java - What is the best way to read pixels of a JavaFX Canvas? -


i want color specific coordinates inside canvas. tried getting snapshot using code:

writableimage snap = gc.getcanvas().snapshot(null, null); snap.getpixelreader().getargb(x, y); //this gets color without assigning it.

but takes time application. wondering if there other way access color of pixel know coordinates.

a canvas buffers drawing instructions prescribed invoking methods of graphicscontext. there are no pixels read until canvas rendered in later pulse, , internal format of instruction buffer not exposed in api.

as alternative, consider drawing bufferedimage, illustrated here, allows access image's pixels directly , via writableraster. adding following line complete example outputs expected value opaque red in argb order: ffff0000.

system.out.println(integer.tohexstring(bi.getrgb(50, 550)));

image


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