From 32ff3cf2d7d7a5ae82f5ca400b320c67e6984ad6 Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@member.fsf.org>
Date: Sun, 18 Feb 2018 18:54:25 +0200
Subject: [PATCH] BSP construction debugging

---
 src/bsptree.c  |   50 ++++++++++++++++++++++++++++----------------------
 src/bsptree.h  |    2 +-
 src/mesh.c     |    1 +
 src/polytest.c |   10 ++++++++++
 4 files changed, 40 insertions(+), 23 deletions(-)

diff --git a/src/bsptree.c b/src/bsptree.c
index 6ad4046..dc8f2af 100644
--- a/src/bsptree.c
+++ b/src/bsptree.c
@@ -92,7 +92,7 @@ int bsp_add_poly(struct bsptree *bsp, struct g3d_vertex *v, int vnum)
 	return 0;
 }
 
-void bsp_add_mesh(struct bsptree *bsp, struct g3d_mesh *m)
+int bsp_add_mesh(struct bsptree *bsp, struct g3d_mesh *m)
 {
 	int i, j, nfaces;
 	struct g3d_vertex v[4];
@@ -109,8 +109,11 @@ void bsp_add_mesh(struct bsptree *bsp, struct g3d_mesh *m)
 				v[j] = *vptr++;
 			}
 		}
-		bsp_add_poly(bsp, v, m->prim);
+		if(bsp_add_poly(bsp, v, m->prim) == -1) {
+			return -1;
+		}
 	}
+	return 0;
 }
 
 void draw_bsp(struct bsptree *bsp, float view_x, float view_y, float view_z)
@@ -180,39 +183,42 @@ static struct bspnode *add_poly_tree(struct bspnode *n, struct g3d_vertex *v, in
 	clipped = alloca((vnum + 1) * sizeof *clipped);
 
 	clipres = clip_poly(clipped, &clipped_vnum, v, vnum, &n->plane);
-	if(clipres > 0) {	/* polygon completely in the positive subspace */
+	if(clipres > 0) {
+		/* polygon completely in the positive subspace */
 		if(!(nres = add_poly_tree(n->front, v, vnum))) {
 			return 0;
 		}
 		n->front = nres;
-	}
-	if(clipres < 0) {	/* polygon completely in the negative subspace */
+
+	} else if(clipres < 0) {
+		/* polygon completely in the negative subspace */
 		if(!(nres = add_poly_tree(n->back, v, vnum))) {
 			return 0;
 		}
 		n->back = nres;
-	}
 
-	/* polygon is straddling the plane */
-	if(!(nres = add_poly_tree(n->front, clipped, clipped_vnum))) {
-		return 0;
-	}
-	n->front = nres;
+	} else {
+		/* polygon is straddling the plane */
+		if(!(nres = add_poly_tree(n->front, clipped, clipped_vnum))) {
+			return 0;
+		}
+		n->front = nres;
 
-	negplane.x = n->plane.x;
-	negplane.y = n->plane.y;
-	negplane.z = n->plane.z;
-	negplane.nx = -n->plane.nx;
-	negplane.ny = -n->plane.ny;
-	negplane.nz = -n->plane.nz;
+		negplane.x = n->plane.x;
+		negplane.y = n->plane.y;
+		negplane.z = n->plane.z;
+		negplane.nx = -n->plane.nx;
+		negplane.ny = -n->plane.ny;
+		negplane.nz = -n->plane.nz;
 
-	clipres = clip_poly(clipped, &clipped_vnum, v, vnum, &negplane);
-	assert(clipres == 0);
+		clipres = clip_poly(clipped, &clipped_vnum, v, vnum, &negplane);
+		/*assert(clipres == 0);*/
 
-	if(!(nres = add_poly_tree(n->back, clipped, clipped_vnum))) {
-		return 0;
+		if(!(nres = add_poly_tree(n->back, clipped, clipped_vnum))) {
+			return 0;
+		}
+		n->back = nres;
 	}
-	n->back = nres;
 	return n;
 }
 
diff --git a/src/bsptree.h b/src/bsptree.h
index 53b4cd2..ff29051 100644
--- a/src/bsptree.h
+++ b/src/bsptree.h
@@ -23,7 +23,7 @@ int save_bsp(struct bsptree *bsp, const char *fname);
 int load_bsp(struct bsptree *bsp, const char *fname);
 
 int bsp_add_poly(struct bsptree *bsp, struct g3d_vertex *v, int vnum);
-void bsp_add_mesh(struct bsptree *bsp, struct g3d_mesh *m);
+int bsp_add_mesh(struct bsptree *bsp, struct g3d_mesh *m);
 
 void draw_bsp(struct bsptree *bsp, float view_x, float view_y, float view_z);
 
diff --git a/src/mesh.c b/src/mesh.c
index bde8266..0dc6bf6 100644
--- a/src/mesh.c
+++ b/src/mesh.c
@@ -394,6 +394,7 @@ int gen_torus_mesh(struct g3d_mesh *mesh, float rad, float ringrad, int usub, in
 			int chess = (i & 1) == (j & 1);
 
 			torusvec(&vptr->x, theta, phi, rad, ringrad);
+			vptr->w = 1.0f;
 
 			vptr->nx = (vptr->x - rcent[0]) / ringrad;
 			vptr->ny = (vptr->y - rcent[1]) / ringrad;
diff --git a/src/polytest.c b/src/polytest.c
index 85b3128..8d81262 100644
--- a/src/polytest.c
+++ b/src/polytest.c
@@ -9,6 +9,7 @@
 #include "polyfill.h"	/* just for struct pimage */
 #include "cfgopt.h"
 #include "mesh.h"
+#include "bsptree.h"
 
 static int init(void);
 static void destroy(void);
@@ -28,6 +29,7 @@ static struct screen scr = {
 static float cam_theta, cam_phi = 25;
 static float cam_dist = 3;
 static struct g3d_mesh cube, torus;
+static struct bsptree torus_bsp;
 
 static struct pimage tex;
 
@@ -52,6 +54,12 @@ static int init(void)
 		torus.varr[i].v *= 2.0;
 	}
 
+	init_bsp(&torus_bsp);
+	if(bsp_add_mesh(&torus_bsp, &torus) == -1) {
+		fprintf(stderr, "failed to construct torus BSP tree\n");
+		return -1;
+	}
+
 	gen_texture(&tex, 128, 128);
 
 #ifdef DEBUG_POLYFILL
@@ -70,6 +78,7 @@ static void destroy(void)
 	free(cube.varr);
 	free(torus.varr);
 	free(torus.iarr);
+	destroy_bsp(&torus_bsp);
 }
 
 static void start(long trans_time)
@@ -115,6 +124,7 @@ static void draw(void)
 	g3d_set_texture(tex.width, tex.height, tex.pixels);
 
 	draw_mesh(&torus);
+	/*draw_bsp(&torus_bsp);*/
 
 	/*draw_mesh(&cube);*/
 	swap_buffers(fb_pixels);
-- 
1.7.10.4