1 | /*
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2 | glh - is a platform-indepenedent C++ OpenGL helper library
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3 |
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4 |
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5 | Copyright (c) 2000 Cass Everitt
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6 | Copyright (c) 2000 NVIDIA Corporation
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7 | All rights reserved.
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8 |
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9 | Redistribution and use in source and binary forms, with or
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10 | without modification, are permitted provided that the following
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11 | conditions are met:
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12 |
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13 | * Redistributions of source code must retain the above
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14 | copyright notice, this list of conditions and the following
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15 | disclaimer.
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16 |
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17 | * Redistributions in binary form must reproduce the above
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18 | copyright notice, this list of conditions and the following
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19 | disclaimer in the documentation and/or other materials
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20 | provided with the distribution.
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21 |
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22 | * The names of contributors to this software may not be used
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23 | to endorse or promote products derived from this software
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24 | without specific prior written permission.
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25 |
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26 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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27 | ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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28 | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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29 | FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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30 | REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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31 | INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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32 | BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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33 | LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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34 | CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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35 | LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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36 | ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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37 | POSSIBILITY OF SUCH DAMAGE.
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38 |
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39 |
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40 | Cass Everitt - cass@r3.nu
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41 | */
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42 |
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43 | #ifndef GLH_CONVENIENCE_H
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44 | #define GLH_CONVENIENCE_H
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45 |
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46 | // Convenience methods for using glh_linear objects
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47 | // with opengl...
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48 |
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49 |
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50 |
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51 | // debugging hack...
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52 | #include <iostream>
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53 |
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54 | using namespace std;
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55 |
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56 | #ifdef MACOS
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57 | #include <OpenGL/gl.h>
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58 | #else
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59 | #include <GL/gl.h>
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60 | #endif
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61 |
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62 | #include <glh/glh_linear.h>
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63 | #include <glh/glh_extensions.h>
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64 |
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65 |
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66 | namespace glh
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67 | {
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68 |
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69 | // matrix helpers
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70 |
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71 | inline matrix4f get_matrix(GLenum matrix)
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72 | {
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73 | GLfloat m[16];
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74 | glGetFloatv(matrix, m);
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75 | return matrix4f(m);
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76 | }
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77 |
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78 | // transform helpers
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79 |
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80 | inline void glh_rotate(const quaternionf & r)
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81 | {
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82 | float angle;
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83 | vec3f axis;
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84 | r.get_value(axis, angle);
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85 | glRotatef(to_degrees(angle), axis.v[0], axis.v[1], axis.v[2]);
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86 | }
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87 |
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88 | // inverse of camera_lookat
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89 | inline matrix4f object_lookat(const vec3f & from, const vec3f & to, const vec3f & Up)
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90 | {
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91 | vec3f look = to - from;
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92 | look.normalize();
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93 | vec3f up(Up);
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94 | up -= look * look.dot(up);
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95 | up.normalize();
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96 |
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97 | quaternionf r(vec3f(0,0,-1), vec3f(0,1,0), look, up);
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98 | matrix4f m;
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99 | r.get_value(m);
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100 | m.set_translate(from);
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101 | return m;
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102 | }
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103 |
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104 |
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105 | // inverse of object_lookat
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106 | inline matrix4f camera_lookat(const vec3f & eye, const vec3f & lookpoint, const vec3f & Up)
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107 | {
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108 | vec3f look = lookpoint - eye;
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109 | look.normalize();
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110 | vec3f up(Up);
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111 | up -= look * look.dot(up);
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112 | up.normalize();
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113 |
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114 | matrix4f t;
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115 | t.set_translate(-eye);
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116 |
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117 | quaternionf r(vec3f(0,0,-1), vec3f(0,1,0), look, up);
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118 | r.invert();
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119 | matrix4f rm;
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120 | r.get_value(rm);
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121 | return rm*t;
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122 | }
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123 |
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124 |
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125 | inline matrix4f frustum(float left, float right,
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126 | float bottom, float top,
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127 | float zNear, float zFar)
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128 | {
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129 | matrix4f m;
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130 | m.make_identity();
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131 |
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132 | m(0,0) = (2*zNear) / (right - left);
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133 | m(0,2) = (right + left) / (right - left);
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134 |
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135 | m(1,1) = (2*zNear) / (top - bottom);
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136 | m(1,2) = (top + bottom) / (top - bottom);
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137 |
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138 | m(2,2) = -(zFar + zNear) / (zFar - zNear);
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139 | m(2,3) = -2*zFar*zNear / (zFar - zNear);
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140 |
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141 | m(3,2) = -1;
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142 | m(3,3) = 0;
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143 |
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144 | return m;
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145 | }
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146 |
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147 | inline matrix4f frustum_inverse(float left, float right,
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148 | float bottom, float top,
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149 | float zNear, float zFar)
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150 | {
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151 | matrix4f m;
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152 | m.make_identity();
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153 |
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154 | m(0,0) = (right - left) / (2 * zNear);
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155 | m(0,3) = (right + left) / (2 * zNear);
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156 |
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157 | m(1,1) = (top - bottom) / (2 * zNear);
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158 | m(1,3) = (top + bottom) / (2 * zNear);
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159 |
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160 | m(2,2) = 0;
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161 | m(2,3) = -1;
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162 |
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163 | m(3,2) = -(zFar - zNear) / (2 * zFar * zNear);
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164 | m(3,3) = (zFar + zNear) / (2 * zFar * zNear);
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165 |
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166 | return m;
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167 | }
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168 |
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169 | inline matrix4f perspective(float fovy, float aspect, float zNear, float zFar)
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170 | {
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171 | double tangent = tan(to_radians(fovy/2.0f));
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172 | float y = (float)tangent * zNear;
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173 | float x = aspect * y;
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174 | return frustum(-x, x, -y, y, zNear, zFar);
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175 | }
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176 |
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177 | inline matrix4f perspective_inverse(float fovy, float aspect, float zNear, float zFar)
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178 | {
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179 | double tangent = tan(to_radians(fovy/2.0f));
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180 | float y = (float)tangent * zNear;
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181 | float x = aspect * y;
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182 | return frustum_inverse(-x, x, -y, y, zNear, zFar);
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183 | }
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184 |
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185 |
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186 |
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187 | // are these names ok?
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188 |
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189 | inline void set_texgen_planes(GLenum plane_type, const matrix4f & m)
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190 | {
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191 | GLenum coord[] = {GL_S, GL_T, GL_R, GL_Q };
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192 | for(int i = 0; i < 4; i++)
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193 | {
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194 | vec4f row;
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195 | m.get_row(i,row);
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196 | glTexGenfv(coord[i], plane_type, row.v);
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197 | }
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198 | }
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199 |
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200 | // handy for register combiners
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201 | inline vec3f range_compress(const vec3f & v)
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202 | { vec3f vret(v); vret *= .5f; vret += .5f; return vret; }
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203 |
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204 | inline vec3f range_uncompress(const vec3f & v)
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205 | { vec3f vret(v); vret -= .5f; vret *= 2.f; return vret; }
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206 |
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207 | } // namespace glh
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208 |
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209 | #endif
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