[Piglit] [PATCH] arb_shader_texture_lod-texgradcube: Test explicit derivatives for cube maps
Roland Scheidegger
sroland at vmware.com
Thu Apr 4 16:12:28 PDT 2013
Am 04.04.2013 17:48, schrieb Brian Paul:
> On 04/04/2013 09:33 AM, Roland Scheidegger wrote:
>> Am 04.04.2013 01:55, schrieb Brian Paul:
>>> On 04/03/2013 05:14 PM, sroland at vmware.com wrote:
>>>> From: Roland Scheidegger<sroland at vmware.com>
>>>>
>>>> Similar to arb_shader_texture_lod-texgrad, but using cube maps instead.
>>>> Given the somewhat undefined behavior of explicit gradients with cube
>>>> maps, the main purpose of the test is really to test that those work at
>>>> all, as there doesn't seem to be any other test covering this.
>>>> That said, drivers which simply drop explicit derivatives on the floor
>>>> (like softpipe) pass this perfectly as it simply compares implicit vs.
>>>> explicit behavior (which, given the fuzzy specification, might not be
>>>> really required to be the same here, though given the chosen values,
>>>> that
>>>> is the major axis derivatives being zero, it might seem like a
>>>> reasonable
>>>> assumption).
>>>> I guess something which would also test that the implementation is
>>>> really
>>>> using explicit derivatives instead of implicit ones would also be
>>>> desirable,
>>>> but I'll leave that for now, I couldn't really come up with something.
>>>> ---
>>>> .../execution/CMakeLists.gl.txt | 1 +
>>>> .../arb_shader_texture_lod/execution/texgradcube.c | 195
>>>> ++++++++++++++++++++
>>>> 2 files changed, 196 insertions(+)
>>>> create mode 100644
>>>> tests/spec/arb_shader_texture_lod/execution/texgradcube.c
>>>>
>>>> diff --git
>>>> a/tests/spec/arb_shader_texture_lod/execution/CMakeLists.gl.txt
>>>> b/tests/spec/arb_shader_texture_lod/execution/CMakeLists.gl.txt
>>>> index c403939..2366fa9 100644
>>>> --- a/tests/spec/arb_shader_texture_lod/execution/CMakeLists.gl.txt
>>>> +++ b/tests/spec/arb_shader_texture_lod/execution/CMakeLists.gl.txt
>>>> @@ -10,5 +10,6 @@ link_libraries (
>>>> )
>>>>
>>>> piglit_add_executable (arb_shader_texture_lod-texgrad texgrad.c)
>>>> +piglit_add_executable (arb_shader_texture_lod-texgradcube
>>>> texgradcube.c)
>>>>
>>>> # vim: ft=cmake:
>>>> diff --git a/tests/spec/arb_shader_texture_lod/execution/texgradcube.c
>>>> b/tests/spec/arb_shader_texture_lod/execution/texgradcube.c
>>>> new file mode 100644
>>>> index 0000000..90f7ddc
>>>> --- /dev/null
>>>> +++ b/tests/spec/arb_shader_texture_lod/execution/texgradcube.c
>>>> @@ -0,0 +1,195 @@
>>>> +/*
>>>> + * Copyright (c) 2013 VMware, Inc.
>>>> + *
>>>> + * 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
>>>> + * on the rights to use, copy, modify, merge, publish, distribute, sub
>>>> + * license, 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
>>>> + * NON-INFRINGEMENT. IN NO EVENT SHALL THE AUTHORS AND/OR THEIR
>>>> + * SUPPLIERS 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.
>>>> + *
>>>> + * Authors:
>>>> + * Roland Scheidegger<sroland at vmware.com>
>>>> + *
>>>> + * Based on arb_shader_texture_lod-texgrad:
>>>> + * Marek Olšák<maraeo at gmail.com>
>>>> + */
>>>> +
>>>> +#include "piglit-util-gl-common.h"
>>>> +
>>>> +PIGLIT_GL_TEST_CONFIG_BEGIN
>>>> +
>>>> + config.supports_gl_compat_version = 10;
>>>> +
>>>> + config.window_width = 512;
>>>> + config.window_height = 256;
>>>> + config.window_visual = PIGLIT_GL_VISUAL_RGB |
>>>> PIGLIT_GL_VISUAL_DOUBLE;
>>>> +
>>>> +PIGLIT_GL_TEST_CONFIG_END
>>>> +
>>>> +#define TEX_WIDTH 256
>>>> +#define TEX_HEIGHT 256
>>>> +
>>>> +static const float colors[][3] = {
>>>> + {1.0, 0.0, 0.0},
>>>> + {0.0, 1.0, 0.0},
>>>> + {0.0, 0.0, 1.0},
>>>> + {1.0, 1.0, 0.0},
>>>> + {0.0, 1.0, 1.0},
>>>> + {1.0, 0.0, 1.0},
>>>> + {0.5, 0.0, 0.5},
>>>> + {1.0, 1.0, 1.0},
>>>> +};
>>>> +
>>>> +static const char *sh_tex =
>>>> + "uniform samplerCube tex;"
>>>> + "void main()"
>>>> + "{"
>>>> + " gl_FragColor = textureCube(tex, gl_TexCoord[0].xyz);"
>>>> + "}";
>>>> +
>>>> +static const char *sh_texgrad =
>>>> + "#extension GL_ARB_shader_texture_lod : enable\n"
>>>> + "uniform samplerCube tex;"
>>>> + "void main()"
>>>> + "{"
>>>> + " gl_FragColor = textureCubeGradARB(tex, gl_TexCoord[0].xyz,"
>>>> + " dFdx(gl_TexCoord[0].xyz),"
>>>> + " dFdy(gl_TexCoord[0].xyz));"
>>>> + "}";
>>>> +
>>>> +static GLint prog_tex, prog_texgrad;
>>>> +
>>>> +void piglit_init(int argc, char **argv)
>>>> +{
>>>> + GLuint tex, fb;
>>>> + GLenum status;
>>>> + int i, j, dim;
>>>> + static GLuint fs_tex, fs_texgrad;
>>>> +
>>>> + piglit_require_GLSL();
>>>> + piglit_require_extension("GL_EXT_framebuffer_object");
>>>> + piglit_require_extension("GL_ARB_shader_texture_lod");
>>>> +
>>>> + fs_tex = piglit_compile_shader_text(GL_FRAGMENT_SHADER, sh_tex);
>>>> + fs_texgrad = piglit_compile_shader_text(GL_FRAGMENT_SHADER,
>>>> sh_texgrad);
>>>> + prog_tex = piglit_link_simple_program(0, fs_tex);
>>>> + prog_texgrad = piglit_link_simple_program(0, fs_texgrad);
>>>> +
>>>> + glGenTextures(1,&tex);
>>>> + glBindTexture(GL_TEXTURE_CUBE_MAP, tex);
>>>> +
>>>> + glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER,
>>>> GL_LINEAR_MIPMAP_LINEAR);
>>>> + glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER,
>>>> GL_LINEAR);
>>>> +
>>>> + for (j = GL_TEXTURE_CUBE_MAP_POSITIVE_X; j<=
>>>> GL_TEXTURE_CUBE_MAP_NEGATIVE_Z; j++) {
>>>> + for (i = 0, dim = TEX_WIDTH; dim>0; i++, dim /= 2) {
>>>> + glTexImage2D(j, i, GL_RGBA,
>>>> + dim, dim,
>>>> + 0,
>>>> + GL_RGBA, GL_UNSIGNED_BYTE, NULL);
>>>> + }
>>>> + }
>>>> + assert(glGetError() == 0);
>>>> +
>>>> + glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
>>>> + glDisable(GL_TEXTURE_CUBE_MAP);
>>>> +
>>>> + glGenFramebuffersEXT(1,&fb);
>>>> + glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fb);
>>>> +
>>>> + for (j = GL_TEXTURE_CUBE_MAP_POSITIVE_X; j<=
>>>> GL_TEXTURE_CUBE_MAP_NEGATIVE_Z; j++) {
>>>> + for (i = 0, dim = TEX_WIDTH; dim>0; i++, dim /= 2) {
>>>> + glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT,
>>>> + GL_COLOR_ATTACHMENT0_EXT,
>>>> + j,
>>>> + tex,
>>>> + i);
>>>> +
>>>> + status = glCheckFramebufferStatusEXT (GL_FRAMEBUFFER_EXT);
>>>> + if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
>>>> + fprintf(stderr, "FBO incomplete\n");
>>>> + piglit_report_result(PIGLIT_SKIP);
>>>> + }
>>>> +
>>>> + glClearColor(colors[i][0],
>>>> + colors[i][1],
>>>> + colors[i][2],
>>>> + 0.0);
>>>> + glClear(GL_COLOR_BUFFER_BIT);
>>>> +
>>>> + assert(glGetError() == 0);
>>>> + }
>>>> + }
>>>> +
>>>> + glDeleteFramebuffersEXT(1,&fb);
>>>> + glBindTexture(GL_TEXTURE_CUBE_MAP, tex);
>>>> +
>>>> + glMatrixMode(GL_PROJECTION);
>>>> + glLoadIdentity();
>>>> + glFrustum(-0.1, 0.1, -0.1, 0.1, 0.1, 1000.0);
>>>> +
>>>> + glMatrixMode(GL_MODELVIEW);
>>>> + glLoadIdentity();
>>>> + glTranslatef(-0.5, -0.5, -1.2);
>>>> + glRotatef(68, 0, 1, 0);
>>>> + glScalef(2000, 1, 1);
>>>> +
>>>> + glEnable(GL_TEXTURE_CUBE_MAP);
>>>> + glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
>>>> +
>>>> + piglit_set_tolerance_for_bits(7, 7, 7, 7);
>>>> +
>>>> + printf("Left: textureCube, Right: textureCubeGradARB\n");
>>>> +}
>>>> +
>>>> +static void draw_quad()
>>>> +{
>>>> + glBegin(GL_QUADS);
>>>> + glTexCoord3f(-0.5, -0.5, 1);
>>>> + glVertex2f(0, 0);
>>>> + glTexCoord3f(0.5, -0.5, 1);
>>>> + glVertex2f(1, 0);
>>>> + glTexCoord3f(0.5, 0.5, 1);
>>>> + glVertex2f(1, 1);
>>>> + glTexCoord3f(-0.5, 0.5, 1);
>>>> + glVertex2f(0, 1);
>>>> + glEnd();
>>>> +}
>>>> +
>>>> +enum piglit_result piglit_display(void)
>>>> +{
>>>> + GLboolean pass = GL_TRUE;
>>>> +
>>>> + glViewport(0, 0, piglit_width, piglit_height);
>>>> + glClearColor(0.5, 0.5, 0.5, 0.5);
>>>> + glClear(GL_COLOR_BUFFER_BIT);
>>>> +
>>>> + glViewport(0, 0, piglit_width/2, piglit_height);
>>>> + glUseProgram(prog_tex);
>>>> + draw_quad();
>>>> +
>>>> + glViewport(piglit_width/2, 0, piglit_width/2, piglit_height);
>>>> + glUseProgram(prog_texgrad);
>>>> + draw_quad();
>>>> +
>>>> + if (!piglit_probe_rect_halves_equal_rgba(0, 0, piglit_width,
>>>> piglit_height))
>>>> + pass = GL_FALSE;
>>>> +
>>>> + piglit_present_results();
>>>> +
>>>> + return pass ? PIGLIT_PASS : PIGLIT_FAIL;
>>>> +}
>>>
>>> It looks like you're building a complete mipmap but only testing the 0th
>>> mipmap level. Could you hit those other levels by drawing some smaller
>>> quads?
>> No the test does hit all mip levels (or rather, 6 out of 8 here). Don't
>> ask me how but that's the same as the noncube version.
>
> Ah, so the texcoords "cross" multiple mipmap levels? I see.
Yes exactly.
>
>
>> It is true however that only one cube face is hit (but it doesn't matter
>> which one in any case as they are all the same color, and just the same
>> the texel doesn't matter neither - only the derivatives matter for
>> picking the right level). I guess I could make the faces which are
>> supposed to not get picked a different color though.
>
> Your call.
I actually decided against this since because how the test works it
wouldn't really matter - if the wrong face would be chosen for explicit
derivatives surely the wrong face would be chosen for implicit
derivatives too.
Roland
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