1 | |
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2 | #include "terrain.h" |
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3 | #include "terrain_page.h" |
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4 | #include "glincl.h" |
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5 | #include "util/loading/resource_manager.h" |
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6 | #include "debug.h" |
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7 | #include <math.h> |
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8 | #ifdef HAVE_SDL_SDL_IMAGE_H |
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9 | #include <SDL/SDL_image.h> |
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10 | #else |
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11 | #include <SDL_image.h> |
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12 | #endif |
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13 | |
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14 | bool validateSize( int _s ) { |
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15 | _s-=1; |
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16 | int s = 16; |
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17 | while ( s <= _s ) { |
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18 | if (s == _s ) |
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19 | return true; |
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20 | s*=2; |
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21 | } |
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22 | return false; |
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23 | } |
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24 | void Terrain::build() |
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25 | { |
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26 | ResourceManager *MANAGER = ResourceManager::getInstance(); |
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27 | std::string full = MANAGER->getFullName( heightmapSource ); |
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28 | SDL_Surface *tmpData = IMG_Load( full.c_str() ); |
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29 | if ( !tmpData ) { |
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30 | PRINT(0)( "I' sorry, I can't load %s\n", full.c_str() ); |
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31 | return; |
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32 | } |
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33 | if ( !validateSize( tmpData->h ) || !validateSize( tmpData->w ) ) { |
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34 | PRINT(0)( "The size of the elevation map must be 2^n+1x2^m+1. and at least 17x17" ); |
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35 | return; |
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36 | } |
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37 | if ( tmpData->format->BytesPerPixel != 1 ) { |
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38 | PRINT(0)( "The elevetation map must be an 8bit image not %d", |
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39 | tmpData->format->BytesPerPixel*8 ); |
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40 | return; |
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41 | } |
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42 | PRINTF(2)( "Loaded the elevation map\n" ); |
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43 | heightfield.height = tmpData->h; |
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44 | heightfield.width = tmpData->w; |
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45 | heightfield.pitch = tmpData->pitch; |
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46 | int dataSize = heightfield.pitch*heightfield.height; |
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47 | heightfield.data = new Uint8[dataSize]; |
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48 | memcpy( heightfield.data, tmpData->pixels, sizeof(Uint8)*dataSize ); |
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49 | SDL_FreeSurface( tmpData ); |
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50 | pagesX = (heightfield.width/(pageSize-1) ); |
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51 | pagesZ = (heightfield.height/(pageSize-1) ); |
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52 | |
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53 | |
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54 | pages = new pTerrainPage[pagesX*pagesZ]; |
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55 | for ( int x = 0; x < pagesX; ++x ) |
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56 | for ( int z = 0; z < pagesZ; ++z ) |
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57 | pages[z*pagesX+x] = createPage( x, z ); |
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58 | //Inform each page about its neighbors. |
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59 | for ( int x = 0; x < pagesX; ++x ) |
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60 | for ( int z = 0; z < pagesZ; ++z ) |
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61 | pages[z*pagesX+x]->setNeighbors( |
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62 | x > 0 ? getPage( x-1, z+0 ) : NULL, |
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63 | x < pagesX-1 ? getPage( x+1, z+0 ) : NULL, |
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64 | z < pagesZ-1 ? getPage( x+0, z+1 ) : NULL, |
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65 | z > 0 ? getPage( x+0, z-1 ) : NULL ); |
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66 | |
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67 | root = createQuadTree( 0, 0, pagesX, pagesZ ); |
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68 | |
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69 | for ( unsigned int i = 0; i < layers.size(); ++i ) { |
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70 | determineLayerVisibility( i ); |
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71 | } |
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72 | activePages = NULL; |
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73 | } |
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74 | |
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75 | pTerrainQuad Terrain::createQuadTree( int _x0, int _z0, int _x1, int _z1, int _depth ) |
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76 | { |
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77 | int _x01 = (_x1+_x0)/2; int _z01 = (_z1+_z0)/2; |
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78 | pTerrainQuad node; |
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79 | if ( _x1-_x0 == 1 ) { |
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80 | node = getPage( _x0, _z0 ); |
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81 | node->setChildren( NULL, NULL, NULL, NULL ); |
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82 | } |
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83 | else { |
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84 | node = new TerrainQuad( this, _x0, _z0, _x1, _z1 ); |
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85 | node->setChildren( |
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86 | createQuadTree( _x0, _z0, _x01, _z01, _depth+1 ), |
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87 | createQuadTree( _x01, _z0, _x1, _z01, _depth+1 ), |
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88 | createQuadTree( _x0, _z01, _x01, _z1, _depth+1 ), |
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89 | createQuadTree( _x01, _z01, _x1, _z1, _depth+1 ) ); |
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90 | } |
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91 | node->calculateBounds(); |
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92 | return node; |
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93 | } |
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94 | |
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95 | pTerrainPage Terrain::createPage( int _xOffset, int _zOffset ) const |
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96 | { |
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97 | pTerrainPage newPage = new TerrainPage( const_cast<Terrain*>( this ), _xOffset, _zOffset ); |
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98 | newPage->setScale( scale ); |
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99 | newPage->setPosition( Vector( scale.x*_xOffset, 0.0f, scale.z*_zOffset ) ); |
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100 | newPage->calculateErrors(); |
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101 | return newPage; |
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102 | } |
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103 | |
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104 | void Terrain::addLevelFourPage( int _numVertices, Vertex *_vertices, |
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105 | int _numIndices, unsigned short *_indices ) |
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106 | { |
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107 | assert( indices ); assert( vertices ); |
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108 | BufferInfo bi = buffers[current]; |
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109 | if ( ( MAX_VERTICES < _numVertices+bi.numVertices ) || |
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110 | ( MAX_INDICES < _numIndices+bi.numIndices+2 ) ) { |
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111 | //So, we need the next vb and ib. Lets put the old into vram... |
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112 | glBindBufferARB( GL_ARRAY_BUFFER_ARB, bi.vbIdentifier ); |
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113 | glBufferDataARB( GL_ARRAY_BUFFER_ARB, MAX_VERTICES*sizeof( Vertex ), |
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114 | vertices, GL_DYNAMIC_DRAW_ARB ); |
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115 | glBindBufferARB( GL_ELEMENT_ARRAY_BUFFER_ARB, bi.ibIdentifier ); |
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116 | glBufferDataARB( GL_ELEMENT_ARRAY_BUFFER_ARB, MAX_INDICES*sizeof( short ), |
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117 | indices, GL_DYNAMIC_DRAW_ARB ); |
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118 | BufferInfo newInfo; |
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119 | broker->acquire( newInfo.vbIdentifier, newInfo.ibIdentifier ); |
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120 | current++; |
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121 | buffers.push_back( newInfo ); |
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122 | bi = newInfo; |
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123 | } |
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124 | //For the vertex data, a simple copy operation is sufficient... |
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125 | memcpy( &vertices[bi.numVertices], _vertices, |
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126 | _numVertices*sizeof( Vertex ) ); |
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127 | //The indices need to be updated with an offset :( |
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128 | unsigned short *dst= &indices[bi.numIndices]; |
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129 | unsigned short offset = bi.numVertices; |
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130 | unsigned short *src= _indices; |
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131 | unsigned short *end= src+_numIndices; |
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132 | bi.numVertices+=_numVertices; |
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133 | if ( bi.numIndices ) { |
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134 | dst[0] = *(dst-1); |
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135 | dst[1] = *src+offset; |
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136 | dst+=2; bi.numIndices+=2; |
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137 | } |
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138 | while ( src < end ) { |
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139 | *dst= *src+offset; |
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140 | dst++; |
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141 | src++; |
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142 | } |
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143 | bi.numIndices+=_numIndices; |
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144 | buffers[current] = bi; |
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145 | } |
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146 | |
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147 | void Terrain::determineVisiblePages( pTerrainQuad _node ) |
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148 | { |
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149 | switch( _node->cull() ) { |
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150 | case Frustum::INTERSECT: |
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151 | if ( !_node->isChildless() ) { |
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152 | pTerrainQuad *children = _node->getChildren(); |
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153 | for ( int i = 0; i < 4; ++i, ++children ) |
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154 | determineVisiblePages( *children ); |
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155 | } |
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156 | else { |
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157 | showPages( _node->getXOffset(), |
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158 | _node->getZOffset(), 1, 1 ); |
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159 | } |
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160 | break; |
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161 | case Frustum::INSIDE: |
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162 | showPages( _node->getXOffset(), |
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163 | _node->getZOffset(), |
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164 | _node->getWidth() , |
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165 | _node->getHeight() ); |
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166 | break; |
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167 | case Frustum::OUTSIDE: |
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168 | break; |
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169 | } |
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170 | } |
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171 | |
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172 | void Terrain::tick( float _dt ) |
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173 | { |
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174 | for ( unsigned int i = 0; i < buffers.size(); ++i ) |
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175 | broker->release( buffers[i].vbIdentifier, buffers[i].ibIdentifier ); |
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176 | buffers.clear(); |
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177 | pTerrainPage page = NULL; |
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178 | //Extract the frustum planes out of the modelview matrix. |
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179 | frustum->extractPlanes(); |
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180 | // Lets see which pages are visible. |
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181 | determineVisiblePages( root ); |
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182 | int wantedLeft, wantedRight, wantedBottom, wantedTop, minLOD; |
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183 | pTerrainPage neighbor = NULL; |
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184 | page = activePages; |
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185 | bool dirty; |
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186 | current = 0; |
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187 | BufferInfo bi; |
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188 | broker->acquire( bi.vbIdentifier, bi.ibIdentifier ); |
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189 | buffers.push_back( bi ); |
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190 | int dirtyRounds = 0; |
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191 | do { |
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192 | dirtyRounds++; |
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193 | dirty = false; |
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194 | page = activePages; |
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195 | while ( page ) { |
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196 | if ( !page->isActive() ) { |
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197 | pTerrainPage tmp = page; |
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198 | page = tmp->getNext(); |
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199 | tmp->setVisibility( false ); |
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200 | continue; |
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201 | } |
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202 | wantedLeft = wantedRight = wantedBottom = wantedTop = page->getWantedLOD(); |
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203 | if ( ( neighbor = page->getLeft() ) && ( neighbor->isActive() ) ) |
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204 | wantedLeft = neighbor->getWantedLOD(); |
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205 | if ( ( neighbor = page->getRight() ) && ( neighbor->isActive() ) ) |
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206 | wantedRight = neighbor->getWantedLOD(); |
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207 | if ( ( neighbor = page->getTop() ) && ( neighbor->isActive() ) ) |
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208 | wantedTop = neighbor->getWantedLOD(); |
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209 | if ( ( neighbor = page->getBottom() ) && ( neighbor->isActive() ) ) |
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210 | wantedBottom = neighbor->getWantedLOD(); |
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211 | |
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212 | minLOD = std::min( std::min( wantedBottom, wantedTop ), |
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213 | std::min( wantedLeft, wantedRight ) ); |
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214 | if ( minLOD < page->getWantedLOD()-1 ) { |
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215 | page->setWantedLOD( minLOD+1 ); |
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216 | dirty = true; |
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217 | } |
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218 | page = page->getNext(); |
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219 | } |
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220 | } while ( dirty ); |
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221 | |
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222 | page = activePages; |
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223 | while ( page ) { |
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224 | assert( page->isActive() ); |
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225 | page->updateTesselation(); |
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226 | page = page->getNext(); |
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227 | } |
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228 | //If there is some data in the buffer, we need to upload the data |
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229 | //into the vram... |
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230 | if ( buffers[current].numIndices != 0 ) { |
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231 | BufferInfo bi = buffers[current]; |
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232 | glBindBufferARB( GL_ARRAY_BUFFER_ARB, bi.vbIdentifier ); |
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233 | glBufferDataARB( GL_ARRAY_BUFFER_ARB, MAX_VERTICES*sizeof( Vertex ), |
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234 | vertices, GL_DYNAMIC_DRAW_ARB ); |
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235 | glBindBufferARB( GL_ELEMENT_ARRAY_BUFFER_ARB, bi.ibIdentifier ); |
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236 | glBufferDataARB( GL_ELEMENT_ARRAY_BUFFER_ARB, MAX_INDICES*sizeof( short ), |
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237 | indices, GL_DYNAMIC_DRAW_ARB ); |
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238 | } |
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239 | } |
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240 | |
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241 | void Terrain::draw( ) |
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242 | { |
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243 | pTerrainPage page = NULL; |
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244 | glGetError(); |
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245 | /*pTerrainPage page = NULL; |
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246 | frustum->extractPlanes();*/ |
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247 | Plane far = frustum->getPlane( Frustum::FAR ); |
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248 | //Due to some reason, the OpenGL implementors chose the plane equation |
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249 | //to an array of doubles. So we will make them happy. |
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250 | double farPlane[] = { far.n.x, far.n.y, far.n.z, far.k }; |
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251 | glEnable( GL_CLIP_PLANE0 ); |
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252 | glClipPlane( GL_CLIP_PLANE0, farPlane ); |
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253 | glPushAttrib( GL_ALL_ATTRIB_BITS ); |
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254 | glPushClientAttrib( GL_CLIENT_VERTEX_ARRAY_BIT ); |
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255 | /* |
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256 | * Enable texture and vertex arrays for the first and the second texture |
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257 | * units and disable the normal arrays. |
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258 | */ |
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259 | glClientActiveTextureARB( GL_TEXTURE0_ARB ); |
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260 | glEnableClientState( GL_VERTEX_ARRAY ); |
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261 | glEnableClientState( GL_TEXTURE_COORD_ARRAY ); |
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262 | glDisableClientState( GL_NORMAL_ARRAY ); |
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263 | |
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264 | glClientActiveTextureARB( GL_TEXTURE1_ARB ); |
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265 | glEnableClientState( GL_VERTEX_ARRAY ); |
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266 | glEnableClientState( GL_TEXTURE_COORD_ARRAY ); |
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267 | glDisableClientState( GL_NORMAL_ARRAY ); |
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268 | glDisable( GL_CULL_FACE ); |
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269 | glDisable( GL_LIGHTING ); |
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270 | glColor3f( 1.0f, 1.0f, 1.0f ); |
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271 | //glPolygonMode( GL_FRONT_AND_BACK, GL_LINE ); |
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272 | cullCount = 0; |
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273 | glEnable( GL_BLEND ); |
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274 | glDepthFunc( GL_LEQUAL ); |
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275 | glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ); |
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276 | for ( unsigned int i = 0; i < layers.size(); ++i ) { |
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277 | LayerInfo* layer= layers[i]; |
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278 | page = activePages; |
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279 | |
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280 | glActiveTextureARB( GL_TEXTURE1_ARB ); |
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281 | glClientActiveTextureARB( GL_TEXTURE1_ARB ); |
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282 | if ( layer->detail ) { |
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283 | //glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_BLEND ); |
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284 | glEnable( GL_TEXTURE_2D ); |
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285 | glBindTexture( GL_TEXTURE_2D, layer->detail->getTexture() ); |
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286 | glMatrixMode( GL_TEXTURE ); |
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287 | glLoadIdentity(); |
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288 | glScalef( layer->repeatX, layer->repeatZ, 1.0f ); |
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289 | } |
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290 | else { |
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291 | glDisable( GL_TEXTURE_2D ); |
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292 | } |
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293 | glEnable( GL_CULL_FACE ); |
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294 | glCullFace( GL_BACK ); |
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295 | glClientActiveTextureARB( GL_TEXTURE0_ARB ); |
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296 | glActiveTextureARB( GL_TEXTURE0_ARB ); |
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297 | glEnable( GL_TEXTURE_2D ); |
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298 | if ( layer->alpha ) { |
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299 | //glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_BLEND ); |
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300 | glBindTexture( GL_TEXTURE_2D, layer->alpha->getTexture() ); |
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301 | } |
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302 | else { |
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303 | |
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304 | glBindTexture( GL_TEXTURE_2D, lightmap->getTexture() ); |
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305 | } |
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306 | glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT ); |
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307 | glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT ); |
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308 | |
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309 | for ( unsigned j = 0; j < buffers.size(); ++j ) { |
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310 | BufferInfo bi = buffers[j]; |
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311 | glBindBufferARB( GL_ARRAY_BUFFER_ARB, bi.vbIdentifier ); |
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312 | glClientActiveTextureARB( GL_TEXTURE0_ARB ); |
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313 | glInterleavedArrays( GL_T2F_V3F, 0, NULL ); |
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314 | |
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315 | glClientActiveTextureARB( GL_TEXTURE1_ARB ); |
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316 | glInterleavedArrays( GL_T2F_V3F, 0, NULL ); |
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317 | |
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318 | glBindBufferARB( GL_ELEMENT_ARRAY_BUFFER_ARB, |
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319 | bi.ibIdentifier ); |
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320 | |
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321 | glDrawElements( GL_TRIANGLE_STRIP, bi.numIndices, |
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322 | GL_UNSIGNED_SHORT, NULL ); |
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323 | } |
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324 | while ( page ) { |
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325 | if ( page->hasMaterial( i ) ) |
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326 | page->draw(); |
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327 | page = page->getNext(); |
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328 | } |
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329 | } |
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330 | glClientActiveTextureARB( GL_TEXTURE1_ARB ); |
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331 | glActiveTextureARB( GL_TEXTURE1_ARB ); |
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332 | glDisable( GL_TEXTURE_2D ); |
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333 | glActiveTextureARB( GL_TEXTURE0_ARB ); |
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334 | glEnable( GL_LIGHTING ); |
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335 | glMatrixMode( GL_TEXTURE ); |
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336 | glLoadIdentity(); |
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337 | glPopAttrib(); |
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338 | glPopClientAttrib(); |
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339 | glCullFace( GL_FRONT ); |
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340 | glDisable( GL_CLIP_PLANE0 ); |
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341 | } |
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342 | |
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343 | inline Uint8 getAlpha( const SDL_Surface *_s, int _x, int _y ) |
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344 | { |
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345 | int bpp = _s->format->BytesPerPixel; |
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346 | Uint8 *p = (Uint8 *)_s->pixels + _y*_s->pitch + _x * bpp; |
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347 | Uint32 pixel = 0; |
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348 | switch( bpp ) { |
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349 | case 1: |
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350 | pixel = *p; |
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351 | break; |
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352 | case 2: |
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353 | if ( SDL_BYTEORDER == SDL_BIG_ENDIAN ) |
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354 | pixel = p[0] << 8 | p[1]; |
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355 | else |
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356 | pixel = *(Uint16 *)p; |
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357 | break; |
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358 | case 3: |
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359 | if( SDL_BYTEORDER == SDL_BIG_ENDIAN ) |
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360 | pixel = p[0] << 16 | p[1] << 8 | p[2]; |
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361 | else |
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362 | pixel = p[0] | p[1] << 8 | p[2] << 16; |
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363 | break; |
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364 | case 4: |
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365 | pixel = *(Uint32 *)p; |
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366 | break; |
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367 | default: |
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368 | return 255; /* shouldn't happen, but avoids warnings */ |
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369 | } |
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370 | Uint8 r,g,b,a; |
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371 | SDL_GetRGBA( pixel, _s->format, &r, &g, &b, &a ); |
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372 | return a; |
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373 | } |
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374 | |
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375 | void Terrain::determineLayerVisibility( int _layer ) |
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376 | { |
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377 | LayerInfo * layer = layers[_layer]; |
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378 | if ( !layer->alpha ) { |
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379 | int numPages = pagesX*pagesZ; |
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380 | for ( int i = 0; i < numPages; ++i ) |
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381 | pages[i]->setLayerVisibility( _layer, LV_FULL ); |
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382 | |
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383 | return; |
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384 | } |
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385 | SDL_Surface *alpha = const_cast<SDL_Surface*>( layer->alpha->getStoredImage() ); |
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386 | SDL_LockSurface( alpha ); |
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387 | float du = ( (float)alpha->w)/pagesX; |
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388 | float dv = ( (float)alpha->h)/pagesZ; |
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389 | float u = 0.0f, v = 0.0f; |
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390 | for ( int pageX = 0; pageX < pagesX; ++pageX ) { |
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391 | v = 0.0f; |
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392 | for ( int pageZ = 0; pageZ < pagesZ; ++pageZ ) { |
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393 | bool full = true; bool has = false; |
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394 | for ( int x = 0; x < (int)PAGE_SIZE; ++x ) { |
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395 | for ( int z = 0; z < (int)PAGE_SIZE; ++z ) { |
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396 | Uint8 a = getAlpha( alpha, (int)u, (int)v ); |
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397 | if ( a ) |
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398 | has = true; |
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399 | if ( a < 255 ) |
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400 | full = false; |
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401 | } |
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402 | } |
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403 | LayerVisibility lv; |
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404 | if ( has ) { |
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405 | if ( full ) |
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406 | lv = LV_FULL; |
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407 | else |
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408 | lv = LV_PARTIAL; |
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409 | } |
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410 | else { |
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411 | lv = LV_NO; |
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412 | } |
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413 | getPage( pageX, pageZ )->setLayerVisibility( _layer, lv ); |
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414 | v+= dv; |
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415 | } |
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416 | u+= du; |
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417 | } |
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418 | SDL_UnlockSurface( alpha ); |
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419 | } |
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420 | |
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421 | void Terrain::getAltitude( Vector& _alt, Vector& _normal ) |
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422 | { |
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423 | float xScaled = _alt.x / scale.x, zScaled = _alt.z / scale.z; |
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424 | //The offset on the map |
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425 | int xOff = (int)xScaled, zOff = (int)zScaled; |
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426 | //The interpolation values. |
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427 | float u = xScaled-xOff, v = zScaled-zOff; |
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428 | |
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429 | float dX = scale.x / ( pageSize-1 ); |
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430 | float dZ = scale.z / ( pageSize-1 ); |
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431 | |
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432 | //If u is bigger than v, we are on the lower triangle... |
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433 | if ( u > v ) { |
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434 | |
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435 | float alt[] = { |
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436 | getAltitude( xOff+0, zOff+0 )*scale.y, |
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437 | getAltitude( xOff+1, zOff+0 )*scale.y, |
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438 | getAltitude( xOff+1, zOff+1 )*scale.y }; |
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439 | _alt.y = (1.0f-u-v)*alt[0]+u*alt[1]+v*alt[2]; |
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440 | |
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441 | //Since we know about the directions of some x and z-coordinates, |
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442 | //not the whole cross products needs to be calculated. Grab yourself |
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443 | //pen and paper :) |
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444 | _normal.x = dZ*( alt[0] - alt[1] ); |
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445 | _normal.y = dZ*dX; |
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446 | _normal.z = -dX*( alt[2] - alt[1] ); |
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447 | } |
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448 | else { |
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449 | float alt[] = { |
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450 | getAltitude( xOff+0, zOff+0 )*scale.y, |
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451 | getAltitude( xOff+0, zOff+1 )*scale.y, |
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452 | getAltitude( xOff+1, zOff+1 )*scale.y }; |
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453 | _alt.y = (1.0f-u-v)*alt[0]+v*alt[1]+u*alt[2]; |
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454 | //Since we know about the directions of some x and z-coordinates, |
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455 | //not the whole cross products needs to be calculated. Grab yourself |
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456 | //pen and paper :) |
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457 | _normal.x = -dZ*( alt[2] - alt[1] ); |
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458 | _normal.y = dZ*dX; |
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459 | _normal.z = dX*( alt[0] - alt[1] ); |
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460 | } |
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461 | } |
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462 | |
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463 | void Terrain::showPages( int _x0, int _z0, int _width, int _height ) |
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464 | { |
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465 | for ( int x = 0; x < _width; ++x ) { |
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466 | for ( int z = 0; z < _height; ++z ) { |
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467 | pTerrainPage page = getPage( _x0+x, _z0+z ); |
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468 | page->setVisibility( true ); |
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469 | page->chooseLOD(); |
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470 | |
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471 | } |
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472 | } |
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473 | } |
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