1/* 2 3Copyright (c) 2002, Calum Robinson 4All rights reserved. 5 6Redistribution and use in source and binary forms, with or without 7modification, are permitted provided that the following conditions are met: 8 9* Redistributions of source code must retain the above copyright notice, this 10 list of conditions and the following disclaimer. 11 12* Redistributions in binary form must reproduce the above copyright notice, 13 this list of conditions and the following disclaimer in the documentation 14 and/or other materials provided with the distribution. 15 16* Neither the name of the author nor the names of its contributors may be used 17 to endorse or promote products derived from this software without specific 18 prior written permission. 19 20THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 21ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 22WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 23DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR 24ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 25(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 26LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 27ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 29SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 31*/ 32 33 34#include "Texture.h" 35#include "Shared.h" 36 37 38static GLubyte smallTextureArray[32][32]; 39static GLubyte bigTextureArray[256][256][2]; 40GLuint theTexture = 0; 41 42 43// simple smoothing routine 44static void 45SmoothTexture(void) 46{ 47 GLubyte filter[32][32]; 48 float t; 49 for (int i = 1; i < 31; i++) { 50 for (int j = 1; j < 31; j++) { 51 t = (float)smallTextureArray[i][j] * 4; 52 t += (float)smallTextureArray[i - 1][j]; 53 t += (float)smallTextureArray[i + 1][j]; 54 t += (float)smallTextureArray[i][j - 1]; 55 t += (float)smallTextureArray[i][j + 1]; 56 t /= 8.0f; 57 filter[i][j] = (GLubyte) t; 58 } 59 } 60 61 for (int i = 1; i < 31; i++){ 62 for (int j = 1; j < 31; j++) 63 smallTextureArray[i][j] = filter[i][j]; 64 } 65} 66 67 68// add some randomness to texture data 69static void 70SpeckleTexture(void) 71{ 72 int speck; 73 float t; 74 for (int i = 2; i < 30; i++) { 75 for (int j = 2; j < 30; j++) { 76 speck = 1; 77 while (speck <= 32 && random() % 2) { 78 t = (float) MIN_(255, smallTextureArray[i][j] + speck); 79 smallTextureArray[i][j] = (GLubyte)t; 80 speck += speck; 81 } 82 speck = 1; 83 while (speck <= 32 && random() % 2) { 84 t = (float)MAX_(0, smallTextureArray[i][j] - speck); 85 smallTextureArray[i][j] = (GLubyte)t; 86 speck += speck; 87 } 88 } 89 } 90} 91 92 93static void 94MakeSmallTexture(void) 95{ 96 static int firstTime = 1; 97 98 if (firstTime) { 99 firstTime = 0; 100 for (int i = 0; i < 32; i++) { 101 for (int j = 0; j < 32; j++) { 102 float r = (float)sqrt((i - 15.5) * (i - 15.5) + (j - 15.5) 103 * (j - 15.5)); 104 if (r > 15.0f) 105 smallTextureArray[i][j] = 0; 106 else { 107 float t = 255.0f * (float) cos(r * M_PI / 31.0); 108 smallTextureArray[i][j] = (GLubyte)t; 109 } 110 } 111 } 112 } else { 113 for (int i = 0; i < 32; i++) { 114 for (int j = 0; j < 32; j++) { 115 float t; 116 float r = (float)sqrt((i - 15.5) * (i - 15.5) + (j - 15.5) 117 * (j - 15.5)); 118 if (r > 15.0f) 119 t = 0.0f; 120 else 121 t = 255.0f * (float) cos(r*M_PI/31.0); 122 123 smallTextureArray[i][j] 124 = (GLubyte)MIN_(255, (t + smallTextureArray[i][j] 125 + smallTextureArray[i][j]) / 3); 126 } 127 } 128 } 129 130 SpeckleTexture(); 131 SmoothTexture(); 132 SmoothTexture(); 133} 134 135 136static void 137CopySmallTextureToBigTexture(int k, int l) 138{ 139 for (int i = 0; i < 32; i++) { 140 for (int j = 0; j < 32; j++) { 141 bigTextureArray[i + k][j + l][0] = smallTextureArray[i][j]; 142 bigTextureArray[i + k][j + l][1] = smallTextureArray[i][j]; 143 } 144 } 145} 146 147 148static void 149AverageLastAndFirstTextures(void) 150{ 151 for (int i = 0; i < 32; i++) { 152 for (int j = 0; j < 32; j++) { 153 int t = (smallTextureArray[i][j] + bigTextureArray[i][j][0]) / 2; 154 smallTextureArray[i][j] = (GLubyte)MIN_(255, t); 155 } 156 } 157} 158 159 160void 161MakeTexture() 162{ 163 for (int i = 0; i < 8; i++) { 164 for (int j = 0; j < 8; j++) { 165 if (i == 7 && j == 7) 166 AverageLastAndFirstTextures(); 167 else 168 MakeSmallTexture(); 169 170 CopySmallTextureToBigTexture(i * 32, j * 32); 171 } 172 } 173 174 glPixelStorei(GL_UNPACK_ALIGNMENT, 1); 175 176 glGenTextures(1, &theTexture); 177 glBindTexture(GL_TEXTURE_2D, theTexture); 178 179 // Set the tiling mode (this is generally always GL_REPEAT). 180 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); 181 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); 182 183 // Set the filtering. 184 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); 185 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, 186 GL_LINEAR_MIPMAP_NEAREST); 187 188 gluBuild2DMipmaps(GL_TEXTURE_2D, 2, 256, 256, GL_LUMINANCE_ALPHA, 189 GL_UNSIGNED_BYTE, bigTextureArray); 190 glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); 191} 192