Add a conformance test for setting the color mask on a framebuffer

There is a currently a bug where pushing a buffer with a different
color mask will not cause the color mask to be flushed. This adds a
test to demonstrate that.

Reviewed-by: Robert Bragg <robert@linux.intel.com>

tests/conform/Makefile.am

@@ -42,6 +42,7 @@ unported_test_sources = \
 
 test_sources = \
 	test-depth-test.c \
+	test-color-mask.c \
 	$(NULL)
 
 test_conformance_SOURCES = $(common_sources) $(test_sources)

tests/conform/test-color-mask.c

@@ -0,0 +1,119 @@
+#include <cogl/cogl.h>
+
+#include "test-utils.h"
+
+#define TEX_SIZE 128
+
+#define NUM_FBOS 3
+
+typedef struct _TestState
+{
+  int width;
+  int height;
+
+  CoglHandle tex[NUM_FBOS];
+  CoglFramebuffer *fbo[NUM_FBOS];
+} TestState;
+
+static void
+check_pixel (int x, int y, guint8 r, guint8 g, guint8 b)
+{
+  guint32 pixel;
+  char *screen_pixel;
+  char *intended_pixel;
+
+  cogl_read_pixels (x, y, 1, 1, COGL_READ_PIXELS_COLOR_BUFFER,
+                    COGL_PIXEL_FORMAT_RGBA_8888_PRE,
+                    (guint8 *) &pixel);
+
+  screen_pixel = g_strdup_printf ("#%06x", GUINT32_FROM_BE (pixel) >> 8);
+  intended_pixel = g_strdup_printf ("#%02x%02x%02x", r, g, b);
+
+  g_assert_cmpstr (screen_pixel, ==, intended_pixel);
+
+  g_free (screen_pixel);
+  g_free (intended_pixel);
+}
+
+static void
+paint (TestState *state)
+{
+  CoglColor bg;
+  int i;
+
+  cogl_set_source_color4ub (255, 255, 255, 255);
+
+  /* We push the third framebuffer first so that later we can switch
+     back to it by popping to test that that works */
+  cogl_push_framebuffer (state->fbo[2]);
+
+  cogl_push_framebuffer (state->fbo[0]);
+  cogl_rectangle (-1.0, -1.0, 1.0, 1.0);
+  cogl_pop_framebuffer ();
+
+  cogl_push_framebuffer (state->fbo[1]);
+  cogl_rectangle (-1.0, -1.0, 1.0, 1.0);
+  cogl_pop_framebuffer ();
+
+  /* We should now be back on the third framebuffer */
+  cogl_rectangle (-1.0, -1.0, 1.0, 1.0);
+  cogl_pop_framebuffer ();
+
+  cogl_color_init_from_4ub (&bg, 128, 128, 128, 255);
+  cogl_clear (&bg, COGL_BUFFER_BIT_COLOR | COGL_BUFFER_BIT_DEPTH);
+
+  /* Render all of the textures to the screen */
+  for (i = 0; i < NUM_FBOS; i++)
+    {
+      cogl_set_source_texture (state->tex[i]);
+      cogl_rectangle (2.0f / NUM_FBOS * i - 1.0f, -1.0f,
+                      2.0f / NUM_FBOS * (i + 1) - 1.0f, 1.0f);
+    }
+
+  /* Verify all of the fbos drew the right color */
+  for (i = 0; i < NUM_FBOS; i++)
+    {
+      guint8 expected_colors[NUM_FBOS][4] =
+        { { 0xff, 0x00, 0x00, 0xff },
+          { 0x00, 0xff, 0x00, 0xff },
+          { 0x00, 0x00, 0xff, 0xff } };
+
+      check_pixel (state->width * (i + 0.5f) / NUM_FBOS,
+                   state->height / 2,
+                   expected_colors[i][0],
+                   expected_colors[i][1],
+                   expected_colors[i][2]);
+    }
+}
+
+void
+test_cogl_color_mask (TestUtilsGTestFixture *fixture,
+                      void *data)
+{
+  TestUtilsSharedState *shared_state = data;
+  TestState state;
+  int i;
+
+  state.width = cogl_framebuffer_get_width (shared_state->fb);
+  state.height = cogl_framebuffer_get_height (shared_state->fb);
+
+  for (i = 0; i < NUM_FBOS; i++)
+    {
+      state.tex[i] = cogl_texture_new_with_size (128, 128,
+                                                 COGL_TEXTURE_NO_ATLAS,
+                                                 COGL_PIXEL_FORMAT_RGB_888);
+
+
+      state.fbo[i] = cogl_offscreen_new_to_texture (state.tex[i]);
+      cogl_framebuffer_set_color_mask (state.fbo[i],
+                                       i == 0 ? COGL_COLOR_MASK_RED :
+                                       i == 1 ? COGL_COLOR_MASK_GREEN :
+                                       COGL_COLOR_MASK_BLUE);
+    }
+
+  paint (&state);
+
+  if (g_test_verbose ())
+    g_print ("OK\n");
+}
+

tests/conform/test-conform-main.c

@@ -140,6 +140,7 @@ main (int argc, char **argv)
   UNPORTED_TEST ("/cogl", test_cogl_readpixels);
   UNPORTED_TEST ("/cogl", test_cogl_path);
   ADD_TEST ("/cogl", test_cogl_depth_test);
+  ADD_TEST ("/cogl", test_cogl_color_mask);
 
   UNPORTED_TEST ("/cogl/texture", test_cogl_npot_texture);
   UNPORTED_TEST ("/cogl/texture", test_cogl_multitexture);