xbzk 73918d23d5 [video_core, maxwell] fixes for homebrew games that use MESA compiler (#4012) ... two main issues: shader_environment.cpp Support Mesa nv50_ir-compiled homebrew fragment shaders Mesa nv50_ir (used by NZP-Switch via libdrm_nouveau) emits Maxwell SASS that differs from NVN in two ways our shader pipeline didn't account for, causing "infinite" loops during shader scanning. How? TryFindSize() previously detected end-of-shader only via NVN's "BRA $-1" self-branch trailer (SELF_BRANCH_A/B). Mesa-compiled shaders end with an unconditional @PT EXIT and emit no trailer, so scanning ran past the shader and looped to MAXIMUM_SIZE. Fix: Added a secondary match against @PT EXIT T (opcode 0xE30, predicate PT, flow T) as a fallback terminator. The mask is estrictive enough to reject predicated EXITs, conditional-flow EXITs, and sched control words, so well-formed NVN shaders see no ehavior change (their single @PT EXIT immediately precedes BRA $-1, and both detections return the same size). load_store_attribute.cpp + attribute.h IPA's is_perspective check only applied the ×position_w correction for IR::IsGeneric() attributes, and used a per-component SPH lookup. Two failure modes followed: 1. Mesa fragment shaders read varyings via legacy attribute slots (ColorFrontDiffuse, FixedFncTexture, FogCoordinate) which are remapped to generic varyings later by ConvertLegacyToGeneric. At IPA-translation time they're still legacy, so IsGeneric() was false and the inject was skipped — but the resulting GLSL/SPIR-V varying was Smooth (perspective-correct), and the SASS still issued its manual perspective dance via MUFU.RCP(ATTR_W)+FMUL, compounding an extra ×clip_w factor. NZP fog (eye_z distance varying) ended up as eye_z⁴×density² instead of eye_z²×density², saturating fog to white everywhere. 2. Even for legacy attrs that should inject, Mesa stores them in two formats selected by the IPA's interpolation_mode field: Pass/Multiply/Constant → attr/w (perspective); inject ×position_w Sc (ScreenLinear) → raw attr; do NOT inject Unconditionally injecting for Sc dims vertex colors by 1/clip_w because there's no SASS multiplier to round-trip it back. Fix: extend the IPA correction path to also fire on IsLegacyAttribute(), gated on interpolation_mode != Sc. While here, the generic-path check is widened from per-component to vector-level (first non-Unused PixelImap, with all-Unused fallthrough treated as Perspective) so it matches the GLSL interpolation qualifier picked by CollectInterpolationInfo — this fixes the same all-zeroed-imap case Mesa exposes for explicit generics. IsLegacyAttribute moved from translate_program.cpp's anonymous namespace into attribute.h next to IsGeneric so IPA can reach it. Tested on NaziZombies:Portable (Switch homebrew): fog now matches real hardware, vertex-colored geometry (hand, gun, decals) renders correctly. Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4012 Reviewed-by: Lizzie <lizzie@eden-emu.dev> Reviewed-by: MaranBr <maranbr@eden-emu.dev>		2026-06-15 03:05:11 +02:00
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ir	[video_core, maxwell] fixes for homebrew games that use MESA compiler (#4012)	2026-06-15 03:05:11 +02:00
maxwell	[video_core, maxwell] fixes for homebrew games that use MESA compiler (#4012)	2026-06-15 03:05:11 +02:00