[Piglit] [PATCH] gl-2.1: Add a test for alpha testing with multiple render targets

Brian Paul brianp at vmware.com
Thu Oct 27 00:56:31 UTC 2016


On 10/26/2016 04:01 PM, Anuj Phogat wrote:
> In a situation when there are multiple render targets with alpha testing
> enabled, if fragment shader doesn't write to draw buffer zero, alpha
> value used for alpha testing will be undefined. Such case should not
> cause a GPU hang.
>
> Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
> ---
>   tests/all.py                                       |   1 +
>   tests/spec/gl-2.1/CMakeLists.gl.txt                |   1 +
>   .../fbo-mrt-alphatest-no-buffer-zero-write.c       | 152 +++++++++++++++++++++
>   3 files changed, 154 insertions(+)
>   create mode 100644 tests/spec/gl-2.1/fbo-mrt-alphatest-no-buffer-zero-write.c
>
> diff --git a/tests/all.py b/tests/all.py
> index 9b67bae..e56cae8 100644
> --- a/tests/all.py
> +++ b/tests/all.py
> @@ -1155,6 +1155,7 @@ with profile.group_manager(
>       g(['gl-2.1-minmax'], 'minmax')
>       g(['gl-2.1-pbo'], 'pbo')
>       g(['gl-2.1-polygon-stipple-fs'], 'polygon-stipple-fs')
> +    g(['gl-2.1-fbo-mrt-alphatest-no-buffer-zero-write'], 'fbo-mrt-alphatest-no-buffer-zero-write')
>
>   with profile.group_manager(
>           PiglitGLTest,
> diff --git a/tests/spec/gl-2.1/CMakeLists.gl.txt b/tests/spec/gl-2.1/CMakeLists.gl.txt
> index dbd1e7a..1ce1443 100644
> --- a/tests/spec/gl-2.1/CMakeLists.gl.txt
> +++ b/tests/spec/gl-2.1/CMakeLists.gl.txt
> @@ -12,3 +12,4 @@ link_libraries (
>   piglit_add_executable (gl-2.1-minmax minmax.c)
>   piglit_add_executable (gl-2.1-pbo pbo.c)
>   piglit_add_executable (gl-2.1-polygon-stipple-fs polygon-stipple-fs.c)
> +piglit_add_executable (gl-2.1-fbo-mrt-alphatest-no-buffer-zero-write fbo-mrt-alphatest-no-buffer-zero-write.c)
> diff --git a/tests/spec/gl-2.1/fbo-mrt-alphatest-no-buffer-zero-write.c b/tests/spec/gl-2.1/fbo-mrt-alphatest-no-buffer-zero-write.c
> new file mode 100644
> index 0000000..51e694b
> --- /dev/null
> +++ b/tests/spec/gl-2.1/fbo-mrt-alphatest-no-buffer-zero-write.c
> @@ -0,0 +1,152 @@
> +/*
> + * Copyright © 2016 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.
> + */
> +
> +/*
> + * This test asserts correct behavior for alpha-testing of fragments when
> + * multiple color buffers are being rendered to. In particular, the alpha
> + * component of the color output to draw buffer zero is used for the alpha
> + * test. If draw buffer zero is not written by the fragment shader, alpha
> + * value used for alpha testing is undefined.
> + * From OpenGL 2.1 specification:
> + * "If a fragment shader writes to neither gl FragColor nor gl FragData,
> + * the values of the fragment colors following shader execution are
> + * undefined, and may differ for each fragment color."
> + *
> + * Test should run to completion without a GPU hang.
> + *
> + * This is important for deferred renderers which use alpha-test, and is a
> + * significant edge case for the i965 driver.
> + */
> +
> +#include "piglit-util-gl.h"
> +
> +PIGLIT_GL_TEST_CONFIG_BEGIN
> +
> +	config.supports_gl_compat_version = 21;
> +
> +	config.window_visual = PIGLIT_GL_VISUAL_RGBA | PIGLIT_GL_VISUAL_DOUBLE;
> +
> +PIGLIT_GL_TEST_CONFIG_END
> +
> +GLenum buffers[] = {GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2};
> +GLuint fbo;
> +GLint prog;
> +GLuint color0, color1, color2;
> +
> +void
> +piglit_init(int argc, char **argv)
> +{
> +	piglit_require_GLSL_version(130);
> +
> +	glGenFramebuffers(1, &fbo);
> +	glBindFramebuffer(GL_FRAMEBUFFER, fbo);
> +
> +	glGenTextures(1, &color0);
> +	glBindTexture(GL_TEXTURE_2D, color0);
> +	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 64, 64, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
> +	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
> +	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
> +	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, color0, 0);
> +
> +	glGenTextures(1, &color1);
> +	glBindTexture(GL_TEXTURE_2D, color1);
> +	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 64, 64, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
> +	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
> +	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
> +	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, color1, 0);
> +
> +	glGenTextures(1, &color2);
> +	glBindTexture(GL_TEXTURE_2D, color2);
> +	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 64, 64, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
> +	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
> +	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
> +	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, GL_TEXTURE_2D, color2, 0);
> +
> +	glDrawBuffers(3, buffers);
> +
> +	prog = piglit_build_simple_program(
> +		"#version 130\n"
> +		"in vec4 pos;\n"
> +		"void main() {\n"
> +		"	gl_Position = pos;\n"
> +		"}\n",
> +
> +		"#version 130\n"
> +		"void main() {\n"
> +		"	float alpha = float(int(gl_FragCoord.x / 16 + gl_FragCoord.y / 16) % 2);\n"
> +		"	/*Don't write color to draw buffer zero i.e. gl_FragData[0] */\n"
> +		"	gl_FragData[1] = vec4(1.0, 0.0, 0.0, alpha);\n"
> +		"	gl_FragData[2] = vec4(0.0, 1.0, 0.0, 1.0);\n"
> +		"}\n"
> +		);
> +
> +	if (!piglit_check_gl_error(GL_NO_ERROR)) {
> +		printf("Setup for test failed.\n");
> +		piglit_report_result(PIGLIT_SKIP);
> +	}
> +
> +	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
> +		printf("Framebuffer not complete.\n");
> +		piglit_report_result(PIGLIT_SKIP);
> +	}
> +}
> +
> +
> +enum piglit_result
> +piglit_display(void)
> +{
> +	glBindFramebuffer(GL_FRAMEBUFFER, fbo);
> +	glClearColor(0,0,1,0);
> +	glClear(GL_COLOR_BUFFER_BIT);
> +
> +	glAlphaFunc(GL_GEQUAL, 0.5f);
> +	glEnable(GL_ALPHA_TEST);
> +
> +	glUseProgram(prog);
> +	glViewport(0, 0, 64, 64);
> +	piglit_draw_rect(-1, -1, 2, 2);
> +
> +	glDisable(GL_ALPHA_TEST);
> +
> +	/* Visualize it */
> +	glUseProgram(0);
> +	glBindFramebuffer(GL_FRAMEBUFFER, piglit_winsys_fbo);
> +	glViewport(0, 0, 128, 64);
> +	glClearColor(0,0,0.5,0);
> +	glClear(GL_COLOR_BUFFER_BIT);
> +
> +	glEnable(GL_TEXTURE_2D);
> +	glBindTexture(GL_TEXTURE_2D, color1);
> +	piglit_draw_rect_tex(-1, -1, 1, 2,
> +			0, 0, 1, 1);
> +	glBindTexture(GL_TEXTURE_2D, color2);
> +	piglit_draw_rect_tex(0, -1, 1, 2,
> +			0, 0, 1, 1);
> +	glDisable(GL_TEXTURE_2D);
> +	piglit_present_results();
> +
> +	/* The fragment colors are undefined in this test. So, we can't probe the
> +	 * pixels. If test executes to completion, return PIGLIT_PASS.
> +	 */
> +	return PIGLIT_PASS;
> +}
>

Looks great.

Reviewed-by: Brian Paul <brianp at vmware.com>




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