[Piglit] [PATCH] fbo: Add a test for alpha testing with multiple render targets
Brian Paul
brianp at vmware.com
Wed Oct 26 00:05:51 UTC 2016
On 10/25/2016 03:58 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/fbo/CMakeLists.gl.txt | 1 +
> tests/fbo/fbo-mrt-alphatest-no-buffer-zero-write.c | 145 +++++++++++++++++++++
I think we're trying to get away from putting new tests in general/,
bugs/, fbo/, etc.
How about tests/spec/gl-2.1/fbo-mrt-alphatest-no-buffer-zero-write.c ?
-Brian
> 3 files changed, 147 insertions(+)
> create mode 100644 tests/fbo/fbo-mrt-alphatest-no-buffer-zero-write.c
>
> diff --git a/tests/all.py b/tests/all.py
> index 9b67bae..9e4420e 100644
> --- a/tests/all.py
> +++ b/tests/all.py
> @@ -4196,6 +4196,7 @@ with profile.group_manager(
> grouptools.join('spec', 'arb_draw_buffers')) as g:
> g(['arb_draw_buffers-state_change'], run_concurrent=False)
> g(['fbo-mrt-alphatest'], run_concurrent=False)
> + g(['fbo-mrt-alphatest-no-buffer-zero-write'], run_concurrent=False)
> g(['fbo-mrt-new-bind'], run_concurrent=False)
>
> with profile.group_manager(
> diff --git a/tests/fbo/CMakeLists.gl.txt b/tests/fbo/CMakeLists.gl.txt
> index 2e2cac9..e2c03ca 100644
> --- a/tests/fbo/CMakeLists.gl.txt
> +++ b/tests/fbo/CMakeLists.gl.txt
> @@ -73,6 +73,7 @@ piglit_add_executable (fbo-integer fbo-integer.c)
> piglit_add_executable (fbo-maxsize fbo-maxsize.c)
> piglit_add_executable (fbo-mipmap-copypix fbo-mipmap-copypix.c)
> piglit_add_executable (fbo-mrt-alphatest fbo-mrt-alphatest.c)
> +piglit_add_executable (fbo-mrt-alphatest-no-buffer-zero-write fbo-mrt-alphatest-no-buffer-zero-write.c)
> piglit_add_executable (fbo-mrt-new-bind fbo-mrt-new-bind.c)
> piglit_add_executable (fbo-nodepth-test fbo-nodepth-test.c)
> piglit_add_executable (fbo-nostencil-test fbo-nostencil-test.c)
> diff --git a/tests/fbo/fbo-mrt-alphatest-no-buffer-zero-write.c b/tests/fbo/fbo-mrt-alphatest-no-buffer-zero-write.c
> new file mode 100644
> index 0000000..ef56d89
> --- /dev/null
> +++ b/tests/fbo/fbo-mrt-alphatest-no-buffer-zero-write.c
> @@ -0,0 +1,145 @@
> +/*
> + * 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. This 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.
> + */
Where in the GL 2.1 spec does it describe this (the undefined behavior,
that is)? I took a quick look and didn't see it in the "4.1.4 Alpha
Test" section. Can you add a spec quotation?
> +
> +#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_ATTACHMENT1, 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();
If behavior is undefined, I guess we can't probe any pixels for any
thing. Maybe put a comment here to that effect.
> +
> + /* If test executes to completion, return PIGLIT_PASS */
> + return PIGLIT_PASS;
> +}
>
Looks good otherwise.
-Brian
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