5 files changed, 16 insertions, 19 deletions

diff --git a/camera.c b/camera.c
index 82d0b0b..eb6f181 100644
--- a/camera.c
+++ b/camera.c
@@ -17,6 +17,7 @@ updatestats(Camera *c, uvlong v)
 	c->stats.avg = c->stats.acc/c->stats.n;
 	c->stats.min = v < c->stats.min || c->stats.n == 1? v: c->stats.min;
 	c->stats.max = v > c->stats.max || c->stats.n == 1? v: c->stats.max;
+	c->stats.nframes++;
 }
 
 static void
diff --git a/graphics.h b/graphics.h
index 94ce2ea..af8cdd0 100644
--- a/graphics.h
+++ b/graphics.h
@@ -210,6 +210,7 @@ struct Camera
 
 	struct {
 		uvlong min, avg, max, acc, n, v;
+		uvlong nframes;
 	} stats;
 };
 
@@ -256,6 +257,7 @@ double fmax(double, double);
 Memimage *rgb(ulong);
 
 /* shadeop */
+double sign(double);
 double step(double, double);
 double smoothstep(double, double, double);
 
diff --git a/render.c b/render.c
index aba3d45..d88f6c3 100644
--- a/render.c
+++ b/render.c
@@ -323,7 +323,7 @@ rasterize(SUparams *params, Triangle t)
 			if(bc.x < 0 || bc.y < 0 || bc.z < 0)
 				continue;
 
-			z = t[0].p.z*bc.x + t[1].p.z*bc.y + t[2].p.z*bc.z;
+			z = fberp(t[0].p.z, t[1].p.z, t[2].p.z, bc);
 			depth = fclamp(z, 0, 1);
 			lock(&params->fb->zbuflk);
 			if(depth <= params->fb->zbuf[p.x + p.y*Dx(params->fb->r)]){
@@ -334,7 +334,7 @@ rasterize(SUparams *params, Triangle t)
 			unlock(&params->fb->zbuflk);
 
 			/* interpolate z⁻¹ and get actual z */
-			z = t[0].p.w*bc.x + t[1].p.w*bc.y + t[2].p.w*bc.z;
+			z = fberp(t[0].p.w, t[1].p.w, t[2].p.w, bc);
 			z = 1.0/(z < 1e-5? 1e-5: z);
 
 			/* perspective-correct attribute interpolation  */
diff --git a/shadeop.c b/shadeop.c
index c1484c3..c6080e3 100644
--- a/shadeop.c
+++ b/shadeop.c
@@ -9,6 +9,12 @@
 #include "internal.h"
 
 double
+sign(double n)
+{
+	return n == 0? 0: n < 0? -1: 1;
+}
+
+double
 step(double edge, double n)
 {
 	if(n < edge)
diff --git a/vertex.c b/vertex.c
index d18d9ac..bc7759f 100644
--- a/vertex.c
+++ b/vertex.c
@@ -76,18 +76,9 @@ berpvertex(Vertex *v, Vertex *v0, Vertex *v1, Vertex *v2, Point3 bc)
 	Vertexattr va;
 	int i;
 
-	v->n = addpt3(addpt3(
-		mulpt3(v0->n, bc.x),
-		mulpt3(v1->n, bc.y)),
-		mulpt3(v2->n, bc.z));
-	v->c = addpt3(addpt3(
-		mulpt3(v0->c, bc.x),
-		mulpt3(v1->c, bc.y)),
-		mulpt3(v2->c, bc.z));
-	v->uv = addpt2(addpt2(
-		mulpt2(v0->uv, bc.x),
-		mulpt2(v1->uv, bc.y)),
-		mulpt2(v2->uv, bc.z));
+	v->n = berp3(v0->n, v1->n, v2->n, bc);
+	v->c = berp3(v0->c, v1->c, v2->c, bc);
+	v->uv = berp2(v0->uv, v1->uv, v2->uv, bc);
 	v->mtl = v0->mtl != nil? v0->mtl: v1->mtl != nil? v1->mtl: v2->mtl;
 	v->attrs = nil;
 	v->nattrs = 0;
@@ -95,12 +86,9 @@ berpvertex(Vertex *v, Vertex *v0, Vertex *v1, Vertex *v2, Point3 bc)
 		va.id = v0->attrs[i].id;
 		va.type = v0->attrs[i].type;
 		if(va.type == VAPoint)
-			va.p = addpt3(addpt3(
-				mulpt3(v0->attrs[i].p, bc.x),
-				mulpt3(v1->attrs[i].p, bc.y)),
-				mulpt3(v2->attrs[i].p, bc.z));
+			va.p = berp3(v0->attrs[i].p, v1->attrs[i].p, v2->attrs[i].p, bc);
 		else
-			va.n = dotvec3(Vec3(v0->attrs[i].n, v1->attrs[i].n, v2->attrs[i].n), bc);
+			va.n = fberp(v0->attrs[i].n, v1->attrs[i].n, v2->attrs[i].n, bc);
 		_addvattr(v, &va);
 	}
 }