Add a test for cogl_framebuffer_push_path_clip

The test makes an L-shaped path that fills the whole framebuffer
except for the top right quadrant. It then clips to that and tries to
fill the framebuffer with a rectangle. Then it verifies that all of
the quadrants have the expected colour.

This is currently failing due to a bug in the primitive clipping.

Reviewed-by: Robert Bragg <robert@linux.intel.com>
(cherry picked from commit 5404033220099b4a3c6cf32a0d269c4e98489fee)

tests/conform/Makefile.am

@@ -76,7 +76,9 @@ test_sources += test-fence.c
 endif
 
 if BUILD_COGL_PATH
-test_sources += test-path.c
+test_sources += \
+	test-path.c \
+	test-path-clip.c
 endif
 
 test_conformance_SOURCES = $(common_sources) $(test_sources)

tests/conform/test-conform-main.c

@@ -59,6 +59,7 @@ main (int argc, char **argv)
   UNPORTED_TEST (test_readpixels);
 #ifdef COGL_HAS_COGL_PATH_SUPPORT
   ADD_TEST (test_path, 0, 0);
+  ADD_TEST (test_path_clip, 0, TEST_KNOWN_FAILURE);
 #endif
   ADD_TEST (test_depth_test, 0, 0);
   ADD_TEST (test_color_mask, 0, 0);

tests/conform/test-path-clip.c

@@ -0,0 +1,68 @@
+#define COGL_ENABLE_EXPERIMENTAL_2_0_API
+#include <cogl/cogl.h>
+#include <cogl-path/cogl-path.h>
+
+#include <string.h>
+
+#include "test-utils.h"
+
+void
+test_path_clip (void)
+{
+  CoglPath *path;
+  CoglPipeline *pipeline;
+  int fb_width, fb_height;
+
+  fb_width = cogl_framebuffer_get_width (test_fb);
+  fb_height = cogl_framebuffer_get_height (test_fb);
+
+  cogl_framebuffer_orthographic (test_fb,
+                                 0, 0, fb_width, fb_height, -1, 100);
+
+  path = cogl_path_new ();
+
+  cogl_framebuffer_clear4f (test_fb,
+                            COGL_BUFFER_BIT_COLOR,
+                            1.0f, 0.0f, 0.0f, 1.0f);
+
+  /* Make an L-shape with the top right corner left untouched */
+  cogl_path_move_to (path, 0, fb_height);
+  cogl_path_line_to (path, fb_width, fb_height);
+  cogl_path_line_to (path, fb_width, fb_height / 2);
+  cogl_path_line_to (path, fb_width / 2, fb_height / 2);
+  cogl_path_line_to (path, fb_width / 2, 0);
+  cogl_path_line_to (path, 0, 0);
+  cogl_path_close (path);
+
+  cogl_framebuffer_push_path_clip (test_fb, path);
+
+  /* Try to fill the framebuffer with a blue rectangle. This should be
+   * clipped to leave the top right quadrant as is */
+  pipeline = cogl_pipeline_new (test_ctx);
+  cogl_pipeline_set_color4ub (pipeline, 0, 0, 255, 255);
+  cogl_framebuffer_draw_rectangle (test_fb,
+                                   pipeline,
+                                   0, 0, fb_width, fb_height);
+
+  cogl_framebuffer_pop_clip (test_fb);
+
+  cogl_object_unref (pipeline);
+  cogl_object_unref (path);
+
+  /* Check each of the four quadrants */
+  test_utils_check_pixel (test_fb,
+                          fb_width / 4, fb_height / 4,
+                          0x0000ffff);
+  test_utils_check_pixel (test_fb,
+                          fb_width * 3 / 4, fb_height / 4,
+                          0xff0000ff);
+  test_utils_check_pixel (test_fb,
+                          fb_width / 4, fb_height * 3 / 4,
+                          0x0000ffff);
+  test_utils_check_pixel (test_fb,
+                          fb_width * 3 / 4, fb_height * 3 / 4,
+                          0x0000ffff);
+
+  if (cogl_test_verbose ())
+    g_print ("OK\n");
+}