--- /dev/null
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <assert.h>
+#if defined(__WATCOMC__) || defined(_MSC_VER) || defined(__DJGPP__)
+#include <malloc.h>
+#else
+#include <alloca.h>
+#endif
+#include "bsptree.h"
+#include "dynarr.h"
+#include "inttypes.h"
+#include "polyclip.h"
+#include "vmath.h"
+#include "util.h"
+
+struct bspfile_header {
+ char magic[4];
+ uint32_t num_nodes;
+};
+
+static int count_nodes(struct bspnode *n);
+static void free_tree(struct bspnode *n);
+
+static int init_poly(struct bsppoly *poly, struct g3d_vertex *v, int vnum);
+static int init_poly_noplane(struct bsppoly *poly, struct g3d_vertex *v, int vnum);
+
+static struct bspnode *build_tree(struct bsppoly *polyarr, int num_polys);
+
+static void draw_bsp_tree(struct bspnode *n, const vec3_t *vdir);
+
+static void save_bsp_tree(struct bspnode *n, FILE *fp);
+static struct bspnode *load_bsp_tree(FILE *fp);
+
+int init_bsp(struct bsptree *bsp)
+{
+ bsp->root = 0;
+ bsp->soup = 0;
+ return 0;
+}
+
+void destroy_bsp(struct bsptree *bsp)
+{
+ int i;
+
+ free_tree(bsp->root);
+
+ if(bsp->soup) {
+ for(i=0; i<dynarr_size(bsp->soup); i++) {
+ free(bsp->soup[i].verts);
+ }
+ dynarr_free(bsp->soup);
+ }
+}
+
+int save_bsp(struct bsptree *bsp, const char *fname)
+{
+ FILE *fp;
+ struct bspfile_header hdr;
+
+ if(!(fp = fopen(fname, "wb"))) {
+ fprintf(stderr, "save_bsp: failed to open %s for writing\n", fname);
+ return -1;
+ }
+
+ memcpy(hdr.magic, "MBSP", 4);
+ hdr.num_nodes = count_nodes(bsp->root);
+ fwrite(&hdr, sizeof hdr, 1, fp);
+
+ save_bsp_tree(bsp->root, fp);
+
+ fclose(fp);
+ return 0;
+}
+
+int load_bsp(struct bsptree *bsp, const char *fname)
+{
+ FILE *fp;
+ struct bspfile_header hdr;
+
+ if(!(fp = fopen(fname, "rb"))) {
+ fprintf(stderr, "load_bsp: failed to open %s\n", fname);
+ return -1;
+ }
+
+ if(fread(&hdr, sizeof hdr, 1, fp) < 1) {
+ fprintf(stderr, "load_bsp: %s: failed to read header\n", fname);
+ fclose(fp);
+ return -1;
+ }
+ if(memcmp(hdr.magic, "MBSP", 4) != 0) {
+ fprintf(stderr, "load_bsp: %s: invalid magic\n", fname);
+ fclose(fp);
+ return -1;
+ }
+ bsp->root = load_bsp_tree(fp);
+
+ fclose(fp);
+ return 0;
+}
+
+int bsp_add_poly(struct bsptree *bsp, struct g3d_vertex *v, int vnum)
+{
+ struct bsppoly poly, *tmp;
+
+ if(!bsp->soup && !(bsp->soup = dynarr_alloc(0, sizeof *bsp->soup))) {
+ fprintf(stderr, "bsp_add_poly: failed to create polygon soup dynamic array\n");
+ return -1;
+ }
+
+ if(init_poly(&poly, v, vnum) == -1) {
+ return -1;
+ }
+
+ if(!(tmp = dynarr_push(bsp->soup, &poly))) {
+ fprintf(stderr, "bsp_add_poly: failed to reallocate polygon soup\n");
+ free(poly.verts);
+ return -1;
+ }
+ bsp->soup = tmp;
+
+ return 0;
+}
+
+int bsp_add_mesh(struct bsptree *bsp, struct g3d_mesh *m)
+{
+ int i, j, nfaces;
+ struct g3d_vertex v[4];
+ struct g3d_vertex *vptr = m->varr;
+ uint16_t *iptr = m->iarr;
+
+ nfaces = m->iarr ? m->icount / m->prim : m->vcount / m->prim;
+
+ for(i=0; i<nfaces; i++) {
+ for(j=0; j<m->prim; j++) {
+ if(m->iarr) {
+ v[j] = m->varr[*iptr++];
+ } else {
+ v[j] = *vptr++;
+ }
+ }
+ if(bsp_add_poly(bsp, v, m->prim) == -1) {
+ return -1;
+ }
+ }
+ return 0;
+}
+
+int bsp_build(struct bsptree *bsp)
+{
+ assert(bsp->soup);
+ assert(!dynarr_empty(bsp->soup));
+
+ free_tree(bsp->root);
+
+ printf("building BSP tree with %d source polygons ...\n", dynarr_size(bsp->soup));
+ if(!(bsp->root = build_tree(bsp->soup, dynarr_size(bsp->soup)))) {
+ fprintf(stderr, "bsp_build failed\n");
+ return -1;
+ }
+ printf("done. created a tree with %d nodes\n", count_nodes(bsp->root));
+
+ /* build_tree has called dynarr_free on bsp->soup */
+ bsp->soup = 0;
+
+ return 0;
+}
+
+void draw_bsp(struct bsptree *bsp, float view_x, float view_y, float view_z)
+{
+ vec3_t vdir;
+
+ assert(bsp->root);
+
+ vdir.x = view_x;
+ vdir.y = view_y;
+ vdir.z = view_z;
+ draw_bsp_tree(bsp->root, &vdir);
+}
+
+static int count_nodes(struct bspnode *n)
+{
+ if(!n) return 0;
+ return count_nodes(n->front) + count_nodes(n->back) + 1;
+}
+
+static void free_tree(struct bspnode *n)
+{
+ if(n) {
+ free_tree(n->front);
+ free_tree(n->back);
+ free(n->poly.verts);
+ free(n);
+ }
+}
+
+
+static int init_poly(struct bsppoly *poly, struct g3d_vertex *v, int vnum)
+{
+ vec3_t va, vb, norm;
+
+ if(init_poly_noplane(poly, v, vnum) == -1) {
+ return -1;
+ }
+
+ va.x = v[1].x - v[0].x;
+ va.y = v[1].y - v[0].y;
+ va.z = v[1].z - v[0].z;
+ vb.x = v[2].x - v[0].x;
+ vb.y = v[2].y - v[0].y;
+ vb.z = v[2].z - v[0].z;
+ norm = v3_cross(va, vb);
+ v3_normalize(&norm);
+
+ poly->plane.x = v[0].x;
+ poly->plane.y = v[0].y;
+ poly->plane.z = v[0].z;
+ poly->plane.nx = norm.x;
+ poly->plane.ny = norm.y;
+ poly->plane.nz = norm.z;
+ return 0;
+}
+
+static int init_poly_noplane(struct bsppoly *poly, struct g3d_vertex *v, int vnum)
+{
+ if(!(poly->verts = malloc(vnum * sizeof *poly->verts))) {
+ fprintf(stderr, "failed to allocate BSP polygon\n");
+ return -1;
+ }
+ poly->vcount = vnum;
+ memcpy(poly->verts, v, vnum * sizeof *poly->verts);
+ return 0;
+}
+
+static int choose_poly(struct bsppoly *polyarr, int num_polys)
+{
+ int i, j, best, best_splits;
+
+ if(num_polys <= 1) {
+ return 0;
+ }
+
+ best = -1;
+ best_splits = INT_MAX;
+
+ for(i=0; i<num_polys; i++) {
+ struct cplane *plane = &polyarr[i].plane;
+ int num_splits = 0;
+
+#pragma omp parallel for reduction(+:num_splits)
+ for(j=0; j<num_polys; j++) {
+ if(i == j) continue;
+
+ if(check_clip_poly(polyarr[j].verts, polyarr[j].vcount, plane) == 0) {
+ num_splits++;
+ }
+ }
+
+ if(num_splits < best_splits) {
+ best_splits = num_splits;
+ best = i;
+ }
+ }
+
+ //printf("choose_poly(..., %d) -> %d splits\n", num_polys, best_splits);
+
+ return best;
+}
+
+static struct bspnode *build_tree(struct bsppoly *polyarr, int num_polys)
+{
+ int i, pidx, vnum;
+ struct bsppoly *sp, *tmp;
+ struct bsppoly *front_polys, *back_polys;
+ struct bspnode *node;
+
+ struct bspnode *nres;
+ int clipres, clipres_neg, clipped_vnum, clipped_neg_vnum, max_clipped_vnum = 0;
+ struct g3d_vertex *v, *clipped = 0, *clipped_neg = 0;
+ struct cplane negplane;
+
+ if((pidx = choose_poly(polyarr, num_polys)) == -1) {
+ return 0;
+ }
+ sp = polyarr + pidx;
+
+ negplane.x = sp->plane.x;
+ negplane.y = sp->plane.y;
+ negplane.z = sp->plane.z;
+ negplane.nx = -sp->plane.nx;
+ negplane.ny = -sp->plane.ny;
+ negplane.nz = -sp->plane.nz;
+
+ if(!(front_polys = dynarr_alloc(0, sizeof *front_polys)) ||
+ !(back_polys = dynarr_alloc(0, sizeof *back_polys))) {
+ fprintf(stderr, "build_tree: failed to allocate front/back polygon arrays\n");
+ dynarr_free(front_polys);
+ return 0;
+ }
+
+ for(i=0; i<num_polys; i++) {
+ if(i == pidx) continue;
+
+ vnum = polyarr[i].vcount;
+
+ if(vnum * 2 > max_clipped_vnum) {
+ /* resize clipped polygon buffers if necessary */
+ max_clipped_vnum = vnum * 2;
+ if(!(v = realloc(clipped, max_clipped_vnum * sizeof *clipped))) {
+ fprintf(stderr, "build_tree: failed to reallocate clipped polygon buffer\n");
+ goto fail;
+ }
+ clipped = v;
+ if(!(v = realloc(clipped_neg, max_clipped_vnum * sizeof *clipped))) {
+ fprintf(stderr, "build_tree: failed to reallocate clipped polygon buffer\n");
+ goto fail;
+ }
+ clipped_neg = v;
+ }
+
+ v = polyarr[i].verts;
+
+ clipres = clip_poly(clipped, &clipped_vnum, v, vnum, &sp->plane);
+ clipres_neg = clip_poly(clipped_neg, &clipped_neg_vnum, v, vnum, &negplane);
+
+ /* detect edge cases where due to floating point imprecision, clipping
+ * by the positive plane clips the polygon, but clipping by the negative
+ * plane doesn't. If that happens, consider the polygon completely on
+ * the side indicated by -clipres_neg
+ */
+ if(clipres == 0 && clipres_neg != 0) {
+ clipres = -clipres_neg;
+ }
+
+ if(clipres > 0) {
+ /* polygon completely in the positive subspace */
+ if(!(tmp = dynarr_push(front_polys, polyarr + i))) {
+ fprintf(stderr, "build_tree: failed to reallocate polygon array\n");
+ goto fail;
+ }
+ front_polys = tmp;
+
+ } else if(clipres < 0) {
+ /* polygon completely in the negative subspace */
+ if(!(tmp = dynarr_push(back_polys, polyarr + i))) {
+ fprintf(stderr, "build_tree: failed to reallocate polygon array\n");
+ goto fail;
+ }
+ back_polys = tmp;
+
+ } else {
+ /* polygon is straddling the plane */
+ struct bsppoly poly;
+ poly.plane = polyarr[i].plane;
+
+ if(init_poly_noplane(&poly, clipped, clipped_vnum) == -1) {
+ goto fail;
+ }
+ if(!(tmp = dynarr_push(front_polys, &poly))) {
+ fprintf(stderr, "build_tree: failed to reallocate polygon array\n");
+ free(poly.verts);
+ goto fail;
+ }
+ front_polys = tmp;
+
+ if(init_poly_noplane(&poly, clipped_neg, clipped_neg_vnum) == -1) {
+ goto fail;
+ }
+ if(!(tmp = dynarr_push(back_polys, &poly))) {
+ fprintf(stderr, "build_tree: failed to reallocate polygon array\n");
+ free(poly.verts);
+ goto fail;
+ }
+ back_polys = tmp;
+
+ /* we allocated new sub-polygons, so we need to free the original vertex array */
+ free(polyarr[i].verts);
+ }
+ }
+
+ if(!(node = malloc(sizeof *node))) {
+ fprintf(stderr, "build_tree: failed to allocate new BSP node\n");
+ goto fail;
+ }
+ node->poly = *sp;
+ node->front = node->back = 0;
+
+ if(dynarr_size(front_polys)) {
+ if(!(node->front = build_tree(front_polys, dynarr_size(front_polys)))) {
+ goto fail;
+ }
+ }
+ if(dynarr_size(back_polys)) {
+ if(!(node->back = build_tree(back_polys, dynarr_size(back_polys)))) {
+ goto fail;
+ }
+ }
+
+ free(clipped);
+ free(clipped_neg);
+
+ /* we no longer need the original polygon array */
+ dynarr_free(polyarr);
+
+ return node;
+
+fail:
+ free(clipped);
+ free(clipped_neg);
+
+ for(i=0; i<dynarr_size(front_polys); i++) {
+ free(front_polys[i].verts);
+ }
+ dynarr_free(front_polys);
+
+ for(i=0; i<dynarr_size(back_polys); i++) {
+ free(back_polys[i].verts);
+ }
+ dynarr_free(back_polys);
+
+ return 0;
+}
+
+#undef DRAW_NGONS
+
+#ifndef DRAW_NGONS
+static void debug_draw_poly(struct g3d_vertex *varr, int vcount)
+{
+ int i, nfaces = vcount - 2;
+ int vbuf_size = nfaces * 3;
+ struct g3d_vertex *vbuf = alloca(vbuf_size * sizeof *vbuf);
+ struct g3d_vertex *vptr = varr + 1;
+
+ for(i=0; i<nfaces; i++) {
+ vbuf[i * 3] = varr[0];
+ vbuf[i * 3 + 1] = *vptr++;
+ vbuf[i * 3 + 2] = *vptr;
+ }
+
+ g3d_draw_indexed(G3D_TRIANGLES, vbuf, vbuf_size, 0, 0);
+}
+#endif
+
+static void draw_bsp_tree(struct bspnode *n, const vec3_t *vdir)
+{
+ float dot;
+ struct bsppoly *p;
+
+ if(!n) return;
+
+ p = &n->poly;
+
+ dot = vdir->x * p->plane.nx + vdir->y * p->plane.ny + vdir->z * p->plane.nz;
+ if(dot >= 0.0f) {
+ draw_bsp_tree(n->front, vdir);
+#ifdef DRAW_NGONS
+ g3d_draw_indexed(p->vcount, p->verts, p->vcount, 0, 0);
+#else
+ debug_draw_poly(p->verts, p->vcount);
+#endif
+ draw_bsp_tree(n->back, vdir);
+ } else {
+ draw_bsp_tree(n->back, vdir);
+#ifdef DRAW_NGONS
+ g3d_draw_indexed(p->vcount, p->verts, p->vcount, 0, 0);
+#else
+ debug_draw_poly(p->verts, p->vcount);
+#endif
+ draw_bsp_tree(n->front, vdir);
+ }
+}
+
+static void save_bsp_tree(struct bspnode *n, FILE *fp)
+{
+ /* TODO */
+}
+
+static struct bspnode *load_bsp_tree(FILE *fp)
+{
+ return 0; /* TODO */
+}
projects / dosrtxon / blobdiff