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]> > > 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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