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-rw-r--r--src/video_core/rasterizer.cpp38
1 files changed, 27 insertions, 11 deletions
diff --git a/src/video_core/rasterizer.cpp b/src/video_core/rasterizer.cpp
index 046c010ef..5769bd81e 100644
--- a/src/video_core/rasterizer.cpp
+++ b/src/video_core/rasterizer.cpp
@@ -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