Family 7 — the SNES's signature trick. Mode 7 turns one background into a single texture the hardware can rotate, scale and skew per scanline — the floor of F-Zero, the map of Super Mario Kart, the world bending under Pilotwings. It gets its own family because it is a distinct render model with its own matrix API and its own "I want to do THAT" pull.

The ladder

Rung	Example	Developer question
7.1	rotate_scale	How do I rotate and scale a background?
7.2	perspective	How do I fake perspective with an HDMA matrix split (F-Zero floor)?
7.3	perspective_rotate	How do I drive the full matrix (A/B/C/D) per scanline — rotating perspective?

Climb from a flat spinning plane (7.1) to a receding horizon (7.2) to a horizon that also rotates (7.3).

The idea in one screen

A Mode 7 background is one 128×128-tile plane (1024×1024 px) plus a 2×2 affine matrix (M7A–M7D) and a centre of rotation. Set the matrix once and the whole plane rotates/scales (7.1). Rewrite the matrix every scanline with HDMA and each line samples the texture at a different scale, so the plane appears to recede into the distance (7.2 does the diagonal terms; 7.3 drives all four for a horizon that rotates too).

The capstone games live in games/: mode7_racing (F-Zero style) and mode7_flying (Pilotwings style) put this whole family to work.

luna models the Mode 7 PPU natively, so each rung's render is verified by the visual-regression baseline — no emulator side channel needed.

Mode 7 Perspective -- Pseudo-3D Ground Effect Mode 7 rotating perspective — the full matrix, per scanline Mode 7 -- Rotation and Scaling