Fix 4444 on Vulkan devices who don't support RGBA_4444

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2238563002

Committed: https://skia.googlesource.com/skia/+/637b3bf2b9c10398d823bd015a722842d4f2f971
Review-Url: https://codereview.chromium.org/2238563002

diff --git a/src/gpu/GrGpu.cpp b/src/gpu/GrGpu.cpp
index 7199b4d..e14e892 100644 (file)
--- a/src/gpu/GrGpu.cpp
+++ b/src/gpu/GrGpu.cpp
@@ -277,6 +277,12 @@ bool GrGpu::getReadPixelsInfo(GrSurface* srcSurface, int width, int height, size
         return false;
     }
 
+    // We currently do not support reading into the packed formats 565 or 4444 as they are not
+    // required to have read back support on all devices and backends.
+    if (kRGB_565_GrPixelConfig == readConfig || kRGBA_4444_GrPixelConfig == readConfig) {
+        return false;
+    }
+
     if (!this->onGetReadPixelsInfo(srcSurface, width, height, rowBytes, readConfig, drawPreference,
                                    tempDrawInfo)) {
         return false;

diff --git a/src/gpu/vk/GrVkCaps.cpp b/src/gpu/vk/GrVkCaps.cpp
index cf9f4f0..9027f68 100644 (file)
--- a/src/gpu/vk/GrVkCaps.cpp
+++ b/src/gpu/vk/GrVkCaps.cpp
@@ -137,7 +137,16 @@ void GrVkCaps::initGLSLCaps(const VkPhysicalDeviceProperties& properties,
             glslCaps->fConfigTextureSwizzle[i] = GrSwizzle::RRRR();
             glslCaps->fConfigOutputSwizzle[i] = GrSwizzle::AAAA();
         } else {
-            glslCaps->fConfigTextureSwizzle[i] = GrSwizzle::RGBA();
+            if (kRGBA_4444_GrPixelConfig == config) {
+                // The vulkan spec does not require R4G4B4A4 to be supported for texturing so we
+                // store the data in a B4G4R4A4 texture and then swizzle it when doing texture reads
+                // or writing to outputs. Since we're not actually changing the data at all, the
+                // only extra work is the swizzle in the shader for all operations.
+                glslCaps->fConfigTextureSwizzle[i] = GrSwizzle::BGRA();
+                glslCaps->fConfigOutputSwizzle[i] = GrSwizzle::BGRA();
+            } else {
+                glslCaps->fConfigTextureSwizzle[i] = GrSwizzle::RGBA();
+            }
         }
     }
 

diff --git a/src/gpu/vk/GrVkCaps.h b/src/gpu/vk/GrVkCaps.h
index ca92e59..3733f2c 100644 (file)
--- a/src/gpu/vk/GrVkCaps.h
+++ b/src/gpu/vk/GrVkCaps.h
@@ -101,7 +101,7 @@ private:
         uint16_t fLinearFlags;
     };
     ConfigInfo fConfigTable[kGrPixelConfigCnt];
-    
+
     StencilFormat fPreferedStencilFormat;
 
     // Tells of if we can pass in straight GLSL string into vkCreateShaderModule

diff --git a/src/gpu/vk/GrVkUtil.cpp b/src/gpu/vk/GrVkUtil.cpp
index 760b20b..ffbad25 100644 (file)
--- a/src/gpu/vk/GrVkUtil.cpp
+++ b/src/gpu/vk/GrVkUtil.cpp
@@ -30,7 +30,9 @@ bool GrPixelConfigToVkFormat(GrPixelConfig config, VkFormat* format) {
             *format = VK_FORMAT_R5G6B5_UNORM_PACK16;
             break;
         case kRGBA_4444_GrPixelConfig:
-            *format = VK_FORMAT_R4G4B4A4_UNORM_PACK16;
+            // R4G4B4A4 is not required to be supported so we actually
+            // store the data is if it was B4G4R4A4 and swizzle in shaders
+            *format = VK_FORMAT_B4G4R4A4_UNORM_PACK16;
             break;
         case kIndex_8_GrPixelConfig:
             // No current vulkan support for this config
@@ -88,7 +90,9 @@ bool GrVkFormatToPixelConfig(VkFormat format, GrPixelConfig* config) {
         case VK_FORMAT_R5G6B5_UNORM_PACK16:
             *config = kRGB_565_GrPixelConfig;
             break;
-        case VK_FORMAT_R4G4B4A4_UNORM_PACK16:
+        case VK_FORMAT_B4G4R4A4_UNORM_PACK16:
+            // R4G4B4A4 is not required to be supported so we actually
+            // store RGBA_4444 data as B4G4R4A4.
             *config = kRGBA_4444_GrPixelConfig;
             break;
         case VK_FORMAT_R8_UNORM:

diff --git a/tests/PackedConfigsTextureTest.cpp b/tests/PackedConfigsTextureTest.cpp
new file mode 100644 (file)
index 0000000..89ca6ac
--- /dev/null
+++ b/tests/PackedConfigsTextureTest.cpp
@@ -0,0 +1,144 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/*
+ * This is a straightforward test of using packed pixel configs (4444, 565).
+ * This test will make sure that these RGBA_4444 and RGB_565 are always supported
+ * as valid texturing configs.
+ */
+
+#include "Test.h"
+
+#if SK_SUPPORT_GPU
+#include "GrContext.h"
+#include "GrTexture.h"
+
+static const int DEV_W = 10, DEV_H = 10;
+static const SkIRect DEV_RECT = SkIRect::MakeWH(DEV_W, DEV_H);
+static const uint8_t TOL = 0x4;
+
+static void check_component(skiatest::Reporter* reporter, uint8_t control, uint8_t test) {
+    uint8_t diff = 0;
+    if (control >= test) {
+        diff = control - test;
+    } else {
+        diff = test - control;
+    }
+    REPORTER_ASSERT(reporter, diff < TOL);
+}
+
+static uint8_t expand_value(uint8_t original, int sigBits) {
+    SkASSERT(sigBits >= 4);
+    uint8_t inSigBitShift = 8 - sigBits;
+    uint8_t duplBitShift = sigBits - inSigBitShift;
+    return (original << inSigBitShift) + (original >> duplBitShift);
+}
+
+static void check_4444(skiatest::Reporter* reporter,
+                       const SkTDArray<uint16_t>& controlData,
+                       const SkTDArray<uint32_t>& readBuffer) {
+    for (int j = 0; j < DEV_H; ++j) {
+        for (int i = 0; i < DEV_W; ++i) {
+            uint16_t control = controlData[i + j * DEV_H];
+            uint32_t test = readBuffer[i + j * DEV_H];
+
+            // Test alpha component
+            uint8_t ctrlComp = expand_value(control & 0xF, 4);
+            uint8_t testComp = GrColorUnpackA(test);
+            check_component(reporter, ctrlComp, testComp);
+
+            // Test blue component
+            ctrlComp = expand_value((control >> 4) & 0xF, 4);
+            testComp = GrColorUnpackB(test);
+            check_component(reporter, ctrlComp, testComp);
+
+            // Test green component
+            ctrlComp = expand_value((control >> 8) & 0xF, 4);
+            testComp = GrColorUnpackG(test);
+            check_component(reporter, ctrlComp, testComp);
+
+            // Test red component
+            ctrlComp = expand_value((control >> 12) & 0xF, 4);
+            testComp = GrColorUnpackR(test);
+            check_component(reporter, ctrlComp, testComp);
+        }
+    }
+}
+
+static void check_565(skiatest::Reporter* reporter,
+                      const SkTDArray<uint16_t>& controlData,
+                      const SkTDArray<GrColor>& readBuffer) {
+    for (int j = 0; j < DEV_H; ++j) {
+        for (int i = 0; i < DEV_W; ++i) {
+            uint16_t control = controlData[i + j * DEV_H];
+            GrColor test = readBuffer[i + j * DEV_H];
+            // Test blue component (5 bit control)
+            uint8_t ctrlComp = expand_value(control & 0x1F, 5);
+            uint8_t testComp = GrColorUnpackB(test);
+            check_component(reporter, ctrlComp, testComp);
+
+            // Test green component (6 bit control)
+            ctrlComp = expand_value((control >> 5) & 0x3F, 6);
+            testComp = GrColorUnpackG(test);
+            check_component(reporter, ctrlComp, testComp);
+
+            // Test red component (5 bit control)
+            ctrlComp = expand_value((control >> 11) & 0x1F, 5);
+            testComp = GrColorUnpackR(test);
+            check_component(reporter, ctrlComp, testComp);
+        }
+    }
+}
+
+template <typename T>
+void runTest(skiatest::Reporter* reporter, GrContext* context,
+             T val1, T val2, int arraySize, GrPixelConfig config) {
+    SkTDArray<T> controlPixelData;
+    // We will read back into an 8888 buffer since 565/4444 read backes aren't supported
+    SkTDArray<GrColor> readBuffer;
+    controlPixelData.setCount(arraySize);
+    readBuffer.setCount(arraySize);
+
+    for (int i = 0; i < arraySize; i += 2) {
+        controlPixelData[i] = val1;
+        controlPixelData[i + 1] = val2;
+    }
+
+    for (int origin = 0; origin < 2; ++origin) {
+        GrSurfaceDesc desc;
+        desc.fFlags = kNone_GrSurfaceFlags;
+        desc.fWidth = DEV_W;
+        desc.fHeight = DEV_H;
+        desc.fConfig = config;
+        desc.fOrigin = 0 == origin ?
+            kTopLeft_GrSurfaceOrigin : kBottomLeft_GrSurfaceOrigin;
+        SkAutoTUnref<GrTexture> fpTexture(context->textureProvider()->createTexture(
+            desc, SkBudgeted::kNo, controlPixelData.begin(), 0));
+        SkASSERT(fpTexture);
+        fpTexture->readPixels(0, 0, DEV_W, DEV_H, kRGBA_8888_GrPixelConfig, readBuffer.begin(), 0);
+        if (kRGBA_4444_GrPixelConfig == config) {
+            check_4444(reporter, controlPixelData, readBuffer);
+        } else {
+            SkASSERT(kRGB_565_GrPixelConfig == config);
+            check_565(reporter, controlPixelData, readBuffer);
+        }
+    }
+}
+
+static const int CONTROL_ARRAY_SIZE = DEV_W * DEV_H;
+
+DEF_GPUTEST_FOR_RENDERING_CONTEXTS(RGBA4444TextureTest, reporter, ctxInfo) {
+    runTest<uint16_t>(reporter, ctxInfo.grContext(), 0xFF00, 0xFA62,
+                      CONTROL_ARRAY_SIZE, kRGBA_4444_GrPixelConfig);
+}
+
+DEF_GPUTEST_FOR_RENDERING_CONTEXTS(RGB565TextureTest, reporter, ctxInfo) {
+    runTest<uint16_t>(reporter, ctxInfo.grContext(), 0xFF00, 0xFA62,
+                      CONTROL_ARRAY_SIZE, kRGB_565_GrPixelConfig);
+}
+
+#endif