mirror of
https://github.com/storytold/vectorcraft.git
synced 2026-10-25 02:07:09 -06:00
dotCooCoo
e22b6a5d45
A knockout group that is not isolated, and whose elements blend, is drawn over a copy of the art below it when the renderer has no layer open around it. Each element was drawn over the whole copy in a layer, and the layer was cut to the element's knockout shape with DestIn. Where the shape covers part of a pixel, the cut counted the element's coverage a second time. With Page Knockout Group on and Page Isolated Blending off, the page is drawn this way as soon as an object on it outside an isolated group has a blend mode other than Normal, on itself or on a fill or stroke. On a test page, adding a Multiply square changed the half-covered edge of a blue square over orange from [115, 115, 141] to [172, 159, 147] on white. Each element is now drawn over the copy offscreen, over its own bounds. With the DestOut pass before it, each pixel gets (1 - shape) times what was below plus shape times the element composited with the copy at a shape of 1, as ISO 32000-1 section 11.4.6 describes. Pixels that the shape covers fully or not at all are drawn as before.