void View::getMinMaxDistance(float* mindist, float* maxdist)
{
//Save min/max distance
float vert[3], dist;
glGetFloatv(GL_MODELVIEW_MATRIX, modelView);
*maxdist = -HUGE_VAL;
*mindist = HUGE_VAL;
for (int i=0; i<2; i++)
{
vert[0] = i==0 ? min[0] : max[0];
for (int j=0; j<2; j++)
{
vert[1] = j==0 ? min[1] : max[1];
for (int k=0; k<2; k++)
{
vert[2] = k==0 ? min[2] : max[2];
dist = eyeDistance(modelView, vert);
if (dist < *mindist) *mindist = dist;
if (dist > *maxdist) *maxdist = dist;
}
}
}
if (*maxdist == *mindist) *maxdist += 0.0000001;
//printf("DISTANCE MIN %f MAX %f\n", *mindist, *maxdist);
}
void QuadSurfaces::update()
{
clock_t t1,t2,tt;
t1 = tt = clock();
// Update and depth sort surfaces..
//Calculate distances from view plane
float maxdist, mindist;
view->getMinMaxDistance(&mindist, &maxdist);
Geometry::update();
tt=clock();
if (geom.size() == 0) return;
//Get element/quad count
debug_print("Reloading and sorting %d quad surfaces...\n", geom.size());
total = 0;
hiddencache.resize(geom.size());
surf_sort.clear();
int quadverts = 0;
for (unsigned int i=0; i<geom.size(); i++)
{
int quads = (geom[i]->width-1) * (geom[i]->height-1);
quadverts += quads * 4;
total += geom[i]->count; //Actual vertices
hiddencache[i] = !drawable(i); //Save flags
debug_print("Surface %d, quads %d hidden? %s\n", i, quadverts/4, (hiddencache[i] ? "yes" : "no"));
//Get corners of strip
float* posmin = geom[i]->vertices[0];
float* posmax = geom[i]->vertices[geom[i]->count - 1];
float pos[3] = {posmin[0] + (posmax[0] - posmin[0]) * 0.5f,
posmin[1] + (posmax[1] - posmin[1]) * 0.5f,
posmin[2] + (posmax[2] - posmin[2]) * 0.5f
};
//Calculate distance from viewing plane
geom[i]->distance = eyeDistance(view->modelView, pos);
if (geom[i]->distance < mindist) mindist = geom[i]->distance;
if (geom[i]->distance > maxdist) maxdist = geom[i]->distance;
//printf("%d) %f %f %f distance = %f\n", i, pos[0], pos[1], pos[2], geom[i]->distance);
surf_sort.push_back(Distance(i, geom[i]->distance));
//Disable triangle sorting for these surfaces
geom[i]->opaque = true;
}
if (total == 0) return;
t2 = clock();
debug_print(" %.4lf seconds to calculate distances\n", (t2-t1)/(double)CLOCKS_PER_SEC);
t1 = clock();
//Sort
std::sort(surf_sort.begin(), surf_sort.end());
t2 = clock();
debug_print(" %.4lf seconds to sort\n", (t2-t1)/(double)CLOCKS_PER_SEC);
t1 = clock();
//Only reload the vbo data when required
//Not needed when objects hidden/shown but required if colours changed
//To force, use Geometry->reset() which sets elements to -1
if (elements < 0 || elements != quadverts)
{
//Clear buffers
close();
elements = quadverts;
//Load & optimise the mesh data
render();
//Send the data to the GPU via VBO
loadBuffers();
}
}