add phong interpolation (lighting)

[chaz/rasterize] / raster.c

diff --git a/raster.c b/raster.c
index aca2c5a860315c0cc70f44c8cab3069fb1ce0441..766e6ea7ba4ce6cb22ad0b687e5eccd8bc377c0e 100644 (file)
--- a/raster.c
+++ b/raster.c
@@ -61,7 +61,7 @@ raster_t* raster_alloc(int width, int height, color_t fill)
     p->specular = COLOR_WHITE;
     p->shininess = S(1.0);
 #endif
- /*= light_new(COLOR_WHITE, vec_new(S(-2.0), S(4.0), S(0.0)));*/
+
     p->zbuf = (scal_t*)mem_alloc(sizeof(scal_t) * size);
     for (size_t i = 0; i < size; ++i) {
         p->zbuf[i] = S(1.0);
@@ -304,7 +304,7 @@ bool _try_cull_backface(tri_t t)
  * Determine what color is associated with the given vertex.
  */
 INLINE_MAYBE
-color_t _get_vertex_color(raster_t* p, vert_t vert)
+color_t _do_phong_lighting(raster_t* p, vert_t vert)
 {
 #if LIGHTING
     color_t color = COLOR_BLACK;
@@ -315,7 +315,7 @@ color_t _get_vertex_color(raster_t* p, vert_t vert)
         vec_t   vpos = p->eye;
         vec_t   n = vert.n;
         vec_t   l = vec_normalize(vec_sub(lpos, mpos));
-        vec_t   r = vec_sub(vec_scale(n, S(2.0) * vec_dot(n, l)), l);
+        vec_t   r = vec_normalize(vec_sub(vec_scale(n, S(2.0) * vec_dot(n, l)), l));
         vec_t   v = vec_normalize(vec_sub(vpos, mpos));
 
         scal_t  kd = scal_max(vec_dot(l, n), S(0.0));
@@ -364,17 +364,34 @@ void raster_draw_tri(raster_t* p, const tri_t* triangle)
         return;
     }
 
-    tri_t   temp = tri_transform(*triangle, p->model);
-#if LIGHTING && (!PRE_NORMALS || (!SMOOTH_COLOR && PRE_NORMALS >= 2))
-    temp.a.n = temp.b.n = temp.c.n = vec_normalize(tri_normal(temp));
+#if LIGHTING >= 1
+    tri_t tl = tri_transform(*triangle, p->model);
+#if !PRE_NORMALS
+    tl.a.n = tl.b.n = tl.c.n = vec_normalize(tri_normal(tl));
 #endif
-#if !SMOOTH_COLOR
-    temp.a.c = tri_color(temp);
 #endif
-    color_t color1 = _get_vertex_color(p, temp.a);
-#if SMOOTH_COLOR
-    color_t color2 = _get_vertex_color(p, temp.b);
-    color_t color3 = _get_vertex_color(p, temp.c);
+
+#if LIGHTING == 1
+    vert_t tv = vert_new(tri_midpoint(tl));
+    tv.n = vec_normalize(tri_normal(tl));
+    tv.c = tri_color(tl);
+    color_t color = _do_phong_lighting(p, tv);
+#elif LIGHTING == 2 && SMOOTH_COLOR
+    color_t color1 = _do_phong_lighting(p, tl.a);
+    color_t color2 = _do_phong_lighting(p, tl.b);
+    color_t color3 = _do_phong_lighting(p, tl.c);
+#elif LIGHTING == 2 && !SMOOTH_COLOR
+    color_t c = tri_color(t);
+    tl.a.c = tl.b.c = tl.c.c = c;
+    color_t color1 = _do_phong_lighting(p, tl.a);
+    color_t color2 = _do_phong_lighting(p, tl.b);
+    color_t color3 = _do_phong_lighting(p, tl.c);
+#elif !LIGHTING && SMOOTH_COLOR
+    color_t color1 = t.a.c;
+    color_t color2 = t.b.c;
+    color_t color3 = t.c.c;
+#else
+    color_t color = tri_color(t);
 #endif
 
     for (int y = bottom; y < top; ++y) {
@@ -388,11 +405,20 @@ void raster_draw_tri(raster_t* p, const tri_t* triangle)
                 if (S(-1.0) < v.z && v.z < *n) {
 #endif
                     color_t* c = p->pixels + y * p->w + x;
-#if SMOOTH_COLOR
+
+#if LIGHTING == 2 || (!LIGHTING && SMOOTH_COLOR)
                     *c = color_interp2(color1, color2, color3, b);
+#elif LIGHTING == 3 && SMOOTH_COLOR
+                    *c = _do_phong_lighting(p, tri_interp(tl, b));
+#elif LIGHTING == 3 && !SMOOTH_COLOR
+                    vert_t d = vert_new(tri_point(t, b));
+                    d.c = tri_color(t);
+                    d.n = tri_normal2(t, b);
+                    *c = _do_phong_lighting(p, d);
 #else
-                    *c = color1;
+                    *c = color;
 #endif
+
 #if DEPTH_TEST
                     *n = v.z;
                 }