[Piglit] [PATCH 2/2] More comprehensive test for alpha blending with multisampling.

Ian Romanick idr at freedesktop.org
Thu Nov 14 14:16:26 PST 2013


On 11/04/2013 06:27 PM, Paul Berry wrote:
> This test validates a corner case of the fix for
> https://bugs.freedesktop.org/show_bug.cgi?id=53077 ([IVB] Output error
> with msaa when both of framebuffer and source color's alpha are not
> 1).  Specifically, it verifies that the first time alpha blending is
> used on a multisampled framebuffer, the contents of the framebuffer
> are properly preserved.

I had one infinitesimal nit, but meh.

Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>

> ---
>  tests/all.tests                                    |   1 +
>  .../ext_framebuffer_multisample/CMakeLists.gl.txt  |   2 +
>  .../alpha-blending-after-rendering.c               | 203 +++++++++++++++++++++
>  3 files changed, 206 insertions(+)
>  create mode 100644 tests/spec/ext_framebuffer_multisample/alpha-blending-after-rendering.c
> 
> diff --git a/tests/all.tests b/tests/all.tests
> index 43394a2..81f6a85 100644
> --- a/tests/all.tests
> +++ b/tests/all.tests
> @@ -1775,6 +1775,7 @@ ext_framebuffer_multisample['renderbuffer-samples'] = concurrent_test('ext_frame
>  ext_framebuffer_multisample['samples'] = concurrent_test('ext_framebuffer_multisample-samples')
>  ext_framebuffer_multisample['alpha-blending'] = PlainExecTest('ext_framebuffer_multisample-alpha-blending -auto')
>  ext_framebuffer_multisample['alpha-blending slow_cc'] = PlainExecTest('ext_framebuffer_multisample-alpha-blending slow_cc -auto')
> +ext_framebuffer_multisample['alpha-blending-after-rendering'] = PlainExecTest('ext_framebuffer_multisample-alpha-blending-after-rendering -auto')
>  
>  for num_samples in MSAA_SAMPLE_COUNTS:
>      for test_type in ('color', 'srgb', 'stencil_draw', 'stencil_resolve',
> diff --git a/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt b/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
> index 7f7958f..bb2ebac 100644
> --- a/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
> +++ b/tests/spec/ext_framebuffer_multisample/CMakeLists.gl.txt
> @@ -17,6 +17,8 @@ piglit_add_executable (ext_framebuffer_multisample-alpha-to-coverage-dual-src-bl
>  piglit_add_executable (ext_framebuffer_multisample-alpha-to-one-dual-src-blend common.cpp
>  		       draw-buffers-common.cpp alpha-to-one-dual-src-blend.cpp)
>  piglit_add_executable (ext_framebuffer_multisample-alpha-blending alpha-blending.c)
> +piglit_add_executable (ext_framebuffer_multisample-alpha-blending-after-rendering
> +		       alpha-blending-after-rendering.c)
>  piglit_add_executable (ext_framebuffer_multisample-alpha-to-one-msaa-disabled common.cpp
>  		       draw-buffers-common.cpp alpha-to-one-msaa-disabled.cpp)
>  piglit_add_executable (ext_framebuffer_multisample-alpha-to-one-single-sample-buffer common.cpp
> diff --git a/tests/spec/ext_framebuffer_multisample/alpha-blending-after-rendering.c b/tests/spec/ext_framebuffer_multisample/alpha-blending-after-rendering.c
> new file mode 100644
> index 0000000..8c7c4ee
> --- /dev/null
> +++ b/tests/spec/ext_framebuffer_multisample/alpha-blending-after-rendering.c
> @@ -0,0 +1,203 @@
> +/*
> + * Copyright © 2013 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.
> + */
> +
> +/** \file
> + *
> + * Verify that alpha blending works properly in multisample
> + * framebuffers even if it is preceded by normal (non-blended)
> + * rendering.
> + *
> + * In the fix for https://bugs.freedesktop.org/show_bug.cgi?id=53077,
> + * Mesa's i965 driver must convert a compressed multisampled buffer to
> + * an uncompressed buffer the first time it notices that alpha
> + * blending is being performed on the buffer.  This test verifies that
> + * the conversion happens correctly.  It specifically exercises pixels
> + * that are in the following states at the time of conversion:
> + *
> + * - Clear
> + * - Fully covered
> + * - Partially covered, partially clear
> + * - Partially covered by one color, partially by another color
> + */
> +
> +#include "piglit-util-gl-common.h"
> +
> +PIGLIT_GL_TEST_CONFIG_BEGIN
> +
> +	config.supports_gl_compat_version = 30;
> +	config.supports_gl_core_version = 31;
> +	config.window_visual = PIGLIT_GL_VISUAL_RGBA | PIGLIT_GL_VISUAL_DOUBLE;
> +
> +PIGLIT_GL_TEST_CONFIG_END
> +
> +const char *vs_text =
> +	"#version 130\n"
> +	"in vec4 piglit_vertex;\n"
> +	"void main()\n"
> +	"{\n"
> +	"  gl_Position = piglit_vertex;\n"
> +	"}\n";
> +
> +const char *fs_text =
> +	"#version 130\n"
> +	"uniform vec4 color;\n"
> +	"void main()\n"
> +	"{\n"
> +	"  gl_FragColor = color;\n"
> +	"}\n";
> +
> +static GLuint prog, singlesampled_fbo;
> +static GLint color_loc;
> +
> +
> +void
> +piglit_init(int argc, char **argv)
> +{
> +	GLuint rb;
> +
> +	prog = piglit_build_simple_program(vs_text, fs_text);
> +	color_loc = glGetUniformLocation(prog, "color");
> +
> +	/* Create the single-sampled fbo.  We only need to create this
> +	 * once, since it isn't subject to the bugfix.
> +	 */
> +	glGenFramebuffers(1, &singlesampled_fbo);
> +	glGenRenderbuffers(1, &rb);
> +	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, singlesampled_fbo);
> +	glBindRenderbuffer(GL_RENDERBUFFER, rb);
> +	glRenderbufferStorageMultisample(GL_RENDERBUFFER,
> +					 0 /* samples */,
> +					 GL_RGBA8 /* internalformat */,
> +					 piglit_width, piglit_height);
> +	glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
> +				  GL_RENDERBUFFER, rb);
> +	if (glCheckFramebufferStatus(GL_DRAW_FRAMEBUFFER)
> +	    != GL_FRAMEBUFFER_COMPLETE) {
> +		printf("Single-sampled framebuffer incomplete\n");
> +		piglit_report_result(PIGLIT_FAIL);
> +	}
> +}
> +
> +
> +enum piglit_result
> +piglit_display(void)
> +{
> +	GLuint msaa_fbo, rb;
> +	bool pass = true;
> +	GLfloat expected_ul[] = { 0.25, 0.0,  0.25, 0.75 };
> +	GLfloat expected_ur[] = { 0.0,  0.25, 0.25, 0.75 };
> +	GLfloat expected_ll[] = { 0.5,  0.0,  0.0,  0.75 };
> +	GLfloat expected_lr[] = { 0.0,  0.5,  0.0,  0.75 };
> +
> +	/* Create a multisampled framebuffer.  We need to do this here
> +	 * (rather than in piglit_init()) because the bugfix we are
> +	 * verifying only converts any given buffer once; we want to
> +	 * make sure we trigger the bugfix for every call to
> +	 * piglit_display().
> +	 */
> +	glGenFramebuffers(1, &msaa_fbo);
> +	glGenRenderbuffers(1, &rb);
> +	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, msaa_fbo);
> +	glBindRenderbuffer(GL_RENDERBUFFER, rb);
> +	glRenderbufferStorageMultisample(GL_RENDERBUFFER,
> +					 4 /* samples */,
> +					 GL_RGBA8 /* internalformat */,
> +					 piglit_width, piglit_height);
> +	glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
> +				  GL_RENDERBUFFER, rb);
> +	if (glCheckFramebufferStatus(GL_DRAW_FRAMEBUFFER)
> +	    != GL_FRAMEBUFFER_COMPLETE) {
> +		printf("MSAA framebuffer incomplete\n");
> +		pass = false;
> +	}
> +
> +	/* Clear the framebuffer to red. */
> +	glClearColor(1, 0, 0, 1);
> +	glClear(GL_COLOR_BUFFER_BIT);
> +
> +	/* Paint the right half of the framebuffer green. */
> +	glUseProgram(prog);
> +	glDisable(GL_SAMPLE_COVERAGE);
> +	glDisable(GL_BLEND);
> +	glUniform4f(color_loc, 0, 1, 0, 1);
> +	piglit_draw_rect(0, -1, 1, 2);
> +
> +	/* Paint the top half of the framebuffer blue, using 50%
> +	 * sample coverage.
> +	 */
> +	glEnable(GL_SAMPLE_COVERAGE);
> +	glSampleCoverage(0.5, GL_FALSE);
> +	glUniform4f(color_loc, 0, 0, 1, 1);
> +	piglit_draw_rect(-1, 0, 2, 1);
> +
> +	/* Paint black over the entire framebuffer, using 50% alpha
> +	 * blending.
> +	 */
> +	glDisable(GL_SAMPLE_COVERAGE);
> +	glEnable(GL_BLEND);
> +	glBlendEquation(GL_FUNC_ADD);
> +	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
> +	glUniform4f(color_loc, 0, 0, 0, 0.5);
> +	piglit_draw_rect(-1, -1, 2, 2);
> +
> +	/* Blit to the single-sampled fbo to force a multisample
> +	 * resolve.  Note that we don't blit directly to the screen
> +	 * because the screen may be using SRGB, which might trigger
> +	 * the driver to do something other than linear averaging when
> +	 * resolving the samples.
> +	 */
> +	glBindFramebuffer(GL_READ_FRAMEBUFFER, msaa_fbo);
> +	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, singlesampled_fbo);
> +	glBlitFramebuffer(0, 0, piglit_width, piglit_height,
> +			  0, 0, piglit_width, piglit_height,
> +			  GL_COLOR_BUFFER_BIT, GL_NEAREST);
> +
> +	/* Blit to the screen for ease in diagnosing failures. */
> +	glBindFramebuffer(GL_READ_FRAMEBUFFER, singlesampled_fbo);
> +	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, piglit_winsys_fbo);
> +	glBlitFramebuffer(0, 0, piglit_width, piglit_height,
> +			  0, 0, piglit_width, piglit_height,
> +			  GL_COLOR_BUFFER_BIT, GL_NEAREST);
> +
> +	/* Check that the color is correct in each quadrant. */
> +	pass = piglit_probe_rect_rgba(0, 0, piglit_width / 2,
> +				      piglit_height / 2, expected_ll) && pass;
> +	pass = piglit_probe_rect_rgba(piglit_width - piglit_width / 2, 0,
> +				      piglit_width / 2, piglit_height / 2,
> +				      expected_lr) && pass;
> +	pass = piglit_probe_rect_rgba(0, piglit_height - piglit_height / 2,
> +				      piglit_width / 2, piglit_height / 2,
> +				      expected_ul) && pass;
> +	pass = piglit_probe_rect_rgba(piglit_width - piglit_width / 2,
> +				      piglit_height - piglit_height / 2,
> +				      piglit_width / 2, piglit_height / 2,
> +				      expected_ur) && pass;
> +
> +	piglit_present_results();
> +
> +	/* Clean up */
> +	glDeleteRenderbuffers(1, &rb);
> +	glDeleteFramebuffers(1, &msaa_fbo);
> +
> +	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
> +}
> 



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