If the line color image is larger than the screen size (the canvas size), getImageData function returns transparent zero outside the image range, regardless of the actual context.
Possible solution: Scale image to screen size while drawing but remove coordinate scaling in sampling line colors.
If the line color image is larger than the screen size (the canvas size),
getImageDatafunction returns transparent zero outside the image range, regardless of the actual context.Possible solution: Scale image to screen size while drawing but remove coordinate scaling in sampling line colors.