Handle reflection of light and transmitted rays.

2 files changed, 5 insertions, 3 deletions

diff --git a/libdimension/dimension/color.h b/libdimension/dimension/color.h
index b135c70..6d706eb 100644
--- a/libdimension/dimension/color.h
+++ b/libdimension/dimension/color.h
@@ -84,7 +84,9 @@ dmnsn_color dmnsn_color_to_sRGB(dmnsn_color color);
 /** Greyscale color intensity. */
 double dmnsn_color_intensity(dmnsn_color color);
 /** Add two colors together. */
-dmnsn_color dmnsn_color_add(dmnsn_color color1, dmnsn_color color2);
+dmnsn_color dmnsn_color_add(dmnsn_color lhs, dmnsn_color rhs);
+/** Subtract two colors. */
+dmnsn_color dmnsn_color_sub(dmnsn_color lhs, dmnsn_color rhs);
 /** Multiply a color's intensity by \p n. */
 dmnsn_color dmnsn_color_mul(double n, dmnsn_color color);
 /** Return the color at \p n on a gradient from \p c1 at 0 to \p c2 at 1. */
diff --git a/libdimension/dimension/light.h b/libdimension/dimension/light.h
index b41a524..36c724a 100644
--- a/libdimension/dimension/light.h
+++ b/libdimension/dimension/light.h
@@ -34,8 +34,8 @@ typedef struct dmnsn_light dmnsn_light;
  * @param[in] v      The point to illuminate.
  * @return The direction of light rays pointing from \p v
  */
-typedef dmnsn_line dmnsn_light_direction_fn(const dmnsn_light *light,
-                                            dmnsn_vector v);
+typedef dmnsn_vector dmnsn_light_direction_fn(const dmnsn_light *light,
+                                              dmnsn_vector v);
 
 /**
  * Light illumination callback.