tag

#gba

4 posts

RetrogamingDeep Dive October 4, 2026 10 min read

GBA Affine Backgrounds: Fixed-Point Matrices and Scanline Reference Accumulators

Implement Game Boy Advance affine backgrounds correctly: 8.8 transform steps, signed reference points, per-scanline accumulators, pivots, and wrap behavior.

#game-boy-advance#gba#affine

RetrogamingDeep Dive October 4, 2026 8 min read

Game Boy Advance Affine OBJ: OAM Matrix Slots, Fixed-Point Mapping, and Double Size

Decode GBA affine OBJ state across OAM attributes and interleaved PA/PB/PC/PD slots, then map pixels with signed 8.8 coefficients.

#game-boy-advance#gba#obj

RetrogamingDeep Dive October 4, 2026 10 min read

Game Boy Advance Windows and Blending: Layer Masks, Priority, and Pixel Rules

Build accurate GBA window and color-effect logic: decode WININ/WINOUT masks, region priority, exclusive bounds, alpha weights, and emulator tests.

#game-boy-advance#gba#graphics

RetrogamingDeep Dive October 3, 2026 8 min read

Game Boy Advance DMA: Channel Priority, Trigger Timing, and Sound FIFOs

Configure GBA DMA with correct channel priority, immediate and video triggers, address modes, sound FIFO bursts, and measurable emulator tests.

#gba#dma#memory