Ticket #1987: normal.diff

source/graphics/Terrain.cpp

@@ -144 +144 @@
 {
     CVector3D left, right, up, down;
 
-    // Calculate normals of the four half-tile triangles surrounding this vertex:
+    // Use the cross product of the vectors cutting this position
 
-    // get position of vertex where normal is being evaluated
-    CVector3D basepos;
-    CalcPosition(i, j, basepos);
+    CalcPosition(i-1, j, left);
+    CalcPosition(i+1, j, right);
+    CalcPosition(i, j-1, up);
+    CalcPosition(i, j+1, down);
 
-    if (i > 0) {
-        CalcPosition(i-1, j, left);
-        left -= basepos;
-        left.Normalize();
-    }
+    // calculate cross product, leave out zero terms
+    normal = CVector3D(left.Y-right.Y, 2*TERRAIN_TILE_SIZE, up.Y-down.Y);
 
-    if (i < m_MapSize-1) {
-        CalcPosition(i+1, j, right);
-        right -= basepos;
-        right.Normalize();
-    }
-
-    if (j > 0) {
-        CalcPosition(i, j-1, up);
-        up -= basepos;
-        up.Normalize();
-    }
-
-    if (j < m_MapSize-1) {
-        CalcPosition(i, j+1, down);
-        down -= basepos;
-        down.Normalize();
-    }
-
-    CVector3D n0 = up.Cross(left);
-    CVector3D n1 = left.Cross(down);
-    CVector3D n2 = down.Cross(right);
-    CVector3D n3 = right.Cross(up);
-
-    // Compute the mean of the normals
-    normal = n0 + n1 + n2 + n3;
+    // Normalize
     float nlen=normal.Length();
     if (nlen>0.00001f) normal*=1.0f/nlen;
 }
@@ -191 +165 @@
 {
     CFixedVector3D left, right, up, down;
 
-    // Calculate normals of the four half-tile triangles surrounding this vertex:
+    // Use the cross product of the vectors cutting this position
 
-    // get position of vertex where normal is being evaluated
-    CFixedVector3D basepos;
-    CalcPositionFixed(i, j, basepos);
+    CalcPositionFixed(i-1, j, left);
+    CalcPositionFixed(i+1, j, right);
+    CalcPositionFixed(i, j-1, up);
+    CalcPositionFixed(i, j+1, down);
 
-    if (i > 0) {
-        CalcPositionFixed(i-1, j, left);
-        left -= basepos;
-        left.Normalize();
-    }
+    // calculate cross product, leave out zero terms
+    normal = CFixedVector3D(left.Y-right.Y,fixed::FromInt(2*TERRAIN_TILE_SIZE), up.Y-down.Y);
 
-    if (i < m_MapSize-1) {
-        CalcPositionFixed(i+1, j, right);
-        right -= basepos;
-        right.Normalize();
-    }
-
-    if (j > 0) {
-        CalcPositionFixed(i, j-1, up);
-        up -= basepos;
-        up.Normalize();
-    }
-
-    if (j < m_MapSize-1) {
-        CalcPositionFixed(i, j+1, down);
-        down -= basepos;
-        down.Normalize();
-    }
-
-    CFixedVector3D n0 = up.Cross(left);
-    CFixedVector3D n1 = left.Cross(down);
-    CFixedVector3D n2 = down.Cross(right);
-    CFixedVector3D n3 = right.Cross(up);
-
-    // Compute the mean of the normals
-    normal = n0 + n1 + n2 + n3;
+    // Normalize 
     normal.Normalize();
 }