The software renderer kept depth linear in VRAM, where the GE stores it
in the layout GPU/Common/DepthSwizzle.h describes, from the EDRAM address
translation and the color format. So a texture or anything else sharing
VRAM with a depth buffer saw depth land in the wrong places (the player's
shadow in Silent Hill: Origins, #22415). Now every depth access goes
through the layout: the generic pixel functions, the 2x2 depth test, the
depth clear in 16-pixel runs, and the x86 pixel JIT, whose IDs carry the
translation so the layout's constants are compiled in. It changes with
the color format and sceGeEdramSetAddrTranslation, after a flush.
Reading VRAM through its 0x04200000 and 0x04600000 mirrors undoes the
layout, as the GE does: texturing from them (drawn from a linear copy
made after a flush), and block transfers from or to them (Hayate no
Gotoku restores its depth buffer through 0x04600000, #17878). Saved and
debugger depth buffers read through the layout, so they're linear.
Socom's lens flare dump now matches a PSP replay where it changes. About
2-3% more cycles in God of War, Tekken 6, Wipeout and Burnout.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
The x86 sampler JIT returned zero for a whole sample when a texture level
pointer was null, and for a mipmapped texture it checked the next level
too, even when it isn't blended in. Tactics Ogre draws its font from a
mipmapped texture whose next level has an invalid address, at level 0,
so all its text was missing on x86-64. The generic samplers read a null
level's texels as zero only where they use that level, and still apply
the texture function. Now samplers for such textures aren't compiled,
and the JIT's null checks are gone. Test: gpu/textures/mipinvalid.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
* samplerjit: Remove unused x/y parameters.
Still need to tune the accuracy of filtering, but those were not the
right way.
* softgpu: Better approximate slope mip level mode.
This isn't exactly right, but it's closer.
* softgpu: Calculate auto from largest difference.
Direction shouldn't matter.
