cleaned Texture interface
new C++ demo: textures
slightly adjusted SAH for kd-tree
slightly optimized kd-tree building -- moved termination cond. so it's tested before recursion
minor sphere intersection optimization
/* * Pyrit Ray Tracer * file: octree.cc * * Radek Brich, 2006-2007 */#include "octree.h"OctreeNode::~OctreeNode(){ if (shapes != NULL) delete shapes; else delete[] children;}void OctreeNode::subdivide(BBox bbox, int maxdepth){ // make children children = new OctreeNode[8]; // evaluate centres for axes const Float xsplit = (bbox.L.x + bbox.H.x)*0.5; const Float ysplit = (bbox.L.y + bbox.H.y)*0.5; const Float zsplit = (bbox.L.z + bbox.H.z)*0.5; // set bounding boxes for children BBox childbb[8] = {bbox, bbox, bbox, bbox, bbox, bbox, bbox, bbox}; for (int i = 0; i < 4; i++) { // this is little obfuscated, so on right are listed affected children // the idea is to cut every axis once per child, making 8 combinations childbb[i].H.x = xsplit; // 0,1,2,3 childbb[i+4].L.x = xsplit; // 4,5,6,7 childbb[i+(i>>1<<1)].H.y = ysplit; // 0,1,4,5 childbb[i+(i>>1<<1)+2].L.y = ysplit;// 2,3,6,7 childbb[i<<1].H.z = zsplit; // 0,2,4,6 childbb[(i<<1)+1].L.z = zsplit; // 1,3,5,7 } // distribute shapes to children ShapeList::iterator sh; unsigned int shapenum = 0; for (sh = shapes->begin(); sh != shapes->end(); sh++) { for (int i = 0; i < 8; i++) if ((*sh)->intersect_bbox(childbb[i])) { getChild(i)->addShape(*sh); shapenum++; } } if ((shapes->size() <= 8 && shapenum > 2*shapes->size()) || shapenum >= 6*shapes->size()) { // bad subdivision, revert delete[] children; return; } // remove shapes and set this node to non-leaf delete shapes; shapes = NULL; // recursive subdivision for (int i = 0; i < 8; i++) if (maxdepth > 1 && getChild(i)->shapes->size() > 4) children[i].subdivide(childbb[i], maxdepth-1);}void Octree::build(){ dbgmsg(1, "* building octree\n"); root = new OctreeNode(); ShapeList::iterator shape; for (shape = shapes.begin(); shape != shapes.end(); shape++) root->addShape(*shape); root->subdivide(bbox, max_depth); built = true;}/*******************************************************octree traversal algorithm as described in paper"An Efficient Parametric Algorithm for Octree Traversal"by J. Revelles, C. Urena and M. Lastra.see revision 37 for original recursive version*******************************************************/struct OctreeTravState{ Float tx0,ty0,tz0,tx1,ty1,tz1,txm,tym,tzm; OctreeNode *node; int next; OctreeTravState() {}; OctreeTravState( const Float atx0, const Float aty0, const Float atz0, const Float atx1, const Float aty1, const Float atz1, const Float atxm, const Float atym, const Float atzm, OctreeNode *const anode, const int anext): tx0(atx0), ty0(aty0), tz0(atz0), tx1(atx1), ty1(aty1), tz1(atz1), txm(atxm), tym(atym), tzm(atzm), node(anode), next(anext) {};};inline const int &next_node(const Float &txm, const int &xnode, const Float &tym, const int &ynode, const Float &tzm, const int &znode){ if (txm < tym) { if (txm < tzm) return xnode; else return znode; } else { if (tym < tzm) return ynode; else return znode; }}Shape * Octree::nearest_intersection(const Shape *origin_shape, const Ray &ray, Float &nearest_distance){ /* if we have no tree, fall back to naive test */ if (!built) return Container::nearest_intersection(origin_shape, ray, nearest_distance); OctreeTravState st[max_depth+1]; register OctreeTravState *st_cur = st;# define node st_cur->node# define tx0 st_cur->tx0# define ty0 st_cur->ty0# define tz0 st_cur->tz0# define tx1 st_cur->tx1# define ty1 st_cur->ty1# define tz1 st_cur->tz1# define txm st_cur->txm# define tym st_cur->tym# define tzm st_cur->tzm int a = 0; Vector3 ro(ray.o); Vector3 rdir(1.0/ray.dir.x, 1.0/ray.dir.y, 1.0/ray.dir.z); if (rdir.x < 0.0) { ro.x = (bbox.L.x+bbox.H.x) - ro.x; rdir.x = -rdir.x; a |= 4; } if (rdir.y < 0.0) { ro.y = (bbox.L.y+bbox.H.y) - ro.y; rdir.y = -rdir.y; a |= 2; } if (rdir.z < 0.0) { ro.z = (bbox.L.z+bbox.H.z) - ro.z; rdir.z = -rdir.z; a |= 1; } tx0 = (bbox.L.x - ro.x) * rdir.x; tx1 = (bbox.H.x - ro.x) * rdir.x; ty0 = (bbox.L.y - ro.y) * rdir.y; ty1 = (bbox.H.y - ro.y) * rdir.y; tz0 = (bbox.L.z - ro.z) * rdir.z; tz1 = (bbox.H.z - ro.z) * rdir.z; if (max3(tx0,ty0,tz0) > min3(tx1,ty1,tz1)) return NULL; node = root; st_cur->next = -1; Shape *nearest_shape = NULL; for (;;) { if (st_cur->next == -1) { st_cur->next = 8; // if ray does intersect this node if (!(tx1 < 0.0 || ty1 < 0.0 || tz1 < 0.0)) { if (node->isLeaf()) { ShapeList::iterator shape; //register Float mindist = max3(tx0,ty0,tz0); register Float dist = min(nearest_distance, min3(tx1,ty1,tz1)); for (shape = node->shapes->begin(); shape != node->shapes->end(); shape++) if (*shape != origin_shape && (*shape)->intersect(ray, dist)) { nearest_shape = *shape; nearest_distance = dist; } if (nearest_shape != NULL) return nearest_shape; } else { txm = 0.5 * (tx0+tx1); tym = 0.5 * (ty0+ty1); tzm = 0.5 * (tz0+tz1); // first node st_cur->next = 0; if (tx0 > ty0) { if (tx0 > tz0) { // YZ if (tym < tx0) st_cur->next |= 2; if (tzm < tx0) st_cur->next |= 1; } else { // XY if (txm < tz0) st_cur->next |= 4; if (tym < tz0) st_cur->next |= 2; } } else { if (ty0 > tz0) { // XZ if (txm < ty0) st_cur->next |= 4; if (tzm < ty0) st_cur->next |= 1; } else { // XY if (txm < tz0) st_cur->next |= 4; if (tym < tz0) st_cur->next |= 2; } } } } } while (st_cur->next == 8) { // pop state from stack if (st_cur == st) return NULL; // nothing to pop, finish --st_cur; } // push current state *(st_cur+1) = *st_cur; ++st_cur; switch (st_cur->next) { case 0: tx1 = txm; ty1 = tym; tz1 = tzm; node = node->getChild(a); (st_cur-1)->next = next_node(txm, 4, tym, 2, tzm, 1); break; case 1: tz0 = tzm; tx1 = txm; ty1 = tym; node = node->getChild(1^a); (st_cur-1)->next = next_node(txm, 5, tym, 3, tz1, 8); break; case 2: ty0 = tym; tx1 = txm; tz1 = tzm; node = node->getChild(2^a); (st_cur-1)->next = next_node(txm, 6, ty1, 8, tzm, 3); break; case 3: ty0 = tym; tz0 = tzm; tx1 = txm; node = node->getChild(3^a); (st_cur-1)->next = next_node(txm, 7, ty1, 8, tz1, 8); break; case 4: tx0 = txm; ty1 = tym; tz1 = tzm; node = node->getChild(4^a); (st_cur-1)->next = next_node(tx1, 8, tym, 6, tzm, 5); break; case 5: tx0 = txm; tz0 = tzm; ty1 = tym; node = node->getChild(5^a); (st_cur-1)->next = next_node(tx1, 8, tym, 7, tz1, 8); break; case 6: tx0 = txm; ty0 = tym; tz1 = tzm; node = node->getChild(6^a); (st_cur-1)->next = next_node(tx1, 8, ty1, 8, tzm, 7); break; case 7: tx0 = txm; ty0 = tym; tz0 = tzm; node = node->getChild(7^a); (st_cur-1)->next = 8; break; } st_cur->next = -1; }}