Destination Processing

DstMode selects the source/destination Boolean ALU function, blend factors, Z comparison, fog, dithering and transparency rejection. DstFmt selects 8-bit 332/intensity/alpha, 16-bit 565/4444/1555 or 32-bit 8888 output. DstBGR selects red rather than blue in the least significant destination bits.

The Pixel Engine reads destination data when the plane mask, ALU function or blend factors need it, unless DstRdDisable is set. If a destination result equals the value read, the write is omitted. If destination data was not read, the result is written.

DstRdDisable substitutes DstColor for memory destination data. Write DstColor after entering this mode. Any destination read destroys its stored value. DstBGR does not swap DstColor in this mode.

PMask enables output planes bit by bit and must be replicated across 32 bits for 8- or 16-bit pixels. PMask is applied after PickHit determination.

ZBufMode selects always, less, equal, less/equal, greater, not-equal, greater/equal or never. Always and never do not read Z. ZBufWrMode enables Z writes when the Z test passes. An equal Z value is not rewritten after a Z read.

SrcMode.ZScissorEn also rejects Z overflow independently of the Z-buffer mode. Overflow is computed when Z is written:

ZOvf = ((Z & 0xF8000000) != 0) && ZScissorEn

Write a new Z value after clearing ZScissorEn to clear the stored overflow condition.

TranspReject rejects texture-unit alpha ≤ AlphaThres, whether or not destination data is read. The spr summary calls this destination alpha; the detailed DstMode table explicitly describes texture-unit output alpha.

FogEnable blends source color toward FogColor. Fog factor zero produces full fog and 255 produces no fog. The source equation is NewColor = f × (SrcColor − FogColor) + FogColor.

SrcMode.SpecularEn enables specular color addition for Triangle Engine primitives. It does not apply to compatibility draw/rdraw. YUV2RGB reuses blend hardware, so normal blending and fog are unavailable during conversion.

Dither · Color conversion · Pick

Sources: Technical Spec, p.29, Technical Spec, p.30, Technical Spec, p.32, Technical Spec, p.33, Technical Spec, p.34, Technical Spec, p.35, Technical Spec, p.36, Technical Spec, p.37