X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?a=blobdiff_plain;f=src%2Fgeom.c;fp=src%2Fgeom.c;h=996a4849412ab16b529f6c3b34d560124e701ffd;hb=59a8deae3d561aa3797a6bf25c76803fe098cdf0;hp=25c4d0afcd888786cacff9e01ccaeee7a42c21cb;hpb=f1410762198ad4b0ca8c0b47bd484ff2d3e09ddd;p=meshfrac

diff --git a/src/geom.c b/src/geom.c
index 25c4d0a..996a484 100644
--- a/src/geom.c
+++ b/src/geom.c
@@ -10,19 +10,19 @@ float plane_dist(const struct plane *p, const cgm_vec3 *pt)
 
 float plane_sdist(const struct plane *p, const cgm_vec3 *pt)
 {
-	cgm_vec3 v = p->pt;
-	cgm_vsub(&v, pt);
+	cgm_vec3 v = *pt;
+	cgm_vsub(&v, &p->pt);
 	return cgm_vdot(&v, &p->norm);
 }
 
-void midplane(struct plane *p, const cgm_vec3 *a, const cgm_vec3 *b)
+void midplane(struct plane *p, const cgm_vec3 *a, const cgm_vec3 *b, float offs)
 {
 	p->norm = *b;
 	cgm_vsub(&p->norm, a);
 	cgm_vnormalize(&p->norm);
-	p->pt.x = a->x + p->norm.x * 0.5f;
-	p->pt.y = a->y + p->norm.y * 0.5f;
-	p->pt.z = a->z + p->norm.z * 0.5f;
+	p->pt.x = (a->x + b->x) * 0.5f + p->norm.x * offs;
+	p->pt.y = (a->y + b->y) * 0.5f + p->norm.y * offs;
+	p->pt.z = (a->z + b->z) * 0.5f + p->norm.z * offs;
 }
 
 void poly_normal(const struct poly *poly, cgm_vec3 *n)
@@ -170,7 +170,10 @@ static int clip_edge(struct poly *pout, const struct vertex *v0, const struct ve
 			return 1;
 		} else {
 			/* going out */
-			t = ray_plane(&ray, plane);
+			if((t = ray_plane(&ray, plane)) < 0.0f) {
+				t = 0.0f;
+			}
+			assert(t <= 1.0f);
 			cgm_raypos(&vnew.pos, &ray, t);
 
 			cgm_vlerp(&vnew.norm, &v0->norm, &v1->norm, t);
@@ -183,7 +186,10 @@ static int clip_edge(struct poly *pout, const struct vertex *v0, const struct ve
 		/* start outside */
 		if(d1 >= 0) {
 			/* going in */
-			t = ray_plane(&ray, plane);
+			if((t = ray_plane(&ray, plane)) < 0.0f) {
+				t = 0.0f;
+			}
+			assert(t <= 1.0f);
 			cgm_raypos(&vnew.pos, &ray, t);
 
 			cgm_vlerp(&vnew.norm, &v0->norm, &v1->norm, t);