mutter/tests/conform/test-alpha-test.c
Neil Roberts 9b59588c53 Add a simple conformance test for alpha testing
This adds a simple test which sets an alpha test on a pipeline and
then renders a texture. It then verifies that the transparent parts of
the texture aren't drawn. This is currently failing with the GL3
driver because GL3 requires the alpha test to be implemented in GLSL
but the generated alpha test uniform is only updated for the GLES2
driver.

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

(cherry picked from commit 4ec04507bfaf2d61707dccfb59ac7326962ee741)
2013-01-22 17:48:01 +00:00

75 lines
2.5 KiB
C

#include <cogl/cogl.h>
#include <string.h>
#include "test-utils.h"
static CoglTexture2D *
create_texture (CoglContext *context)
{
static const uint8_t data[] =
{
0xff, 0x00, 0x00, 0xff,
0x00, 0xfa, 0x00, 0xfa
};
return cogl_texture_2d_new_from_data (context,
2, 1, /* width/height */
COGL_PIXEL_FORMAT_RGBA_8888_PRE,
COGL_PIXEL_FORMAT_ANY,
4, /* rowstride */
data,
NULL /* error */);
}
void
test_alpha_test (void)
{
CoglTexture *tex = COGL_TEXTURE (create_texture (ctx));
CoglPipeline *pipeline = cogl_pipeline_new (ctx);
int fb_width = cogl_framebuffer_get_width (fb);
int fb_height = cogl_framebuffer_get_height (fb);
CoglColor clear_color;
cogl_pipeline_set_layer_texture (pipeline, 0, tex);
cogl_pipeline_set_layer_filters (pipeline, 0,
COGL_PIPELINE_FILTER_NEAREST,
COGL_PIPELINE_FILTER_NEAREST);
cogl_pipeline_set_alpha_test_function (pipeline,
COGL_PIPELINE_ALPHA_FUNC_GEQUAL,
254 / 255.0f /* alpha reference */);
cogl_color_init_from_4ub (&clear_color, 0x00, 0x00, 0xff, 0xff);
cogl_framebuffer_clear (fb,
COGL_BUFFER_BIT_COLOR,
&clear_color);
cogl_framebuffer_draw_rectangle (fb,
pipeline,
-1, -1,
1, 1);
cogl_object_unref (pipeline);
cogl_object_unref (tex);
/* The left side of the framebuffer should use the first pixel from
* the texture which is red */
test_utils_check_region (fb,
2, 2,
fb_width / 2 - 4,
fb_height - 4,
0xff0000ff);
/* The right side of the framebuffer should use the clear color
* because the second pixel from the texture is clipped from the
* alpha test */
test_utils_check_region (fb,
fb_width / 2 + 2,
2,
fb_width / 2 - 4,
fb_height - 4,
0x0000ffff);
if (cogl_test_verbose ())
g_print ("OK\n");
}