Fix bugs in Model, GLFrustum, and rendering; improve algorithmic performance

Author: tomas-soltys

src/Config.cmake

@@ -1,4 +1,4 @@
-set(PROJECT_VERSION "1.1.2")
+set(PROJECT_VERSION "1.1.3")
 set(PROJECT_YEAR "2026")
 set(PROJECT_RELEASE_DATE "2026-02-08")
 set(PROJECT_PACKAGE_NAME "range-fea")

src/fea/doc/RELEASE_NOTES.txt

@@ -1,3 +1,13 @@
+------------------------------------------------------------------
+Version 1.1.3
+
+- Performance improvements in mesh repair functions
+
+Bug fixes:
+
+- Element entities are not painted in 3D area
+- Bug in edge element detection
+
 ------------------------------------------------------------------
 Version 1.1.2
 

src/fea/src/gl_entity_list.cpp

@@ -2,14 +2,14 @@
 
 GLEntityList::GLEntityList()
     : GLList(GL_ENTITY_LIST_ITEM_N_LISTS)
-    , useVBO(true)  // Enable VBO by default for better performance
+    , useVBO(false)  // VBO disabled: VAO + legacy client-state mixing is incompatible
 {
     this->_init();
 }
 
 GLEntityList::GLEntityList(const GLEntityList &glEntityList)
     : GLList(glEntityList)
-    , useVBO(true)
+    , useVBO(false)
 {
     this->_init(&glEntityList);
 }

src/fea/src/gl_frustum.cpp

@@ -30,15 +30,18 @@ void GLFrustum::extractFromGL()
     glGetDoublev(GL_MODELVIEW_MATRIX, modelview);
     glGetDoublev(GL_PROJECTION_MATRIX, projection);
 
-    // Multiply projection * modelview to get combined matrix
+    // Multiply projection * modelview to get combined matrix.
+    // OpenGL matrices are column-major: element at (row r, col c) is stored at index c*4+r.
+    // For C = A * B: C[i*4+j] = sum_k A[k*4+j] * B[i*4+k]
+    // where i=col, j=row. Here A=projection, B=modelview.
     for (int i = 0; i < 4; i++)
     {
         for (int j = 0; j < 4; j++)
         {
             mvp[i * 4 + j] = 0.0;
             for (int k = 0; k < 4; k++)
             {
-                mvp[i * 4 + j] += projection[i * 4 + k] * modelview[k * 4 + j];
+                mvp[i * 4 + j] += projection[k * 4 + j] * modelview[i * 4 + k];
             }
         }
     }