[Piglit] [PATCH] fbo: Add a test for alpha testing with multiple render targets
Anuj Phogat
anuj.phogat at gmail.com
Wed Oct 26 17:59:54 UTC 2016
On Tue, Oct 25, 2016 at 10:34 PM, Tapani Pälli <tapani.palli at intel.com> wrote:
>
>
> 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 ?
sounds good to me.
>>
>> -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'll add this reference in a comment. ARB_draw_buffers has similar
mention for MRTs.
> 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.
>>
I'll add a comment here.
>>> +
>>> + /* 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