Separate finishes into single-purpose finishes.

1 files changed, 153 insertions, 21 deletions

diff --git a/libdimension/finishes.c b/libdimension/finishes.c
index a7cfaea..a8347bd 100644
--- a/libdimension/finishes.c
+++ b/libdimension/finishes.c
@@ -22,7 +22,151 @@
 #include <stdlib.h> /* For malloc */
 #include <math.h>
 
-dmnsn_color
+/*
+ * Finish combinations
+ */
+
+static dmnsn_color
+dmnsn_finish_combination_fn(const dmnsn_finish *finish,
+                            dmnsn_color light, dmnsn_color color,
+                            dmnsn_vector ray, dmnsn_vector normal,
+                            dmnsn_vector viewer)
+{
+  dmnsn_finish **params = finish->ptr;
+  if (params[0]->finish_fn && params[1]->finish_fn) {
+    return dmnsn_color_add((*params[0]->finish_fn)(params[0], light, color, ray,
+                                                   normal, viewer),
+                           (*params[1]->finish_fn)(params[1], light, color, ray,
+                                                   normal, viewer));
+  } else if (params[0]->finish_fn) {
+    return (*params[0]->finish_fn)(params[0], light, color, ray,
+                                   normal, viewer);
+  } else if (params[1]->finish_fn) {
+    return (*params[1]->finish_fn)(params[1], light, color, ray,
+                                   normal, viewer);
+  } else {
+    return dmnsn_black;
+  }
+}
+
+static dmnsn_color
+dmnsn_finish_combination_ambient_fn(const dmnsn_finish *finish,
+                                    dmnsn_color pigment)
+{
+  dmnsn_finish **params = finish->ptr;
+  if (params[0]->ambient_fn && params[1]->ambient_fn) {
+    return dmnsn_color_add((*params[0]->ambient_fn)(params[0], pigment),
+                           (*params[1]->ambient_fn)(params[1], pigment));
+  } else if (params[0]->ambient_fn) {
+    return (*params[0]->ambient_fn)(params[0], pigment);
+  } else if (params[1]->ambient_fn) {
+    return (*params[1]->ambient_fn)(params[1], pigment);
+  } else {
+    return dmnsn_black;
+  }
+}
+
+static void
+dmnsn_finish_combination_free_fn(void *ptr)
+{
+  dmnsn_finish **params = ptr;
+  dmnsn_delete_finish(params[0]);
+  dmnsn_delete_finish(params[1]);
+  free(ptr);
+}
+
+dmnsn_finish *
+dmnsn_new_finish_combination(dmnsn_finish *f1, dmnsn_finish *f2)
+{
+  dmnsn_finish *finish = dmnsn_new_finish();
+  if (finish) {
+    dmnsn_finish **params = malloc(2*sizeof(dmnsn_finish *));
+    if (!params) {
+      dmnsn_delete_finish(finish);
+      return NULL;
+    }
+
+    params[0] = f1;
+    params[1] = f2;
+
+    finish->ptr        = params;
+    finish->finish_fn  = &dmnsn_finish_combination_fn;
+    finish->ambient_fn = &dmnsn_finish_combination_ambient_fn;
+    finish->free_fn    = &dmnsn_finish_combination_free_fn;
+  }
+  return finish;
+}
+
+/*
+ * Ambient finish
+ */
+
+static dmnsn_color
+dmnsn_ambient_finish_fn(const dmnsn_finish *finish, dmnsn_color pigment)
+{
+  dmnsn_color *ambient = finish->ptr;
+  return dmnsn_color_illuminate(*ambient, pigment);
+}
+
+dmnsn_finish *
+dmnsn_new_ambient_finish(dmnsn_color ambient)
+{
+  dmnsn_finish *finish = dmnsn_new_finish();
+  if (finish) {
+    dmnsn_color *param = malloc(sizeof(dmnsn_color));
+    if (!param) {
+      dmnsn_delete_finish(finish);
+      return NULL;
+    }
+
+    *param = ambient;
+    finish->ptr        = param;
+    finish->ambient_fn = &dmnsn_ambient_finish_fn;
+    finish->free_fn    = &free;
+  }
+  return finish;
+}
+
+/*
+ * Diffuse finish
+ */
+
+static dmnsn_color
+dmnsn_diffuse_finish_fn(const dmnsn_finish *finish,
+                        dmnsn_color light, dmnsn_color color,
+                        dmnsn_vector ray, dmnsn_vector normal,
+                        dmnsn_vector viewer)
+{
+  double *diffuse = finish->ptr;
+  double diffuse_factor = (*diffuse)*dmnsn_vector_dot(ray, normal);
+  return dmnsn_color_mul(diffuse_factor, dmnsn_color_illuminate(light, color));
+}
+
+dmnsn_finish *
+dmnsn_new_diffuse_finish(double diffuse)
+{
+  dmnsn_finish *finish = dmnsn_new_finish();
+  if (finish) {
+    double *param = malloc(sizeof(double));
+    if (!param) {
+      dmnsn_delete_finish(finish);
+      return NULL;
+    }
+
+    *param = diffuse;
+
+    finish->ptr       = param;
+    finish->finish_fn = &dmnsn_diffuse_finish_fn;
+    finish->free_fn   = &free;
+  }
+  return finish;
+}
+
+/*
+ * Phong finish
+ */
+
+static dmnsn_color
 dmnsn_phong_finish_fn(const dmnsn_finish *finish,
                       dmnsn_color light, dmnsn_color color,
                       dmnsn_vector ray, dmnsn_vector normal,
@@ -30,42 +174,30 @@ dmnsn_phong_finish_fn(const dmnsn_finish *finish,
 {
   double *params = finish->ptr;
 
-  double diffuse  = params[0];
-  double specular = params[1];
-  double exp      = params[2];
-
-  /* Diffuse component */
-  double diffuse_factor = diffuse*dmnsn_vector_dot(ray, normal);
-  dmnsn_color diffuse_color
-    = dmnsn_color_mul(diffuse_factor, dmnsn_color_illuminate(light, color));
-
-  /* Specular component */
+  double specular = params[0];
+  double exp      = params[1];
 
   dmnsn_vector proj = dmnsn_vector_mul(2*dmnsn_vector_dot(ray, normal), normal);
   dmnsn_vector reflected = dmnsn_vector_sub(proj, ray);
 
-  double specular_factor
-    = specular*pow(dmnsn_vector_dot(reflected, viewer), exp);
-  dmnsn_color specular_color = dmnsn_color_mul(specular_factor, light);
-
-  return dmnsn_color_add(diffuse_color, specular_color);
+  double specular_factor = pow(dmnsn_vector_dot(reflected, viewer), exp);
+  return dmnsn_color_mul(specular*specular_factor, light);
 }
 
 /* A phong finish */
 dmnsn_finish *
-dmnsn_new_phong_finish(double diffuse, double specular, double exp)
+dmnsn_new_phong_finish(double specular, double exp)
 {
   dmnsn_finish *finish = dmnsn_new_finish();
   if (finish) {
-    double *params = malloc(3*sizeof(double));
+    double *params = malloc(2*sizeof(double));
     if (!params) {
       dmnsn_delete_finish(finish);
       return NULL;
     }
 
-    params[0] = diffuse;
-    params[1] = specular;
-    params[2] = exp;
+    params[0] = specular;
+    params[1] = exp;
 
     finish->ptr       = params;
     finish->finish_fn = &dmnsn_phong_finish_fn;