John@15: #include <math.h>
nuclear@25: #include <float.h>
nuclear@22: #include "scene.h"
nuclear@6: 
John@15: #define FEQ(a, b)	(fabs((a) - (b)) < 1e-8)
John@15: bool Face::operator ==(const Face &f) const
John@15: {
John@15: 	for(int i=0; i<3; i++) {
John@15: 		for(int j=0; j<3; j++) {
John@15: 			if(!FEQ(v[i].pos[j], f.v[i].pos[j])) {
John@15: 				return false;
John@15: 			}
John@15: 			if(!FEQ(v[i].normal[j], f.v[i].normal[j])) {
John@15: 				return false;
John@15: 			}
John@15: 		}
John@15: 		if(!FEQ(normal[i], f.normal[i])) {
John@15: 			return false;
John@15: 		}
John@15: 	}
John@15: 	return true;
John@15: }
John@15: 
nuclear@25: float AABBox::calc_surface_area() const
nuclear@25: {
nuclear@25: 	float area1 = (max[0] - min[0]) * (max[1] - min[1]);
nuclear@25: 	float area2 = (max[3] - min[3]) * (max[1] - min[1]);
nuclear@25: 	float area3 = (max[0] - min[0]) * (max[3] - min[3]);
nuclear@25: 
nuclear@25: 	return 2.0f * (area1 + area2 + area3);
nuclear@25: }
nuclear@25: 
nuclear@25: 
nuclear@24: Scene::Scene()
nuclear@24: {
nuclear@24: 	facebuf = 0;
nuclear@24: 	num_faces = -1;
nuclear@24: 	kdtree = 0;
nuclear@24: }
nuclear@24: 
nuclear@24: Scene::~Scene()
nuclear@24: {
nuclear@24: 	delete [] facebuf;
nuclear@24: }
nuclear@24: 
nuclear@13: bool Scene::add_mesh(Mesh *m)
nuclear@13: {
nuclear@13: 	// make sure triangles have material ids
nuclear@13: 	for(size_t i=0; i<m->faces.size(); i++) {
nuclear@13: 		m->faces[i].matid = m->matid;
nuclear@13: 	}
nuclear@24: 
nuclear@24: 	try {
nuclear@24: 		meshes.push_back(m);
nuclear@24: 	}
nuclear@24: 	catch(...) {
nuclear@24: 		return false;
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	// invalidate facebuffer and count
nuclear@24: 	delete [] facebuf;
nuclear@24: 	facebuf = 0;
nuclear@24: 	num_faces = -1;
nuclear@24: 
nuclear@13: 	return true;
nuclear@13: }
nuclear@13: 
John@14: int Scene::get_num_meshes() const
John@14: {
John@14: 	return (int)meshes.size();
John@14: }
John@14: 
nuclear@13: int Scene::get_num_faces() const
nuclear@13: {
nuclear@24: 	if(num_faces >= 0) {
nuclear@24: 		return num_faces;
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	num_faces = 0;
nuclear@13: 	for(size_t i=0; i<meshes.size(); i++) {
nuclear@13: 		num_faces += meshes[i]->faces.size();
nuclear@13: 	}
nuclear@13: 	return num_faces;
nuclear@13: }
nuclear@13: 
John@14: int Scene::get_num_materials() const
John@14: {
John@14: 	return (int)matlib.size();
John@14: }
John@14: 
John@14: Material *Scene::get_materials()
John@14: {
John@14: 	if(matlib.empty()) {
John@14: 		return 0;
John@14: 	}
John@14: 	return &matlib[0];
John@14: }
John@14: 
John@14: const Material *Scene::get_materials() const
John@14: {
John@14: 	if(matlib.empty()) {
John@14: 		return 0;
John@14: 	}
John@14: 	return &matlib[0];
John@14: }
nuclear@24: 
nuclear@24: const Face *Scene::get_face_buffer() const
nuclear@24: {
nuclear@24: 	if(facebuf) {
nuclear@24: 		return facebuf;
nuclear@24: 	}
nuclear@24: 
nuclear@24: 	int num_meshes = get_num_meshes();
nuclear@24: 
nuclear@24: 	printf("constructing face buffer with %d faces (out of %d meshes)\n", get_num_faces(), num_meshes);
nuclear@24: 	facebuf = new Face[num_faces];
nuclear@24: 	Face *fptr = facebuf;
nuclear@24: 
nuclear@24: 	for(int i=0; i<num_meshes; i++) {
nuclear@24: 		for(size_t j=0; j<meshes[i]->faces.size(); j++) {
nuclear@24: 			*fptr++ = meshes[i]->faces[j];
nuclear@24: 		}
nuclear@24: 	}
nuclear@24: 	return facebuf;
nuclear@24: }
nuclear@24: 
nuclear@25: static int build_kdtree(KDNode *kd);
nuclear@25: static void free_kdtree(KDNode *node);
nuclear@24: 
nuclear@24: void Scene::build_kdtree()
nuclear@24: {
nuclear@24: 	const Face *faces = get_face_buffer();
nuclear@24: 	int num_faces = get_num_faces();
nuclear@24: 
nuclear@25: 	printf("Constructing kd-tree out of %d faces ...\n", num_faces);
nuclear@25: 
nuclear@25: 	free_kdtree(kdtree);
nuclear@25: 	kdtree = new KDNode;
nuclear@25: 	kdtree->left = kdtree->right = 0;
nuclear@25: 
nuclear@25: 	/* Start the construction of the kdtree by adding all faces of the scene
nuclear@25: 	 * to the new root node. At the same time calculate the root's AABB.
nuclear@25: 	 */
nuclear@25: 	kdtree->aabb.min[0] = kdtree->aabb.min[1] = kdtree->aabb.min[2] = FLT_MAX;
nuclear@25: 	kdtree->aabb.max[0] = kdtree->aabb.max[1] = kdtree->aabb.max[2] = -FLT_MAX;
nuclear@25: 
nuclear@24: 	for(int i=0; i<num_faces; i++) {
nuclear@25: 		const Face *face = faces + i;
nuclear@25: 
nuclear@25: 		// for each vertex of the face ...
nuclear@25: 		for(int j=0; j<3; j++) {
nuclear@25: 			const float *pos = face->v[j].pos;
nuclear@25: 
nuclear@25: 			// for each element (xyz) of the position vector ...
nuclear@25: 			for(int k=0; k<3; k++) {
nuclear@25: 				if(pos[k] < kdtree->aabb.min[k]) {
nuclear@25: 					kdtree->aabb.min[k] = pos[k];
nuclear@25: 				}
nuclear@25: 				if(pos[k] > kdtree->aabb.max[k]) {
nuclear@25: 					kdtree->aabb.max[k] = pos[k];
nuclear@25: 				}
nuclear@25: 			}
nuclear@25: 		}
nuclear@25: 
nuclear@25: 		kdtree->faces.push_back(face);	// add the face
nuclear@24: 	}
nuclear@24: 
nuclear@25: 	// now proceed splitting the root recursively
nuclear@25: 	::build_kdtree(kdtree);
nuclear@24: }
nuclear@24: 
nuclear@25: static int build_kdtree(KDNode *kd)
nuclear@24: {
nuclear@25: 	if(kd->faces.empty()) {
nuclear@25: 		return 0;
nuclear@25: 	}
nuclear@25: 
nuclear@25: 	// XXX cont.
nuclear@25: 	return -1;
nuclear@24: }
nuclear@25: 
nuclear@25: static void free_kdtree(KDNode *node)
nuclear@25: {
nuclear@25: 	if(node) {
nuclear@25: 		free_kdtree(node->left);
nuclear@25: 		free_kdtree(node->right);
nuclear@25: 		delete node;
nuclear@25: 	}
nuclear@25: }