Contents

minimumTileExtendRect(forTileRect:sourceRGBASize:)

Returns the minimum source rect that must be sampled to render tileRect without edge artifacts.

Declaration

class func minimumTileExtendRect(forTileRect tileRect: CGRect, sourceRGBASize: CGSize) -> CGRect

Parameters

  • tileRect:

    The destination tile rect in full-image pixel coordinates.

  • sourceRGBASize:

    The dimensions of the full (un-tiled) source image.

Return Value

A rect (in full-image pixel coordinates) covering the minimum required source region, clamped to the image bounds.

Discussion

When applying a bokeh blur near a tile boundary, the renderer needs pixels from outside the destination tile. This method computes how far that border region extends. Pass the returned rect’s origin as tileExtendOffset and allocate sourceTileRGBA with the returned rect’s size.