Pica/Rasterizer: Clean up and fix backface culling.
This commit is contained in:
parent
365236fa4c
commit
638b370fb5
|
@ -90,9 +90,14 @@ static int SignedArea (const Math::Vec2<Fix12P4>& vtx1,
|
|||
return Math::Cross(vec1, vec2).z;
|
||||
};
|
||||
|
||||
void ProcessTriangle(const VertexShader::OutputVertex& v0,
|
||||
const VertexShader::OutputVertex& v1,
|
||||
const VertexShader::OutputVertex& v2)
|
||||
/**
|
||||
* Helper function for ProcessTriangle with the "reversed" flag to allow for implementing
|
||||
* culling via recursion.
|
||||
*/
|
||||
static void ProcessTriangleInternal(const VertexShader::OutputVertex& v0,
|
||||
const VertexShader::OutputVertex& v1,
|
||||
const VertexShader::OutputVertex& v2,
|
||||
bool reversed = false)
|
||||
{
|
||||
// vertex positions in rasterizer coordinates
|
||||
auto FloatToFix = [](float24 flt) {
|
||||
|
@ -106,17 +111,22 @@ void ProcessTriangle(const VertexShader::OutputVertex& v0,
|
|||
ScreenToRasterizerCoordinates(v1.screenpos),
|
||||
ScreenToRasterizerCoordinates(v2.screenpos) };
|
||||
|
||||
if (registers.cull_mode == Regs::CullMode::KeepCounterClockWise) {
|
||||
// Reverse vertex order and use the CW code path.
|
||||
std::swap(vtxpos[1], vtxpos[2]);
|
||||
}
|
||||
if (registers.cull_mode == Regs::CullMode::KeepAll) {
|
||||
// Make sure we always end up with a triangle wound counter-clockwise
|
||||
if (!reversed && SignedArea(vtxpos[0].xy(), vtxpos[1].xy(), vtxpos[2].xy()) <= 0) {
|
||||
ProcessTriangleInternal(v0, v2, v1, true);
|
||||
return;
|
||||
}
|
||||
} else {
|
||||
if (!reversed && registers.cull_mode == Regs::CullMode::KeepClockWise) {
|
||||
// Reverse vertex order and use the CCW code path.
|
||||
ProcessTriangleInternal(v0, v2, v1, true);
|
||||
return;
|
||||
}
|
||||
|
||||
if (registers.cull_mode != Regs::CullMode::KeepAll) {
|
||||
// Cull away triangles which are wound counter-clockwise.
|
||||
// Cull away triangles which are wound clockwise.
|
||||
if (SignedArea(vtxpos[0].xy(), vtxpos[1].xy(), vtxpos[2].xy()) <= 0)
|
||||
return;
|
||||
} else {
|
||||
// TODO: Consider A check for degenerate triangles ("SignedArea == 0")
|
||||
}
|
||||
|
||||
// TODO: Proper scissor rect test!
|
||||
|
@ -695,6 +705,12 @@ void ProcessTriangle(const VertexShader::OutputVertex& v0,
|
|||
}
|
||||
}
|
||||
|
||||
void ProcessTriangle(const VertexShader::OutputVertex& v0,
|
||||
const VertexShader::OutputVertex& v1,
|
||||
const VertexShader::OutputVertex& v2) {
|
||||
ProcessTriangleInternal(v0, v1, v2);
|
||||
}
|
||||
|
||||
} // namespace Rasterizer
|
||||
|
||||
} // namespace Pica
|
||||
|
|
Reference in New Issue