Java Games Continued: Fun with Polygons - Pro Android Games - page 87

this.npoints = npoints;
this.xpoints = new int[npoints];
this.ypoints = new int[npoints];
System.arraycopy(xpoints, 0, this.xpoints, 0, npoints);
System.arraycopy(ypoints, 0, this.ypoints, 0, npoints);
}
void calculateBounds(int xpoints[], int ypoints[], int npoints) {
int boundsMinX = Integer.MAX_VALUE;
int boundsMinY = Integer.MAX_VALUE;
int boundsMaxX = Integer.MIN_VALUE;
int boundsMaxY = Integer.MIN_VALUE;
for (int i = 0; i < npoints; i++) {
int x = xpoints[i];
boundsMinX = Math.min(boundsMinX, x);
boundsMaxX = Math.max(boundsMaxX, x);
int y = ypoints[i];
boundsMinY = Math.min(boundsMinY, y);
boundsMaxY = Math.max(boundsMaxY, y);
}
bounds = new Rectangle(boundsMinX, boundsMinY, boundsMaxX
- boundsMinX, boundsMaxY - boundsMinY);
}
public void reset() {
npoints = 0;
bounds = null;
}
/**
* Appends the specified coordinates to this <code>Polygon</code>.
*
* @param x
* @param y
*/
public void addPoint(int x, int y) {
if (npoints == xpoints.length) {
int tmp[];
tmp = new int[npoints * 2];
System.arraycopy(xpoints, 0, tmp, 0, npoints);
xpoints = tmp;
tmp = new int[npoints * 2];
System.arraycopy(ypoints, 0, tmp, 0, npoints);
ypoints = tmp;
}
xpoints[npoints] = x;
ypoints[npoints] = y;