public Raster getRaster(int x, int y, int w, int h) {
WritableRaster rast = cm.createCompatibleWritableRaster(w, h);
int[] buf = rast.getDataBuffer();
int c = x * dy - y * dx - delta;
int cx = dy;
int cy = -w * dy - dx;
int k = 0;
if (cyclic) {
for (int j = 0; j < h; j++) {
for (int i = 0; i < w; i++) {
buf[k++] = table[(c >> 8) & LOOKUP_MASK];
c += cx;
}
c += cy;
}
} else {
for (int j = 0; j < h; j++) {
for (int i = 0; i < w; i++) {
int index = c >> 8;
buf[k++] = index < 0 ? c1 : index >= LOOKUP_SIZE ? c2 : table[index];
c += cx;
}
c += cy;
}
}
return rast;
}
/**
* Constructs a new GradientPaintcontext
*
* @param cm - not used
* @param t - the fill transformation
* @param point1 - the start fill point
* @param color1 - color of the start point
* @param point2 - the end fill point
* @param color2 - color of the end point
* @param cyclic - the indicator of cycle filling
*/
GradientPaintContext(
ColorModel cm,
AffineTransform t,
Point2D point1,
Color color1,
Point2D point2,
Color color2,
boolean cyclic) {
this.cyclic = cyclic;
this.cm = ColorModel.getRGBdefault();
c1 = color1.getRGB();
c2 = color2.getRGB();
double px = point2.getX() - point1.getX();
double py = point2.getY() - point1.getY();
Point2D p = t.transform(point1, null);
Point2D bx = new Point2D.Double(px, py);
Point2D by = new Point2D.Double(py, -px);
t.deltaTransform(bx, bx);
t.deltaTransform(by, by);
double vec = bx.getX() * by.getY() - bx.getY() * by.getX();
if (Math.abs(vec) < ZERO) {
dx = dy = delta = 0;
table = new int[1];
table[0] = c1;
} else {
double mult = LOOKUP_SIZE * 256 / vec;
dx = (int) (by.getX() * mult);
dy = (int) (by.getY() * mult);
delta = (int) ((p.getX() * by.getY() - p.getY() * by.getX()) * mult);
createTable();
}
}