Ticket #169: terrain_triangulation.patch

PatchRData.cpp

@@ -330 +330 @@
         for (ssize_t j=0;j<PATCH_SIZE;j++) {
             for (ssize_t i=0;i<PATCH_SIZE;i++) {
                 if (texgrid[j][i]==h){
+
+                    //save these values for convenience
+                    u16 index1 = u16(((j+0)*vsize+(i+0))+base);
+                    u16 index2 = u16(((j+0)*vsize+(i+1))+base);
+                    u16 index3 = u16(((j+1)*vsize+(i+1))+base);
+                    u16 index4 = u16(((j+1)*vsize+(i+0))+base);
+
+                    //calculate triangulation
+                    //reminder: incrementing i shifts x coordinates, j shifts z
+                    //first, get all the positions of the vertices in world space
+                    CVector3D v1 = m_Vertices[(j+0)*vsize+(i+0)].m_Position;
+                    CVector3D v2 = m_Vertices[(j+0)*vsize+(i+1)].m_Position;
+                    CVector3D v3 = m_Vertices[(j+1)*vsize+(i+1)].m_Position;
+                    CVector3D v4 = m_Vertices[(j+1)*vsize+(i+0)].m_Position;
+                    
+                    /*
+                    debug_printf(L"Vertex 1 is at position: %f, %f, %f\n", v1.X, v1.Y, v1.Z);
+                    debug_printf(L"Vertex 2 is at position: %f, %f, %f\n", v2.X, v2.Y, v2.Z);
+                    debug_printf(L"Vertex 3 is at position: %f, %f, %f\n", v3.X, v3.Y, v3.Z);
+                    debug_printf(L"Vertex 4 is at position: %f, %f, %f\n", v4.X, v4.Y, v4.Z);
+                    */
+
+                    
+                    //we have two possible triangulations to check: (123, 143) and (234, 214)
+                    //our goal is to pick the one that minimizes the angle between the planes formed by the triangles
+                    CVector3D normal1 = (v2-v1).Cross(v3-v1);
+                    CVector3D normal2 = (v3-v1).Cross(v4-v1);
+                    CVector3D normal3 = (v4-v2).Cross(v3-v2);
+                    CVector3D normal4 = (v1-v2).Cross(v4-v2);
+                    normal1.Normalize();
+                    normal2.Normalize();
+                    normal3.Normalize();
+                    normal4.Normalize();
+                    float angle1 = normal1.Dot(normal2);    //since we don't need the exact angle, we can just use the value of the dot product
+                    float angle2 = normal3.Dot(normal4);
+
+                    //cos gets smaller as the angle increases so we take the triangulation with the larger value
+                    if (angle1 < angle2)
+                    {
+                        
+                        
+                        m_Indices.push_back(index3);
+                        m_Indices.push_back(index4);
+                        m_Indices.push_back(index2);
+                        m_Indices.push_back(index2);
+                        m_Indices.push_back(index4);
+                        m_Indices.push_back(index1);
+                        
+                        /*
+                        //for triangle strip
+                        m_Indices.push_back(index3);
+                        m_Indices.push_back(index4);
+                        m_Indices.push_back(index2);
+                        m_Indices.push_back(index1);
+                        */
+                    }
+                    else
+                    {
+                        
+                        m_Indices.push_back(index2);
+                        m_Indices.push_back(index3);
+                        m_Indices.push_back(index1);
+                        m_Indices.push_back(index1);
+                        m_Indices.push_back(index3);
+                        m_Indices.push_back(index4);
+                        
+                        /*
+                        //for triangle strip
+                        m_Indices.push_back(index2);
+                        m_Indices.push_back(index3);
+                        m_Indices.push_back(index1);
+                        m_Indices.push_back(index4);
+                        */
+                    }
+                    
+                    /*
                     m_Indices.push_back(u16(((j+0)*vsize+(i+0))+base));
                     m_Indices.push_back(u16(((j+0)*vsize+(i+1))+base));
                     m_Indices.push_back(u16(((j+1)*vsize+(i+1))+base));
                     m_Indices.push_back(u16(((j+1)*vsize+(i+0))+base));
+                    */
+
                 }
             }
         }
         splat.m_IndexCount=m_Indices.size()-splat.m_IndexStart;
     }
-
-    // build indices for the shadow map pass
-    for (ssize_t j=0;j<PATCH_SIZE;j++) {
-        for (ssize_t i=0;i<PATCH_SIZE;i++) {
-            m_ShadowMapIndices.push_back(u16(((j+0)*vsize+(i+0))+base));
-            m_ShadowMapIndices.push_back(u16(((j+0)*vsize+(i+1))+base));
-            m_ShadowMapIndices.push_back(u16(((j+1)*vsize+(i+1))+base));
-            m_ShadowMapIndices.push_back(u16(((j+1)*vsize+(i+0))+base));
-        }
-    }
 }
 
 
@@ -517 +585 @@
         ogl_tex_bind(splat.m_Texture);
 
         if (!g_Renderer.m_SkipSubmit) {
-            glDrawElements(GL_QUADS, (GLsizei)splat.m_IndexCount,
+            glDrawElements(GL_TRIANGLES, (GLsizei)splat.m_IndexCount,
                 GL_UNSIGNED_SHORT, &m_Indices[splat.m_IndexStart]);
         }
-
+        
         // bump stats
         g_Renderer.m_Stats.m_DrawCalls++;
         g_Renderer.m_Stats.m_TerrainTris+=splat.m_IndexCount/2;
@@ -548 +616 @@
 
     // render all base splats at once
     if (!g_Renderer.m_SkipSubmit) {
-        glDrawElements(GL_QUADS,(GLsizei)m_Indices.size(),GL_UNSIGNED_SHORT,&m_Indices[0]);
+        glDrawElements(GL_TRIANGLES,(GLsizei)m_Indices.size(),GL_UNSIGNED_SHORT,&m_Indices[0]);
     }
 
     // bump stats

TerrainRenderer.cpp

@@ -216 +216 @@
     for(size_t i = 0; i < m->visiblePatches.size(); ++i)
     {
         CPatchRData* patchdata = (CPatchRData*)m->visiblePatches[i]->GetRenderData();
-        patchdata->RenderBlends();
+        //patchdata->RenderBlends();
     }
     
     // Disable second texcoord array