FilterGraph Class

The primitives are computed in order. Each one reads its inputs (FilterInput: by default the result of the primitive before it, or the drawing for the first one) and computes its result in its subregion (FilterPrimitive.Subregion), transparent outside it. The result of the last primitive is the result of the filter, and nothing is drawn outside FilterGraph.Region.

Each primitive computes with the colors of its FilterPrimitive.ColorSpace (color-interpolation-filters): by default, as in SVG, in linear light, the inputs decoded by the transfer function of sRGB and the result encoded again, evaluated without any function of the platform (within a few units in the last place of double precision of the exact function, so the same values on every platform). A primitive that only moves or copies pixels (OffsetPrimitive, TilePrimitive) or makes a color (FloodPrimitive) gives the same pixels in both, and converts nothing.

The rectangles of the graph are in the coordinates of the drawing: a subregion is the set of pixels whose center is in the box of the image of its rectangle on the canvas. The inputs BackgroundImage, BackgroundAlpha, FillPaint and StrokePaint of SVG are not supported.