[Piglit] [PATCH] fbo: Add a test for alpha testing with multiple render targets
Tapani Pälli
tapani.palli at intel.com
Wed Oct 26 05:34:03 UTC 2016
On 10/26/2016 03:05 AM, Brian Paul wrote:
> 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?
Maybe this? (4.2.1):
"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."
I believe we've actually had earlier bug where MRT shader did not write
anything to one of its outputs but I can't find it now.
>
>> +
>> +#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
>
> _______________________________________________
> Piglit mailing list
> Piglit at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/piglit
More information about the Piglit
mailing list