Refactored MatrixVectorMultiply(), added TransformDivide() for cases where perspective divide is needed

src/graphics/engine/engine.cpp

@@ -3923,25 +3923,25 @@ void CEngine::RenderDebugBox(const glm::vec3& mins, const glm::vec3& maxs, const
 
     auto vert = m_pendingDebugDraws.vertices.begin() + firstVert;
 
-    *vert++ = VertexCol{Math::MatrixVectorMultiply(transform, glm::vec3{mins.x, mins.y, mins.z}), color};
+    *vert++ = VertexCol{Math::Transform(transform, glm::vec3{mins.x, mins.y, mins.z}), color};
-    *vert++ = VertexCol{Math::MatrixVectorMultiply(transform, glm::vec3{maxs.x, mins.y, mins.z}), color};
+    *vert++ = VertexCol{Math::Transform(transform, glm::vec3{maxs.x, mins.y, mins.z}), color};
-    *vert++ = VertexCol{Math::MatrixVectorMultiply(transform, glm::vec3{maxs.x, maxs.y, mins.z}), color};
+    *vert++ = VertexCol{Math::Transform(transform, glm::vec3{maxs.x, maxs.y, mins.z}), color};
-    *vert++ = VertexCol{Math::MatrixVectorMultiply(transform, glm::vec3{maxs.x, maxs.y, maxs.z}), color};
+    *vert++ = VertexCol{Math::Transform(transform, glm::vec3{maxs.x, maxs.y, maxs.z}), color};
 
-    *vert++ = VertexCol{Math::MatrixVectorMultiply(transform, glm::vec3{mins.x, mins.y, maxs.z}), color};
+    *vert++ = VertexCol{Math::Transform(transform, glm::vec3{mins.x, mins.y, maxs.z}), color};
-    *vert++ = VertexCol{Math::MatrixVectorMultiply(transform, glm::vec3{mins.x, mins.y, mins.z}), color};
+    *vert++ = VertexCol{Math::Transform(transform, glm::vec3{mins.x, mins.y, mins.z}), color};
-    *vert++ = VertexCol{Math::MatrixVectorMultiply(transform, glm::vec3{mins.x, maxs.y, mins.z}), color};
+    *vert++ = VertexCol{Math::Transform(transform, glm::vec3{mins.x, maxs.y, mins.z}), color};
-    *vert++ = VertexCol{Math::MatrixVectorMultiply(transform, glm::vec3{maxs.x, maxs.y, mins.z}), color};
+    *vert++ = VertexCol{Math::Transform(transform, glm::vec3{maxs.x, maxs.y, mins.z}), color};
 
-    *vert++ = VertexCol{Math::MatrixVectorMultiply(transform, glm::vec3{maxs.x, mins.y, maxs.z}), color};
+    *vert++ = VertexCol{Math::Transform(transform, glm::vec3{maxs.x, mins.y, maxs.z}), color};
-    *vert++ = VertexCol{Math::MatrixVectorMultiply(transform, glm::vec3{mins.x, mins.y, maxs.z}), color};
+    *vert++ = VertexCol{Math::Transform(transform, glm::vec3{mins.x, mins.y, maxs.z}), color};
-    *vert++ = VertexCol{Math::MatrixVectorMultiply(transform, glm::vec3{mins.x, maxs.y, maxs.z}), color};
+    *vert++ = VertexCol{Math::Transform(transform, glm::vec3{mins.x, maxs.y, maxs.z}), color};
-    *vert++ = VertexCol{Math::MatrixVectorMultiply(transform, glm::vec3{mins.x, maxs.y, mins.z}), color};
+    *vert++ = VertexCol{Math::Transform(transform, glm::vec3{mins.x, maxs.y, mins.z}), color};
 
-    *vert++ = VertexCol{Math::MatrixVectorMultiply(transform, glm::vec3{maxs.x, mins.y, mins.z}), color};
+    *vert++ = VertexCol{Math::Transform(transform, glm::vec3{maxs.x, mins.y, mins.z}), color};
-    *vert++ = VertexCol{Math::MatrixVectorMultiply(transform, glm::vec3{maxs.x, mins.y, maxs.z}), color};
+    *vert++ = VertexCol{Math::Transform(transform, glm::vec3{maxs.x, mins.y, maxs.z}), color};
-    *vert++ = VertexCol{Math::MatrixVectorMultiply(transform, glm::vec3{maxs.x, maxs.y, maxs.z}), color};
+    *vert++ = VertexCol{Math::Transform(transform, glm::vec3{maxs.x, maxs.y, maxs.z}), color};
-    *vert++ = VertexCol{Math::MatrixVectorMultiply(transform, glm::vec3{mins.x, maxs.y, maxs.z}), color};
+    *vert++ = VertexCol{Math::Transform(transform, glm::vec3{mins.x, maxs.y, maxs.z}), color};
 }
 
 void CEngine::RenderPendingDebugDraws()
@@ -4071,7 +4071,7 @@ void CEngine::RenderShadowMap()
             // axes are aligned with the x/y/z axes (not necessarily in that order, and +/- signs don't matter).
             glm::mat4 lightRotation;
             Math::LoadViewMatrix(lightRotation, glm::vec3{0, 0, 0}, lightDir, worldUp);
-            pos = Math::MatrixVectorMultiply(lightRotation, pos);
+            pos = Math::Transform(lightRotation, pos);
             // ...then we round to the nearest worldUnitsPerTexel:
             const float worldUnitsPerTexel = (dist * 2.0f) / m_shadowMap.size.x;
             pos /= worldUnitsPerTexel;
@@ -4080,7 +4080,7 @@ void CEngine::RenderShadowMap()
             pos.z = round(pos.z);
             pos *= worldUnitsPerTexel;
             // ...and convert back to world space.
-            pos = Math::MatrixVectorMultiply(glm::inverse(lightRotation), pos);
+            pos = Math::Transform(glm::inverse(lightRotation), pos);
         }
 
         glm::vec3 lookAt = pos - lightDir;

src/math/geometry.h

@@ -612,26 +612,11 @@ inline glm::vec3 Transform(const glm::mat4 &m, const glm::vec3 &p)
 }
 
 
-//! Calculates the result of multiplying m * v
+//! Transforms a vector \v by a matrix \m with perspective divide
-/**
+inline glm::vec3 TransformDivide(const glm::mat4& m, const glm::vec3& v)
-    The multiplication is performed thus:
-
-\verbatim
-[  m.m[0 ] m.m[4 ] m.m[8 ] m.m[12]  ]   [ v.x ]
-[  m.m[1 ] m.m[5 ] m.m[9 ] m.m[13]  ]   [ v.y ]
-[  m.m[2 ] m.m[6 ] m.m[10] m.m[14]  ] * [ v.z ]
-[  m.m[3 ] m.m[7 ] m.m[11] m.m[15]  ]   [  1  ]
-\endverbatim
-
-   The result, a 4x1 vector is then converted to 3x1 by dividing
-   x,y,z coords by the fourth coord (w). */
-inline glm::vec3 MatrixVectorMultiply(const glm::mat4& m, const glm::vec3& v, bool wDivide = false)
 {
     glm::vec4 result = m * glm::vec4(v, 1.0f);
 
-    if (!wDivide)
-        return result;
-
     if (IsZero(result.w))
         return glm::vec3(result);