Merge pull request #10584 from Pokechu22/emboss-single-normal-v2

VideoCommon: Handle emboss texgen with only a single normal

1 files changed, 10 insertions, 13 deletions

diff --git a/Source/Core/VideoBackends/Software/TransformUnit.cpp b/Source/Core/VideoBackends/Software/TransformUnit.cpp
index bf56307025..6fcf42df9e 100644
--- a/Source/Core/VideoBackends/Software/TransformUnit.cpp
+++ b/Source/Core/VideoBackends/Software/TransformUnit.cpp
@@ -90,22 +90,19 @@ void TransformPosition(const InputVertexData* src, OutputVertexData* dst)
   }
 }
 
-void TransformNormal(const InputVertexData* src, bool nbt, OutputVertexData* dst)
+void TransformNormal(const InputVertexData* src, OutputVertexData* dst)
 {
   const float* mat = &xfmem.normalMatrices[(src->posMtx & 31) * 3];
 
-  if (nbt)
-  {
-    MultiplyVec3Mat33(src->normal[0], mat, dst->normal[0]);
-    MultiplyVec3Mat33(src->normal[1], mat, dst->normal[1]);
-    MultiplyVec3Mat33(src->normal[2], mat, dst->normal[2]);
-    dst->normal[0].Normalize();
-  }
-  else
-  {
-    MultiplyVec3Mat33(src->normal[0], mat, dst->normal[0]);
-    dst->normal[0].Normalize();
-  }
+  MultiplyVec3Mat33(src->normal[0], mat, dst->normal[0]);
+  MultiplyVec3Mat33(src->normal[1], mat, dst->normal[1]);
+  MultiplyVec3Mat33(src->normal[2], mat, dst->normal[2]);
+  // The scale of the transform matrix is used to control the size of the emboss map effect, by
+  // changing the scale of the transformed binormals (which only get used by emboss map texgens).
+  // By normalising the first transformed normal (which is used by lighting calculations and needs
+  // to be unit length), the same transform matrix can do double duty, scaling for emboss mapping,
+  // and not scaling for lighting.
+  dst->normal[0].Normalize();
 }
 
 static void TransformTexCoordRegular(const TexMtxInfo& texinfo, int coordNum,