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add offset parameter to pointInPoly

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This commit is contained in:
Hannes Janetzek 2013-04-18 20:20:00 +02:00
parent 5739eb5b93
commit fde9109695
1 changed files with 13 additions and 8 deletions
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21
src/org/oscim/utils/GeometryUtils.java
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@ -313,21 +313,26 @@ public final class GeometryUtils {
}
// from www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/pnpoly.html
public static boolean pointInPoly(int nvert, float[] vert, float testx, float testy) {
int i, j;
/**
* test if point x/y is in polygon defined by vertices[offset ... offset+length]
* */
public static boolean pointInPoly(float x, float y, float[] vertices, int length,
int offset) {
int end = (offset + length);
boolean inside = false;
for (i = 0, j = (nvert - 1) * 2; i < nvert * 2; j = i++) {
if (((vert[i * 2 + 1] > testy) != (vert[j * j + 1] > testy)) &&
(testx < (vert[j * 2] - vert[i * 2])
* (testy - vert[i * 2 + 1])
/ (vert[j * 2 + 1] - vert[i * 2 + 1]) + vert[i * 2]))
for (int i = offset, j = (end - 2); i < end; j = i, i += 2) {
if (((vertices[i + 1] > y) != (vertices[j + 1] > y)) &&
(x < (vertices[j] - vertices[i]) * (y - vertices[i + 1])
/ (vertices[j + 1] - vertices[i + 1]) + vertices[i]))
inside = !inside;
}
return inside;
}
public static float areaSigned(Point p1, Point p2, Point p3) {
return ((p1.x - p3.x) * (p2.y - p3.y) - (p2.x - p3.x) * (p1.y - p3.y))*0.5f;
return ((p1.x - p3.x) * (p2.y - p3.y) - (p2.x - p3.x) * (p1.y - p3.y)) * 0.5f;
}
public static float areaSigned(float ax, float ay, float bx, float by, float cx, float cy) {