Добавлен TriangleClip
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@ -27,7 +27,7 @@ public class Clip extends Rect {
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public double[] clip(double x1, double y1, double x2, double y2) {
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int c1 = getClipCode(x1, y1);
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int c2 = getClipCode(x2, y2);
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while (c1 != 0 || (c2 != 0)) {
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while (c1 != 0 || c2 != 0) {
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if (c1 == 0 && c2 == 0) {
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return new double[] { x1, y1, x2, y2 };
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}
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@ -66,7 +66,7 @@ public class Clip extends Rect {
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}
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}
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return new double[] { x1, y1, x2, y2 };
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}
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}
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public int getClipCode(double x, double y) {
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int xmin = (x < super.x) ? 1 : 0;
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@ -6,7 +6,7 @@ package com.annimon.graphics;
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*/
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public class Point {
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private double x, y;
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public double x, y;
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public Point() {
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x = y = 0;
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111
src/com/annimon/graphics/TriangleClip.java
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111
src/com/annimon/graphics/TriangleClip.java
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@ -0,0 +1,111 @@
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package com.annimon.graphics;
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/**
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*
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* @author aNNiMON
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*/
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public class TriangleClip extends Clip {
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private Polygon poly;
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public TriangleClip(Point[] points) {
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super(0, 0, 0, 0);
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poly = new Polygon(points);
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}
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@Override
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public double[] clip(double x1, double y1, double x2, double y2) {
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return clipCyrusBeck(new Point(x1, y1), new Point(x2, y2), calcNormals(poly, poly.v));
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}
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private Point[] calcNormals(Polygon p, Point[] n) {
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Point v = new Point();
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for (int i = 0; i < p.nPoints; i++) {
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int j = (i+1) % p.nPoints;
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int k = (i+2) % p.nPoints;
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// make vector be -1/mI + 1J
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n[i].setX( -(p.v[j].getY() - p.v[i].getY()) / (p.v[j].getX() - p.v[i].getX()) );
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n[i].setY(1.0);
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v.setX( p.v[k].getX() - p.v[i].getX() );
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v.setY( p.v[k].getY() - p.v[i].getY() );
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if (pointProduction(n[i], v) > 0) {
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// inner normal
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n[i].setX(n[i].getX() * -1);
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n[i].setY(n[i].getY() * -1);
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}
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}
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return n;
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}
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private double pointProduction(Point v1, Point v2) {
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return v1.getX() * v2.getX() + v1.getY() * v2.getY();
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}
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private double[] clipCyrusBeck(Point p1, Point p2, Point[] n) {
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double t,num,den;
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// vectors
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Point dirV = new Point();
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Point F = new Point();
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// start largest at smallest legal value and smallest
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// at largest legal value
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double t1 = 0.0;
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double t2 = 1.0;
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// compute the direction vector
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dirV.x = p2.x - p1.x;
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dirV.y = p2.y - p1.y;
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boolean visible = true;
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int i = 0;
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while ((i < poly.nPoints) && visible) {
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F.x = p1.x - poly.v[i].x;
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F.y = p1.y - poly.v[i].y;
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num = pointProduction(n[i], F);
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den = pointProduction(n[i], dirV);
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// Parallel or Point
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if (den == 0.0) {
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// parallel - if outside then forget the line; if inside then there are no
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// intersections with this side
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// but there may be with other edges, so in this case just keep going
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if (num > 0.0) {
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// Parallel and outside or point (p1 == p2) and outside
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visible = false;
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}
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} else {
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t = -(num/den);
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if (den < 0.0) {
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// entering
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if (t <= 1.0 && t > t1) t1 = t;
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} else if ( t >= 0.0 && t < t2) t2 = t;
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}
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i++;
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}
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/*if (t1 <= t2) {
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return new double[] {
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p1.x + t1*dirV.x,
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p1.y + t1*dirV.y,
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p1.x + t2*dirV.x,
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p1.y + t2*dirV.y
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};
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} else visible = false;*/
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return new double[] {
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p1.x + t1*dirV.x,
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p1.y + t1*dirV.y,
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p1.x + t2*dirV.x,
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p1.y + t2*dirV.y
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};
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}
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private class Polygon {
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int nPoints;
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Point[] v;
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public Polygon(Point[] points) {
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this.v = points;
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nPoints = points.length;
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}
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}
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}
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