On 22 June 2012 14:40, Paul Berry <[email protected]> wrote: > On 20 June 2012 19:01, Anuj Phogat <[email protected]> wrote: > >> This test varifies that with GL_SAMPLE_ALPHA_TO_COVERAGE enabled, the >> coverage >> value is set by fragment alpha value. Coverage value decides the number of >> samples in multisample buffer covered by an incoming fragment, which >> receive >> the fragment data. >> >> It also includes testing of GL_SAMPLE_ALPHA_TO_COVERAGE with >> GL_SAMPLE_ALPHA_TO_ONE >> enabled. >> >> V2: Add testing for coverage values which may result in dithering for all >> sample >> counts. Dropping the testing for multisample depth buffer. >> > > This patch is: > > Reviewed-by: Paul Berry <[email protected]> >
BTW, I just noticed that we don't yet have any tests for GL_SAMPLE_COVERAGE_INVERT. Would it be possible to add that to this test (preferably as a command line parameter)? > > >> >> Signed-off-by: Anuj Phogat <[email protected]> >> --- >> This test fails on AMD's catalyst drivers with GL_SAMPLE_ALPHA_TO_ONE >> enabled. But >> as I remember it passed on NVIDIA last time. I will confirm it before >> pushing the >> test case. >> >> tests/all.tests | 6 + >> .../ext_framebuffer_multisample/CMakeLists.gl.txt | 1 + >> .../sample-alpha-to-coverage.cpp | 412 >> ++++++++++++++++++++ >> 3 files changed, 419 insertions(+), 0 deletions(-) >> create mode 100644 >> tests/spec/ext_framebuffer_multisample/sample-alpha-to-coverage.cpp >> >> diff --git a/tests/all.tests b/tests/all.tests >> index 5fdc9e7..6745037 100644 >> --- a/tests/all.tests >> +++ b/tests/all.tests >> @@ -1391,6 +1391,12 @@ for num_samples in (2, 4, 8, 16, 32): >> test_name) >> ext_framebuffer_multisample[test_name] = PlainExecTest(executable) >> >> +for num_samples in (2, 4, 8, 16, 32): >> + test_name = ' '.join(['sample-alpha-to-coverage', >> str(num_samples)]) >> + executable = 'ext_framebuffer_multisample-{0} -auto'.format( >> + test_name) >> + ext_framebuffer_multisample[test_name] = >> PlainExecTest(executable) >> + >> ext_framebuffer_object = Group() >> spec['EXT_framebuffer_object'] = ext_framebuffer_object >> add_fbo_stencil_tests(ext_framebuffer_object, 'GL_STENCIL_INDEX1') >> diff --git a/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt >> b/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt >> index c746328..c6566be 100644 >> --- a/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt >> +++ b/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt >> @@ -29,6 +29,7 @@ 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-turn-on-off >> common.cpp turn-on-off.cpp) >> piglit_add_executable (ext_framebuffer_multisample-unaligned-blit >> common.cpp unaligned-blit.cpp) >> piglit_add_executable (ext_framebuffer_multisample-upsample common.cpp >> upsample.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 >> new file mode 100644 >> index 0000000..540396b >> --- /dev/null >> +++ b/tests/spec/ext_framebuffer_multisample/sample-alpha-to-coverage.cpp >> @@ -0,0 +1,412 @@ >> +/* >> + * Copyright © 2012 Intel Corporation >> + * >> + * Permission is hereby granted, free of charge, to any person obtaining >> a >> + * copy of this software and associated documentation files (the >> "Software"), >> + * to deal in the Software without restriction, including without >> limitation >> + * the rights to use, copy, modify, merge, publish, distribute, >> sublicense, >> + * and/or sell copies of the Software, and to permit persons to whom the >> + * Software is furnished to do so, subject to the following conditions: >> + * >> + * The above copyright notice and this permission notice (including the >> next >> + * paragraph) shall be included in all copies or substantial portions of >> the >> + * Software. >> + * >> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, >> EXPRESS OR >> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF >> MERCHANTABILITY, >> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT >> SHALL >> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR >> OTHER >> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, >> ARISING >> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER >> DEALINGS >> + * IN THE SOFTWARE. >> + */ >> + >> +#include "common.h" >> + >> +/** >> + * \file sample-alpha-to-coverage.cpp >> + * >> + * Verify GL_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. >> + * >> + * 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. >> + * >> + * Compute the expected color values based on the coverage value used to >> + * draw the test pattern. >> + * >> + * 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. >> + * >> + * Author: Anuj Phogat <[email protected]> >> + */ >> + >> +int piglit_width = 512; int piglit_height = 256; >> +int piglit_window_mode = 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); >> + 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++) { >> + /* Randomly select color for each rectangle */ >> + color[i * 4 + 0] = (rand() % 1000) * .001; >> + color[i * 4 + 1] = (rand() % 1000) * .001; >> + color[i * 4 + 2] = (rand() % 1000) * .001; >> + /* 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; >> + if (argc < 2) >> + print_usage_and_exit(argv[0]); >> + { >> + char *endptr = NULL; >> + samples = strtol(argv[1], &endptr, 0); >> + if (endptr != argv[1] + strlen(argv[1])) >> + print_usage_and_exit(argv[0]); >> + } >> + >> + piglit_require_gl_version(30); >> + piglit_ortho_projection(pattern_width, pattern_height, GL_TRUE); >> + >> + /* Skip the test if samples > GL_MAX_SAMPLES */ >> + GLint max_samples; >> + glGetIntegerv(GL_MAX_SAMPLES, &max_samples); >> + >> + 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; >> + shader_compile(); >> +} >> + >> +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); >> + >> + /* Draw test pattern in multisample ms_fbo with >> + * GL_SAMPLE_ALPHA_TO_COVERAGE disabled. >> + */ >> + glBindFramebuffer(GL_DRAW_FRAMEBUFFER, ms_fbo.handle); >> + ms_fbo.set_viewport(); >> + draw_pattern(false /* 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); >> + >> + /* Test with sample_alpha_to_one = false */ >> + pass = test_sample_alpha_to_coverage(false) && pass; >> + >> + /* Test sample alpha to coverage with sample_alpha_to_one = true >> */ >> + pass = test_sample_alpha_to_coverage(true) && pass; >> + >> + /* Free the memory allocated for data arrays */ >> + free_data_arrays(); >> + >> + if (!piglit_automatic && >> + buffer_to_test != GL_DEPTH_BUFFER_BIT) >> + piglit_present_results(); >> + >> + return pass ? PIGLIT_PASS : PIGLIT_FAIL; >> +} >> -- >> 1.7.7.6 >> >> >
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