1 | // |
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2 | // Lol Engine |
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3 | // |
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4 | // Copyright: (c) 2010-2011 Sam Hocevar <sam@hocevar.net> |
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5 | // This program is free software; you can redistribute it and/or |
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6 | // modify it under the terms of the Do What The Fuck You Want To |
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7 | // Public License, Version 2, as published by Sam Hocevar. See |
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8 | // http://sam.zoy.org/projects/COPYING.WTFPL for more details. |
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9 | // |
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10 | |
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11 | #if defined HAVE_CONFIG_H |
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12 | # include "config.h" |
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13 | #endif |
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14 | |
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15 | #include <cstdio> |
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16 | #include <cstdlib> /* free() */ |
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17 | #include <cstring> /* strdup() */ |
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18 | |
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19 | #include "core.h" |
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20 | |
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21 | namespace lol |
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22 | { |
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23 | |
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24 | static inline float det3(float a, float b, float c, |
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25 | float d, float e, float f, |
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26 | float g, float h, float i) |
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27 | { |
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28 | return a * (e * i - h * f) |
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29 | + b * (f * g - i * d) |
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30 | + c * (d * h - g * e); |
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31 | } |
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32 | |
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33 | static inline float cofact3(mat4 const &mat, int i, int j) |
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34 | { |
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35 | return det3(mat[(i + 1) & 3][(j + 1) & 3], |
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36 | mat[(i + 2) & 3][(j + 1) & 3], |
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37 | mat[(i + 3) & 3][(j + 1) & 3], |
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38 | mat[(i + 1) & 3][(j + 2) & 3], |
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39 | mat[(i + 2) & 3][(j + 2) & 3], |
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40 | mat[(i + 3) & 3][(j + 2) & 3], |
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41 | mat[(i + 1) & 3][(j + 3) & 3], |
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42 | mat[(i + 2) & 3][(j + 3) & 3], |
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43 | mat[(i + 3) & 3][(j + 3) & 3]) * (((i + j) & 1) ? -1.0f : 1.0f); |
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44 | } |
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45 | |
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46 | template<> float mat4::det() const |
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47 | { |
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48 | float ret = 0; |
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49 | for (int n = 0; n < 4; n++) |
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50 | ret += (*this)[n][0] * cofact3(*this, n, 0); |
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51 | return ret; |
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52 | } |
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53 | |
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54 | template<> mat4 mat4::invert() const |
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55 | { |
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56 | mat4 ret; |
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57 | float d = det(); |
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58 | if (d) |
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59 | { |
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60 | d = 1.0f / d; |
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61 | for (int j = 0; j < 4; j++) |
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62 | for (int i = 0; i < 4; i++) |
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63 | ret[j][i] = cofact3(*this, i, j) * d; |
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64 | } |
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65 | return ret; |
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66 | } |
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67 | |
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68 | template<> mat4 mat4::ortho(float left, float right, float bottom, |
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69 | float top, float near, float far) |
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70 | { |
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71 | float invrl = (right != left) ? 1.0f / (right - left) : 0.0f; |
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72 | float invtb = (top != bottom) ? 1.0f / (top - bottom) : 0.0f; |
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73 | float invfn = (far != near) ? 1.0f / (far - near) : 0.0f; |
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74 | |
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75 | mat4 ret(0.0f); |
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76 | ret[0][0] = 2.0f * invrl; |
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77 | ret[1][1] = 2.0f * invtb; |
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78 | ret[2][2] = -2.0f * invfn; |
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79 | ret[3][0] = - (right + left) * invrl; |
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80 | ret[3][1] = - (top + bottom) * invtb; |
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81 | ret[3][2] = - (far + near) * invfn; |
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82 | ret[3][3] = 1.0f; |
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83 | return ret; |
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84 | } |
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85 | |
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86 | template<> mat4 mat4::frustum(float left, float right, float bottom, |
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87 | float top, float near, float far) |
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88 | { |
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89 | float invrl = (right != left) ? 1.0f / (right - left) : 0.0f; |
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90 | float invtb = (top != bottom) ? 1.0f / (top - bottom) : 0.0f; |
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91 | float invfn = (far != near) ? 1.0f / (far - near) : 0.0f; |
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92 | |
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93 | mat4 ret(0.0f); |
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94 | ret[0][0] = 2.0f * near * invrl; |
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95 | ret[1][1] = 2.0f * near * invtb; |
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96 | ret[2][0] = (right + left) * invrl; |
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97 | ret[2][1] = (top + bottom) * invtb; |
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98 | ret[2][2] = - (far + near) * invfn; |
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99 | ret[2][3] = -1.0f; |
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100 | ret[3][2] = -2.0f * far * near * invfn; |
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101 | return ret; |
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102 | } |
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103 | |
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104 | template<> mat4 mat4::perspective(float theta, float width, |
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105 | float height, float near, float far) |
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106 | { |
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107 | float t1 = tanf(theta / 2.0f); |
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108 | float t2 = t1 * height / width; |
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109 | |
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110 | return frustum(-near * t1, near * t1, -near * t2, near * t2, near, far); |
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111 | } |
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112 | |
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113 | template<> mat4 mat4::translate(float x, float y, float z) |
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114 | { |
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115 | mat4 ret(1.0f); |
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116 | ret[3][0] = x; |
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117 | ret[3][1] = y; |
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118 | ret[3][2] = z; |
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119 | return ret; |
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120 | } |
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121 | |
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122 | template<> mat4 mat4::rotate(float theta, float x, float y, float z) |
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123 | { |
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124 | float st = sinf(theta); |
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125 | float ct = cosf(theta); |
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126 | |
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127 | float len = sqrtf(x * x + y * y + z * z); |
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128 | float invlen = len ? 1.0f / len : 0.0f; |
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129 | x *= invlen; |
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130 | y *= invlen; |
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131 | z *= invlen; |
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132 | |
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133 | float mtx = (1.0f - ct) * x; |
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134 | float mty = (1.0f - ct) * y; |
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135 | float mtz = (1.0f - ct) * z; |
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136 | |
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137 | mat4 ret(1.0f); |
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138 | |
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139 | ret[0][0] = x * mtx + ct; |
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140 | ret[0][1] = x * mty + st * z; |
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141 | ret[0][2] = x * mtz - st * y; |
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142 | |
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143 | ret[1][0] = y * mtx - st * z; |
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144 | ret[1][1] = y * mty + ct; |
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145 | ret[1][2] = y * mtz + st * x; |
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146 | |
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147 | ret[2][0] = z * mtx + st * y; |
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148 | ret[2][1] = z * mty - st * x; |
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149 | ret[2][2] = z * mtz + ct; |
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150 | |
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151 | return ret; |
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152 | } |
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153 | |
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154 | } /* namespace lol */ |
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155 | |
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