/**
* First Pass: We do sweep and mark of all layers requiring a repaint, the areas behind a visible
* opaque layers need no repaint
*/
private void sweepAndMarkLayers() {
if (CGraphicsQ.DEBUG) {
System.err.println("[Sweep and mark layers]");
}
CLayer l;
CLayerElement changed;
CLayerElement le = layers.getTop();
while (le != null) {
l = le.getLayer();
if (l.visible && l.opaque) {
cleanLowerDirtyRegions(le);
}
// The dirty layer can be invisible, that means it
// has been hidden since the previous paint.
if (l.isDirty()) {
// In the case higher layer was changed we need to
// restart all the algorithm from the changed layer
changed = sweepAndMarkDirtyLayer(le, !l.visible);
if (changed != null) {
if (CGraphicsQ.DEBUG) {
System.err.println("Restart sweep and mark: " + changed.getLayer());
}
le = changed;
changed = null;
continue;
}
}
// Go to next lower layer
le = le.getLower();
}
}
/**
* Copy dirty layer references to array for further painting. The copying is needed to not keep
* lock on layers list when layers painting will happen. Dirty states of the layers are cleaned
* after the copying. Layers painting can change layers state again, but it will be served on next
* repaint only.
*/
private void copyAndCleanDirtyLayers() {
if (CGraphicsQ.DEBUG) {
System.err.println("[Copy dirty layers]");
}
CLayer l;
dirtyCount = 0;
int layersCount = layers.size();
// Heuristics to increase array for copied dirty layers
if (layersCount > dirtyMaxCount) {
dirtyMaxCount += layersCount;
dirtyLayers = new CLayer[dirtyMaxCount];
}
// Copy dirty layer references and reset dirty layer states
for (CLayerElement le = layers.getBottom(); le != null; le = le.getUpper()) {
l = le.getLayer();
if (l.visible && l.isDirty()) {
l.copyAndCleanDirtyState();
dirtyLayers[dirtyCount++] = l;
} else { // !(visible && dirty)
if (CGraphicsQ.DEBUG) {
System.err.println("Skip Layer: " + l);
}
} // if
} // for
}
/**
* Subtract this layer area from an underlying dirty regions. The method is designed to reduce
* dirty regions of a layres below the opaque visible layer.
*
* @param le layer list element
*/
private void cleanLowerDirtyRegions(CLayerElement le) {
if (CGraphicsQ.DEBUG) {
System.err.println("Clean dirty regions under opaque layer: " + le.getLayer());
}
CLayer l = le.getLayer();
for (CLayerElement le2 = le.getLower(); le2 != null; le2 = le2.getLower()) {
CLayer l2 = le2.getLayer();
if (l2.isDirty()) {
l2.subDirtyRegion(
l.bounds[X] - l2.bounds[X], l.bounds[Y] - l2.bounds[Y], l.bounds[W], l.bounds[H]);
}
}
}
