nx_raster_sw_test.nx

nx_raster_sw_test.nx -- KAT for nx_raster_sw.nx Pineda 1988 edge-function triangle rasterizer. Verifies: T1 signed-area sign convention (positive = front, zero = degenerate, negative = back-facing). T2 edge function on a known directed edge. T3 reference triangle (2,2)(12,2)(2,12) -> exactly 36 pixels covered with strict-interior convention. T4 individual known-in / known-out pixels for the reference triangle. T5 vertex corners themselves are NOT drawn (strict-interior convention; edge function evaluates to zero on vertex). T6 degenerate (collinear) triangle -> 0 pixels written. T7 back-facing (CW; negative area) triangle -> 0 pixels written. T8 triangle fully outside framebuffer -> 0 pixels written; no crash; bounding-box clip is honest. T9 triangle partially outside framebuffer -> only in-bounds pixels written; clipped pixels are silently not drawn (not silently corrupted past the buffer).