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undo everything

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Jaklyy 2024-08-16 20:11:59 -04:00
parent f8589d5566
commit f79eb72ca5
1 changed files with 33 additions and 34 deletions
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65
src/GPU3D.cpp
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@ -965,51 +965,50 @@ void GPU3D::SubmitPolygon() noexcept
VertexSlotCounter = 1; VertexSlotCounter = 1;
VertexSlotsFree = 0b11110; VertexSlotsFree = 0b11110;
// determine polygon facing direction // culling
// TODO: work out how it works on the real thing
// the normalization part is a wild guess
Vertex *v0, *v1, *v2, *v3; Vertex *v0, *v1, *v2, *v3;
s64 normalX, normalY, normalZ;
s64 dot;
v0 = &TempVertexBuffer[0]; v0 = &TempVertexBuffer[0];
v1 = &TempVertexBuffer[1]; v1 = &TempVertexBuffer[1];
v2 = &TempVertexBuffer[2]; v2 = &TempVertexBuffer[2];
v3 = &TempVertexBuffer[3]; v3 = &TempVertexBuffer[3];
s32 vector[6]; normalX = ((s64)(v0->Position[1]-v1->Position[1]) * (v2->Position[3]-v1->Position[3]))
vector[0] = v0->Position[0] - v2->Position[0]; - ((s64)(v0->Position[3]-v1->Position[3]) * (v2->Position[1]-v1->Position[1]));
vector[1] = v0->Position[1] - v2->Position[1]; normalY = ((s64)(v0->Position[3]-v1->Position[3]) * (v2->Position[0]-v1->Position[0]))
vector[2] = v0->Position[3] - v2->Position[3]; - ((s64)(v0->Position[0]-v1->Position[0]) * (v2->Position[3]-v1->Position[3]));
vector[3] = v1->Position[0] - v2->Position[0]; normalZ = ((s64)(v0->Position[0]-v1->Position[0]) * (v2->Position[1]-v1->Position[1]))
vector[4] = v1->Position[1] - v2->Position[1]; - ((s64)(v0->Position[1]-v1->Position[1]) * (v2->Position[0]-v1->Position[0]));
vector[5] = v1->Position[3] - v2->Position[3];
bool facingview; while ((((normalX>>31) ^ (normalX>>63)) != 0) ||
if ((vector[0] | vector[1] | vector[2]) == 0 || (vector[3] | vector[4] | vector[5]) == 0) [[unlikely]] // if either vector is 0 the polygon is accepted and treated as front facing. (((normalY>>31) ^ (normalY>>63)) != 0) ||
(((normalZ>>31) ^ (normalZ>>63)) != 0))
{ {
facingview = true; normalX >>= 4;
normalY >>= 4;
normalZ >>= 4;
} }
else
dot = ((s64)v1->Position[0] * normalX) + ((s64)v1->Position[1] * normalY) + ((s64)v1->Position[3] * normalZ);
bool facingview = (dot <= 0);
if (dot < 0)
{ {
// calculate z component of cross product if (!(CurPolygonAttr & (1<<7)))
s64 crossx = ((s64)vector[1] * vector[5]) - ((s64)vector[2] * vector[4]); {
s64 crossy = ((s64)vector[2] * vector[3]) - ((s64)vector[0] * vector[5]); LastStripPolygon = NULL;
s64 crossz = ((s64)vector[0] * vector[4]) - ((s64)vector[1] * vector[3]); return;
}
crossx *= v2->Position[0]; }
crossy *= v2->Position[1]; else if (dot > 0)
crossz *= v2->Position[3]; {
if (!(CurPolygonAttr & (1<<6)))
s64 dot = crossx + crossy + crossz;
// set a flag for the rasterizer used for:
// unwinding vertices
// determining whether slopes are swapped
// the less than depth test's == special case
facingview = (dot >= 0);
// cull polygon if corresponding render flag isn't set
if (((dot >= 0) && (CurPolygonAttr & (1<<7))) || // front facing
((dot <= 0) && (CurPolygonAttr & (1<<6)))); // back facing
else
{ {
LastStripPolygon = NULL; LastStripPolygon = NULL;
return; return;