+/*
+ * Get an interpolated z-value at the barycentric coordinates.
+ */
+INLINE_MAYBE
+scal_t tri_z(tri_t t, scal_t b[3])
+{
+ return t.a.v.z * b[0] + t.b.v.z * b[1] + t.c.v.z * b[2];
+}
+
+/*
+ * Calculate an interpolated point.
+ */
+INLINE_MAYBE
+vec_t tri_point(tri_t t, scal_t b[3])
+{
+ return vec_interp(t.a.v, t.b.v, t.c.v, b);
+}
+
+/*
+ * Calculate an interpolated normal.
+ */
+INLINE_MAYBE
+vec_t tri_normal2(tri_t t, scal_t b[3])
+{
+ return vec_normalize(vec_interp(t.a.n, t.b.n, t.c.n, b));
+}
+
+/*
+ * Calculate an interpolated texture coordinate.
+ */
+INLINE_MAYBE
+vec_t tri_tcoord(tri_t t, scal_t b[3])
+{
+#if PERSPECTIVE_FIX
+ return vec_tinterp(t.a.t, t.b.t, t.c.t, b);
+#else
+ return vec_interp(t.a.t, t.b.t, t.c.t, b);
+#endif
+}
+
+/*
+ * Calculate an entirely new vertex within the triangle based on barycentric
+ * coordinates.
+ */
+INLINE_MAYBE
+vert_t tri_interp(tri_t t, scal_t b[3])
+{
+ vert_t v = vert_new(tri_point(t, b));
+ v.c = color_interp2(t.a.c, t.b.c, t.c.c, b);
+ v.n = tri_normal2(t, b);
+ v.t = tri_tcoord(t, b);
+ return v;
+}
+
+