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1 /* |
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2 * Copyright (c) 2003 Nokia Corporation and/or its subsidiary(-ies). |
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3 * All rights reserved. |
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4 * This component and the accompanying materials are made available |
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5 * under the terms of the License "Eclipse Public License v1.0" |
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6 * which accompanies this distribution, and is available |
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7 * at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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8 * |
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9 * Initial Contributors: |
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10 * Nokia Corporation - initial contribution. |
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11 * |
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12 * Contributors: |
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13 * |
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14 * Description: Fog implementation |
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15 * |
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16 */ |
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17 |
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18 |
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19 /*! |
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20 * \internal |
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21 * \file |
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22 * \brief Fog implementation |
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23 */ |
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24 |
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25 #ifndef M3G_CORE_INCLUDE |
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26 # error included by m3g_core.c; do not compile separately. |
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27 #endif |
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28 |
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29 #include "m3g_fog.h" |
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30 #include "m3g_animationtrack.h" |
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31 |
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32 /*---------------------------------------------------------------------- |
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33 * Internal functions |
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34 *--------------------------------------------------------------------*/ |
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35 |
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36 /*! |
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37 * \internal |
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38 * \brief Destroys this Fog object. |
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39 * |
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40 * \param obj Fog object |
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41 */ |
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42 static void m3gDestroyFog(Object *obj) |
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43 { |
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44 Fog *fog = (Fog *) obj; |
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45 M3G_VALIDATE_OBJECT(fog); |
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46 |
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47 m3gDestroyObject(&fog->object); |
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48 } |
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49 |
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50 /*! |
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51 * \internal |
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52 * \brief Overloaded Object3D method. |
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53 * |
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54 * \param property animation property |
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55 * \retval M3G_TRUE property supported |
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56 * \retval M3G_FALSE property not supported |
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57 */ |
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58 static M3Gbool m3gFogIsCompatible(M3Gint property) |
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59 { |
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60 switch (property) { |
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61 case M3G_ANIM_COLOR: |
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62 case M3G_ANIM_DENSITY: |
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63 case M3G_ANIM_FAR_DISTANCE: |
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64 case M3G_ANIM_NEAR_DISTANCE: |
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65 return M3G_TRUE; |
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66 default: |
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67 return m3gObjectIsCompatible(property); |
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68 } |
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69 } |
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70 |
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71 /*! |
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72 * \internal |
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73 * \brief Overloaded Object3D method. |
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74 * |
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75 * \param self Fog object |
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76 * \param property animation property |
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77 * \param valueSize size of value array |
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78 * \param value value array |
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79 */ |
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80 static void m3gFogUpdateProperty(Object *self, |
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81 M3Gint property, |
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82 M3Gint valueSize, |
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83 const M3Gfloat *value) |
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84 { |
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85 Fog *fog = (Fog *)self; |
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86 M3G_VALIDATE_OBJECT(fog); |
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87 M3G_ASSERT_PTR(value); |
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88 |
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89 switch (property) { |
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90 case M3G_ANIM_COLOR: |
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91 M3G_ASSERT(valueSize >= 3); |
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92 fog->color = m3gColor3f(value[0], value[1], value[2]) & M3G_RGB_MASK; |
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93 break; |
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94 case M3G_ANIM_DENSITY: |
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95 M3G_ASSERT(valueSize >= 1); |
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96 fog->density = (value[0] < 0.f) ? 0.f : value[0]; |
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97 break; |
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98 case M3G_ANIM_FAR_DISTANCE: |
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99 M3G_ASSERT(valueSize >= 1); |
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100 fog->end = value[0]; |
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101 break; |
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102 case M3G_ANIM_NEAR_DISTANCE: |
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103 M3G_ASSERT(valueSize >= 1); |
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104 fog->start = value[0]; |
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105 break; |
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106 default: |
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107 m3gObjectUpdateProperty(self, property, valueSize, value); |
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108 } |
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109 } |
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110 |
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111 /*! |
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112 * \internal |
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113 * \brief Overloaded Object3D method. |
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114 * |
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115 * \param originalObj original Fog object |
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116 * \param cloneObj pointer to cloned Fog object |
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117 * \param pairs array for all object-duplicate pairs |
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118 * \param numPairs number of pairs |
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119 */ |
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120 static M3Gbool m3gFogDuplicate(const Object *originalObj, |
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121 Object **cloneObj, |
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122 Object **pairs, |
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123 M3Gint *numPairs) |
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124 { |
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125 Fog *original = (Fog *)originalObj; |
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126 Fog *clone = (Fog *)m3gCreateFog(originalObj->interface); |
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127 *cloneObj = (Object *)clone; |
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128 if (*cloneObj == NULL) { |
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129 return M3G_FALSE; |
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130 } |
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131 |
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132 if(m3gObjectDuplicate(originalObj, cloneObj, pairs, numPairs)) { |
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133 clone->color = original->color; |
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134 clone->density = original->density; |
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135 clone->start = original->start; |
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136 clone->end = original->end; |
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137 clone->mode = original->mode; |
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138 return M3G_TRUE; |
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139 } |
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140 else { |
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141 return M3G_FALSE; |
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142 } |
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143 } |
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144 |
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145 /*! |
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146 * \internal |
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147 * \brief Initializes a Fog object. See specification |
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148 * for default values. |
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149 * |
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150 * \param m3g M3G interface |
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151 * \param fog Fog object |
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152 */ |
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153 static void m3gInitFog(Interface *m3g, Fog *fog) |
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154 { |
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155 /* Fog is derived from object */ |
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156 m3gInitObject(&fog->object, m3g, M3G_CLASS_FOG); |
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157 |
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158 fog->density = 1.0f; |
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159 fog->start = 0.0f; |
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160 fog->end = 1.0f; |
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161 fog->mode = M3G_LINEAR_FOG; |
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162 } |
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163 |
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164 /*! |
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165 * \internal |
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166 * \brief Applies fog to OpenGL. This is used for |
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167 * all Mesh objects. |
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168 * |
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169 * \param self Fog object |
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170 */ |
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171 static void m3gApplyFog(const Fog *self) |
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172 { |
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173 if (self != NULL) { |
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174 GLfixed temp[4]; |
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175 |
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176 m3gGLColor(self->color, temp); |
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177 |
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178 switch (self->mode) { |
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179 case M3G_LINEAR_FOG: |
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180 glEnable(GL_FOG); |
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181 glFogf(GL_FOG_MODE, GL_LINEAR); |
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182 glFogf(GL_FOG_START, self->start); |
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183 glFogf(GL_FOG_END, self->end); |
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184 glFogxv(GL_FOG_COLOR, temp); |
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185 break; |
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186 case M3G_EXPONENTIAL_FOG: |
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187 glEnable(GL_FOG); |
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188 glFogf(GL_FOG_MODE, GL_EXP); |
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189 glFogf(GL_FOG_DENSITY, self->density); |
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190 glFogxv(GL_FOG_COLOR, temp); |
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191 break; |
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192 } |
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193 } |
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194 else { |
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195 glDisable(GL_FOG); |
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196 } |
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197 M3G_ASSERT_GL; |
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198 } |
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199 |
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200 /*! |
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201 * \internal |
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202 * \brief Applies fog to OpenGL. This is used for |
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203 * Sprite3D objects only. |
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204 * |
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205 * \param self Fog object |
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206 * \param eyeZ Eye space Z (e.g. after modelview) |
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207 * \param finalZ Final Z (e.g. after modelview and projection) |
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208 */ |
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209 static void m3gApplySpriteFog(const Fog *self, M3Gfloat eyeZ, M3Gfloat finalZ) |
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210 { |
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211 if(self != NULL) { |
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212 M3Gint temp[4]; |
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213 M3Gfloat fogValue = 1; |
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214 |
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215 /* Calculate fog value and use OpenGL linear fog |
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216 * to result in same value. Sprites are drawn with |
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217 * identity MV and P and therefore the fog has to |
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218 * be adjusted like this */ |
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219 switch (self->mode) { |
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220 case M3G_LINEAR_FOG: |
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221 fogValue = m3gDiv(m3gAdd(self->end, eyeZ), m3gSub(self->end, self->start)); |
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222 break; |
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223 case M3G_EXPONENTIAL_FOG: |
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224 fogValue = m3gExp(m3gMul(self->density, eyeZ)); |
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225 break; |
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226 default: |
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227 M3G_ASSERT(M3G_FALSE); |
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228 break; |
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229 } |
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230 |
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231 m3gGLColor(self->color, temp); |
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232 |
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233 glEnable(GL_FOG); |
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234 glFogf(GL_FOG_MODE, GL_LINEAR); |
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235 #ifdef M3G_USE_NGL_API |
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236 /* NGL works differently in fog calculation */ |
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237 glFogf(GL_FOG_START, -m3gDiv(finalZ, fogValue)); |
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238 #else |
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239 glFogf(GL_FOG_START, m3gAbs(m3gDiv(finalZ, fogValue))); |
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240 #endif |
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241 glFogf(GL_FOG_END, 0.f); |
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242 glFogxv(GL_FOG_COLOR, temp); |
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243 } |
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244 else { |
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245 glDisable(GL_FOG); |
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246 } |
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247 } |
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248 |
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249 /*---------------------------------------------------------------------- |
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250 * Virtual function table |
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251 *--------------------------------------------------------------------*/ |
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252 |
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253 static const ObjectVFTable m3gvf_Fog = { |
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254 m3gObjectApplyAnimation, |
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255 m3gFogIsCompatible, |
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256 m3gFogUpdateProperty, |
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257 m3gObjectDoGetReferences, |
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258 m3gObjectFindID, |
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259 m3gFogDuplicate, |
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260 m3gDestroyFog |
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261 }; |
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262 |
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263 |
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264 /*---------------------------------------------------------------------- |
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265 * Public API functions |
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266 *--------------------------------------------------------------------*/ |
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267 |
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268 /*! |
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269 * \brief Creates a Fog object. |
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270 * |
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271 * \param interface M3G interface |
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272 * \retval Fog new Fog object |
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273 * \retval NULL Fog creating failed |
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274 */ |
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275 M3G_API M3GFog m3gCreateFog(M3GInterface interface) |
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276 { |
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277 Interface *m3g = (Interface *) interface; |
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278 M3G_VALIDATE_INTERFACE(m3g); |
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279 |
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280 { |
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281 Fog *fog = m3gAllocZ(m3g, sizeof(Fog)); |
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282 |
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283 if (fog != NULL) { |
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284 m3gInitFog(m3g, fog); |
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285 } |
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286 |
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287 return (M3GFog) fog; |
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288 } |
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289 } |
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290 |
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291 /*! |
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292 * \brief Sets fog mode. |
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293 * |
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294 * \param handle Fog object |
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295 * \param mode fog mode |
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296 */ |
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297 M3G_API void m3gSetFogMode(M3GFog handle, M3Gint mode) |
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298 { |
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299 Fog *fog = (Fog *) handle; |
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300 M3G_VALIDATE_OBJECT(fog); |
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301 |
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302 /* Check for errors */ |
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303 if(mode < M3G_EXPONENTIAL_FOG || mode > M3G_LINEAR_FOG) { |
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304 m3gRaiseError(M3G_INTERFACE(fog), M3G_INVALID_VALUE); |
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305 return; |
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306 } |
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307 |
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308 fog->mode = mode; |
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309 } |
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310 |
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311 /*! |
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312 * \brief Gets fog mode. |
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313 * |
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314 * \param handle Fog object |
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315 * \return fog mode |
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316 */ |
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317 M3G_API M3Gint m3gGetFogMode(M3GFog handle) |
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318 { |
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319 Fog *fog = (Fog *) handle; |
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320 M3G_VALIDATE_OBJECT(fog); |
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321 |
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322 return fog->mode; |
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323 } |
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324 |
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325 /*! |
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326 * \brief Sets linear fog parameters. |
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327 * |
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328 * \param handle Fog object |
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329 * \param fogNear near distance |
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330 * \param fogFar far distance |
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331 */ |
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332 M3G_API void m3gSetFogLinear(M3GFog handle, M3Gfloat fogNear, M3Gfloat fogFar) |
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333 { |
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334 Fog *fog = (Fog *) handle; |
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335 M3G_VALIDATE_OBJECT(fog); |
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336 |
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337 fog->start = fogNear; |
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338 fog->end = fogFar; |
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339 } |
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340 |
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341 /*! |
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342 * \brief Gets linear fog parameters. |
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343 * |
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344 * \param handle Fog object |
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345 * \param which which parameter to return |
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346 * \arg M3G_GET_NEAR |
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347 * \arg M3G_GET_FAR |
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348 * \return near or far distance |
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349 */ |
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350 M3G_API M3Gfloat m3gGetFogDistance(M3GFog handle, M3Gint which) |
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351 { |
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352 Fog *fog = (Fog *) handle; |
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353 M3G_VALIDATE_OBJECT(fog); |
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354 |
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355 switch(which) { |
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356 case M3G_GET_NEAR: |
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357 return fog->start; |
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358 case M3G_GET_FAR: |
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359 default: |
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360 return fog->end; |
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361 } |
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362 } |
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363 |
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364 /*! |
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365 * \brief Sets exponential fog density. |
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366 * |
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367 * \param handle Fog object |
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368 * \param density fog density |
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369 */ |
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370 M3G_API void m3gSetFogDensity(M3GFog handle, M3Gfloat density) |
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371 { |
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372 Fog *fog = (Fog *) handle; |
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373 M3G_VALIDATE_OBJECT(fog); |
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374 |
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375 if(density < 0.f) { |
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376 m3gRaiseError(M3G_INTERFACE(fog), M3G_INVALID_VALUE); |
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377 return; |
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378 } |
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379 |
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380 fog->density = density; |
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381 } |
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382 |
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383 /*! |
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384 * \brief Gets exponential fog density. |
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385 * |
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386 * \param handle Fog object |
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387 * \return fog density |
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388 */ |
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389 M3G_API M3Gfloat m3gGetFogDensity(M3GFog handle) |
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390 { |
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391 Fog *fog = (Fog *) handle; |
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392 M3G_VALIDATE_OBJECT(fog); |
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393 |
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394 return fog->density; |
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395 } |
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396 |
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397 /*! |
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398 * \brief Sets fog color as RGB. |
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399 * |
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400 * \param handle Fog object |
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401 * \param rgb fog color as RGB |
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402 */ |
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403 M3G_API void m3gSetFogColor(M3GFog handle, M3Guint rgb) |
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404 { |
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405 Fog *fog = (Fog *) handle; |
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406 M3G_VALIDATE_OBJECT(fog); |
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407 |
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408 fog->color = rgb & M3G_RGB_MASK; |
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409 } |
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410 |
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411 /*! |
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412 * \brief Gets fog color as RGB. |
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413 * |
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414 * \param handle Fog object |
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415 * \return fog color as RGB |
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416 */ |
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417 M3G_API M3Guint m3gGetFogColor(M3GFog handle) |
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418 { |
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419 Fog *fog = (Fog *) handle; |
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420 M3G_VALIDATE_OBJECT(fog); |
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421 |
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422 return fog->color; |
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423 } |
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424 |