JavaScript canvas2d object property: globalCompositeOperation
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The globalCompositeOperation property of
the JavaScript
DOM object returned
by the getContext("2d")
method applied to the HTML <canvas>
element sets / returns how new images are drawn onto existing images.
It can take the following
values:
|
Value
|
Meaning
|
|
copy
|
Source image only
(destination image is ignored)
|
|
destination-atop
|
As per source-atop but
with source and destination flipped
|
|
destination-in
|
As per source-in but
with source and destination flipped
|
|
destination-out
|
As per source-out but
with source and destination flipped
|
|
destination-over
|
As per source-over but
with source and destination flipped
|
|
lighter
|
Source image +
destination image
|
|
source-atop
|
Source image on top of
destination image (part of source image outside destination image is ignored)
|
|
source-in
|
Source image into
destination image (only part of source image inside destination image is
shown, destination image is transparent)
|
|
source-out
|
Source image out of
destination image (only part of source image outside destination image is
shown, destination image is transparent)
|
|
source-over
|
(default). Source image
over destination image
|
|
xor
|
Source and destination
images combined using XOR operation
|
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