ProsperoPuzzles (PPSA99006) on Windows / NVIDIA: MSAA blockers

[AchrafReyani]

Title: ProsperoPuzzles, PPSA99006, 01.000.010 (open-source homebrew: blackbearreloaded/ProsperoPuzzles, GPL-3.0; renders through blackbearreloaded/ps5-opengl, Mesa gallium on AGC)
Host: Windows 11 (26200), RTX 4070 Laptop (NVIDIA 616.92), WinLibs GCC 15.2.0 r7, Release. Catalog build: eboot.bin and sce_module/libc.prx unwrapped, relinked with --windows, 60 s runs.

Updated 2026-10-12.

On main 9bc3623 it starts, opens its window and stops at its first draw into its 4x color target:

  what():  AGC graphics: a color target's sample count differs from the rasterizer's

That draw scans one sample per pixel (PA_SC_AA_CONFIG 0, MSAA_ENABLE off) into a 4-sample, 4-fragment target (CB_COLOR0_ATTRIB 0x00012000) with no depth: GL rendering with multisampling disabled on a multisampled framebuffer.

Open pull requests it needs, in order:

1. fix(agc): rasterize a single-sample scan into a multisampled target at the pixel center #4414: rasterize that single-sample scan at the target's sample count with every sample at the pixel center (what radeonsi programs for disabled GL multisampling). With it the title gets one draw further.
2. AGC: sampled 2D MSAA image has no descriptor shape (PPSA99902 conditional startup) #3036 (issue; Amoenus has a fork implementation): the next draw samples that 4x image, DescriptorBindingBuilder::Populate multisampled image resources have no descriptor image shape.

Before #419 it stopped earlier, at color samples, fragments or destination alpha override is unsupported (register 0x31d = 0x00012000).

[LeandroLP23]

Update 2026-10-13: #4820 (@nicolasabosch) gets ProsperoPuzzles past the MSAA stop. Windows 11 (26300), AMD Radeon 860M (driver 32.0.13058.8001), WinLibs GCC 15.2.0, Release, relinked with --windows --trap-sdk-syscall-stubs, 60 s runs:

Build	Result
main 9ba9ac1c8	DescriptorBindingBuilder::Populate multisampled image resources have no descriptor image shape, exit after 15 s
main + #4820	runs the full 60 s, ProsperoPuzzles | FPS: 13.18

ctest -R '^agc_' -j 1 is 461/461 with #4820 on that GPU. Open pull request it needs: #4820.

AI-assisted: yes (Claude Code)