tests/texturing/lodclamp-between-max.c

   1 /*
   2  * Copyright © 2008-2009 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *    Eric Anholt <eric@anholt.net>
  25  *
  26  */
  27
  28 /**
  29  * @file lodclamp-between-max.c
  30  *
  31  * Tests that setting maximum LOD clamp to between two texture levels
  32  * results in appropriate mipmap filtering.
  33  */
  34
  35 #include "piglit-util.h"
  36
  37 #define MAX_SIZE        32
  38 #define MAX_LOD 5
  39 #define PAD             5
  40
  41 int piglit_window_mode = GLUT_DOUBLE | GLUT_RGB;
  42 int piglit_width = 100;
  43 int piglit_height = 200;
  44
  45 static GLfloat colors[][3] = {
  46         {1.0, 0.0, 0.0},
  47         {0.0, 1.0, 0.0},
  48         {0.0, 0.0, 1.0},
  49         {1.0, 0.0, 1.0},
  50         {0.0, 1.0, 1.0},
  51         {1.0, 1.0, 0.0},
  52 };
  53
  54 static void
  55 set_level_color(int level, int size, int color)
  56 {
  57         GLfloat *tex;
  58         int x, y;
  59
  60         tex = malloc(size * size * 3 * sizeof(GLfloat));
  61
  62         for (y = 0; y < size; y++) {
  63                 for (x = 0; x < size; x++) {
  64                         tex[(y * size + x) * 3 + 0] = colors[color][0];
  65                         tex[(y * size + x) * 3 + 1] = colors[color][1];
  66                         tex[(y * size + x) * 3 + 2] = colors[color][2];
  67                 }
  68         }
  69
  70         glTexImage2D(GL_TEXTURE_2D, level, GL_RGB,
  71                      size, size, 0,
  72                      GL_RGB, GL_FLOAT, tex);
  73
  74         free(tex);
  75 }
  76
  77 enum piglit_result
  78 piglit_display(void)
  79 {
  80         int dim;
  81         GLboolean pass = GL_TRUE;
  82         int level, x, y;
  83         GLuint tex;
  84
  85         piglit_ortho_projection(piglit_width, piglit_height, GL_FALSE);
  86
  87         /* Clear background to gray */
  88         glClearColor(0.5, 0.5, 0.5, 1.0);
  89         glClear(GL_COLOR_BUFFER_BIT);
  90
  91         /* Create the texture. */
  92         glGenTextures(1, &tex);
  93         glBindTexture(GL_TEXTURE_2D, tex);
  94
  95         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
  96                         GL_LINEAR_MIPMAP_LINEAR);
  97         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  98         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
  99         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 100
 101         /* Fill in each level */
 102         for (level = 0, dim = MAX_SIZE; dim > 0; level++, dim /= 2) {
 103                 set_level_color(level, dim, level);
 104         }
 105
 106         glEnable(GL_TEXTURE_2D);
 107
 108         /* Draw areas of the base level size with clamping to mip lods
 109          * between each texture level.
 110          */
 111         x = 10;
 112         y = 10;
 113         for (level = 0, dim = MAX_SIZE; dim > 1; level++, dim /= 2) {
 114                 float clamp = (float)level + 0.5;
 115
 116                 glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_LOD, clamp);
 117
 118                 piglit_draw_rect_tex(x, y, 1, 1,
 119                                      0.0, 0.0, 1.0, 1.0);
 120
 121                 y += 1 + PAD;
 122         }
 123
 124         /* Verify that the resulting images are blended between the levels. */
 125         y = 10;
 126         for (level = 0, dim = MAX_SIZE; dim > 1; level++, dim /= 2) {
 127                 float expected[3];
 128                 int i;
 129
 130                 for (i = 0; i < 3; i++) {
 131                         expected[i] = (colors[level    ][i] +
 132                                        colors[level + 1][i]) / 2.0;
 133                 }
 134
 135                 pass = piglit_probe_pixel_rgb(x,
 136                                               y,
 137                                               expected) && pass;
 138
 139                 y += 1 + PAD;
 140         }
 141
 142         glDeleteTextures(1, &tex);
 143
 144         glutSwapBuffers();
 145
 146         return pass ? PIGLIT_SUCCESS : PIGLIT_FAILURE;
 147 }
 148
 149 void
 150 piglit_init(int argc, char **argv)
 151 {
 152 }