/**
* Get the Zone under the specified coordinates.
*
* @param x x coordinate of the specified pixel
* @param y y coordinate of the specified pixel
* @return If there is a Zone at the specified coordinates, that zone, otherwise null.
*/
public Zone pick(int x, int y) {
// clamp x and y
if (y >= picking_context.height) y = picking_context.height - 1;
if (x >= picking_context.width) x = picking_context.width - 1;
if (y < 0) y = 0;
if (x < 0) x = 0;
PGL pgl = picking_context.beginPGL();
int pixel;
// force fallback until 2.0b10
if (!SMT.fastPickingEnabled() || pgl == null) {
// really slow way(max 70 fps on a high end card vs 200+ fps with readPixels), with loadPixels
// at the end of render()
pixel = picking_context.pixels[x + y * picking_context.width];
} else {
buffer.clear();
pgl.readPixels(x, picking_context.height - y, 1, 1, GL.GL_RGBA, GL.GL_UNSIGNED_BYTE, buffer);
pixel = buffer.getInt();
}
picking_context.endPGL();
if (zoneMap.containsKey(pixel)) {
// if mapped it is either a Zone or null (background)
Zone picked = zoneMap.get(pixel);
Zone current = picked;
while (current != null) {
if (current.stealChildrensTouch) return current;
current = current.getParent();
}
return picked;
} else return null;
}
/** Prepare the picking graphics context for picking */
public void render() {
// set up for rendering the pick buffer
renderer.pushDelegate(picking_context);
renderer.beginDraw();
renderer.clear();
renderer.ortho();
// render the pick buffer
SMT.getRootZone().invokePickDraw();
renderer.endDraw();
renderer.flush();
// If fast picking disabled, use loadPixels() which is really slow (max 70 fps on a high end
// card vs 200+ fps with readPixels) as a backup.
PGL pgl = renderer.beginPGL();
if (!SMT.fastPickingEnabled() || pgl == null) renderer.loadPixels();
renderer.endPGL();
renderer.popDelegate();
}