+
+   if (data->submission_semaphore) {
+      device_data->vtable.DestroySemaphore(device_data->device,
+                                           data->submission_semaphore,
+                                           NULL);
+   }
+   /* Submission semaphore */
+   VkSemaphoreCreateInfo semaphore_info = {};
+   semaphore_info.sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
+   err = device_data->vtable.CreateSemaphore(device_data->device, &semaphore_info,
+                                             NULL, &data->submission_semaphore);
+   check_vk_result(err);
+
+   VkSubmitInfo submit_info = {};
+   submit_info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
+   submit_info.commandBufferCount = 1;
+   submit_info.pCommandBuffers = &command_buffer;
+   submit_info.signalSemaphoreCount = 1;
+   submit_info.pSignalSemaphores = &data->submission_semaphore;
+
+   device_data->vtable.WaitForFences(device_data->device, 1, &data->fence, VK_TRUE, UINT64_MAX);
+   device_data->vtable.ResetFences(device_data->device, 1, &data->fence);
+   device_data->vtable.QueueSubmit(device_data->graphic_queue->queue, 1, &submit_info, data->fence);
+}
+
+static const uint32_t overlay_vert_spv[] = {
+#include "overlay.vert.spv.h"
+};
+static const uint32_t overlay_frag_spv[] = {
+#include "overlay.frag.spv.h"
+};
+
+static void setup_swapchain_data_pipeline(struct swapchain_data *data)
+{
+   struct device_data *device_data = data->device;
+   VkShaderModule vert_module, frag_module;
+   VkResult err;
+
+   /* Create shader modules */
+   VkShaderModuleCreateInfo vert_info = {};
+   vert_info.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
+   vert_info.codeSize = sizeof(overlay_vert_spv);
+   vert_info.pCode = overlay_vert_spv;
+   err = device_data->vtable.CreateShaderModule(device_data->device,
+                                                &vert_info, NULL, &vert_module);
+   check_vk_result(err);
+   VkShaderModuleCreateInfo frag_info = {};
+   frag_info.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
+   frag_info.codeSize = sizeof(overlay_frag_spv);
+   frag_info.pCode = (uint32_t*)overlay_frag_spv;
+   err = device_data->vtable.CreateShaderModule(device_data->device,
+                                                &frag_info, NULL, &frag_module);
+   check_vk_result(err);
+
+   /* Font sampler */
+   VkSamplerCreateInfo sampler_info = {};
+   sampler_info.sType = VK_STRUCTURE_TYPE_SAMPLER_CREATE_INFO;
+   sampler_info.magFilter = VK_FILTER_LINEAR;
+   sampler_info.minFilter = VK_FILTER_LINEAR;
+   sampler_info.mipmapMode = VK_SAMPLER_MIPMAP_MODE_LINEAR;
+   sampler_info.addressModeU = VK_SAMPLER_ADDRESS_MODE_REPEAT;
+   sampler_info.addressModeV = VK_SAMPLER_ADDRESS_MODE_REPEAT;
+   sampler_info.addressModeW = VK_SAMPLER_ADDRESS_MODE_REPEAT;
+   sampler_info.minLod = -1000;
+   sampler_info.maxLod = 1000;
+   sampler_info.maxAnisotropy = 1.0f;
+   err = device_data->vtable.CreateSampler(device_data->device, &sampler_info,
+                                           NULL, &data->font_sampler);
+   check_vk_result(err);
+
+   /* Descriptor pool */
+   VkDescriptorPoolSize sampler_pool_size = {};
+   sampler_pool_size.type = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
+   sampler_pool_size.descriptorCount = 1;
+   VkDescriptorPoolCreateInfo desc_pool_info = {};
+   desc_pool_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
+   desc_pool_info.maxSets = 1;
+   desc_pool_info.poolSizeCount = 1;
+   desc_pool_info.pPoolSizes = &sampler_pool_size;
+   err = device_data->vtable.CreateDescriptorPool(device_data->device,
+                                                  &desc_pool_info,
+                                                  NULL, &data->descriptor_pool);
+   check_vk_result(err);
+
+   /* Descriptor layout */
+   VkSampler sampler[1] = { data->font_sampler };
+   VkDescriptorSetLayoutBinding binding[1] = {};
+   binding[0].descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
+   binding[0].descriptorCount = 1;
+   binding[0].stageFlags = VK_SHADER_STAGE_FRAGMENT_BIT;
+   binding[0].pImmutableSamplers = sampler;
+   VkDescriptorSetLayoutCreateInfo set_layout_info = {};
+   set_layout_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
+   set_layout_info.bindingCount = 1;
+   set_layout_info.pBindings = binding;
+   err = device_data->vtable.CreateDescriptorSetLayout(device_data->device,
+                                                       &set_layout_info,
+                                                       NULL, &data->descriptor_layout);
+   check_vk_result(err);
+
+   /* Descriptor set */
+   VkDescriptorSetAllocateInfo alloc_info = {};
+   alloc_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
+   alloc_info.descriptorPool = data->descriptor_pool;
+   alloc_info.descriptorSetCount = 1;
+   alloc_info.pSetLayouts = &data->descriptor_layout;
+   err = device_data->vtable.AllocateDescriptorSets(device_data->device,
+                                                    &alloc_info,
+                                                    &data->descriptor_set);
+   check_vk_result(err);
+
+   /* Constants: we are using 'vec2 offset' and 'vec2 scale' instead of a full
+    * 3d projection matrix
+    */
+   VkPushConstantRange push_constants[1] = {};
+   push_constants[0].stageFlags = VK_SHADER_STAGE_VERTEX_BIT;
+   push_constants[0].offset = sizeof(float) * 0;
+   push_constants[0].size = sizeof(float) * 4;
+   VkPipelineLayoutCreateInfo layout_info = {};
+   layout_info.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
+   layout_info.setLayoutCount = 1;
+   layout_info.pSetLayouts = &data->descriptor_layout;
+   layout_info.pushConstantRangeCount = 1;
+   layout_info.pPushConstantRanges = push_constants;
+   err = device_data->vtable.CreatePipelineLayout(device_data->device,
+                                                  &layout_info,
+                                                  NULL, &data->pipeline_layout);
+   check_vk_result(err);
+
+
+   VkPipelineShaderStageCreateInfo stage[2] = {};
+   stage[0].sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
+   stage[0].stage = VK_SHADER_STAGE_VERTEX_BIT;
+   stage[0].module = vert_module;
+   stage[0].pName = "main";
+   stage[1].sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
+   stage[1].stage = VK_SHADER_STAGE_FRAGMENT_BIT;
+   stage[1].module = frag_module;
+   stage[1].pName = "main";
+
+   VkVertexInputBindingDescription binding_desc[1] = {};
+   binding_desc[0].stride = sizeof(ImDrawVert);
+   binding_desc[0].inputRate = VK_VERTEX_INPUT_RATE_VERTEX;
+
+   VkVertexInputAttributeDescription attribute_desc[3] = {};
+   attribute_desc[0].location = 0;
+   attribute_desc[0].binding = binding_desc[0].binding;
+   attribute_desc[0].format = VK_FORMAT_R32G32_SFLOAT;
+   attribute_desc[0].offset = IM_OFFSETOF(ImDrawVert, pos);
+   attribute_desc[1].location = 1;
+   attribute_desc[1].binding = binding_desc[0].binding;
+   attribute_desc[1].format = VK_FORMAT_R32G32_SFLOAT;
+   attribute_desc[1].offset = IM_OFFSETOF(ImDrawVert, uv);
+   attribute_desc[2].location = 2;
+   attribute_desc[2].binding = binding_desc[0].binding;
+   attribute_desc[2].format = VK_FORMAT_R8G8B8A8_UNORM;
+   attribute_desc[2].offset = IM_OFFSETOF(ImDrawVert, col);
+
+   VkPipelineVertexInputStateCreateInfo vertex_info = {};
+   vertex_info.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;
+   vertex_info.vertexBindingDescriptionCount = 1;
+   vertex_info.pVertexBindingDescriptions = binding_desc;
+   vertex_info.vertexAttributeDescriptionCount = 3;
+   vertex_info.pVertexAttributeDescriptions = attribute_desc;
+
+   VkPipelineInputAssemblyStateCreateInfo ia_info = {};
+   ia_info.sType = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO;
+   ia_info.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;
+
+   VkPipelineViewportStateCreateInfo viewport_info = {};
+   viewport_info.sType = VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO;
+   viewport_info.viewportCount = 1;
+   viewport_info.scissorCount = 1;
+
+   VkPipelineRasterizationStateCreateInfo raster_info = {};
+   raster_info.sType = VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO;
+   raster_info.polygonMode = VK_POLYGON_MODE_FILL;
+   raster_info.cullMode = VK_CULL_MODE_NONE;
+   raster_info.frontFace = VK_FRONT_FACE_COUNTER_CLOCKWISE;
+   raster_info.lineWidth = 1.0f;
+
+   VkPipelineMultisampleStateCreateInfo ms_info = {};
+   ms_info.sType = VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO;
+   ms_info.rasterizationSamples = VK_SAMPLE_COUNT_1_BIT;
+
+   VkPipelineColorBlendAttachmentState color_attachment[1] = {};
+   color_attachment[0].blendEnable = VK_TRUE;
+   color_attachment[0].srcColorBlendFactor = VK_BLEND_FACTOR_SRC_ALPHA;
+   color_attachment[0].dstColorBlendFactor = VK_BLEND_FACTOR_ONE_MINUS_SRC_ALPHA;
+   color_attachment[0].colorBlendOp = VK_BLEND_OP_ADD;
+   color_attachment[0].srcAlphaBlendFactor = VK_BLEND_FACTOR_ONE_MINUS_SRC_ALPHA;
+   color_attachment[0].dstAlphaBlendFactor = VK_BLEND_FACTOR_ZERO;
+   color_attachment[0].alphaBlendOp = VK_BLEND_OP_ADD;
+   color_attachment[0].colorWriteMask = VK_COLOR_COMPONENT_R_BIT |
+      VK_COLOR_COMPONENT_G_BIT | VK_COLOR_COMPONENT_B_BIT | VK_COLOR_COMPONENT_A_BIT;
+
+   VkPipelineDepthStencilStateCreateInfo depth_info = {};
+   depth_info.sType = VK_STRUCTURE_TYPE_PIPELINE_DEPTH_STENCIL_STATE_CREATE_INFO;
+
+   VkPipelineColorBlendStateCreateInfo blend_info = {};
+   blend_info.sType = VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO;
+   blend_info.attachmentCount = 1;
+   blend_info.pAttachments = color_attachment;
+
+   VkDynamicState dynamic_states[2] = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR };
+   VkPipelineDynamicStateCreateInfo dynamic_state = {};
+   dynamic_state.sType = VK_STRUCTURE_TYPE_PIPELINE_DYNAMIC_STATE_CREATE_INFO;
+   dynamic_state.dynamicStateCount = (uint32_t)IM_ARRAYSIZE(dynamic_states);
+   dynamic_state.pDynamicStates = dynamic_states;
+
+   VkGraphicsPipelineCreateInfo info = {};
+   info.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO;
+   info.flags = 0;
+   info.stageCount = 2;
+   info.pStages = stage;
+   info.pVertexInputState = &vertex_info;
+   info.pInputAssemblyState = &ia_info;
+   info.pViewportState = &viewport_info;
+   info.pRasterizationState = &raster_info;
+   info.pMultisampleState = &ms_info;
+   info.pDepthStencilState = &depth_info;
+   info.pColorBlendState = &blend_info;
+   info.pDynamicState = &dynamic_state;
+   info.layout = data->pipeline_layout;
+   info.renderPass = data->render_pass;
+   err = device_data->vtable.CreateGraphicsPipelines(device_data->device, VK_NULL_HANDLE,
+                                                     1, &info,
+                                                     NULL, &data->pipeline);
+   check_vk_result(err);
+
+   device_data->vtable.DestroyShaderModule(device_data->device, vert_module, NULL);
+   device_data->vtable.DestroyShaderModule(device_data->device, frag_module, NULL);
+
+   ImGuiIO& io = ImGui::GetIO();
+   unsigned char* pixels;
+   int width, height;
+   io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);
+
+   /* Font image */
+   VkImageCreateInfo image_info = {};
+   image_info.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;
+   image_info.imageType = VK_IMAGE_TYPE_2D;
+   image_info.format = VK_FORMAT_R8G8B8A8_UNORM;
+   image_info.extent.width = width;
+   image_info.extent.height = height;
+   image_info.extent.depth = 1;
+   image_info.mipLevels = 1;
+   image_info.arrayLayers = 1;
+   image_info.samples = VK_SAMPLE_COUNT_1_BIT;
+   image_info.tiling = VK_IMAGE_TILING_OPTIMAL;
+   image_info.usage = VK_IMAGE_USAGE_SAMPLED_BIT | VK_IMAGE_USAGE_TRANSFER_DST_BIT;
+   image_info.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
+   image_info.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
+   err = device_data->vtable.CreateImage(device_data->device, &image_info,
+                                         NULL, &data->font_image);
+   check_vk_result(err);
+   VkMemoryRequirements font_image_req;
+   device_data->vtable.GetImageMemoryRequirements(device_data->device,
+                                                  data->font_image, &font_image_req);
+   VkMemoryAllocateInfo image_alloc_info = {};
+   image_alloc_info.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
+   image_alloc_info.allocationSize = font_image_req.size;
+   image_alloc_info.memoryTypeIndex = vk_memory_type(device_data,
+                                                     VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT,
+                                                     font_image_req.memoryTypeBits);
+   err = device_data->vtable.AllocateMemory(device_data->device, &image_alloc_info,
+                                            NULL, &data->font_mem);
+   check_vk_result(err);
+   err = device_data->vtable.BindImageMemory(device_data->device,
+                                             data->font_image,
+                                             data->font_mem, 0);
+   check_vk_result(err);
+
+   /* Font image view */
+   VkImageViewCreateInfo view_info = {};
+   view_info.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
+   view_info.image = data->font_image;
+   view_info.viewType = VK_IMAGE_VIEW_TYPE_2D;
+   view_info.format = VK_FORMAT_R8G8B8A8_UNORM;
+   view_info.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
+   view_info.subresourceRange.levelCount = 1;
+   view_info.subresourceRange.layerCount = 1;
+   err = device_data->vtable.CreateImageView(device_data->device, &view_info,
+                                             NULL, &data->font_image_view);
+   check_vk_result(err);
+
+   /* Descriptor set */
+   VkDescriptorImageInfo desc_image[1] = {};
+   desc_image[0].sampler = data->font_sampler;
+   desc_image[0].imageView = data->font_image_view;
+   desc_image[0].imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
+   VkWriteDescriptorSet write_desc[1] = {};
+   write_desc[0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
+   write_desc[0].dstSet = data->descriptor_set;
+   write_desc[0].descriptorCount = 1;
+   write_desc[0].descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
+   write_desc[0].pImageInfo = desc_image;
+   device_data->vtable.UpdateDescriptorSets(device_data->device, 1, write_desc, 0, NULL);
+}
+
+static void setup_swapchain_data(struct swapchain_data *data,
+                                 const VkSwapchainCreateInfoKHR *pCreateInfo)
+{
+   data->width = pCreateInfo->imageExtent.width;
+   data->height = pCreateInfo->imageExtent.height;
+   data->format = pCreateInfo->imageFormat;
+
+   data->imgui_context = ImGui::CreateContext();
+   ImGui::SetCurrentContext(data->imgui_context);
+
+   ImGui::GetIO().IniFilename = NULL;
+   ImGui::GetIO().DisplaySize = ImVec2((float)data->width, (float)data->height);
+
+   struct device_data *device_data = data->device;
+   VkResult err;
+
+   /* Render pass */
+   VkAttachmentDescription attachment_desc = {};
+   attachment_desc.format = pCreateInfo->imageFormat;
+   attachment_desc.samples = VK_SAMPLE_COUNT_1_BIT;
+   attachment_desc.loadOp = VK_ATTACHMENT_LOAD_OP_LOAD;
+   attachment_desc.storeOp = VK_ATTACHMENT_STORE_OP_STORE;
+   attachment_desc.stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
+   attachment_desc.stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
+   attachment_desc.initialLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
+   attachment_desc.finalLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
+   VkAttachmentReference color_attachment = {};
+   color_attachment.attachment = 0;
+   color_attachment.layout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
+   VkSubpassDescription subpass = {};
+   subpass.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
+   subpass.colorAttachmentCount = 1;
+   subpass.pColorAttachments = &color_attachment;
+   VkSubpassDependency dependency = {};
+   dependency.srcSubpass = VK_SUBPASS_EXTERNAL;
+   dependency.dstSubpass = 0;
+   dependency.srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
+   dependency.dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
+   dependency.srcAccessMask = 0;
+   dependency.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
+   VkRenderPassCreateInfo render_pass_info = {};
+   render_pass_info.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
+   render_pass_info.attachmentCount = 1;
+   render_pass_info.pAttachments = &attachment_desc;
+   render_pass_info.subpassCount = 1;
+   render_pass_info.pSubpasses = &subpass;
+   render_pass_info.dependencyCount = 1;
+   render_pass_info.pDependencies = &dependency;
+   err = device_data->vtable.CreateRenderPass(device_data->device,
+                                              &render_pass_info,
+                                              NULL, &data->render_pass);
+   check_vk_result(err);
+
+   setup_swapchain_data_pipeline(data);
+
+   device_data->vtable.GetSwapchainImagesKHR(device_data->device,
+                                             data->swapchain,
+                                             &data->n_images,
+                                             NULL);
+   data->images = ralloc_array(data, VkImage, data->n_images);
+   data->image_views = ralloc_array(data, VkImageView, data->n_images);
+   data->framebuffers = ralloc_array(data, VkFramebuffer, data->n_images);
+
+   device_data->vtable.GetSwapchainImagesKHR(device_data->device,
+                                             data->swapchain,
+                                             &data->n_images,
+                                             data->images);
+
+   /* Image views */
+   VkImageViewCreateInfo view_info = {};
+   view_info.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
+   view_info.viewType = VK_IMAGE_VIEW_TYPE_2D;
+   view_info.format = pCreateInfo->imageFormat;
+   view_info.components.r = VK_COMPONENT_SWIZZLE_R;
+   view_info.components.g = VK_COMPONENT_SWIZZLE_G;
+   view_info.components.b = VK_COMPONENT_SWIZZLE_B;
+   view_info.components.a = VK_COMPONENT_SWIZZLE_A;
+   view_info.subresourceRange = { VK_IMAGE_ASPECT_COLOR_BIT, 0, 1, 0, 1 };
+   for (uint32_t i = 0; i < data->n_images; i++) {
+      view_info.image = data->images[i];
+      err = device_data->vtable.CreateImageView(device_data->device, &view_info,
+                                                NULL, &data->image_views[i]);
+      check_vk_result(err);
+   }
+
+   /* Framebuffers */
+   VkImageView attachment[1];
+   VkFramebufferCreateInfo fb_info = {};
+   fb_info.sType = VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO;
+   fb_info.renderPass = data->render_pass;
+   fb_info.attachmentCount = 1;
+   fb_info.pAttachments = attachment;
+   fb_info.width = data->width;
+   fb_info.height = data->height;
+   fb_info.layers = 1;
+   for (uint32_t i = 0; i < data->n_images; i++) {
+      attachment[0] = data->image_views[i];
+      err = device_data->vtable.CreateFramebuffer(device_data->device, &fb_info,
+                                                  NULL, &data->framebuffers[i]);
+      check_vk_result(err);
+   }
+
+   /* Command buffer */
+   VkCommandPoolCreateInfo cmd_buffer_pool_info = {};
+   cmd_buffer_pool_info.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO;
+   cmd_buffer_pool_info.flags = VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT;
+   cmd_buffer_pool_info.queueFamilyIndex = device_data->graphic_queue->family_index;
+   err = device_data->vtable.CreateCommandPool(device_data->device,
+                                               &cmd_buffer_pool_info,
+                                               NULL, &data->command_pool);
+   check_vk_result(err);
+
+   VkCommandBuffer cmd_bufs[ARRAY_SIZE(data->frame_data)];
+
+   VkCommandBufferAllocateInfo cmd_buffer_info = {};
+   cmd_buffer_info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
+   cmd_buffer_info.commandPool = data->command_pool;
+   cmd_buffer_info.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
+   cmd_buffer_info.commandBufferCount = 2;
+   err = device_data->vtable.AllocateCommandBuffers(device_data->device,
+                                                    &cmd_buffer_info,
+                                                    cmd_bufs);
+   check_vk_result(err);
+
+   for (uint32_t i = 0; i < ARRAY_SIZE(data->frame_data); i++)
+      data->frame_data[i].command_buffer = cmd_bufs[i];
+
+
+   /* Submission fence */
+   VkFenceCreateInfo fence_info = {};
+   fence_info.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
+   fence_info.flags = VK_FENCE_CREATE_SIGNALED_BIT;
+   err = device_data->vtable.CreateFence(device_data->device, &fence_info,
+                                         NULL, &data->fence);
+   check_vk_result(err);
+
+}
+
+static void shutdown_swapchain_data(struct swapchain_data *data)
+{
+   struct device_data *device_data = data->device;
+
+   for (uint32_t i = 0; i < data->n_images; i++) {
+      device_data->vtable.DestroyImageView(device_data->device, data->image_views[i], NULL);
+      device_data->vtable.DestroyFramebuffer(device_data->device, data->framebuffers[i], NULL);
+   }
+
+   device_data->vtable.DestroyRenderPass(device_data->device, data->render_pass, NULL);
+
+   for (uint32_t i = 0; i < ARRAY_SIZE(data->frame_data); i++) {
+      device_data->vtable.FreeCommandBuffers(device_data->device,
+                                             data->command_pool,
+                                             1, &data->frame_data[i].command_buffer);
+      if (data->frame_data[i].vertex_buffer)
+         device_data->vtable.DestroyBuffer(device_data->device, data->frame_data[i].vertex_buffer, NULL);
+      if (data->frame_data[i].index_buffer)
+         device_data->vtable.DestroyBuffer(device_data->device, data->frame_data[i].index_buffer, NULL);
+      if (data->frame_data[i].vertex_buffer_mem)
+         device_data->vtable.FreeMemory(device_data->device, data->frame_data[i].vertex_buffer_mem, NULL);
+      if (data->frame_data[i].index_buffer_mem)
+         device_data->vtable.FreeMemory(device_data->device, data->frame_data[i].index_buffer_mem, NULL);
+   }
+   device_data->vtable.DestroyCommandPool(device_data->device, data->command_pool, NULL);
+
+   device_data->vtable.DestroyFence(device_data->device, data->fence, NULL);
+   if (data->submission_semaphore)
+      device_data->vtable.DestroySemaphore(device_data->device, data->submission_semaphore, NULL);
+
+   device_data->vtable.DestroyPipeline(device_data->device, data->pipeline, NULL);
+   device_data->vtable.DestroyPipelineLayout(device_data->device, data->pipeline_layout, NULL);
+
+   device_data->vtable.FreeDescriptorSets(device_data->device, data->descriptor_pool,
+                                          1, &data->descriptor_set);
+   device_data->vtable.DestroyDescriptorPool(device_data->device,
+                                             data->descriptor_pool, NULL);
+   device_data->vtable.DestroyDescriptorSetLayout(device_data->device,
+                                                  data->descriptor_layout, NULL);
+
+   device_data->vtable.DestroySampler(device_data->device, data->font_sampler, NULL);
+   device_data->vtable.DestroyImageView(device_data->device, data->font_image_view, NULL);
+   device_data->vtable.DestroyImage(device_data->device, data->font_image, NULL);
+   device_data->vtable.FreeMemory(device_data->device, data->font_mem, NULL);
+
+   device_data->vtable.DestroyBuffer(device_data->device, data->upload_font_buffer, NULL);
+   device_data->vtable.FreeMemory(device_data->device, data->upload_font_buffer_mem, NULL);
+
+   ImGui::DestroyContext(data->imgui_context);
+}
+
+static void before_present(struct swapchain_data *swapchain_data,
+                           unsigned imageIndex)
+{
+   snapshot_swapchain_frame(swapchain_data);
+
+   compute_swapchain_display(swapchain_data);
+   render_swapchain_display(swapchain_data, imageIndex);
+}
+
+VKAPI_ATTR VkResult VKAPI_CALL overlay_CreateSwapchainKHR(
+    VkDevice                                    device,
+    const VkSwapchainCreateInfoKHR*             pCreateInfo,
+    const VkAllocationCallbacks*                pAllocator,
+    VkSwapchainKHR*                             pSwapchain)
+{
+   struct device_data *device_data = FIND_DEVICE_DATA(device);
+   VkResult result = device_data->vtable.CreateSwapchainKHR(device, pCreateInfo, pAllocator, pSwapchain);
+   if (result != VK_SUCCESS) return result;
+
+   struct swapchain_data *swapchain_data = new_swapchain_data(*pSwapchain, device_data);
+   setup_swapchain_data(swapchain_data, pCreateInfo);
+   return result;
+}
+
+VKAPI_ATTR void VKAPI_CALL overlay_DestroySwapchainKHR(
+    VkDevice                                    device,
+    VkSwapchainKHR                              swapchain,
+    const VkAllocationCallbacks*                pAllocator)
+{
+   struct swapchain_data *swapchain_data = FIND_SWAPCHAIN_DATA(swapchain);
+
+   shutdown_swapchain_data(swapchain_data);
+   swapchain_data->device->vtable.DestroySwapchainKHR(device, swapchain, pAllocator);
+   destroy_swapchain_data(swapchain_data);
+}
+
+VKAPI_ATTR VkResult VKAPI_CALL overlay_QueuePresentKHR(
+    VkQueue                                     queue,
+    const VkPresentInfoKHR*                     pPresentInfo)
+{
+   struct queue_data *queue_data = FIND_QUEUE_DATA(queue);
+   struct device_data *device_data = queue_data->device;
+
+   /* If we present on the graphic queue this layer is using to draw an
+    * overlay, we don't need more than submitting the overlay draw prior to
+    * present.
+    */
+   if (queue_data == device_data->graphic_queue) {
+      for (uint32_t i = 0; i < pPresentInfo->swapchainCount; i++) {
+         struct swapchain_data *swapchain_data = FIND_SWAPCHAIN_DATA(pPresentInfo->pSwapchains[i]);
+         before_present(swapchain_data, pPresentInfo->pImageIndices[i]);
+      }
+      return queue_data->device->vtable.QueuePresentKHR(queue, pPresentInfo);
+   }
+
+   /* Otherwise we need to do cross queue synchronization to tie the overlay
+    * draw into the present queue.
+    */
+   VkPresentInfoKHR present_info = *pPresentInfo;
+   VkSemaphore *semaphores =
+      (VkSemaphore *)malloc(sizeof(VkSemaphore) * (pPresentInfo->waitSemaphoreCount + pPresentInfo->swapchainCount));
+   for (uint32_t i = 0; i < pPresentInfo->waitSemaphoreCount; i++)
+      semaphores[i] = pPresentInfo->pWaitSemaphores[i];
+   for (uint32_t i = 0; i < pPresentInfo->swapchainCount; i++) {
+      struct swapchain_data *swapchain_data = FIND_SWAPCHAIN_DATA(pPresentInfo->pSwapchains[i]);
+      before_present(swapchain_data, pPresentInfo->pImageIndices[i]);
+      semaphores[pPresentInfo->waitSemaphoreCount + i] = swapchain_data->submission_semaphore;
+   }
+   present_info.pWaitSemaphores = semaphores;
+   present_info.waitSemaphoreCount = pPresentInfo->waitSemaphoreCount + pPresentInfo->swapchainCount;
+   VkResult result = queue_data->device->vtable.QueuePresentKHR(queue, &present_info);
+   free(semaphores);
+   return result;
+}
+
+VKAPI_ATTR VkResult VKAPI_CALL overlay_AcquireNextImageKHR(
+    VkDevice                                    device,
+    VkSwapchainKHR                              swapchain,
+    uint64_t                                    timeout,
+    VkSemaphore                                 semaphore,
+    VkFence                                     fence,
+    uint32_t*                                   pImageIndex)
+{
+   struct swapchain_data *swapchain_data = FIND_SWAPCHAIN_DATA(swapchain);
+   struct device_data *device_data = swapchain_data->device;
+
+   uint64_t ts0 = os_time_get();
+   VkResult result = device_data->vtable.AcquireNextImageKHR(device, swapchain, timeout,
+                                                             semaphore, fence, pImageIndex);
+   uint64_t ts1 = os_time_get();
+
+   swapchain_data->acquire_times[swapchain_data->n_acquire %
+                                 ARRAY_SIZE(swapchain_data->acquire_times)] =
+      ((double)ts1 - (double)ts0) / 1000.0;
+   swapchain_data->n_acquire++;
+
+   return result;
+}
+
+VKAPI_ATTR VkResult VKAPI_CALL overlay_AcquireNextImage2KHR(
+    VkDevice                                    device,
+    const VkAcquireNextImageInfoKHR*            pAcquireInfo,
+    uint32_t*                                   pImageIndex)
+{
+   struct swapchain_data *swapchain_data = FIND_SWAPCHAIN_DATA(pAcquireInfo->swapchain);
+   struct device_data *device_data = swapchain_data->device;
+
+   uint64_t ts0 = os_time_get();
+   VkResult result = device_data->vtable.AcquireNextImage2KHR(device, pAcquireInfo, pImageIndex);
+   uint64_t ts1 = os_time_get();
+
+   swapchain_data->acquire_times[swapchain_data->n_acquire %
+                                 ARRAY_SIZE(swapchain_data->acquire_times)] =
+      ((double)ts1 - (double)ts0) / 1000.0;
+   swapchain_data->n_acquire++;
+
+   return result;
+}
+
+VKAPI_ATTR void VKAPI_CALL overlay_CmdDraw(
+    VkCommandBuffer                             commandBuffer,
+    uint32_t                                    vertexCount,
+    uint32_t                                    instanceCount,
+    uint32_t                                    firstVertex,
+    uint32_t                                    firstInstance)
+{
+   struct device_data *device_data = FIND_DEVICE_DATA(commandBuffer);
+   device_data->vtable.CmdDraw(commandBuffer, vertexCount, instanceCount,
+                               firstVertex, firstInstance);
+   device_data->stats.stats[FRAME_STAT_DRAW]++;
+}
+
+VKAPI_ATTR void VKAPI_CALL overlay_CmdDrawIndexed(
+    VkCommandBuffer                             commandBuffer,
+    uint32_t                                    indexCount,
+    uint32_t                                    instanceCount,
+    uint32_t                                    firstIndex,
+    int32_t                                     vertexOffset,
+    uint32_t                                    firstInstance)
+{
+   struct device_data *device_data = FIND_DEVICE_DATA(commandBuffer);
+   device_data->vtable.CmdDrawIndexed(commandBuffer, indexCount, instanceCount,
+                                      firstIndex, vertexOffset, firstInstance);
+   device_data->stats.stats[FRAME_STAT_DRAW_INDEXED]++;
+}
+
+VKAPI_ATTR void VKAPI_CALL overlay_CmdDrawIndirect(
+    VkCommandBuffer                             commandBuffer,
+    VkBuffer                                    buffer,
+    VkDeviceSize                                offset,
+    uint32_t                                    drawCount,
+    uint32_t                                    stride)
+{
+   struct device_data *device_data = FIND_DEVICE_DATA(commandBuffer);
+   device_data->vtable.CmdDrawIndirect(commandBuffer, buffer, offset, drawCount, stride);
+   device_data->stats.stats[FRAME_STAT_DRAW_INDIRECT]++;
+}
+
+VKAPI_ATTR void VKAPI_CALL overlay_CmdDrawIndexedIndirect(
+    VkCommandBuffer                             commandBuffer,
+    VkBuffer                                    buffer,
+    VkDeviceSize                                offset,
+    uint32_t                                    drawCount,
+    uint32_t                                    stride)
+{
+   struct device_data *device_data = FIND_DEVICE_DATA(commandBuffer);
+   device_data->vtable.CmdDrawIndexedIndirect(commandBuffer, buffer, offset, drawCount, stride);
+   device_data->stats.stats[FRAME_STAT_DRAW_INDEXED_INDIRECT]++;
+}
+
+VKAPI_ATTR void VKAPI_CALL overlay_CmdDrawIndirectCountKHR(
+    VkCommandBuffer                             commandBuffer,
+    VkBuffer                                    buffer,
+    VkDeviceSize                                offset,
+    VkBuffer                                    countBuffer,
+    VkDeviceSize                                countBufferOffset,
+    uint32_t                                    maxDrawCount,
+    uint32_t                                    stride)
+{
+   struct device_data *device_data = FIND_DEVICE_DATA(commandBuffer);
+   device_data->vtable.CmdDrawIndirectCountKHR(commandBuffer, buffer, offset,
+                                               countBuffer, countBufferOffset,
+                                               maxDrawCount, stride);
+   device_data->stats.stats[FRAME_STAT_DRAW_INDIRECT_COUNT]++;
+}
+
+VKAPI_ATTR void VKAPI_CALL overlay_CmdDrawIndexedIndirectCountKHR(
+    VkCommandBuffer                             commandBuffer,
+    VkBuffer                                    buffer,
+    VkDeviceSize                                offset,
+    VkBuffer                                    countBuffer,
+    VkDeviceSize                                countBufferOffset,
+    uint32_t                                    maxDrawCount,
+    uint32_t                                    stride)
+{
+   struct device_data *device_data = FIND_DEVICE_DATA(commandBuffer);
+   device_data->vtable.CmdDrawIndexedIndirectCountKHR(commandBuffer, buffer, offset,
+                                                      countBuffer, countBufferOffset,
+                                                      maxDrawCount, stride);
+   device_data->stats.stats[FRAME_STAT_DRAW_INDEXED_INDIRECT_COUNT]++;
+}
+
+VKAPI_ATTR void VKAPI_CALL overlay_CmdDispatch(
+    VkCommandBuffer                             commandBuffer,
+    uint32_t                                    groupCountX,
+    uint32_t                                    groupCountY,
+    uint32_t                                    groupCountZ)
+{
+   struct device_data *device_data = FIND_DEVICE_DATA(commandBuffer);
+   device_data->vtable.CmdDispatch(commandBuffer, groupCountX, groupCountY, groupCountZ);
+   device_data->stats.stats[FRAME_STAT_DISPATCH]++;
+}
+
+VKAPI_ATTR void VKAPI_CALL overlay_CmdDispatchIndirect(
+    VkCommandBuffer                             commandBuffer,
+    VkBuffer                                    buffer,
+    VkDeviceSize                                offset)
+{
+   struct device_data *device_data = FIND_DEVICE_DATA(commandBuffer);
+   device_data->vtable.CmdDispatchIndirect(commandBuffer, buffer, offset);
+   device_data->stats.stats[FRAME_STAT_DISPATCH_INDIRECT]++;
+}
+
+VKAPI_ATTR void VKAPI_CALL overlay_CmdBindPipeline(
+    VkCommandBuffer                             commandBuffer,
+    VkPipelineBindPoint                         pipelineBindPoint,
+    VkPipeline                                  pipeline)
+{
+   struct device_data *device_data = FIND_DEVICE_DATA(commandBuffer);
+   device_data->vtable.CmdBindPipeline(commandBuffer, pipelineBindPoint, pipeline);
+   switch (pipelineBindPoint) {
+   case VK_PIPELINE_BIND_POINT_GRAPHICS: device_data->stats.stats[FRAME_STAT_PIPELINE_GRAPHICS]++; break;
+   case VK_PIPELINE_BIND_POINT_COMPUTE: device_data->stats.stats[FRAME_STAT_PIPELINE_COMPUTE]++; break;
+   case VK_PIPELINE_BIND_POINT_RAY_TRACING_NV: device_data->stats.stats[FRAME_STAT_PIPELINE_RAYTRACING]++; break;
+   default: break;
+   }
+}
+
+VKAPI_ATTR VkResult VKAPI_CALL overlay_AllocateCommandBuffers(VkDevice device,
+                                                              const VkCommandBufferAllocateInfo* pAllocateInfo,
+                                                              VkCommandBuffer* pCommandBuffers)
+{
+   struct device_data *device_data = FIND_DEVICE_DATA(device);
+
+   VkResult result =
+      device_data->vtable.AllocateCommandBuffers(device, pAllocateInfo, pCommandBuffers);
+   if (result != VK_SUCCESS) return result;
+
+   for (uint32_t i = 0; i < pAllocateInfo->commandBufferCount; i++)
+      map_object(pCommandBuffers[i], device_data);
+
+   return result;
+}
+
+VKAPI_ATTR void VKAPI_CALL overlay_FreeCommandBuffers(VkDevice device,
+                                                      VkCommandPool commandPool,
+                                                      uint32_t commandBufferCount,
+                                                      const VkCommandBuffer* pCommandBuffers)
+{
+   struct device_data *device_data = FIND_DEVICE_DATA(device);
+
+   for (uint32_t i = 0; i < commandBufferCount; i++)
+      unmap_object(pCommandBuffers[i]);
+
+   device_data->vtable.FreeCommandBuffers(device, commandPool,
+                                          commandBufferCount, pCommandBuffers);
+}
+
+VKAPI_ATTR VkResult VKAPI_CALL overlay_QueueSubmit(
+    VkQueue                                     queue,
+    uint32_t                                    submitCount,
+    const VkSubmitInfo*                         pSubmits,
+    VkFence                                     fence)
+{
+   struct queue_data *queue_data = FIND_QUEUE_DATA(queue);
+   struct device_data *device_data = queue_data->device;
+
+   device_data->stats.stats[FRAME_STAT_SUBMIT]++;
+
+   return device_data->vtable.QueueSubmit(queue, submitCount, pSubmits, fence);
+}
+
+VKAPI_ATTR VkResult VKAPI_CALL overlay_CreateDevice(
+    VkPhysicalDevice                            physicalDevice,
+    const VkDeviceCreateInfo*                   pCreateInfo,
+    const VkAllocationCallbacks*                pAllocator,
+    VkDevice*                                   pDevice)
+{
+   struct instance_data *instance_data = FIND_PHYSICAL_DEVICE_DATA(physicalDevice);
+   VkLayerDeviceCreateInfo *chain_info = get_chain_info(pCreateInfo, VK_LAYER_LINK_INFO);
+
+   assert(chain_info->u.pLayerInfo);
+   PFN_vkGetInstanceProcAddr fpGetInstanceProcAddr = chain_info->u.pLayerInfo->pfnNextGetInstanceProcAddr;
+   PFN_vkGetDeviceProcAddr fpGetDeviceProcAddr = chain_info->u.pLayerInfo->pfnNextGetDeviceProcAddr;
+   PFN_vkCreateDevice fpCreateDevice = (PFN_vkCreateDevice)fpGetInstanceProcAddr(NULL, "vkCreateDevice");
+   if (fpCreateDevice == NULL) {
+      return VK_ERROR_INITIALIZATION_FAILED;
+   }
+
+   // Advance the link info for the next element on the chain
+   chain_info->u.pLayerInfo = chain_info->u.pLayerInfo->pNext;
+
+   VkResult result = fpCreateDevice(physicalDevice, pCreateInfo, pAllocator, pDevice);
+   if (result != VK_SUCCESS) return result;
+
+   struct device_data *device_data = new_device_data(*pDevice, instance_data);
+   device_data->physical_device = physicalDevice;
+   layer_init_device_dispatch_table(*pDevice, &device_data->vtable, fpGetDeviceProcAddr);
+
+   instance_data->vtable.GetPhysicalDeviceProperties(device_data->physical_device,
+                                                     &device_data->properties);
+
+   device_map_queues(device_data, pCreateInfo);
+
+   return result;
+}
+
+VKAPI_ATTR void VKAPI_CALL overlay_DestroyDevice(
+    VkDevice                                    device,
+    const VkAllocationCallbacks*                pAllocator)
+{
+   struct device_data *device_data = FIND_DEVICE_DATA(device);
+   device_unmap_queues(device_data);
+   device_data->vtable.DestroyDevice(device, pAllocator);
+   destroy_device_data(device_data);
+}
+
+VKAPI_ATTR VkResult VKAPI_CALL overlay_CreateInstance(
+    const VkInstanceCreateInfo*                 pCreateInfo,
+    const VkAllocationCallbacks*                pAllocator,
+    VkInstance*                                 pInstance)
+{
+   VkLayerInstanceCreateInfo *chain_info = get_chain_info(pCreateInfo, VK_LAYER_LINK_INFO);
+
+   assert(chain_info->u.pLayerInfo);
+   PFN_vkGetInstanceProcAddr fpGetInstanceProcAddr =
+      chain_info->u.pLayerInfo->pfnNextGetInstanceProcAddr;
+   PFN_vkCreateInstance fpCreateInstance =
+      (PFN_vkCreateInstance)fpGetInstanceProcAddr(NULL, "vkCreateInstance");
+   if (fpCreateInstance == NULL) {
+      return VK_ERROR_INITIALIZATION_FAILED;
+   }
+
+   // Advance the link info for the next element on the chain
+   chain_info->u.pLayerInfo = chain_info->u.pLayerInfo->pNext;
+
+   VkResult result = fpCreateInstance(pCreateInfo, pAllocator, pInstance);
+   if (result != VK_SUCCESS) return result;
+
+   struct instance_data *instance_data = new_instance_data(*pInstance);
+   layer_init_instance_dispatch_table(instance_data->instance,
+                                      &instance_data->vtable,
+                                      fpGetInstanceProcAddr);
+   instance_data_map_physical_devices(instance_data, true);
+
+   const char *stats_config = getenv("VK_LAYER_MESA_OVERLAY_STATS");
+   instance_data->enabled_stats = parse_debug_string(stats_config,
+                                                     enable_flags);
+
+   if (instance_data->enabled_stats & FRAME_STAT_ENABLED(HELP)) {
+      fprintf(stderr, "Available stats:\n");
+      for (uint32_t i = 0; enable_flags[i].string != NULL; i++)
+         fprintf(stderr, "\t%s\n", enable_flags[i].string);
+      fprintf(stderr, "Position layer using VK_LAYER_MESA_OVERLAY_POSITION=\n"
+              "\ttop-left\n"
+              "\ttop-right\n"
+              "\tbottom-left\n"
+              "\tbottom-right\n");
+   }
+
+   instance_data->position =
+      parse_layer_position(getenv("VK_LAYER_MESA_OVERLAY_POSITION"));
+
+   return result;
+}
+
+VKAPI_ATTR void VKAPI_CALL overlay_DestroyInstance(
+    VkInstance                                  instance,
+    const VkAllocationCallbacks*                pAllocator)
+{
+   struct instance_data *instance_data = FIND_INSTANCE_DATA(instance);
+   instance_data_map_physical_devices(instance_data, false);
+   instance_data->vtable.DestroyInstance(instance, pAllocator);
+   destroy_instance_data(instance_data);
+}
+
+static const struct {
+   const char *name;
+   void *ptr;
+} name_to_funcptr_map[] = {
+   { "vkGetDeviceProcAddr", (void *) vkGetDeviceProcAddr },
+#define ADD_HOOK(fn) { "vk" # fn, (void *) overlay_ ## fn }
+   ADD_HOOK(AllocateCommandBuffers),
+
+   ADD_HOOK(CmdDraw),
+   ADD_HOOK(CmdDrawIndexed),
+   ADD_HOOK(CmdDrawIndexedIndirect),
+   ADD_HOOK(CmdDispatch),
+   ADD_HOOK(CmdDispatchIndirect),
+   ADD_HOOK(CmdDrawIndirectCountKHR),
+   ADD_HOOK(CmdDrawIndexedIndirectCountKHR),
+
+   ADD_HOOK(CmdBindPipeline),
+
+   ADD_HOOK(CreateSwapchainKHR),
+   ADD_HOOK(QueuePresentKHR),
+   ADD_HOOK(DestroySwapchainKHR),
+   ADD_HOOK(AcquireNextImageKHR),
+   ADD_HOOK(AcquireNextImage2KHR),
+
+   ADD_HOOK(QueueSubmit),
+   ADD_HOOK(CreateInstance),
+   ADD_HOOK(DestroyInstance),
+   ADD_HOOK(CreateDevice),
+   ADD_HOOK(DestroyDevice),
+#undef ADD_HOOK
+};
+
+static void *find_ptr(const char *name)
+{
+   for (uint32_t i = 0; i < ARRAY_SIZE(name_to_funcptr_map); i++) {
+      if (strcmp(name, name_to_funcptr_map[i].name) == 0)
+         return name_to_funcptr_map[i].ptr;
+   }
+
+   return NULL;
+}
+
+VK_LAYER_EXPORT VKAPI_ATTR PFN_vkVoidFunction VKAPI_CALL vkGetDeviceProcAddr(VkDevice dev,
+                                                                             const char *funcName)
+{
+   void *ptr = find_ptr(funcName);
+   if (ptr) return reinterpret_cast<PFN_vkVoidFunction>(ptr);
+
+   if (dev == NULL) return NULL;
+
+   struct device_data *device_data = FIND_DEVICE_DATA(dev);
+   if (device_data->vtable.GetDeviceProcAddr == NULL) return NULL;
+   return device_data->vtable.GetDeviceProcAddr(dev, funcName);
+}
+
+VK_LAYER_EXPORT VKAPI_ATTR PFN_vkVoidFunction VKAPI_CALL vkGetInstanceProcAddr(VkInstance instance,
+                                                                               const char *funcName)
+{
+   void *ptr = find_ptr(funcName);
+   if (ptr) return reinterpret_cast<PFN_vkVoidFunction>(ptr);
+
+   if (instance == NULL) return NULL;
+
+   struct instance_data *instance_data = FIND_INSTANCE_DATA(instance);
+   if (instance_data->vtable.GetInstanceProcAddr == NULL) return NULL;
+   return instance_data->vtable.GetInstanceProcAddr(instance, funcName);
+}
diff --git a/src/vulkan/overlay-layer/overlay.frag b/src/vulkan/overlay-layer/overlay.frag
new file mode 100644 (file)
index 0000000..313a888
--- /dev/null
@@ -0,0 +1,14 @@
+#version 450 core
+layout(location = 0) out vec4 fColor;
+
+layout(set=0, binding=0) uniform sampler2D sTexture;
+
+layout(location = 0) in struct{
+    vec4 Color;
+    vec2 UV;
+} In;
+
+void main()
+{
+    fColor = In.Color * texture(sTexture, In.UV.st);
+}
diff --git a/src/vulkan/overlay-layer/overlay.vert b/src/vulkan/overlay-layer/overlay.vert
new file mode 100644 (file)
index 0000000..20b2908
--- /dev/null
@@ -0,0 +1,25 @@
+#version 450 core
+layout(location = 0) in vec2 aPos;
+layout(location = 1) in vec2 aUV;
+layout(location = 2) in vec4 aColor;
+
+layout(push_constant) uniform uPushConstant{
+    vec2 uScale;
+    vec2 uTranslate;
+} pc;
+
+out gl_PerVertex{
+    vec4 gl_Position;
+};
+
+layout(location = 0) out struct{
+    vec4 Color;
+    vec2 UV;
+} Out;
+
+void main()
+{
+    Out.Color = aColor;
+    Out.UV = aUV;
+    gl_Position = vec4(aPos*pc.uScale+pc.uTranslate, 0, 1);
+}
diff --git a/src/vulkan/overlay-layer/vk_layer_table.cpp b/src/vulkan/overlay-layer/vk_layer_table.cpp
new file mode 100644 (file)
index 0000000..4a033b9
--- /dev/null
@@ -0,0 +1,146 @@
+/* Copyright (c) 2015-2016 The Khronos Group Inc.
+ * Copyright (c) 2015-2016 Valve Corporation
+ * Copyright (c) 2015-2016 LunarG, Inc.
+ * Copyright (c) 2015-2016 Google, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Author: Tobin Ehlis <tobin@lunarg.com>
+ */
+#include <assert.h>
+#include <unordered_map>
+#include "vk_dispatch_table_helper.h"
+#include "vulkan/vk_layer.h"
+#include "vk_layer_table.h"
+static device_table_map tableMap;
+static instance_table_map tableInstanceMap;
+
+// Map lookup must be thread safe
+VkLayerDispatchTable *device_dispatch_table(void *object) {
+    dispatch_key key = get_dispatch_key(object);
+    device_table_map::const_iterator it = tableMap.find((void *)key);
+    assert(it != tableMap.end() && "Not able to find device dispatch entry");
+    return it->second;
+}
+
+VkLayerInstanceDispatchTable *instance_dispatch_table(void *object) {
+    dispatch_key key = get_dispatch_key(object);
+    instance_table_map::const_iterator it = tableInstanceMap.find((void *)key);
+    assert(it != tableInstanceMap.end() && "Not able to find instance dispatch entry");
+    return it->second;
+}
+
+void destroy_dispatch_table(device_table_map &map, dispatch_key key) {
+    device_table_map::const_iterator it = map.find((void *)key);
+    if (it != map.end()) {
+        delete it->second;
+        map.erase(it);
+    }
+}
+
+void destroy_dispatch_table(instance_table_map &map, dispatch_key key) {
+    instance_table_map::const_iterator it = map.find((void *)key);
+    if (it != map.end()) {
+        delete it->second;
+        map.erase(it);
+    }
+}
+
+void destroy_device_dispatch_table(dispatch_key key) { destroy_dispatch_table(tableMap, key); }
+
+void destroy_instance_dispatch_table(dispatch_key key) { destroy_dispatch_table(tableInstanceMap, key); }
+
+VkLayerDispatchTable *get_dispatch_table(device_table_map &map, void *object) {
+    dispatch_key key = get_dispatch_key(object);
+    device_table_map::const_iterator it = map.find((void *)key);
+    assert(it != map.end() && "Not able to find device dispatch entry");
+    return it->second;
+}
+
+VkLayerInstanceDispatchTable *get_dispatch_table(instance_table_map &map, void *object) {
+    dispatch_key key = get_dispatch_key(object);
+    instance_table_map::const_iterator it = map.find((void *)key);
+    assert(it != map.end() && "Not able to find instance dispatch entry");
+    return it->second;
+}
+
+VkLayerInstanceCreateInfo *get_chain_info(const VkInstanceCreateInfo *pCreateInfo, VkLayerFunction func) {
+    VkLayerInstanceCreateInfo *chain_info = (VkLayerInstanceCreateInfo *)pCreateInfo->pNext;
+    while (chain_info && !(chain_info->sType == VK_STRUCTURE_TYPE_LOADER_INSTANCE_CREATE_INFO && chain_info->function == func)) {
+        chain_info = (VkLayerInstanceCreateInfo *)chain_info->pNext;
+    }
+    assert(chain_info != NULL);
+    return chain_info;
+}
+
+VkLayerDeviceCreateInfo *get_chain_info(const VkDeviceCreateInfo *pCreateInfo, VkLayerFunction func) {
+    VkLayerDeviceCreateInfo *chain_info = (VkLayerDeviceCreateInfo *)pCreateInfo->pNext;
+    while (chain_info && !(chain_info->sType == VK_STRUCTURE_TYPE_LOADER_DEVICE_CREATE_INFO && chain_info->function == func)) {
+        chain_info = (VkLayerDeviceCreateInfo *)chain_info->pNext;
+    }
+    assert(chain_info != NULL);
+    return chain_info;
+}
+
+/* Various dispatchable objects will use the same underlying dispatch table if they
+ * are created from that "parent" object. Thus use pointer to dispatch table
+ * as the key to these table maps.
+ *    Instance -> PhysicalDevice
+ *    Device -> CommandBuffer or Queue
+ * If use the object themselves as key to map then implies Create entrypoints have to be intercepted
+ * and a new key inserted into map */
+VkLayerInstanceDispatchTable *initInstanceTable(VkInstance instance, const PFN_vkGetInstanceProcAddr gpa, instance_table_map &map) {
+    VkLayerInstanceDispatchTable *pTable;
+    dispatch_key key = get_dispatch_key(instance);
+    instance_table_map::const_iterator it = map.find((void *)key);
+
+    if (it == map.end()) {
+        pTable = new VkLayerInstanceDispatchTable;
+        map[(void *)key] = pTable;
+    } else {
+        return it->second;
+    }
+
+    layer_init_instance_dispatch_table(instance, pTable, gpa);
+
+    // Setup func pointers that are required but not externally exposed.  These won't be added to the instance dispatch table by
+    // default.
+    pTable->GetPhysicalDeviceProcAddr = (PFN_GetPhysicalDeviceProcAddr)gpa(instance, "vk_layerGetPhysicalDeviceProcAddr");
+
+    return pTable;
+}
+
+VkLayerInstanceDispatchTable *initInstanceTable(VkInstance instance, const PFN_vkGetInstanceProcAddr gpa) {
+    return initInstanceTable(instance, gpa, tableInstanceMap);
+}
+
+VkLayerDispatchTable *initDeviceTable(VkDevice device, const PFN_vkGetDeviceProcAddr gpa, device_table_map &map) {
+    VkLayerDispatchTable *pTable;
+    dispatch_key key = get_dispatch_key(device);
+    device_table_map::const_iterator it = map.find((void *)key);
+
+    if (it == map.end()) {
+        pTable = new VkLayerDispatchTable;
+        map[(void *)key] = pTable;
+    } else {
+        return it->second;
+    }
+
+    layer_init_device_dispatch_table(device, pTable, gpa);
+
+    return pTable;
+}
+
+VkLayerDispatchTable *initDeviceTable(VkDevice device, const PFN_vkGetDeviceProcAddr gpa) {
+    return initDeviceTable(device, gpa, tableMap);
+}
diff --git a/src/vulkan/overlay-layer/vk_layer_table.h b/src/vulkan/overlay-layer/vk_layer_table.h
new file mode 100644 (file)
index 0000000..45b8f6e
--- /dev/null
@@ -0,0 +1,51 @@
+/* Copyright (c) 2015-2016 The Khronos Group Inc.
+ * Copyright (c) 2015-2016 Valve Corporation
+ * Copyright (c) 2015-2016 LunarG, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Author: Tobin Ehlis <tobin@lunarg.com>
+ */
+
+#pragma once
+
+#include "vulkan/vk_layer.h"
+#include "vulkan/vulkan.h"
+#include <unordered_map>
+
+typedef std::unordered_map<void *, VkLayerDispatchTable *> device_table_map;
+typedef std::unordered_map<void *, VkLayerInstanceDispatchTable *> instance_table_map;
+VkLayerDispatchTable *initDeviceTable(VkDevice device, const PFN_vkGetDeviceProcAddr gpa, device_table_map &map);
+VkLayerDispatchTable *initDeviceTable(VkDevice device, const PFN_vkGetDeviceProcAddr gpa);
+VkLayerInstanceDispatchTable *initInstanceTable(VkInstance instance, const PFN_vkGetInstanceProcAddr gpa, instance_table_map &map);
+VkLayerInstanceDispatchTable *initInstanceTable(VkInstance instance, const PFN_vkGetInstanceProcAddr gpa);
+
+typedef void *dispatch_key;
+
+static inline dispatch_key get_dispatch_key(const void *object) { return (dispatch_key) * (VkLayerDispatchTable **)object; }
+
+VkLayerDispatchTable *device_dispatch_table(void *object);
+
+VkLayerInstanceDispatchTable *instance_dispatch_table(void *object);
+
+VkLayerDispatchTable *get_dispatch_table(device_table_map &map, void *object);
+
+VkLayerInstanceDispatchTable *get_dispatch_table(instance_table_map &map, void *object);
+
+VkLayerInstanceCreateInfo *get_chain_info(const VkInstanceCreateInfo *pCreateInfo, VkLayerFunction func);
+VkLayerDeviceCreateInfo *get_chain_info(const VkDeviceCreateInfo *pCreateInfo, VkLayerFunction func);
+
+void destroy_device_dispatch_table(dispatch_key key);
+void destroy_instance_dispatch_table(dispatch_key key);
+void destroy_dispatch_table(device_table_map &map, dispatch_key key);
+void destroy_dispatch_table(instance_table_map &map, dispatch_key key);