1 | // Python - C extension for polygon module. |
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2 | // |
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3 | // To compile (Python2.3): |
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4 | // gcc -c polygon_ext.c -I/usr/include/python2.3 -o polygon_ext.o -Wall -O |
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5 | // gcc -shared polygon_ext.o -o polygon_ext.so |
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6 | // |
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7 | // See the module polygon.py |
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8 | // |
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9 | // |
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10 | // Ole Nielsen, GA 2004 |
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11 | // |
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12 | // NOTE: We use long* instead of int* for numeric arrays as this will work both |
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13 | // for 64 as well as 32 bit systems |
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14 | |
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15 | |
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16 | #include "Python.h" |
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17 | #include "numpy/arrayobject.h" |
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18 | #include "math.h" |
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19 | |
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20 | #include "util_ext.h" |
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21 | |
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22 | #define YES 1 |
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23 | #define NO 0 |
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24 | |
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25 | |
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26 | double dist(double x, |
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27 | double y) { |
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28 | |
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29 | return sqrt(x*x + y*y); |
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30 | } |
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31 | |
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32 | |
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33 | int __point_on_line(double x, double y, |
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34 | double x0, double y0, |
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35 | double x1, double y1, |
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36 | double rtol, |
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37 | double atol) { |
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38 | /*Determine whether a point is on a line segment |
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39 | |
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40 | Input: x, y, x0, x0, x1, y1: where |
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41 | point is given by x, y |
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42 | line is given by (x0, y0) and (x1, y1) |
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43 | |
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44 | */ |
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45 | |
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46 | double a0, a1, a_normal0, a_normal1, b0, b1, len_a, len_b; |
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47 | double nominator, denominator; |
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48 | int is_parallel; |
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49 | |
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50 | a0 = x - x0; |
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51 | a1 = y - y0; |
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52 | |
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53 | a_normal0 = a1; |
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54 | a_normal1 = -a0; |
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55 | |
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56 | b0 = x1 - x0; |
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57 | b1 = y1 - y0; |
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58 | |
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59 | nominator = fabs(a_normal0*b0 + a_normal1*b1); |
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60 | denominator = b0*b0 + b1*b1; |
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61 | |
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62 | // Determine if line is parallel to point vector up to a tolerance |
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63 | is_parallel = 0; |
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64 | if (denominator == 0.0) { |
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65 | // Use absolute tolerance |
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66 | if (nominator <= atol) { |
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67 | is_parallel = 1; |
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68 | } |
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69 | } else { |
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70 | // Denominator is positive - use relative tolerance |
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71 | if (nominator/denominator <= rtol) { |
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72 | is_parallel = 1; |
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73 | } |
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74 | } |
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75 | |
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76 | if (is_parallel) { |
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77 | // Point is somewhere on the infinite extension of the line |
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78 | // subject to specified absolute tolerance |
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79 | |
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80 | len_a = dist(a0, a1); //sqrt(a0*a0 + a1*a1); |
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81 | len_b = dist(b0, b1); //sqrt(b0*b0 + b1*b1); |
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82 | |
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83 | if (a0*b0 + a1*b1 >= 0 && len_a <= len_b) { |
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84 | return 1; |
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85 | } else { |
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86 | return 0; |
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87 | } |
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88 | } else { |
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89 | return 0; |
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90 | } |
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91 | } |
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92 | |
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93 | |
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94 | // public domain function by Darel Rex Finley, 2006 |
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95 | // http://www.alienryderflex.com/intersect/ |
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96 | // |
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97 | // Determines the intersection point of the line segment defined by points A and B |
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98 | // with the line segment defined by points C and D. |
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99 | // |
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100 | // Returns YES if the intersection point was found, and stores that point in X,Y. |
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101 | // Returns NO if there is no determinable intersection point, in which case X,Y will |
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102 | // be unmodified. |
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103 | |
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104 | int __line_segment_intersection( |
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105 | double Ax, double Ay, |
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106 | double Bx, double By, |
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107 | double Cx, double Cy, |
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108 | double Dx, double Dy, |
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109 | double *X, double *Y) { |
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110 | |
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111 | double distAB, theCos, theSin, newX, ABpos; |
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112 | |
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113 | // Fail if either line segment is zero-length. |
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114 | if ( (Ax == Bx && Ay == By) || (Cx == Dx && Cy == Dy) ) return NO ; |
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115 | |
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116 | // Fail if the segments share an end-point. |
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117 | if ( (Ax == Cx && Ay == Cy) || (Bx == Cx && By == Cy) |
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118 | || (Ax == Dx && Ay == Dy) || (Bx == Dx && By == Dy) ) { |
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119 | return NO; |
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120 | } |
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121 | |
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122 | // (1) Translate the system so that point A is on the origin. |
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123 | Bx -= Ax; |
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124 | By -= Ay; |
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125 | Cx -= Ax; |
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126 | Cy -= Ay; |
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127 | Dx -= Ax; |
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128 | Dy -= Ay; |
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129 | |
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130 | // Discover the length of segment A-B. |
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131 | distAB = sqrt(Bx * Bx + By * By); |
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132 | |
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133 | // (2) Rotate the system so that point B is on the positive X axis. |
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134 | theCos = Bx / distAB; |
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135 | theSin = By / distAB; |
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136 | newX = Cx * theCos + Cy*theSin; |
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137 | Cy = Cy * theCos - Cx*theSin; |
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138 | Cx = newX; |
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139 | newX = Dx * theCos + Dy*theSin; |
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140 | Dy = Dy * theCos - Dx*theSin; |
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141 | Dx = newX; |
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142 | |
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143 | // Fail if segment C-D doesn't cross line A-B. |
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144 | if ( (Cy < 0. && Dy < 0.) || (Cy >= 0. && Dy >= 0.) ) return NO; |
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145 | |
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146 | // (3) Discover the position of the intersection point along line A-B. |
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147 | ABpos = Dx + (Cx - Dx) * Dy / (Dy - Cy); |
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148 | |
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149 | // Fail if segment C-D crosses line A-B outside of segment A-B. |
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150 | if (ABpos < 0. || ABpos > distAB) return NO; |
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151 | |
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152 | // (4) Apply the discovered position to line A-B in the original coordinate system. |
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153 | *X = Ax + ABpos*theCos; |
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154 | *Y = Ay + ABpos*theSin; |
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155 | |
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156 | // Success. |
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157 | return YES; |
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158 | } |
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159 | |
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160 | /* |
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161 | WORK IN PROGRESS TO OPTIMISE INTERSECTION |
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162 | int __intersection(double x0, double y0, |
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163 | double x1, double y1) { |
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164 | |
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165 | |
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166 | x0 = line0[0,0]; y0 = line0[0,1] |
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167 | x1 = line0[1,0]; y1 = line0[1,1] |
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168 | |
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169 | x2 = line1[0,0]; y2 = line1[0,1] |
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170 | x3 = line1[1,0]; y3 = line1[1,1] |
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171 | |
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172 | denom = (y3-y2)*(x1-x0) - (x3-x2)*(y1-y0) |
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173 | u0 = (x3-x2)*(y0-y2) - (y3-y2)*(x0-x2) |
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174 | u1 = (x2-x0)*(y1-y0) - (y2-y0)*(x1-x0) |
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175 | |
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176 | if allclose(denom, 0.0): |
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177 | # Lines are parallel - check if they coincide on a shared a segment |
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178 | |
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179 | if allclose( [u0, u1], 0.0 ): |
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180 | # We now know that the lines if continued coincide |
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181 | # The remaining check will establish if the finite lines share a segment |
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182 | |
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183 | line0_starts_on_line1 = line0_ends_on_line1 =\ |
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184 | line1_starts_on_line0 = line1_ends_on_line0 = False |
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185 | |
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186 | if point_on_line([x0, y0], line1): |
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187 | line0_starts_on_line1 = True |
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188 | |
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189 | if point_on_line([x1, y1], line1): |
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190 | line0_ends_on_line1 = True |
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191 | |
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192 | if point_on_line([x2, y2], line0): |
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193 | line1_starts_on_line0 = True |
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194 | |
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195 | if point_on_line([x3, y3], line0): |
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196 | line1_ends_on_line0 = True |
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197 | |
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198 | if not(line0_starts_on_line1 or line0_ends_on_line1\ |
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199 | or line1_starts_on_line0 or line1_ends_on_line0): |
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200 | # Lines are parallel and would coincide if extended, but not as they are. |
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201 | return 3, None |
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202 | |
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203 | |
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204 | # One line fully included in the other. Use direction of included line |
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205 | if line0_starts_on_line1 and line0_ends_on_line1: |
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206 | # Shared segment is line0 fully included in line1 |
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207 | segment = array([[x0, y0], [x1, y1]]) |
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208 | |
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209 | if line1_starts_on_line0 and line1_ends_on_line0: |
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210 | # Shared segment is line1 fully included in line0 |
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211 | segment = array([[x2, y2], [x3, y3]]) |
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212 | |
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213 | |
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214 | # Overlap with lines are oriented the same way |
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215 | if line0_starts_on_line1 and line1_ends_on_line0: |
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216 | # Shared segment from line0 start to line 1 end |
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217 | segment = array([[x0, y0], [x3, y3]]) |
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218 | |
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219 | if line1_starts_on_line0 and line0_ends_on_line1: |
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220 | # Shared segment from line1 start to line 0 end |
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221 | segment = array([[x2, y2], [x1, y1]]) |
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222 | |
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223 | |
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224 | # Overlap in opposite directions - use direction of line0 |
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225 | if line0_starts_on_line1 and line1_starts_on_line0: |
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226 | # Shared segment from line0 start to line 1 end |
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227 | segment = array([[x0, y0], [x2, y2]]) |
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228 | |
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229 | if line0_ends_on_line1 and line1_ends_on_line0: |
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230 | # Shared segment from line0 start to line 1 end |
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231 | segment = array([[x3, y3], [x1, y1]]) |
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232 | |
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233 | |
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234 | return 2, segment |
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235 | else: |
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236 | # Lines are parallel but they do not coincide |
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237 | return 4, None #FIXME (Ole): Add distance here instead of None |
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238 | |
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239 | else: |
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240 | # Lines are not parallel or coinciding |
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241 | u0 = u0/denom |
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242 | u1 = u1/denom |
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243 | |
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244 | x = x0 + u0*(x1-x0) |
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245 | y = y0 + u0*(y1-y0) |
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246 | |
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247 | # Sanity check - can be removed to speed up if needed |
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248 | assert allclose(x, x2 + u1*(x3-x2)) |
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249 | assert allclose(y, y2 + u1*(y3-y2)) |
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250 | |
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251 | # Check if point found lies within given line segments |
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252 | if 0.0 <= u0 <= 1.0 and 0.0 <= u1 <= 1.0: |
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253 | # We have intersection |
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254 | |
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255 | return 1, array([x, y]) |
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256 | else: |
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257 | # No intersection |
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258 | return 0, None |
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259 | |
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260 | |
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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 | |
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266 | int __interpolate_polyline(int number_of_nodes, |
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267 | int number_of_points, |
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268 | double* data, |
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269 | double* polyline_nodes, |
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270 | long* gauge_neighbour_id, |
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271 | double* interpolation_points, |
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272 | double* interpolated_values, |
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273 | double rtol, |
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274 | double atol) { |
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275 | |
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276 | int j, i, neighbour_id; |
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277 | double x0, y0, x1, y1, x, y; |
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278 | double segment_len, segment_delta, slope, alpha; |
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279 | |
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280 | for (j=0; j<number_of_nodes; j++) { |
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281 | |
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282 | neighbour_id = gauge_neighbour_id[j]; |
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283 | |
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284 | // FIXME(Ole): I am convinced that gauge_neighbour_id can be discarded, but need to check with John J. |
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285 | // Keep it for now (17 Jan 2009) |
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286 | // When gone, we can simply interpolate between neighbouring nodes, i.e. neighbour_id = j+1. |
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287 | // and the test below becomes something like: if j < number_of_nodes... |
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288 | |
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289 | if (neighbour_id >= 0) { |
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290 | x0 = polyline_nodes[2*j]; |
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291 | y0 = polyline_nodes[2*j+1]; |
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292 | |
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293 | x1 = polyline_nodes[2*neighbour_id]; |
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294 | y1 = polyline_nodes[2*neighbour_id+1]; |
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295 | |
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296 | |
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297 | segment_len = dist(x1-x0, y1-y0); |
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298 | segment_delta = data[neighbour_id] - data[j]; |
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299 | slope = segment_delta/segment_len; |
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300 | |
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301 | for (i=0; i<number_of_points; i++) { |
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302 | x = interpolation_points[2*i]; |
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303 | y = interpolation_points[2*i+1]; |
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304 | |
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305 | if (__point_on_line(x, y, x0, y0, x1, y1, rtol, atol)) { |
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306 | alpha = dist(x-x0, y-y0); |
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307 | interpolated_values[i] = slope*alpha + data[j]; |
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308 | } |
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309 | } |
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310 | } |
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311 | } |
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312 | |
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313 | return 0; |
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314 | } |
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315 | |
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316 | |
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317 | int __polygon_triangle_overlap(double* polygon, |
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318 | double* triangle) |
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319 | { |
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320 | int i, ii, j, jj; |
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321 | double p0_x, p0_y, p1_x, p1_y, pp_x, pp_y; |
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322 | double t0_x, t0_y, t1_x, t1_y, tp_x, tp_y; |
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323 | double u_x, u_y, v_x, v_y, w_x, w_y; |
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324 | double u_dot_tp, v_dot_tp, v_dot_pp, w_dot_pp; |
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325 | double a, b; |
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326 | |
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327 | p0_x = polygon[0]; |
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328 | p0_y = polygon[1]; |
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329 | |
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330 | for (i = 1; i < 5; i++) |
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331 | { |
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332 | ii = i%4; |
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333 | |
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334 | p1_x = polygon[2*ii]; |
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335 | p1_y = polygon[2*ii + 1]; |
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336 | |
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337 | pp_x = -(p1_y - p0_y); |
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338 | pp_y = p1_x - p0_x; |
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339 | |
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340 | t0_x = triangle[0]; |
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341 | t0_y = triangle[1]; |
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342 | |
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343 | for (j = 1; j < 4; j++) |
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344 | { |
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345 | jj = j%3; |
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346 | |
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347 | t1_x = triangle[2*jj]; |
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348 | t1_y = triangle[2*jj + 1]; |
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349 | |
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350 | tp_x = -(t1_y - t0_y); //perpendicular to triangle vector |
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351 | tp_y = t1_x - t0_x; |
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352 | |
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353 | u_x = p1_x - p0_x; |
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354 | u_y = p1_y - p0_y; |
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355 | v_x = t0_x - p0_x; |
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356 | v_y = t0_y - p0_y; |
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357 | w_x = t1_x - t0_x; |
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358 | w_y = t1_y - t0_y; |
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359 | |
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360 | u_dot_tp = (u_x*tp_x) + (u_y*tp_y); |
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361 | |
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362 | if (u_dot_tp != 0.0f) //Vectors are not parallel |
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363 | { |
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364 | v_dot_tp = (v_x*tp_x) + (v_y*tp_y); |
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365 | v_dot_pp = (v_x*pp_x) + (v_y*pp_y); |
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366 | w_dot_pp = (w_x*pp_x) + (w_y*pp_y); |
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367 | |
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368 | a = v_dot_tp/u_dot_tp; |
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369 | b = v_dot_pp/w_dot_pp; |
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370 | |
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371 | if (a >= 0.0f && a <= 1.0f) |
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372 | { |
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373 | return 1; //overlap |
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374 | } |
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375 | |
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376 | if (b >= 0.0f && b <= 1.0f) |
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377 | { |
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378 | return 1; //overlap |
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379 | } |
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380 | } |
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381 | |
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382 | t0_x = t1_x; |
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383 | t0_y = t1_y; |
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384 | } |
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385 | |
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386 | p0_x = p1_x; |
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387 | p0_y = p1_y; |
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388 | } |
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389 | |
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390 | return 0; //no overlap |
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391 | } |
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392 | |
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393 | |
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394 | |
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395 | int __is_inside_triangle(double* point, |
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396 | double* triangle, |
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397 | int closed, |
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398 | double rtol, |
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399 | double atol) { |
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400 | |
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401 | double vx, vy, v0x, v0y, v1x, v1y; |
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402 | double a00, a10, a01, a11, b0, b1; |
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403 | double denom, alpha, beta; |
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404 | |
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405 | double x, y; // Point coordinates |
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406 | int i, j, res; |
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407 | |
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408 | x = point[0]; |
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409 | y = point[1]; |
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410 | |
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411 | // Quickly reject points that are clearly outside |
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412 | if ((x < triangle[0]) && |
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413 | (x < triangle[2]) && |
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414 | (x < triangle[4])) return 0; |
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415 | |
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416 | if ((x > triangle[0]) && |
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417 | (x > triangle[2]) && |
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418 | (x > triangle[4])) return 0; |
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419 | |
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420 | if ((y < triangle[1]) && |
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421 | (y < triangle[3]) && |
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422 | (y < triangle[5])) return 0; |
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423 | |
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424 | if ((y > triangle[1]) && |
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425 | (y > triangle[3]) && |
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426 | (y > triangle[5])) return 0; |
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427 | |
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428 | |
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429 | // v0 = C-A |
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430 | v0x = triangle[4]-triangle[0]; |
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431 | v0y = triangle[5]-triangle[1]; |
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432 | |
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433 | // v1 = B-A |
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434 | v1x = triangle[2]-triangle[0]; |
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435 | v1y = triangle[3]-triangle[1]; |
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436 | |
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437 | // First check if point lies wholly inside triangle |
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438 | a00 = v0x*v0x + v0y*v0y; // innerproduct(v0, v0) |
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439 | a01 = v0x*v1x + v0y*v1y; // innerproduct(v0, v1) |
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440 | a10 = a01; // innerproduct(v1, v0) |
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441 | a11 = v1x*v1x + v1y*v1y; // innerproduct(v1, v1) |
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442 | |
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443 | denom = a11*a00 - a01*a10; |
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444 | |
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445 | if (fabs(denom) > 0.0) { |
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446 | // v = point-A |
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447 | vx = x - triangle[0]; |
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448 | vy = y - triangle[1]; |
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449 | |
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450 | b0 = v0x*vx + v0y*vy; // innerproduct(v0, v) |
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451 | b1 = v1x*vx + v1y*vy; // innerproduct(v1, v) |
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452 | |
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453 | alpha = (b0*a11 - b1*a01)/denom; |
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454 | beta = (b1*a00 - b0*a10)/denom; |
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455 | |
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456 | if ((alpha > 0.0) && (beta > 0.0) && (alpha+beta < 1.0)) return 1; |
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457 | } |
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458 | |
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459 | if (closed) { |
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460 | // Check if point lies on one of the edges |
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461 | |
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462 | for (i=0; i<3; i++) { |
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463 | j = (i+1) % 3; // Circular index into triangle array |
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464 | res = __point_on_line(x, y, |
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465 | triangle[2*i], triangle[2*i+1], |
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466 | triangle[2*j], triangle[2*j+1], |
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467 | rtol, atol); |
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468 | if (res) return 1; |
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469 | } |
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470 | } |
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471 | |
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472 | // Default return if point is outside triangle |
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473 | return 0; |
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474 | } |
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475 | |
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476 | |
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477 | int __separate_points_by_polygon(int M, // Number of points |
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478 | int N, // Number of polygon vertices |
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479 | double* points, |
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480 | double* polygon, |
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481 | long* indices, // M-Array for storage indices |
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482 | int closed, |
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483 | int verbose) { |
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484 | |
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485 | double minpx, maxpx, minpy, maxpy, x, y, px_i, py_i, px_j, py_j, rtol=0.0, atol=0.0; |
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486 | int i, j, k, outside_index, inside_index, inside; |
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487 | |
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488 | // Find min and max of poly used for optimisation when points |
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489 | // are far away from polygon |
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490 | |
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491 | // FIXME(Ole): Pass in rtol and atol from Python |
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492 | |
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493 | minpx = polygon[0]; maxpx = minpx; |
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494 | minpy = polygon[1]; maxpy = minpy; |
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495 | |
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496 | for (i=0; i<N; i++) { |
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497 | px_i = polygon[2*i]; |
---|
498 | py_i = polygon[2*i + 1]; |
---|
499 | |
---|
500 | if (px_i < minpx) minpx = px_i; |
---|
501 | if (px_i > maxpx) maxpx = px_i; |
---|
502 | if (py_i < minpy) minpy = py_i; |
---|
503 | if (py_i > maxpy) maxpy = py_i; |
---|
504 | } |
---|
505 | |
---|
506 | // Begin main loop (for each point) |
---|
507 | inside_index = 0; // Keep track of points inside |
---|
508 | outside_index = M-1; // Keep track of points outside (starting from end) |
---|
509 | if (verbose){ |
---|
510 | printf("Separating %d points\n", M); |
---|
511 | } |
---|
512 | for (k=0; k<M; k++) { |
---|
513 | if (verbose){ |
---|
514 | if (k %((M+10)/10)==0) printf("Doing %d of %d\n", k, M); |
---|
515 | } |
---|
516 | |
---|
517 | x = points[2*k]; |
---|
518 | y = points[2*k + 1]; |
---|
519 | |
---|
520 | inside = 0; |
---|
521 | |
---|
522 | // Optimisation |
---|
523 | if ((x > maxpx) || (x < minpx) || (y > maxpy) || (y < minpy)) { |
---|
524 | // Nothing |
---|
525 | } else { |
---|
526 | // Check polygon |
---|
527 | for (i=0; i<N; i++) { |
---|
528 | j = (i+1)%N; |
---|
529 | |
---|
530 | px_i = polygon[2*i]; |
---|
531 | py_i = polygon[2*i+1]; |
---|
532 | px_j = polygon[2*j]; |
---|
533 | py_j = polygon[2*j+1]; |
---|
534 | |
---|
535 | // Check for case where point is contained in line segment |
---|
536 | if (__point_on_line(x, y, px_i, py_i, px_j, py_j, rtol, atol)) { |
---|
537 | if (closed == 1) { |
---|
538 | inside = 1; |
---|
539 | } else { |
---|
540 | inside = 0; |
---|
541 | } |
---|
542 | break; |
---|
543 | } else { |
---|
544 | //Check if truly inside polygon |
---|
545 | if ( ((py_i < y) && (py_j >= y)) || |
---|
546 | ((py_j < y) && (py_i >= y)) ) { |
---|
547 | if (px_i + (y-py_i)/(py_j-py_i)*(px_j-px_i) < x) |
---|
548 | inside = 1-inside; |
---|
549 | } |
---|
550 | } |
---|
551 | } |
---|
552 | } |
---|
553 | if (inside == 1) { |
---|
554 | indices[inside_index] = k; |
---|
555 | inside_index += 1; |
---|
556 | } else { |
---|
557 | indices[outside_index] = k; |
---|
558 | outside_index -= 1; |
---|
559 | } |
---|
560 | } // End k |
---|
561 | |
---|
562 | return inside_index; |
---|
563 | } |
---|
564 | |
---|
565 | |
---|
566 | |
---|
567 | // Gateways to Python |
---|
568 | PyObject *_point_on_line(PyObject *self, PyObject *args) { |
---|
569 | // |
---|
570 | // point_on_line(x, y, x0, y0, x1, y1) |
---|
571 | // |
---|
572 | |
---|
573 | double x, y, x0, y0, x1, y1, rtol, atol; |
---|
574 | int res; |
---|
575 | PyObject *result; |
---|
576 | |
---|
577 | // Convert Python arguments to C |
---|
578 | if (!PyArg_ParseTuple(args, "dddddddd", &x, &y, &x0, &y0, &x1, &y1, &rtol, &atol)) { |
---|
579 | PyErr_SetString(PyExc_RuntimeError, |
---|
580 | "point_on_line could not parse input"); |
---|
581 | return NULL; |
---|
582 | } |
---|
583 | |
---|
584 | |
---|
585 | // Call underlying routine |
---|
586 | res = __point_on_line(x, y, x0, y0, x1, y1, rtol, atol); |
---|
587 | |
---|
588 | // Return values a and b |
---|
589 | result = Py_BuildValue("i", res); |
---|
590 | return result; |
---|
591 | } |
---|
592 | |
---|
593 | |
---|
594 | |
---|
595 | // Gateways to Python |
---|
596 | PyObject *_interpolate_polyline(PyObject *self, PyObject *args) { |
---|
597 | // |
---|
598 | // _interpolate_polyline(data, polyline_nodes, gauge_neighbour_id, interpolation_points |
---|
599 | // interpolated_values): |
---|
600 | // |
---|
601 | |
---|
602 | |
---|
603 | PyArrayObject |
---|
604 | *data, |
---|
605 | *polyline_nodes, |
---|
606 | *gauge_neighbour_id, |
---|
607 | *interpolation_points, |
---|
608 | *interpolated_values; |
---|
609 | |
---|
610 | double rtol, atol; |
---|
611 | int number_of_nodes, number_of_points, res; |
---|
612 | |
---|
613 | // Convert Python arguments to C |
---|
614 | if (!PyArg_ParseTuple(args, "OOOOOdd", |
---|
615 | &data, |
---|
616 | &polyline_nodes, |
---|
617 | &gauge_neighbour_id, |
---|
618 | &interpolation_points, |
---|
619 | &interpolated_values, |
---|
620 | &rtol, |
---|
621 | &atol)) { |
---|
622 | |
---|
623 | PyErr_SetString(PyExc_RuntimeError, |
---|
624 | "_interpolate_polyline could not parse input"); |
---|
625 | return NULL; |
---|
626 | } |
---|
627 | |
---|
628 | // check that numpy array objects arrays are C contiguous memory |
---|
629 | CHECK_C_CONTIG(data); |
---|
630 | CHECK_C_CONTIG(polyline_nodes); |
---|
631 | CHECK_C_CONTIG(gauge_neighbour_id); |
---|
632 | CHECK_C_CONTIG(interpolation_points); |
---|
633 | CHECK_C_CONTIG(interpolated_values); |
---|
634 | |
---|
635 | number_of_nodes = polyline_nodes -> dimensions[0]; // Number of nodes in polyline |
---|
636 | number_of_points = interpolation_points -> dimensions[0]; //Number of points |
---|
637 | |
---|
638 | |
---|
639 | // Call underlying routine |
---|
640 | res = __interpolate_polyline(number_of_nodes, |
---|
641 | number_of_points, |
---|
642 | (double*) data -> data, |
---|
643 | (double*) polyline_nodes -> data, |
---|
644 | (long*) gauge_neighbour_id -> data, |
---|
645 | (double*) interpolation_points -> data, |
---|
646 | (double*) interpolated_values -> data, |
---|
647 | rtol, |
---|
648 | atol); |
---|
649 | |
---|
650 | // Return |
---|
651 | return Py_BuildValue(""); |
---|
652 | } |
---|
653 | |
---|
654 | |
---|
655 | PyObject *_polygon_triangle_overlap(PyObject *self, PyObject *args) { |
---|
656 | // |
---|
657 | // _polygon_triangle_overlap(polygon, triangle) |
---|
658 | // |
---|
659 | |
---|
660 | |
---|
661 | PyArrayObject |
---|
662 | *polygon, |
---|
663 | *triangle; |
---|
664 | |
---|
665 | int res; |
---|
666 | |
---|
667 | PyObject *result; |
---|
668 | |
---|
669 | // Convert Python arguments to C |
---|
670 | if (!PyArg_ParseTuple(args, "OO", |
---|
671 | &polygon, |
---|
672 | &triangle)) { |
---|
673 | |
---|
674 | PyErr_SetString(PyExc_RuntimeError, |
---|
675 | "_polygon_triangle_overlap could not parse input"); |
---|
676 | return NULL; |
---|
677 | } |
---|
678 | |
---|
679 | // Call underlying routine |
---|
680 | res = __polygon_triangle_overlap((double*) polygon->data, |
---|
681 | (double*) triangle -> data); |
---|
682 | |
---|
683 | |
---|
684 | // Return result |
---|
685 | result = Py_BuildValue("i", res); |
---|
686 | return result; |
---|
687 | } |
---|
688 | |
---|
689 | |
---|
690 | PyObject *_is_inside_triangle(PyObject *self, PyObject *args) { |
---|
691 | // |
---|
692 | // _is_inside_triangle(point, triangle, int(closed), rtol, atol) |
---|
693 | // |
---|
694 | |
---|
695 | |
---|
696 | PyArrayObject |
---|
697 | *point, |
---|
698 | *triangle; |
---|
699 | |
---|
700 | double rtol, atol; |
---|
701 | int closed, res; |
---|
702 | |
---|
703 | PyObject *result; |
---|
704 | |
---|
705 | // Convert Python arguments to C |
---|
706 | if (!PyArg_ParseTuple(args, "OOidd", |
---|
707 | &point, |
---|
708 | &triangle, |
---|
709 | &closed, |
---|
710 | &rtol, |
---|
711 | &atol)) { |
---|
712 | |
---|
713 | PyErr_SetString(PyExc_RuntimeError, |
---|
714 | "_is_inside_triangle could not parse input"); |
---|
715 | return NULL; |
---|
716 | } |
---|
717 | |
---|
718 | // Call underlying routine |
---|
719 | res = __is_inside_triangle((double*) point -> data, |
---|
720 | (double*) triangle -> data, |
---|
721 | closed, |
---|
722 | rtol, |
---|
723 | atol); |
---|
724 | |
---|
725 | |
---|
726 | // Return result |
---|
727 | result = Py_BuildValue("i", res); |
---|
728 | return result; |
---|
729 | } |
---|
730 | |
---|
731 | |
---|
732 | |
---|
733 | /* |
---|
734 | PyObject *_intersection(PyObject *self, PyObject *args) { |
---|
735 | // |
---|
736 | // intersection(x0, y0, x1, y1) |
---|
737 | // |
---|
738 | |
---|
739 | double x, y, x0, y0, x1, y1; |
---|
740 | int res; |
---|
741 | PyObject *result; |
---|
742 | |
---|
743 | // Convert Python arguments to C |
---|
744 | if (!PyArg_ParseTuple(args, "dddddd", &x, &y, &x0, &y0, &x1, &y1)) { |
---|
745 | PyErr_SetString(PyExc_RuntimeError, |
---|
746 | "point_on_line could not parse input"); |
---|
747 | return NULL; |
---|
748 | } |
---|
749 | |
---|
750 | |
---|
751 | // Call underlying routine |
---|
752 | res = __intersection(x, y, x0, y0, x1, y1); |
---|
753 | |
---|
754 | // Return values a and b |
---|
755 | result = Py_BuildValue("i", res); |
---|
756 | return result; |
---|
757 | } |
---|
758 | */ |
---|
759 | |
---|
760 | |
---|
761 | PyObject *_separate_points_by_polygon(PyObject *self, PyObject *args) { |
---|
762 | //def separate_points_by_polygon(points, polygon, closed, verbose, one_point): |
---|
763 | // """Determine whether points are inside or outside a polygon |
---|
764 | // |
---|
765 | // Input: |
---|
766 | // point - Tuple of (x, y) coordinates, or list of tuples |
---|
767 | // polygon - list of vertices of polygon |
---|
768 | // closed - (optional) determine whether points on boundary should be |
---|
769 | // regarded as belonging to the polygon (closed = True) |
---|
770 | // or not (closed = False) |
---|
771 | |
---|
772 | // |
---|
773 | // Output: |
---|
774 | // indices: array of same length as points with indices of points falling |
---|
775 | // inside the polygon listed from the beginning and indices of points |
---|
776 | // falling outside listed from the end. |
---|
777 | // |
---|
778 | // count: count of points falling inside the polygon |
---|
779 | // |
---|
780 | // The indices of points inside are obtained as indices[:count] |
---|
781 | // The indices of points outside are obtained as indices[count:] |
---|
782 | // |
---|
783 | // Examples: |
---|
784 | // separate_polygon( [[0.5, 0.5], [1, -0.5], [0.3, 0.2]] ) |
---|
785 | // will return the indices [0, 2, 1] as only the first and the last point |
---|
786 | // is inside the unit square |
---|
787 | // |
---|
788 | // Remarks: |
---|
789 | // The vertices may be listed clockwise or counterclockwise and |
---|
790 | // the first point may optionally be repeated. |
---|
791 | // Polygons do not need to be convex. |
---|
792 | // Polygons can have holes in them and points inside a hole is |
---|
793 | // regarded as being outside the polygon. |
---|
794 | // |
---|
795 | // |
---|
796 | // Algorithm is based on work by Darel Finley, |
---|
797 | // http://www.alienryderflex.com/polygon/ |
---|
798 | // |
---|
799 | // |
---|
800 | |
---|
801 | PyArrayObject |
---|
802 | *points, |
---|
803 | *polygon, |
---|
804 | *indices; |
---|
805 | |
---|
806 | int closed, verbose; //Flags |
---|
807 | int count, M, N; |
---|
808 | |
---|
809 | // Convert Python arguments to C |
---|
810 | if (!PyArg_ParseTuple(args, "OOOii", |
---|
811 | &points, |
---|
812 | &polygon, |
---|
813 | &indices, |
---|
814 | &closed, |
---|
815 | &verbose)) { |
---|
816 | |
---|
817 | |
---|
818 | PyErr_SetString(PyExc_RuntimeError, |
---|
819 | "separate_points_by_polygon could not parse input"); |
---|
820 | return NULL; |
---|
821 | } |
---|
822 | |
---|
823 | // check that points, polygon and indices arrays are C contiguous |
---|
824 | CHECK_C_CONTIG(points); |
---|
825 | CHECK_C_CONTIG(polygon); |
---|
826 | CHECK_C_CONTIG(indices); |
---|
827 | |
---|
828 | M = points -> dimensions[0]; //Number of points |
---|
829 | N = polygon -> dimensions[0]; //Number of vertices in polygon |
---|
830 | |
---|
831 | //FIXME (Ole): This isn't send to Python's sys.stdout |
---|
832 | if (verbose) printf("Got %d points and %d polygon vertices\n", M, N); |
---|
833 | |
---|
834 | //Call underlying routine |
---|
835 | count = __separate_points_by_polygon(M, N, |
---|
836 | (double*) points -> data, |
---|
837 | (double*) polygon -> data, |
---|
838 | (long*) indices -> data, |
---|
839 | closed, verbose); |
---|
840 | |
---|
841 | //NOTE: return number of points inside.. |
---|
842 | return Py_BuildValue("i", count); |
---|
843 | } |
---|
844 | |
---|
845 | |
---|
846 | |
---|
847 | // Method table for python module |
---|
848 | static struct PyMethodDef MethodTable[] = { |
---|
849 | /* The cast of the function is necessary since PyCFunction values |
---|
850 | * only take two PyObject* parameters, and rotate() takes |
---|
851 | * three. |
---|
852 | */ |
---|
853 | |
---|
854 | {"_point_on_line", _point_on_line, METH_VARARGS, "Print out"}, |
---|
855 | //{"_intersection", _intersection, METH_VARARGS, "Print out"}, |
---|
856 | {"_separate_points_by_polygon", _separate_points_by_polygon, |
---|
857 | METH_VARARGS, "Print out"}, |
---|
858 | {"_interpolate_polyline", _interpolate_polyline, |
---|
859 | METH_VARARGS, "Print out"}, |
---|
860 | {"_is_inside_triangle", _is_inside_triangle, |
---|
861 | METH_VARARGS, "Print out"}, |
---|
862 | {NULL, NULL, 0, NULL} /* sentinel */ |
---|
863 | }; |
---|
864 | |
---|
865 | |
---|
866 | |
---|
867 | // Module initialisation |
---|
868 | void initpolygon_ext(void){ |
---|
869 | Py_InitModule("polygon_ext", MethodTable); |
---|
870 | |
---|
871 | import_array(); //Necessary for handling of NumPY structures |
---|
872 | } |
---|
873 | |
---|
874 | |
---|
875 | |
---|