Hardware Heritage
Mode 7 is a graphics mode on the Super NES that allows for the rotation and scaling of a background layer in real-time. By applying an affine transformation to each scanline, it creates a 2.5D perspective effect that revolutionized racing games and flight simulators in the early 90s.
PC Origin
On the PC, this was known as a "Scanline Raycaster." It was the engine behind games like Doom (for floors) and racing games. It required calculating texture scale per-scanline.
Amiga Copper
Amiga coders simulated Mode 7 by using the Copper to change hardware scroll registers on every line. It was "free" in terms of CPU usage.
SNES Hardware
"Mode 7" is an SNES term. The console had a dedicated hardware matrix multiplier that could rotate and scale background layers in real-time.
Mode 7 Floor
The 2.5D floor effect that revolutionized console gaming.
Legacy SNES
; HDMA register updates LDA #$01 STA $211B ; Matrix A (Scale X) STA $211C ; Matrix B (Rotation)
Modern GLSL
float z = horizon / abs(p.y); vec2 floorUV = vec2(p.x * z, z); col = texture(groundTex, floorUV).rgb;