def filter.draw.pixel

gralha-svg-render@0.1.0.1 · svg.bend:4789

import Base
import gralha-text-scan@0.1.0.1/scan.bend as U
import gralha-image@0.1.0.1/image.bend as Img

4789def filter.draw.pixel(+format: Raster, +x: U32, +y: U32, op: FilterOp, a: FilterInput, b: FilterInput, +window: FilterWindow, linear: Bool, +aa: U32, span: U32) -> Img.Pixels:
4790  +c = filter.op.sample(op, a, b, raster.position(format, (U32.to_f32(x) + 0.5 : F32), (U32.to_f32(y) + 0.5 : F32)), linear)
4791  # Intermediate offscreens include each pixel intersecting the hard clipping
4792  # region; the final filter region clips by the pixel's covered fraction.
4793  +covered = U.branch(F32, filter.window.exact(window) && filter.window.aligned(window), _ => filter.window.area(window, raster.tile.box(format, x, y, 1)),
4794    _ => (filter.window.samples(U32.to_nat((aa * aa : U32)), 0, aa, window, raster.position(format, U32.to_f32(x), U32.to_f32(y)), (raster.scale(format) / U32.to_f32(aa) : F32), 0.0) / U32.to_f32((aa * aa : U32)) : F32))
4795  Img.Flat{U.branch(Img.Color, U32.is_eq(span, 1), _ => c,
4796    _ => U.choose(Img.Color, filter.window.exact(window), color.fade(c, covered), U.choose(Img.Color, F32.is_gt(covered, 0.0), c, Img.clear())))}