[Piglit] [PATCH 09/12] msaa: Rewrite sample-alpha-to-coverage test to utilize the shared code
Anuj Phogat
anuj.phogat at gmail.com
Mon Jul 16 15:56:42 PDT 2012
Lot of the functions defined in this test case are also shared by
draw-buffers-common.cpp. So this refactoring is done to avoid code
duplication.
Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
---
.../ext_framebuffer_multisample/CMakeLists.gl.txt | 3 +-
.../sample-alpha-to-coverage.cpp | 372 +++-----------------
2 files changed, 49 insertions(+), 326 deletions(-)
diff --git a/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt b/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
index ee12e68..f2e366a 100644
--- a/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
+++ b/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
@@ -47,7 +47,8 @@ piglit_add_executable (ext_framebuffer_multisample-renderbuffer-samples renderbu
piglit_add_executable (ext_framebuffer_multisample-renderbufferstorage-samples renderbufferstorage-samples.c)
piglit_add_executable (ext_framebuffer_multisample-samples samples.c)
piglit_add_executable (ext_framebuffer_multisample-sample-coverage common.cpp sample-coverage.cpp)
-piglit_add_executable (ext_framebuffer_multisample-sample-alpha-to-coverage common.cpp sample-alpha-to-coverage.cpp)
+piglit_add_executable (ext_framebuffer_multisample-sample-alpha-to-coverage common.cpp
+ draw-buffers-common.cpp sample-alpha-to-coverage.cpp)
piglit_add_executable (ext_framebuffer_multisample-sample-alpha-to-one common.cpp sample-alpha-to-one.cpp)
piglit_add_executable (ext_framebuffer_multisample-turn-on-off common.cpp turn-on-off.cpp)
piglit_add_executable (ext_framebuffer_multisample-unaligned-blit common.cpp unaligned-blit.cpp)
diff --git a/tests/spec/ext_framebuffer_multisample/sample-alpha-to-coverage.cpp b/tests/spec/ext_framebuffer_multisample/sample-alpha-to-coverage.cpp
index 28ae633..b8ccf5d 100644
--- a/tests/spec/ext_framebuffer_multisample/sample-alpha-to-coverage.cpp
+++ b/tests/spec/ext_framebuffer_multisample/sample-alpha-to-coverage.cpp
@@ -21,311 +21,45 @@
* IN THE SOFTWARE.
*/
-#include "common.h"
+#include "draw-buffers-common.h"
/**
* \file sample-alpha-to-coverage.cpp
*
- * Verify GL_SAMPLE_ALPHA_TO_COVERAGE with multisample FBO.
+ * Verify sample alpha to coverage with multisample FBO
*
- * This test operates by drawing a test pattern to multisample_fbo with
- * GL_SAMPLE_ALPHA_TO_COVERAGE disabled.
+ * When rendering to multiple draw buffers, fragment's alpha value should be
+ * used to determine the coverage value.
*
- * Blit the multisample_fbo to top half of window system framebuffer. This
- * is used as reference image to visually compare the difference caused by
- * sample alpha to coverage value.
+ * This test operates by drawing a pattern in multisample FBO to generate
+ * reference and test image. Reference image is drawn to right half of window
+ * system frame buffer and test image to left half.
*
- * Compute the expected color values based on the coverage value used to
- * draw the test pattern.
+ * Compute the expected color / depth values.
*
- * Clear the multisample framebuffer to a unique color. Draw the same test
- * pattern in multisample buffer with GL_SAMPLE_ALPHA_TO_COVERAGE enabled.
- * Resolve the multisample FBO by blitting it to a single sample FBO. Blit
- * the resolve_fbo to bottom half of window system framebuffer. This is our
- * test image.
- *
- * Probe the rectangles in bottom half of window system framebuffer and
- * compare with expected color values. OpenGL 3.0 specification intends
- * to allow (but not require) the implementation to produce a dithering
- * effect when the coverage value is not a strict multiple of 1/num_samples.
- * We will skip computing expected values and probing for such rectangles.
- * They are drawn just to look for dithering by human inspection.
- *
- * Repeat the above testing with GL_SAMPLE_ALPHA_TO_ONE enabled / disabled.
- * when both GL_SAMPLE_ALPHA_TO_ONE and GL_SAMPLE_ALPHA_TO_COVERAGE are
- * enabled, GL_SAMPLE_ALPHA_TO_COVERAGE takes effect first. i.e. the
- * coverage value is computed from the alpha value before the alpha value
- * is changed to 1.
- *
- * Note: glSampleCoverage() takes effect in the graphics pipeline before
- * the point where the output of the fragment shader is split into the
- * various buffers. So it's very likely that if glSampleCoverage() works
- * properly for color buffers, it will work properly for depth and stencil
- * buffers too.
+ * Probe color / depth buffer blitted to downsampled FBO (resolve_fbo) and
+ * compare against expected color values.
*
* Author: Anuj Phogat <anuj.phogat at gmail.com>
*/
PIGLIT_GL_TEST_MAIN(512 /*window_width*/,
- 256 /*window_height*/,
+ 768 /*window_height*/,
GLUT_DOUBLE | GLUT_RGBA | GLUT_ALPHA)
-const int pattern_width = 512; const int pattern_height = 128;
-static Fbo ms_fbo, resolve_fbo;
-static GLbitfield buffer_to_test;
-
-static float *coverage = NULL;
-static float *color = NULL;
-static float *expected = NULL;
-
-static int num_samples;
-static int num_rects;
-static int prog;
-static int color_loc;
-static int depth_loc;
-
-static const float bg_color[4] = { 0.4, 0.6, 0.0, 0.8 };
-
-static const char *vert =
- "#version 130\n"
- "in vec2 pos;\n"
- "uniform float depth;\n"
- "void main()\n"
- "{\n"
- " vec4 eye_pos = gl_ModelViewProjectionMatrix * vec4(pos, 0.0, 1.0);\n"
- " gl_Position = vec4(eye_pos.xy, depth, 1.0);\n"
- "}\n";
-
-static const char *frag =
- "#version 130\n"
- "uniform vec4 color;\n"
- "void main()\n"
- "{\n"
- " gl_FragColor = color;\n"
- "}\n";
-
-void
-shader_compile()
-{
- /* Compile program */
- GLint vs = piglit_compile_shader_text(GL_VERTEX_SHADER, vert);
- GLint fs = piglit_compile_shader_text(GL_FRAGMENT_SHADER, frag);
- prog = piglit_link_simple_program(vs, fs);
-
- if (!piglit_link_check_status(prog)) {
- piglit_report_result(PIGLIT_FAIL);
- }
-
- glBindAttribLocation(prog, 0, "pos");
- glEnableVertexAttribArray(0);
-
- /* Set up uniforms */
- glUseProgram(prog);
- color_loc = glGetUniformLocation(prog, "color");
- depth_loc = glGetUniformLocation(prog, "depth");
-}
-
-void
-draw_pattern(bool sample_alpha_to_coverage, bool sample_alpha_to_one)
-{
- glUseProgram(prog);
- glClearColor(bg_color[0], bg_color[1],
- bg_color[2], bg_color[3]);
- glClear(buffer_to_test);
-
- if (sample_alpha_to_coverage)
- glEnable (GL_SAMPLE_ALPHA_TO_COVERAGE);
-
- if (sample_alpha_to_one)
- glEnable (GL_SAMPLE_ALPHA_TO_ONE);
-
- unsigned int indices[6] = {0, 1, 2, 0, 2, 3};
-
- for (int i = 0; i < num_rects; ++i) {
-
- float vertex_data[4][2] = {
- { 0.0f + i * (pattern_width / num_rects), 0.0f },
- { 0.0f + i * (pattern_width / num_rects), pattern_height },
- { (i + 1.0f) * (pattern_width / num_rects), pattern_height },
- { (i + 1.0f) * (pattern_width / num_rects), 0.0f } };
-
- glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE,
- sizeof(vertex_data[0]),
- (void *) vertex_data);
-
- glUniform4fv(color_loc, 1, (color + i * 4));
- glUniform1f(depth_loc, 0.0f);
- glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT,
- (void *) indices);
- }
- if (sample_alpha_to_coverage)
- glDisable (GL_SAMPLE_ALPHA_TO_COVERAGE);
-
- if (sample_alpha_to_one)
- glDisable (GL_SAMPLE_ALPHA_TO_ONE);
-}
-
void
print_usage_and_exit(char *prog_name)
{
- printf("Usage: %s <num_samples>\n", prog_name);
+ printf("Usage: %s <num_samples>\n", prog_name);
piglit_report_result(PIGLIT_FAIL);
}
void
-compute_expected(bool sample_alpha_to_one)
-{
- int i, j;
-
- /* Sample alpha to coverage doesn't affect single sample FBO */
- if(num_samples == 0) {
- for(i = 0; i < 4; i++)
- expected[i] = color[i];
- return;
- }
-
- /* Fragment's alpha value is directly used as coverage value */
- for (i = 0; i < num_rects; i++)
- coverage[i] = color[i * 4 + 3];
-
- /* Coverage value decides the number of samples in multisample buffer
- * covered by an incoming fragment, which will then receive the fragment
- * data. When the multisample buffer is resolved it will be blended
- * with the background color which will be written to the remaining
- * samples.
- * Page 254 (page 270 of the PDF) of the OpenGL 3.0 spec says:
- * "The method of combination is not specified, though a simple average
- * computed independently for each color component is recommended."
- */
- if(buffer_to_test == GL_COLOR_BUFFER_BIT) {
- for (i = 0; i < num_rects; i++) {
-
- float samples_used = coverage[i] * num_samples;
- /* Exepected color values are computed only for integer
- * number of samples_used
- */
- if(samples_used == (int)samples_used) {
-
- for(j =0; j < 4; j++)
- expected[i * 4 + j] =
- color[i * 4 + j] * coverage[i] +
- bg_color[j] * (1 - coverage[i]);
-
- if (sample_alpha_to_one)
- expected[i * 4 + 3] =
- 1.0 * coverage[i] +
- bg_color[3] * (1 - coverage[i]);
- }
- }
- }
-}
-
-bool
-probe_framebuffer_color(bool sample_alpha_to_one)
-{
- bool result = true;
- glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
-
- for (int i = 0; i < num_rects; i++) {
- float samples_used = coverage[i] * num_samples;
-
- /* Only probe rectangles with coverage value which is a strict
- * multiple of 1 / num_samples.
- */
- if(samples_used == (int)samples_used) {
- result = piglit_probe_rect_rgba(
- i * (pattern_width / num_rects),
- 0,
- pattern_width / num_rects,
- pattern_height,
- expected + i * 4)
- && result;
- }
- }
- return result;
-}
-
-bool
-test_sample_alpha_to_coverage(bool sample_alpha_to_one)
-{
- bool result = true;
- compute_expected(sample_alpha_to_one);
-
- /* Draw test pattern in multisample ms_fbo with
- * GL_SAMPLE_ALPHA_TO_COVERAGE enabled
- */
- glBindFramebuffer(GL_DRAW_FRAMEBUFFER, ms_fbo.handle);
- draw_pattern(true /* sample_alpha_to_coverage */ , sample_alpha_to_one);
-
- /* Blit ms_fbo to resolve_fbo to resolve multisample buffer */
- glBindFramebuffer(GL_READ_FRAMEBUFFER, ms_fbo.handle);
- glBindFramebuffer(GL_DRAW_FRAMEBUFFER, resolve_fbo.handle);
- glBlitFramebuffer(0, 0, pattern_width, pattern_height,
- 0, 0, pattern_width, pattern_height,
- buffer_to_test, GL_NEAREST);
-
- /* Blit resolve_fbo to the bottom half of window system framebuffer.
- * This is the test image.
- */
- glBindFramebuffer(GL_READ_FRAMEBUFFER, resolve_fbo.handle);
- glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
- glBlitFramebuffer(0, 0, pattern_width, pattern_height,
- 0, 0, pattern_width, pattern_height,
- buffer_to_test, GL_NEAREST);
-
- /* Probe the bottom half of default framebuffer and compare to the
- * expected values */
- if (buffer_to_test == GL_COLOR_BUFFER_BIT)
- result = probe_framebuffer_color(sample_alpha_to_one) && result;
-
- result = piglit_check_gl_error(GL_NO_ERROR) && result;
- return result;
-}
-
-void
-allocate_data_arrays(void)
-{
- /* Draw 2N + 1 rectangles for N samples, each with a unique color
- * and coverage value
- */
- num_rects = 2 * num_samples + 1;
-
- /* Allocate data arrays based on number of samples used */
- color = (float *) malloc(num_rects * 4 * sizeof(float));
- coverage = (float *) malloc(num_rects * sizeof(float));
- expected = (float *) malloc(num_rects * 4 * sizeof(float));
-
- for(int i = 0; i < num_rects; i++) {
- color[i * 4 + 0] = (sin((float)(i * 4 + 0)) + 1) / 2;
- color[i * 4 + 1] = (sin((float)(i * 4 + 1)) + 1) / 2;
- color[i * 4 + 2] = (sin((float)(i * 4 + 2)) + 1) / 2;
-
- /* Alpha value will be used as coverage */
- color[i * 4 + 3] = i * (1.0 / (2 * num_samples));
- }
-}
-
-void
-free_data_arrays(void)
-{
- if(color != NULL) {
- free(color);
- color = NULL;
- }
- if(coverage != NULL) {
- free(coverage);
- coverage = NULL;
- }
- if(expected != NULL) {
- free(expected);
- expected = NULL;
- }
-}
-
-void
piglit_init(int argc, char **argv)
{
int samples;
+ int num_attachments = 1;
+
if (argc < 2)
print_usage_and_exit(argv[0]);
{
@@ -336,7 +70,13 @@ piglit_init(int argc, char **argv)
}
piglit_require_gl_version(30);
- piglit_ortho_projection(pattern_width, pattern_height, GL_TRUE);
+
+ int pattern_width = piglit_width / 2;
+ int pattern_height = piglit_height / num_attachments;
+
+ piglit_ortho_projection(pattern_width,
+ pattern_height,
+ GL_TRUE);
/* Skip the test if samples > GL_MAX_SAMPLES */
GLint max_samples;
@@ -345,24 +85,12 @@ piglit_init(int argc, char **argv)
if (samples > max_samples)
piglit_report_result(PIGLIT_SKIP);
- /* Setup frame buffer objects with required configuration */
- ms_fbo.setup(FboConfig(samples, pattern_width, pattern_height));
- resolve_fbo.setup(FboConfig(0, pattern_width, pattern_height));
-
- if (!piglit_check_gl_error(GL_NO_ERROR)) {
- printf("Error setting up frame buffer objects\n");
- piglit_report_result(PIGLIT_FAIL);
- }
-
- /* Query the number of samples used in ms_fbo. OpenGL implementation
- * may create FBO with more samples per pixel than what is requested.
- */
- glBindRenderbuffer(GL_RENDERBUFFER, ms_fbo.color_rb);
- glGetRenderbufferParameteriv(GL_RENDERBUFFER,
- GL_RENDERBUFFER_SAMPLES,
- &num_samples);
-
- buffer_to_test = GL_COLOR_BUFFER_BIT;
+ ms_fbo_and_draw_buffers_setup(samples,
+ pattern_width,
+ pattern_height,
+ num_attachments,
+ GL_COLOR_BUFFER_BIT,
+ GL_RGBA);
shader_compile();
}
@@ -370,43 +98,37 @@ enum piglit_result
piglit_display()
{
bool pass = true;
- allocate_data_arrays();
-
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
glClearColor(0.0, 0.0, 0.0, 1.0);
- glClear(buffer_to_test);
+ glClear(GL_COLOR_BUFFER_BIT);
+ allocate_data_arrays();
- /* Draw test pattern in multisample ms_fbo with
- * GL_SAMPLE_ALPHA_TO_COVERAGE disabled.
+ /* Reference image drawn when sample_alpha_to_coverage is enabled,
+ * doesn't represent an expected image. Reference image is drawn only
+ * to visualize the image difference caused by enabling
+ * sample_alpha_to_coverage
*/
- glBindFramebuffer(GL_DRAW_FRAMEBUFFER, ms_fbo.handle);
- ms_fbo.set_viewport();
- draw_pattern(false /* sample_alpha_to_coverage */,
- false /* sample_alpha_to_one */ );
+ draw_reference_image(true /* sample_alpha_to_coverage */,
+ false /* sample_alpha_to_one */);
- /* Blit ms_fbo to the top half of window system framebuffer. This
- * is our reference image to visually compare the effect of MSAA
- * with sample alpha to coverage.
- */
- glBindFramebuffer(GL_READ_FRAMEBUFFER, ms_fbo.handle);
- glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
- glBlitFramebuffer(0, 0,
- pattern_width, pattern_height,
- 0, pattern_height,
- pattern_width, 2 * pattern_height,
- buffer_to_test, GL_NEAREST);
+ draw_test_image(true /* sample_alpha_to_coverage */,
+ false /* sample_alpha_to_one */);
- /* Test with sample_alpha_to_one = false */
- pass = test_sample_alpha_to_coverage(false) && pass;
+ pass = piglit_check_gl_error(GL_NO_ERROR) && pass;
- /* Test sample alpha to coverage with sample_alpha_to_one = true */
- pass = test_sample_alpha_to_coverage(true) && pass;
+ /* Probe all the test image blitted to resolve fbo and compare with
+ * expected color values. This method of verification is appropriate
+ * for tests with sample-alpha-to-coverage enabled. Possibility of
+ * dithering effect when the coverage value is not a strict multiple
+ * of 1 / num_samples makes image compare (test / reference image)
+ * unsuitable for this test.
+ */
+ pass = probe_framebuffer_color() && pass;
/* Free the memory allocated for data arrays */
free_data_arrays();
- if (!piglit_automatic &&
- buffer_to_test != GL_DEPTH_BUFFER_BIT)
+ if (!piglit_automatic)
piglit_present_results();
return pass ? PIGLIT_PASS : PIGLIT_FAIL;
--
1.7.7.6
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