Add another shader node demomatthiasc/glshader-demo

This one does stack-like transitions, using
some examples from gl-transitions.com.

1 files changed, 113 insertions, 0 deletions

diff --git a/demos/gtk-demo/gltransition.c b/demos/gtk-demo/gltransition.c
new file mode 100644
index 0000000000..4b994216c4
--- /dev/null
+++ b/demos/gtk-demo/gltransition.c
@@ -0,0 +1,113 @@
+/* OpenGL/Transitions
+ * #Keywords: OpenGL, shader
+ *
+ * Create transitions between pages using a custom fragment shader.
+ *
+ * The examples here are taken from gl-transitions.com.
+ */
+#include <math.h>
+#include <gtk/gtk.h>
+#include "gtkshaderstack.h"
+
+static GtkWidget *demo_window = NULL;
+
+static void
+close_window (GtkWidget *widget)
+{
+  /* Reset the state */
+  demo_window = NULL;
+}
+
+static GskGLShader *
+gsk_shader_new_from_resource (const char *resource_path)
+{
+  GBytes *shader_b;
+  GskGLShader *shader;
+
+  shader_b = g_resources_lookup_data (resource_path, 0, NULL);
+  shader = gsk_glshader_new ((const char *)g_bytes_get_data (shader_b, NULL));
+  g_bytes_unref (shader_b);
+
+  return shader;
+}
+
+static GtkWidget *
+make_shader_stack (const char *resource_path)
+{
+  GtkWidget *stack, *child;
+  GskGLShader *shader;
+
+  stack = gtk_shader_stack_new ();
+  shader = gsk_shader_new_from_resource (resource_path);
+  gtk_shader_stack_set_shader (GTK_SHADER_STACK (stack), shader);
+  g_object_unref (shader);
+
+  child = gtk_picture_new_for_resource ("/css_pixbufs/background.jpg");
+  gtk_picture_set_can_shrink (GTK_PICTURE (child), TRUE);
+  gtk_shader_stack_add_child (GTK_SHADER_STACK (stack), child);
+
+  child = gtk_picture_new_for_resource ("/transparent/portland-rose.jpg");
+  gtk_picture_set_can_shrink (GTK_PICTURE (child), TRUE);
+  gtk_shader_stack_add_child (GTK_SHADER_STACK (stack), child);
+
+  child = gtk_picture_new_for_resource ("/css_blendmodes/ducky.png");
+  gtk_picture_set_can_shrink (GTK_PICTURE (child), TRUE);
+  gtk_shader_stack_add_child (GTK_SHADER_STACK (stack), child);
+
+  return stack;
+}
+
+static GtkWidget *
+create_gltransition_window (GtkWidget *do_widget)
+{
+  GtkWidget *window, *grid;
+
+  window = gtk_window_new ();
+  gtk_window_set_display (GTK_WINDOW (window),  gtk_widget_get_display (do_widget));
+  gtk_window_set_title (GTK_WINDOW (window), "Transitions");
+  gtk_window_set_default_size (GTK_WINDOW (window), 400, 400);
+  g_signal_connect (window, "destroy", G_CALLBACK (close_window), NULL);
+
+  grid = gtk_grid_new ();
+  gtk_widget_set_halign (grid, GTK_ALIGN_CENTER);
+  gtk_widget_set_valign (grid, GTK_ALIGN_CENTER);
+  gtk_widget_set_margin_start (grid, 12);
+  gtk_widget_set_margin_end (grid, 12);
+  gtk_widget_set_margin_top (grid, 12);
+  gtk_widget_set_margin_bottom (grid, 12);
+  gtk_grid_set_row_spacing (GTK_GRID (grid), 6);
+  gtk_grid_set_column_spacing (GTK_GRID (grid), 6);
+  gtk_grid_set_row_homogeneous (GTK_GRID (grid), TRUE);
+  gtk_grid_set_column_homogeneous (GTK_GRID (grid), TRUE);
+
+  gtk_window_set_child (GTK_WINDOW (window), grid);
+
+  gtk_grid_attach (GTK_GRID (grid),
+                   make_shader_stack ("/gltransition/transition1.glsl"),
+                   0, 0, 1, 1);
+  gtk_grid_attach (GTK_GRID (grid),
+                   make_shader_stack ("/gltransition/transition2.glsl"),
+                   1, 0, 1, 1);
+  gtk_grid_attach (GTK_GRID (grid),
+                   make_shader_stack ("/gltransition/transition3.glsl"),
+                   0, 1, 1, 1);
+  gtk_grid_attach (GTK_GRID (grid),
+                   make_shader_stack ("/gltransition/transition4.glsl"),
+                   1, 1, 1, 1);
+
+  return window;
+}
+
+GtkWidget *
+do_gltransition (GtkWidget *do_widget)
+{
+  if (!demo_window)
+    demo_window = create_gltransition_window (do_widget);
+
+  if (!gtk_widget_get_visible (demo_window))
+    gtk_widget_show (demo_window);
+  else
+    gtk_window_destroy (GTK_WINDOW (demo_window));
+
+  return demo_window;
+}