[gtk+/wip/gdk-gl] tests/glarea: Make the UI a bit more complex

[Emmanuele Bassi <ebassi src gnome org>]

commit 5cba7de332e0946aa65d40ebc970236e95620925
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Fri Aug 15 12:40:40 2014 +0100

    tests/glarea: Make the UI a bit more complex
    
    Add sliders to control rotation angles on all three axis.

 tests/testglarea.c |  143 ++++++++++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 134 insertions(+), 9 deletions(-)
---
diff --git a/tests/testglarea.c b/tests/testglarea.c
index 3ad8260..5930079 100644
--- a/tests/testglarea.c
+++ b/tests/testglarea.c
@@ -3,13 +3,21 @@
 
 #include <epoxy/gl.h>
 
-static gboolean
-render (GtkGLArea    *area,
-        GdkGLContext *context)
-{
-  glClearColor (0, 0, 0, 0);
-  glClear (GL_COLOR_BUFFER_BIT);
+enum {
+  X_AXIS,
+  Y_AXIS,
+  Z_AXIS,
+
+  N_AXIS
+};
 
+static float rotation_angles[N_AXIS] = { 0.0 };
+
+static GtkWidget *gl_area;
+
+static void
+draw_triangle (void)
+{
   glColor3f (1.0f, 0.85f, 0.35f);
   glBegin (GL_TRIANGLES);
   {
@@ -18,22 +26,131 @@ render (GtkGLArea    *area,
     glVertex3f ( 0.2, -0.3,  0.0);
   }
   glEnd ();
+}
+
+static gboolean
+render (GtkGLArea    *area,
+        GdkGLContext *context)
+{
+  glClearColor (0.5, 0.5, 0.5, 1.0);
+  glClear (GL_COLOR_BUFFER_BIT);
+
+  glMatrixMode (GL_MODELVIEW);
+  glLoadIdentity ();
+  glRotatef (rotation_angles[X_AXIS], 1, 0, 0);
+  glRotatef (rotation_angles[Y_AXIS], 0, 1, 0);
+  glRotatef (rotation_angles[Z_AXIS], 0, 0, 1);
+
+  draw_triangle ();
+
+  glFlush ();
 
   return TRUE;
 }
 
+static void
+init (GtkWidget *widget)
+{
+  GdkGLContext *context = gtk_gl_area_get_context (GTK_GL_AREA (widget));
+  GdkGLPixelFormat *format = gdk_gl_context_get_pixel_format (context);
+
+  g_print ("GL Pixel format:\n"
+           " - double-buffer: %s\n"
+           " - multi-sample: %s\n"
+           " - stereo: %s\n"
+           " - color-size: %d, alpha-size: %d\n"
+           " - depth-size: %d\n"
+           " - stencil-size: %d\n"
+           " - aux-buffers: %d\n"
+           " - accum-size: %d\n"
+           " - sample-buffers: %d\n"
+           " - samples: %d\n\n",
+           gdk_gl_pixel_format_get_double_buffer (format) ? "yes" : "no",
+           gdk_gl_pixel_format_get_multi_sample (format) ? "yes" : "no",
+           gdk_gl_pixel_format_get_stereo (format) ? "yes" : "no",
+           gdk_gl_pixel_format_get_color_size (format),
+           gdk_gl_pixel_format_get_alpha_size (format),
+           gdk_gl_pixel_format_get_depth_size (format),
+           gdk_gl_pixel_format_get_stencil_size (format),
+           gdk_gl_pixel_format_get_aux_buffers (format),
+           gdk_gl_pixel_format_get_accum_size (format),
+           gdk_gl_pixel_format_get_sample_buffers (format),
+           gdk_gl_pixel_format_get_samples (format));
+}
+
+static void
+on_axis_value_change (GtkAdjustment *adjustment,
+                      gpointer       data)
+{
+  int axis = GPOINTER_TO_INT (data);
+
+  if (axis < 0 || axis >= N_AXIS)
+    return;
+
+  rotation_angles[axis] = gtk_adjustment_get_value (adjustment);
+
+  gtk_widget_queue_draw (gl_area);
+}
+
+static GtkWidget *
+create_axis_slider (int axis)
+{
+  GtkWidget *box, *label, *slider;
+  GtkAdjustment *adj;
+  const char *text;
+
+  box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, FALSE);
+
+  switch (axis)
+    {
+    case X_AXIS:
+      text = "X axis";
+      break;
+
+    case Y_AXIS:
+      text = "Y axis";
+      break;
+
+    case Z_AXIS:
+      text = "Z axis";
+      break;
+
+    default:
+      g_assert_not_reached ();
+    }
+
+  label = gtk_label_new (text);
+  gtk_container_add (GTK_CONTAINER (box), label);
+  gtk_widget_show (label);
+
+  adj = gtk_adjustment_new (0.0, 0.0, 360.0, 1.0, 12.0, 0.0);
+  g_signal_connect (adj, "value-changed",
+                    G_CALLBACK (on_axis_value_change),
+                    GINT_TO_POINTER (axis));
+  slider = gtk_scale_new (GTK_ORIENTATION_HORIZONTAL, adj);
+  gtk_container_add (GTK_CONTAINER (box), slider);
+  gtk_widget_set_hexpand (slider, TRUE);
+  gtk_widget_show (slider);
+
+  gtk_widget_show (box);
+
+  return box;
+}
+
 int
 main (int argc, char *argv[])
 {
-  GtkWidget *window, *gl_area, *box, *button;
+  GtkWidget *window, *box, *button, *controls;
   GdkGLPixelFormat *pixel_format;
+  int i;
 
   gtk_init (&argc, &argv);
 
   /* create a new pixel format; we use this to configure the
    * GL context, and to check for features
    */
-  pixel_format = gdk_gl_pixel_format_new ("double-buffer", TRUE, NULL);
+  pixel_format = gdk_gl_pixel_format_new ("double-buffer", TRUE,
+                                          NULL);
 
   window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
   gtk_window_set_title (GTK_WINDOW (window), "GtkGLArea - Golden Triangle");
@@ -51,10 +168,18 @@ main (int argc, char *argv[])
   gtk_widget_set_hexpand (gl_area, TRUE);
   gtk_widget_set_vexpand (gl_area, TRUE);
   gtk_container_add (GTK_CONTAINER (box), gl_area);
+  g_signal_connect (gl_area, "realize", G_CALLBACK (init), NULL);
+  g_signal_connect (gl_area, "render", G_CALLBACK (render), NULL);
   gtk_widget_show (gl_area);
   g_object_unref (pixel_format);
 
-  g_signal_connect (gl_area, "render", G_CALLBACK (render), NULL);
+  controls = gtk_box_new (GTK_ORIENTATION_VERTICAL, FALSE);
+  gtk_container_add (GTK_CONTAINER (box), controls);
+  gtk_widget_set_hexpand (controls, TRUE);
+  gtk_widget_show (controls);
+
+  for (i = 0; i < N_AXIS; i++)
+    gtk_container_add (GTK_CONTAINER (controls), create_axis_slider (i));
 
   button = gtk_button_new_with_label ("Quit");
   gtk_widget_set_hexpand (button, TRUE);