--- /dev/null
+/*
+ * GStreamer
+ * Copyright (C) 2015 Matthew Waters <matthew@centricular.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include <gst/gst.h>
+#include <gst/gl/gl.h>
+#include <gtk/gtk.h>
+#if GST_GL_HAVE_WINDOW_X11
+#include <X11/Xlib.h>
+#endif
+
+static GMainLoop *loop;
+
+static const gchar *vert = "#version 330\n\
+in vec4 a_position;\n\
+in vec2 a_texcoord;\n\
+out vec2 v_texcoord;\n\
+uniform float time;\n\
+uniform float width;\n\
+uniform float height;\n\
+void main()\n\
+{\n\
+ gl_Position = a_position;\n\
+ v_texcoord = a_texcoord;\n\
+}\n";
+
+static const gchar *geom = "#version 330\n\
+\n\
+layout(triangles) in;\n\
+layout(triangle_strip, max_vertices = 3) out;\n\
+in vec2 v_texcoord[];\n\
+out vec2 g_texcoord;\n\
+\n\
+void main() {\n\
+ for(int i = 0; i < 3; i++) {\n\
+ gl_Position = gl_in[i].gl_Position;\n\
+ g_texcoord = v_texcoord[i];\n\
+ EmitVertex();\n\
+ }\n\
+ EndPrimitive();\n\
+}\n";
+
+static const gchar *frag = "#version 330\n\
+in vec2 g_texcoord;\n\
+uniform sampler2D tex;\n\
+uniform float time;\n\
+uniform float width;\n\
+uniform float height;\n\
+void main()\n\
+{\n\
+ gl_FragColor = texture2D(tex, g_texcoord);\n\
+}\n";
+
+#define MAX_SHADER_STAGES 8
+struct shader_state;
+
+struct text_view_state
+{
+ struct shader_state *state;
+
+ GLenum type;
+ gchar *str;
+};
+
+struct shader_state
+{
+ GstGLContext *context;
+ GstElement *shader;
+ gboolean shader_linked;
+ GtkWidget *label;
+ struct text_view_state text_states[MAX_SHADER_STAGES];
+ gint n_stages;
+};
+
+static gboolean
+bus_call (GstBus * bus, GstMessage * msg, gpointer data)
+{
+ switch (GST_MESSAGE_TYPE (msg)) {
+ case GST_MESSAGE_EOS:
+ g_print ("End of stream\n");
+ g_main_loop_quit (loop);
+ break;
+ case GST_MESSAGE_ERROR:{
+ gchar *debug;
+ GError *error;
+
+ gst_message_parse_error (msg, &error, &debug);
+ g_free (debug);
+
+ g_printerr ("Error: %s\n", error->message);
+ g_error_free (error);
+
+ g_main_loop_quit (loop);
+ break;
+ }
+ default:
+ break;
+ }
+
+ return TRUE;
+}
+
+static gchar *
+_find_source_for_shader_type (struct shader_state *state, GLenum type)
+{
+ int i = 0;
+
+ for (i = 0; i < state->n_stages; i++) {
+ if (state->text_states[i].type == type)
+ return state->text_states[i].str;
+ }
+
+ return NULL;
+}
+
+static gboolean
+_add_stage_to_shader (GstGLShader * shader, struct shader_state *state,
+ GLenum type, const gchar * default_src)
+{
+ GError *error = NULL;
+ GstGLSLVersion version;
+ GstGLSLProfile profile;
+ GstGLSLStage *stage;
+ const gchar *src;
+
+ src = _find_source_for_shader_type (state, type);
+ if (!src)
+ src = default_src;
+ if (!src)
+ /* FIXME: assume this stage is not needed */
+ return TRUE;
+
+ if (!gst_glsl_string_get_version_profile (src, &version, &profile)) {
+ g_print ("Warning: failed to retreive GLSL version and profile for "
+ "shader type 0x%x\nsrc:\n%s\n", type, src);
+ }
+
+ if (!(stage = gst_glsl_stage_new_with_string (shader->context, type,
+ version, profile, src))) {
+ g_print ("Error: Failed to create GLSL Stage from src:\n%s\n", src);
+ return FALSE;
+ }
+
+ if (!gst_gl_shader_compile_attach_stage (shader, stage, &error)) {
+ /* ignore failed shader compilations */
+ g_print ("%s", error->message);
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+static GstGLShader *
+_new_shader (GstGLContext * context, struct shader_state *state)
+{
+ GstGLShader *shader = gst_gl_shader_new (context);
+ GError *error = NULL;
+
+ if (!_add_stage_to_shader (shader, state, GL_VERTEX_SHADER, vert)) {
+ gst_object_unref (shader);
+ return NULL;
+ }
+ if (!_add_stage_to_shader (shader, state, GL_GEOMETRY_SHADER, geom)) {
+ gst_object_unref (shader);
+ return NULL;
+ }
+ if (!_add_stage_to_shader (shader, state, GL_FRAGMENT_SHADER, frag)) {
+ gst_object_unref (shader);
+ return NULL;
+ }
+
+ if (!gst_gl_shader_link (shader, &error)) {
+ /* ignore failed shader compilations */
+ g_print ("%s", error->message);
+ gst_object_unref (shader);
+ return NULL;
+ }
+
+ return shader;
+}
+
+static GstGLShader *
+_create_shader (GstElement * element, struct shader_state *state)
+{
+ GstGLContext *context;
+ GstGLShader *shader;
+
+ g_object_get (G_OBJECT (element), "context", &context, NULL);
+
+ shader = _new_shader (context, state);
+ state->shader_linked = TRUE;
+
+ if (state->context)
+ gst_object_unref (state->context);
+ state->context = context;
+
+ return shader;
+}
+
+static void
+_modify_shader (GstGLContext * context, struct shader_state *state)
+{
+ GstGLShader *shader;
+
+ if (!(shader = _new_shader (context, state))) {
+ state->shader_linked = FALSE;
+ return;
+ }
+ state->shader_linked = TRUE;
+
+ g_object_set (state->shader, "shader", shader, NULL);
+}
+
+static void
+_on_text_changed (GtkTextBuffer * text, struct text_view_state *state)
+{
+ GtkTextIter start, end;
+
+ if (!state->state->context)
+ return;
+
+ gtk_text_buffer_get_bounds (text, &start, &end);
+ if (state->str)
+ g_free (state->str);
+ state->str = gtk_text_buffer_get_text (text, &start, &end, FALSE);
+ gst_gl_context_thread_add (state->state->context,
+ (GstGLContextThreadFunc) _modify_shader, state->state);
+
+ gtk_label_set_text (GTK_LABEL (state->state->label),
+ state->state->shader_linked ? "Success" : "Failure");
+}
+
+static GtkWidget *
+_new_source_view (struct shader_state *state, GLenum type, const gchar * templ)
+{
+ static int i = 0;
+ GtkWidget *scroll, *text_view;
+ GtkTextBuffer *text;
+
+ g_return_val_if_fail (i < MAX_SHADER_STAGES, NULL);
+
+ state->text_states[i].state = state;
+ state->text_states[i].type = type;
+ state->text_states[i].str = g_strdup (templ);
+
+ scroll = gtk_scrolled_window_new (NULL, NULL);
+ gtk_widget_set_size_request (scroll, 20, 20);
+ text_view = gtk_text_view_new ();
+ gtk_container_add (GTK_CONTAINER (scroll), text_view);
+ text = gtk_text_view_get_buffer (GTK_TEXT_VIEW (text_view));
+ if (state->text_states[i].str)
+ gtk_text_buffer_set_text (text, state->text_states[i].str, -1);
+ g_signal_connect (text, "changed", G_CALLBACK (_on_text_changed),
+ &state->text_states[i]);
+ state->n_stages++;
+ i++;
+
+ return scroll;
+}
+
+int
+main (int argc, char *argv[])
+{
+ GstElement *pipeline, *src, *upload, *shader, *sink;
+ GtkWidget *window, *paned, *video, *right_box, *book;
+ struct shader_state state = { 0, };
+ GstBus *bus;
+
+#if GST_GL_HAVE_WINDOW_X11
+ XInitThreads ();
+#endif
+
+ gst_init (&argc, &argv);
+ gtk_init (&argc, &argv);
+
+ loop = g_main_loop_new (NULL, FALSE);
+
+ pipeline = gst_pipeline_new (NULL);
+ src = gst_element_factory_make ("videotestsrc", NULL);
+ upload = gst_element_factory_make ("glupload", NULL);
+ shader = gst_element_factory_make ("glshader", NULL);
+ sink = gst_element_factory_make ("gtkglsink", NULL);
+ g_object_get (sink, "widget", &video, NULL);
+
+ g_assert (src && shader && sink);
+ gst_bin_add_many (GST_BIN (pipeline), src, upload, shader, sink, NULL);
+ g_assert (gst_element_link_many (src, upload, shader, sink, NULL));
+
+ bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
+ gst_bus_add_watch (bus, bus_call, loop);
+ gst_object_unref (bus);
+
+ state.shader = gst_object_ref (shader);
+ g_signal_connect (shader, "create-shader", G_CALLBACK (_create_shader),
+ &state);
+
+ book = gtk_notebook_new ();
+ /* text view inside a scroll view */
+ gtk_notebook_append_page (GTK_NOTEBOOK (book), _new_source_view (&state,
+ GL_VERTEX_SHADER, vert), gtk_label_new ("Vertex"));
+ gtk_notebook_append_page (GTK_NOTEBOOK (book), _new_source_view (&state,
+ GL_GEOMETRY_SHADER, geom), gtk_label_new ("Geometry"));
+ gtk_notebook_append_page (GTK_NOTEBOOK (book), _new_source_view (&state,
+ GL_FRAGMENT_SHADER, frag), gtk_label_new ("Fragment"));
+ /* status label */
+ state.label = gtk_label_new ("Success");
+
+ /* right side source code editor */
+ right_box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
+ gtk_box_pack_start (GTK_BOX (right_box), book, TRUE, TRUE, 0);
+ gtk_box_pack_start (GTK_BOX (right_box), state.label, FALSE, TRUE, 0);
+
+ paned = gtk_paned_new (GTK_ORIENTATION_HORIZONTAL);
+ gtk_paned_pack1 (GTK_PANED (paned), video, TRUE, FALSE);
+ gtk_widget_set_size_request (video, 20, 20);
+ gtk_paned_pack2 (GTK_PANED (paned), right_box, TRUE, FALSE);
+
+ window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
+ gtk_window_set_default_size (GTK_WINDOW (window), 640, 480);
+ gtk_container_add (GTK_CONTAINER (window), paned);
+
+ gtk_widget_show_all (window);
+
+ gst_element_set_state (pipeline, GST_STATE_PLAYING);
+
+ g_main_loop_run (loop);
+
+ gst_element_set_state (pipeline, GST_STATE_NULL);
+
+ /*shader strings leaked here */
+ /*g_free (state.str); */
+ gst_object_unref (state.shader);
+
+ gst_object_unref (pipeline);
+
+ return 0;
+}