1 | package solarsim.sochacki; |
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2 | |
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3 | import solarsim.renderer.Renderer2D; |
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4 | import solarsim.common.State; |
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5 | import solarsim.common.Particle; |
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6 | import solarsim.common.Vector; |
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7 | import java.util.LinkedList; |
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8 | import java.util.List; |
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9 | |
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10 | public class Sochacki { |
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11 | int nt; |
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12 | int Np; |
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13 | static double AU = 149597870691F; // Astronomical Unit |
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14 | static double D = 86400; // Astronomical Day |
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15 | static double K = 0.01720209895; // Gauss' gravitational constant |
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16 | static double G = K*K; |
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17 | static double S = 1.9891E30; // Astronomical Unit for mass - the mass of the Sun |
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18 | //static double Gm = 6.6743E-11; |
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19 | |
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20 | double [] mass; |
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21 | double [][][] xx; |
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22 | double [][][] vv; |
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23 | |
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24 | double [][][] aa; |
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25 | double [][][] u1; |
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26 | double [][][] u2; |
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27 | double [][][] u3; |
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28 | |
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29 | public Sochacki(int nt, int Np) { |
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30 | this.nt = nt; |
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31 | this.Np = Np; |
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32 | mass = new double[2]; |
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33 | xx = new double[3][Np][nt]; |
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34 | vv = new double[3][Np][nt]; |
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35 | |
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36 | aa = new double[Np][Np][nt]; |
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37 | u1 = new double[Np][Np][nt]; |
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38 | u2 = new double[Np][Np][nt]; |
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39 | u3 = new double[Np][Np][nt]; |
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40 | } |
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41 | |
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42 | void initState() { |
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43 | // Sun |
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44 | mass[0] = G; |
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45 | xx[0][0][0] = 0; |
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46 | xx[1][0][0] = 0; |
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47 | xx[2][0][0] = 0; |
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48 | vv[0][0][0] = 0; |
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49 | vv[1][0][0] = 0; |
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50 | vv[2][0][0] = 0; |
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51 | |
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52 | // Earth |
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53 | mass[1] = G / 332840;//S |
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54 | xx[0][1][0] = 0.98328989;//AU |
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55 | xx[1][1][0] = 0; |
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56 | xx[2][1][0] = 0; |
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57 | vv[0][1][0] = 0; |
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58 | vv[1][1][0] = 30286.7 * D / AU; |
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59 | vv[2][1][0] = 0; |
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60 | |
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61 | for( int j = 0; j < Np; j++ ) { |
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62 | for( int k = 0; k < Np; k++ ) { |
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63 | if( j == k ) |
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64 | continue; |
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65 | |
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66 | double s = 0; |
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67 | for( int i = 0; i < 3; i++ ) { |
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68 | double dx = (xx[i][j][0] - xx[i][k][0]); |
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69 | s += dx * dx; |
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70 | } |
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71 | u1[j][k][0] = 1 / Math.sqrt(s); |
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72 | u2[j][k][0] = u1[j][k][0] * u1[j][k][0]; |
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73 | u3[j][k][0] = u2[j][k][0] * u1[j][k][0]; |
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74 | |
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75 | s = 0; |
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76 | for( int i = 0; i < 3; i++ ) { |
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77 | double dx = (xx[i][k][0] - xx[i][j][0]); |
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78 | double dv = (vv[i][k][0] - vv[i][j][0]); |
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79 | s += dx * dv; |
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80 | } |
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81 | aa[j][k][0] = s; |
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82 | } |
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83 | } |
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84 | } |
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85 | |
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86 | void genPoly() { |
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87 | double a, b; |
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88 | int i, j, k, L, m; |
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89 | |
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90 | for( m = 1; m < nt; m++ ) { |
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91 | for( j = 0; j < Np; j++ ) { |
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92 | for( i = 0; i < 3; i++ ) { |
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93 | xx[i][j][m] = vv[i][j][m-1] / m; |
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94 | a = 0; |
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95 | for( k = 0; k < Np; k++ ) { |
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96 | b = 0; |
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97 | for( L = 0; L <= m-1; L++ ) { |
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98 | b = b + (xx[i][k][L] - xx[i][j][L])*u3[j][k][m-1-L]; |
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99 | } |
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100 | a = a + mass[k] * b; |
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101 | } |
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102 | vv[i][j][m] = a / m; |
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103 | } |
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104 | for( k = 0; k <= j-1; k++ ) { |
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105 | a = 0; |
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106 | for( L = 0; L <= m-1; L++ ) { |
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107 | a = a - u3[j][k][L] * aa[j][k][m-1-L]; |
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108 | } |
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109 | u1[j][k][m] = a / m; |
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110 | u1[k][j][m] = a / m; |
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111 | a = 0; |
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112 | for( L = 0 ; L <= m; L++ ) { |
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113 | a = a + u1[j][k][L] * u1[j][k][m-L]; |
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114 | } |
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115 | u2[j][k][m] = a; |
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116 | u2[k][j][m] = a; |
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117 | a = 0; |
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118 | b = 0; |
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119 | for( L = 0; L <= m; L++ ) { |
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120 | b = b + u2[j][k][L] * u1[j][k][m-L]; |
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121 | for( i = 0; i < 3; i++ ) { |
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122 | a = a + (xx[i][j][L]-xx[i][k][L])*(vv[i][j][m-L]-vv[i][k][m-L]); |
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123 | } |
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124 | } |
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125 | aa[j][k][m] = a; |
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126 | aa[k][j][m] = a; |
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127 | u3[j][k][m] = b; |
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128 | u3[k][j][m] = b; |
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129 | } |
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130 | aa[j][j][m] = 0; |
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131 | u1[j][j][m] = 0; |
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132 | u2[j][j][m] = 0; |
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133 | u3[j][j][m] = 0; |
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134 | } |
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135 | } |
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136 | } |
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137 | |
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138 | double evalPoly( double t, double [] c ) { |
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139 | double p = 0; |
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140 | |
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141 | for( int i = c.length-1; i >= 0; i-- ) { |
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142 | p = p * t + c[i]; |
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143 | } |
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144 | |
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145 | return p * AU; |
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146 | } |
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147 | |
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148 | State getState( double time ) { |
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149 | List<Particle> particles = new LinkedList<Particle>(); |
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150 | for( int i = 0; i < Np; i++) { |
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151 | double x = evalPoly(time, xx[0][i]); |
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152 | double y = evalPoly(time, xx[1][i]); |
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153 | double z = evalPoly(time, xx[2][i]); |
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154 | Vector r = new Vector(x, y, z); |
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155 | |
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156 | double vx = evalPoly(time, vv[0][i]); |
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157 | double vy = evalPoly(time, vv[1][i]); |
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158 | double vz = evalPoly(time, vv[2][i]); |
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159 | Vector v = new Vector(vx, vy, vz); |
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160 | |
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161 | Particle p = new Particle(mass[i], r, v); |
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162 | particles.add(p); |
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163 | } |
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164 | |
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165 | return new State(particles); |
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166 | } |
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167 | |
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168 | public static void main(String [] args) { |
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169 | Renderer2D renderer = new Renderer2D(); |
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170 | new Thread(renderer).start(); |
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171 | |
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172 | Sochacki sch = new Sochacki(100,2); |
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173 | sch.initState(); |
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174 | sch.genPoly(); |
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175 | for( double t = -228; t < 229; t += 1 ) { |
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176 | State s = sch.getState(t); |
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177 | //System.out.println(s); |
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178 | renderer.drawState(s); |
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179 | } |
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180 | try { |
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181 | Thread.currentThread().sleep(60 * 1000); |
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182 | } catch( InterruptedException e ) { |
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183 | e.printStackTrace(); |
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184 | } |
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185 | renderer.stop(); |
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186 | } |
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187 | } |
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