static void BSPTreeCreateRecursive(BSPTreeNode *tree,
PolyListNode *pllist,
#if BSPTREE_STATS
int depth,
#endif
struct obstack *scratch)
{
PolyListNode *plnode, *front, *back;
EdgeIntersection edges[2];
tree->front = tree->back = NULL;
ListPop(pllist, plnode);
tree->polylist = plnode;
check_poly(plnode->poly);
PolyPlane(plnode, &tree->plane);
front = back = NULL;
while (pllist) {
ListPop(pllist, plnode);
check_poly(plnode->poly);
switch (ClassifyPoly(&tree->plane, plnode->poly, edges)) {
case BACKOF:
check_poly(plnode->poly);
ListPush(back, plnode);
break;
case COPLANAR:
check_poly(plnode->poly);
ListPush(tree->polylist, plnode);
break;
case INFRONTOF:
check_poly(plnode->poly);
ListPush(front, plnode);
break;
case BOTH_SIDES:
check_poly(plnode->poly);
SplitPolyNode(plnode, &front, &back, edges, scratch);
break;
}
}
if (front) {
tree->front = obstack_alloc(scratch, sizeof(*tree->front));
BSPTreeCreateRecursive(tree->front, front,
#if BSPTREE_STATS
depth+1,
#endif
scratch);
}
if (back) {
tree->back = obstack_alloc(scratch, sizeof(*tree->back));
BSPTreeCreateRecursive(tree->back, back,
#if BSPTREE_STATS
depth+1,
#endif
scratch);
}
#if BSPTREE_STATS
if (depth > tree_depth) {
tree_depth = depth;
}
#endif
}
/*
* OpenGL (GLUT) calls this routine to display the scene
*/
void display()
{
const double len=1.5; // Length of axes
// Erase the window and the depth buffer
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
// Enable Z-buffering in OpenGL
glEnable(GL_DEPTH_TEST);
// Undo previous transformations
glLoadIdentity();
// Set view angle
glRotatef(ph,1,0,0);
glRotatef(th,0,1,0);
// Decide what to draw
switch (mode)
{
// Draw cubes
case 0:
cube(0,0,0 , 0.3,0.3,0.3 , 0);
cube(1,0,0 , 0.2,0.2,0.2 , 45);
cube(0,1,0 , 0.4,0.4,0.2 , 90);
break;
// Draw spheres
case 1:
sphere1(0,0,0 , 0.4);
sphere1(1,0,0 , 0.2);
sphere2(0,1,0 , 0.2);
break;
// Line airplane
case 2:
PolyPlane(GL_LINE_LOOP , 0,0,0);
break;
// Polygon airplane
case 3:
PolyPlane(GL_POLYGON , 0,0,0);
break;
// Three flat airplanes
case 4:
FlatPlane( 0.0, 0.0, 0.0);
FlatPlane(-0.5, 0.5,-0.5);
FlatPlane(-0.5,-0.5,-0.5);
break;
// Three solid airplanes
case 5:
SolidPlane( 0, 0, 0 , 1,0,0 , 0, 1,0);
SolidPlane(-1, 1, 0 ,-1,0,0 , 0,-1,0);
SolidPlane(-1,-1, 0 ,-1,0,0 , 0, 1,0);
break;
// Mix of objects
case 6:
// Cube
cube(-1,0,0 , 0.3,0.3,0.3 , 3*zh);
// Ball
sphere1(0,0,0 , 0.3);
// Solid Airplane
SolidPlane(Cos(zh),Sin(zh), 0 ,-Sin(zh),Cos(zh),0 , Cos(4*zh),0,Sin(4*zh));
// Utah Teapot
glPushMatrix();
glTranslatef(0,0,-1);
glRotatef(zh,0,1,0);
glColor3f(Cos(zh)*Cos(zh),0,Sin(zh)*Sin(zh));
glutSolidTeapot(0.5);
glPopMatrix();
break;
}
// White
glColor3f(1,1,1);
// Draw axes
if (axes)
{
glBegin(GL_LINES);
glVertex3d(0.0,0.0,0.0);
glVertex3d(len,0.0,0.0);
glVertex3d(0.0,0.0,0.0);
glVertex3d(0.0,len,0.0);
glVertex3d(0.0,0.0,0.0);
glVertex3d(0.0,0.0,len);
glEnd();
// Label axes
glRasterPos3d(len,0.0,0.0);
Print("X");
glRasterPos3d(0.0,len,0.0);
Print("Y");
glRasterPos3d(0.0,0.0,len);
Print("Z");
}
// Five pixels from the lower left corner of the window
glWindowPos2i(5,5);
// Print the text string
Print("Angle=%d,%d",th,ph);
// Render the scene
glFlush();
// Make the rendered scene visible
glutSwapBuffers();
}
std::vector<float4> Planes(const std::vector<float3> &verts, const std::vector<int3> &tris) { std::vector<float4> planes; for (auto &t : tris) planes.push_back(PolyPlane({verts[t[0]],verts[t[1]],verts[t[2]] })); return planes; }
