3D: in Z-buffering mode, margin for 'equal' depth test mode is +-0x200, not +-0xFF

fixes #274
This commit is contained in:
StapleButter 2018-12-13 22:46:12 +01:00
parent 32392cc8e2
commit 68d5e3c782
1 changed files with 17 additions and 4 deletions

View File

@ -769,11 +769,24 @@ void TextureLookup(u32 texparam, u32 texpal, s16 s, s16 t, u16* color, u8* alpha
// depth test is 'less or equal' instead of 'less than' under the following conditions:
// * when drawing a front-facing pixel over an opaque back-facing pixel
// * when drawing wireframe edges, under certain conditions (TODO)
//
// range is different based on depth-buffering mode
// Z-buffering: +-0x200
// W-buffering: +-0xFF
bool DepthTest_Equal(s32 dstz, s32 z, u32 dstattr)
bool DepthTest_Equal_Z(s32 dstz, s32 z, u32 dstattr)
{
s32 diff = dstz - z;
if ((u32)(diff + 0xFF) <= 0x1FE) // range is +-0xFF
if ((u32)(diff + 0x200) <= 0x400)
return true;
return false;
}
bool DepthTest_Equal_W(s32 dstz, s32 z, u32 dstattr)
{
s32 diff = dstz - z;
if ((u32)(diff + 0xFF) <= 0x1FE)
return true;
return false;
@ -1099,7 +1112,7 @@ void RenderShadowMaskScanline(RendererPolygon* rp, s32 y)
bool (*fnDepthTest)(s32 dstz, s32 z, u32 dstattr);
if (polygon->Attr & (1<<14))
fnDepthTest = DepthTest_Equal;
fnDepthTest = polygon->WBuffer ? DepthTest_Equal_W : DepthTest_Equal_Z;
else if (polygon->FacingView)
fnDepthTest = DepthTest_LessThan_FrontFacing;
else
@ -1312,7 +1325,7 @@ void RenderPolygonScanline(RendererPolygon* rp, s32 y)
bool (*fnDepthTest)(s32 dstz, s32 z, u32 dstattr);
if (polygon->Attr & (1<<14))
fnDepthTest = DepthTest_Equal;
fnDepthTest = polygon->WBuffer ? DepthTest_Equal_W : DepthTest_Equal_Z;
else if (polygon->FacingView)
fnDepthTest = DepthTest_LessThan_FrontFacing;
else