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Test copy filter with depth copies using Z-textures
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Phire suggested this.  Z pokes don't work properly for some reason, but we can write arbitrary values to the Z buffer by writing to the color buffer, then performing an EFB copy, then using that EFB copy as a texture with the Z-texture functionality enabled.
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@Pokechu22
Pokechu22 committed Apr 23, 2022
1 parent 6e36e41 commit 71f9782
Showing 1 changed file with 132 additions and 12 deletions.
144 changes: 132 additions & 12 deletions gxtest/copyfilter.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -56,9 +56,10 @@ GXTest::Vec4<u8> GenerateEFBColor(u16 x, u16 y)
return {r, g, b, a};
}

u32 GenerateEFBDepth([[maybe_unused]] u16 x, u16 y)
static u32 GenerateEFBDepth(u16 x, u16 y)
{
return y < 4 ? 0x123456 : 0x789abc;
auto color = GenerateEFBColor(x, y);
return (u32(color.r) << 16) | (u32(color.g) << 8) | color.b;
}

static void SetPixelFormat(PixelFormat pixel_fmt)
Expand All @@ -72,24 +73,23 @@ static void SetPixelFormat(PixelFormat pixel_fmt)

static void FillEFB(PixelFormat pixel_fmt)
{
SetPixelFormat(pixel_fmt);
CGX_WaitForGpuToFinish();
// Don't set the format to Z24 here since we need RGB8 for our EFB copy+z-texture hack below
SetPixelFormat(pixel_fmt == PixelFormat::Z24 ? PixelFormat::RGB8_Z24 : pixel_fmt);

ZMode zmode{.hex = BPMEM_ZMODE << 24};
zmode.testenable = true;
zmode.func = CompareMode::Always;
zmode.updateenable = true;
CGX_LOAD_BP_REG(zmode.hex);

// Needed for clear to work properly. GX_CopyTex ors with 0xf, but the top bit indicating update also must be set
CGX_LOAD_BP_REG(BPMEM_ZMODE << 24 | 0x1f);
CGX_LOAD_BP_REG(BPMEM_CLEAR_Z << 24 | 0x123456);
// For some reason, Z isn't cleared properly if the height isn't set to 4 (3 inclusive)
GXTest::CopyToTestBuffer(0, 0, 255, 3, {.clear = true});
CGX_LOAD_BP_REG(BPMEM_CLEAR_Z << 24 | 0x789abc);
GXTest::CopyToTestBuffer(0, 4, 255, 7, {.clear = true});
CGX_WaitForGpuToFinish();

CGX_PEPokeDither(false);
CGX_PEPokeAlphaUpdate(true);
CGX_PEPokeColorUpdate(true);
CGX_PEPokeBlendMode(GX_BM_NONE, SrcBlendFactor::Zero, DstBlendFactor::Zero, LogicOp::Set);
CGX_PEPokeAlphaRead(GX_READ_NONE);
CGX_PEPokeZMode(false, CompareMode::Always, true);
CGX_PEPokeZMode(true, CompareMode::Always, true);

// For some reason GX_PokeARGB hangs when using this format
if (pixel_fmt == PixelFormat::RGB565_Z16)
Expand All @@ -104,6 +104,126 @@ static void FillEFB(PixelFormat pixel_fmt)
// CGX_PokeZ(x, y, GenerateEFBDepth(x, y), pixel_fmt);
}
}

if (pixel_fmt == PixelFormat::Z24)
{
// HACK: Since GX_PokeZ doesn't seem to work, we instead use an EFB copy and then
// draw over it using the z-texture feature to set the depth buffer.
SetCopyFilter(0, 64, 0);
// This value should be overridden, but it's recognizable if it shows up
CGX_LOAD_BP_REG(BPMEM_CLEAR_Z << 24 | 123456);
GXTest::CopyToTestBuffer(0, 0, 255, 7, {.clear = true});
GX_InvalidateTexAll();

AlphaTest alpha{.hex = BPMEM_ALPHACOMPARE << 24};
alpha.comp0 = CompareMode::Always;
alpha.comp1 = CompareMode::Always;
alpha.logic = AlphaTestOp::Or;
CGX_LOAD_BP_REG(alpha.hex);

GenMode genmode{.hex = BPMEM_GENMODE << 24};
genmode.numtexgens = 1;
genmode.numtevstages = 1 - 1;
CGX_LOAD_BP_REG(genmode.hex);

BlendMode blend{.hex = BPMEM_BLENDMODE << 24};
blend.colorupdate = true;
blend.alphaupdate = false;
CGX_LOAD_BP_REG(blend.hex);

CGX_BEGIN_LOAD_XF_REGS(0x1008, 1); // XFMEM_VTXSPECS
wgPipe->U32 = 1<<4; // 1 texture coordinate
CGX_BEGIN_LOAD_XF_REGS(0x1009, 1); // XFMEM_SETNUMCHAN
wgPipe->U32 = 0;
CGX_BEGIN_LOAD_XF_REGS(0x103f, 1); // XFMEM_SETNUMTEXGENS
wgPipe->U32 = 1;
CGX_BEGIN_LOAD_XF_REGS(0x1040, 1); // XFMEM_SETTEXMTXINFO
wgPipe->U32 = 0x280; // regular texgen for tex0

CGX_LOAD_BP_REG(BPMEM_TX_SETMODE0 << 24);
CGX_LOAD_BP_REG(BPMEM_TX_SETMODE1 << 24);
TexImage0 ti0{.hex = BPMEM_TX_SETIMAGE0 << 24};
ti0.width = 256 - 1;
ti0.height = 8 - 1;
ti0.format = TextureFormat::RGBA8;
CGX_LOAD_BP_REG(ti0.hex);
// Assume that TexImage1 and TexImage2 (tmem-related)
// are set properly by libogc's init
TexImage3 ti3{.hex = BPMEM_TX_SETIMAGE3 << 24};
ti3.image_base = MEM_VIRTUAL_TO_PHYSICAL(GXTest::test_buffer) >> 5;
CGX_LOAD_BP_REG(ti3.hex);

CGX_LOAD_BP_REG(BPMEM_BIAS << 24); // ztex bias is 0
ZTex2 ztex2{.hex = BPMEM_ZTEX2 << 24};
ztex2.type = ZTexFormat::U24;
ztex2.op = ZTexOp::Replace;
CGX_LOAD_BP_REG(ztex2.hex);

TwoTevStageOrders tref{.hex = BPMEM_TREF << 24};
tref.texmap0 = 0;
tref.texcoord0 = 0;
tref.enable0 = true;
CGX_LOAD_BP_REG(tref.hex);

TCInfo tc_s{.hex = BPMEM_SU_SSIZE << 24};
tc_s.scale_minus_1 = 256 - 1;
CGX_LOAD_BP_REG(tc_s.hex);
TCInfo tc_t{.hex = BPMEM_SU_TSIZE << 24};
tc_t.scale_minus_1 = 8 - 1;
CGX_LOAD_BP_REG(tc_t.hex);

// We don't care about the actual result here
auto tev = CGXDefault<TevStageCombiner::ColorCombiner>(0);
tev.d = TevColorArg::Half;
CGX_LOAD_BP_REG(tev.hex);

CGX_SetViewport(0.0f, 0.0f, 256.0f, 8.0f, 0.0f, 1.0f);

// Set the vertex format...
CGX_LOAD_CP_REG(0x50, VTXATTR_DIRECT << 9); // VCD_LO: direct position only
CGX_LOAD_CP_REG(0x60, VTXATTR_DIRECT << 0); // VCD_HI: direct texcoord0 only
UVAT_group0 vat0{.Hex = 0};
// NOTE: Using XY results in things not working for some reason.
// We need to supply a Z-value, even if it's not relevant for the final result.
vat0.PosElements = VA_TYPE_POS_XYZ;
vat0.PosFormat = VA_FMT_S8;
vat0.Tex0CoordElements = VA_TYPE_TEX_ST;
vat0.Tex0CoordFormat = VA_FMT_U8;
CGX_LOAD_CP_REG(0x70, vat0.Hex);
CGX_LOAD_CP_REG(0x80, 0x80000000); // CP_VAT_REG_B: vcache enhance only
CGX_LOAD_CP_REG(0x90, 0); // CP_VAT_REG_C

// Actually draw the vertices
GX_Begin(GX_QUADS, GX_VTXFMT0, 4);
wgPipe->S8 = -1;
wgPipe->S8 = -1;
wgPipe->S8 = 1;
wgPipe->U8 = 0;
wgPipe->U8 = 1;

wgPipe->S8 = -1;
wgPipe->S8 = +1;
wgPipe->S8 = 1;
wgPipe->U8 = 0;
wgPipe->U8 = 0;

wgPipe->S8 = +1;
wgPipe->S8 = +1;
wgPipe->S8 = 1;
wgPipe->U8 = 1;
wgPipe->U8 = 0;

wgPipe->S8 = +1;
wgPipe->S8 = -1;
wgPipe->S8 = 1;
wgPipe->U8 = 1;
wgPipe->U8 = 1;
GX_End();

CGX_WaitForGpuToFinish();

SetPixelFormat(pixel_fmt);
}
}

#if FULL_GAMMA
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