/**
* Overlays layers of {@code Sampleable}s with the first element of {@code layers} being on top.
* This method respects the transparency in the alpha component of each layer
*
* @param layers the array of layers
*/
public static Sampleable overlay(Sampleable... layers) {
if (layers.length == 0) {
throw new IllegalArgumentException("Empty array was passed into overlay");
}
if (layers.length == 1) {
return new AbstractSampleable(layers[0].getBoundingBox()) {
@Override
public Color getColorAt(Point<Double> point) {
return layers[0].getColorAt(point);
}
};
}
return overlay(
BoundingBox.containing(layers), layers[layers.length - 1], layers.length - 1, layers);
}
/**
* Overlays several sampleables from top to bottom. This method ignores the alpha channel in the
* sense that it doesn't show lower layers through semi-transparent upper layers.
*
* @param elements the sampleables to overlay, top first
* @return the composed sampleable
*/
public static Sampleable opaqueOverlay(Sampleable... elements) {
return new AbstractSampleable(BoundingBox.containing(elements)) {
@Override
public Color getColorAt(Point<Double> point) {
for (Sampleable element : elements) {
BoundingBox bb = element.getBoundingBox();
if (bb.contains(point)) {
Color color = element.getColorAt(point);
if (!color.isTransparent()) {
return color;
}
}
}
return Colors.TRANSPARENT;
}
};
}