Rotating 8 * 8 isometric checkerboard floor using the trapezoid filler. As it is isometric, rather than perspective, the 64 quads internal angles are all the same and only need to calculated once per frame with double rotation.
This Goboscript program renders a 360-degree yaw rotating 8 * 8 isometric checkerboard floor. The engine transforms a flat floor plane into 2D screen space via isometric projection with a fixed pitch and fills 64 individual trapezoids. Performance Optimizations: -Per-Frame Geometry Caching: Calculates local corner offsets, inner angles, and concentric pen loop ratios just once per frame (CacheTileMath), bypassing heavy trigonometric operations for all 64 individual tiles. -Background Fill Strategy: Renders a single large white trapezoid over the entire 8x8 board first (DrawLargeWhiteBoard), then rasterizes only the 32 black tiles. This cuts overall tile draw operations in half. -Vector Grid Stepping: Iterates through screen positions via simple 2D additions using pre-calculated direction step vectors (stepX, stepZ). - no sorting: the quads on the same plane so no sorting required for the texture. - double rotation: isoProjection computes the angle (anglecos, anglesin) then CacheTileMath applies that rotation to the unrotated trapezoid to generate your static offset points (b1x) and inset vectors (v1x) to ultra low drawCount and reapply rotation in DrawCachedTile. This is faster, as complex math is only done once per frame and can reused across all 64 tiles with fast low drawCount filler.
