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/*
* Copyright © 2011 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.
*/
/**
* \file immediate-reuse.c
*
* Verify that if a transform feedback output buffer is immediately
* re-used as a transform feedback input (changing no GL settings
* except for buffer bindings), rendering is correct.
*
* The test operates by using a shader whose transform feedback
* outputs are the same as its inputs, except with positions and
* colors offset by a constant value. It draws a pair of triangles on
* the left side of the screen, then cycles the transform feedback
* output back through as vertex input 15 times; this should result in
* a stepped gradient being drawn.
*/
#include "piglit-util-gl-common.h"
PIGLIT_GL_TEST_CONFIG_BEGIN
config.window_width = 256;
config.window_height = 16;
config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGB;
PIGLIT_GL_TEST_CONFIG_END
static const char *vstext =
"attribute vec4 in_position;\n"
"attribute vec4 in_color;\n"
"varying vec4 xfb_position;\n"
"varying vec4 xfb_color;\n"
"varying vec4 out_color;\n"
"\n"
"void main()\n"
"{\n"
" gl_Position = in_position;\n"
" out_color = in_color;\n"
" xfb_position = in_position + vec4(0.125, 0.0, 0.0, 0.0);\n"
" xfb_color = in_color + vec4(0.0625, -0.0625, 0.0625, 0.0);\n"
"}\n";
static const char *fstext =
"varying vec4 out_color;\n"
"\n"
"void main()\n"
"{\n"
" gl_FragColor = out_color;\n"
"}\n";
static const char *varyings[] = { "xfb_position", "xfb_color" };
static GLuint bufs[2];
static GLuint prog;
void
piglit_init(int argc, char **argv)
{
GLuint vs, fs;
piglit_require_GLSL();
piglit_require_transform_feedback();
vs = piglit_compile_shader_text(GL_VERTEX_SHADER, vstext);
fs = piglit_compile_shader_text(GL_FRAGMENT_SHADER, fstext);
prog = piglit_CreateProgram();
piglit_AttachShader(prog, vs);
piglit_AttachShader(prog, fs);
piglit_BindAttribLocation(prog, 0, "in_position");
piglit_BindAttribLocation(prog, 1, "in_color");
glTransformFeedbackVaryings(prog, 2, varyings, GL_INTERLEAVED_ATTRIBS);
piglit_LinkProgram(prog);
if (!piglit_link_check_status(prog)) {
piglit_DeleteProgram(prog);
piglit_report_result(PIGLIT_FAIL);
}
glGenBuffers(2, bufs);
}
enum piglit_result
piglit_display(void)
{
int i;
GLboolean pass = GL_TRUE;
static const float initial_vertex_data[6][8] = {
/* position XYZW color RGBA */
{ -1.0, -1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0 },
{ -0.875, -1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0 },
{ -1.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0 },
{ -0.875, -1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0 },
{ -0.875, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0 },
{ -1.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0 }
};
static const float initial_dummy_data[6][8] = {
/* position XYZW color RGBA */
{ -1.0, -1.0, 0.0, 1.0, 1.0, 0.0, 0.0, 1.0 },
{ -0.875, -1.0, 0.0, 1.0, 1.0, 0.0, 0.0, 1.0 },
{ -1.0, 1.0, 0.0, 1.0, 1.0, 0.0, 0.0, 1.0 },
{ -0.875, -1.0, 0.0, 1.0, 1.0, 0.0, 0.0, 1.0 },
{ -0.875, 1.0, 0.0, 1.0, 1.0, 0.0, 0.0, 1.0 },
{ -1.0, 1.0, 0.0, 1.0, 1.0, 0.0, 0.0, 1.0 }
};
/* Setup program and initial buffer contents */
glBindBuffer(GL_ARRAY_BUFFER, bufs[0]);
glBufferData(GL_ARRAY_BUFFER,
sizeof(initial_vertex_data), initial_vertex_data,
GL_STREAM_COPY);
glBindBuffer(GL_TRANSFORM_FEEDBACK_BUFFER, bufs[1]);
glBufferData(GL_TRANSFORM_FEEDBACK_BUFFER,
sizeof(initial_dummy_data), initial_dummy_data,
GL_STREAM_COPY);
glEnableVertexAttribArray(0);
glEnableVertexAttribArray(1);
piglit_UseProgram(prog);
glClear(GL_COLOR_BUFFER_BIT);
/* Draw 16 times, swapping transform feedback and vertex data
* so that transform feedback output is fed back to vertex
* input.
*/
for (i = 0; i < 16; ++i) {
glBindBuffer(GL_ARRAY_BUFFER, bufs[i % 2]);
glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0,
bufs[(i + 1) % 2]);
glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE,
8 * sizeof(float), (void *) 0);
glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE,
8 * sizeof(float),
(void *) (4 * sizeof(float)));
glBeginTransformFeedback(GL_TRIANGLES);
glDrawArrays(GL_TRIANGLES, 0, 6);
glEndTransformFeedback();
}
/* Check that the proper gradient was drawn */
for (i = 0; i < 16; ++i) {
float expected_color[3] = {i/16.0, (16 - i)/16.0, i/16.0 };
pass = piglit_probe_rect_rgb(16 * i, 0, 16, 16,
expected_color) && pass;
}
piglit_present_results();
return pass ? PIGLIT_PASS : PIGLIT_FAIL;
}
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