Canvas Pocket Reference

Name

CRC.putImageData() — copies pixels from an ImageData into the canvas

Synopsis

void putImageData(ImageData data, float dx, float dy, 
                  float sx, float sy, float sw, float sh)

Arguments

data

An ImageData object.

dx, dy

The coordinates of a destination point in the canvas. Pixels from data will be copied to the canvas starting at this point. These arguments are not transformed by the current transformation matrix.

sx, sy, sw, sh

These optional arguments specify a source rectangle within the ImageData. If specified, only the pixels within that rectangle will be copied to the canvas. If omitted, all pixels in the ImageData will be copied. If these arguments specify a rectangle that exceeds the bounds of the ImageData, the rectangle will be clipped to those bounds. Negative values for sx and sy are allowed.

Description

putImageData() copies a rectangular block of pixels from an ImageData object onto the canvas. This is a low-level pixel copy operation: the globalCompositeOperation and globalAlpha attributes are ignored as are the clipping region, transformation matrix, and shadow-drawing attributes.

One use for ImageData objects is as a “backing store” for a canvas—saving a copy of the canvas pixels in an ImageData object (using getImageData()) allows you to draw temporarily on the canvas and then restore it to its original state with putImageData().

See Also

CRC.createImageData(), CRC.getImageData(), ImageData