[Piglit] [PATCH] arb_shader_texture_lod-texgradcube: Test explicit derivatives for cube maps
Brian Paul
brianp at vmware.com
Thu Apr 4 08:48:54 PDT 2013
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.
> 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.
-Brian
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