Global diffuse lighting. (gamma not corrected)

Some operations on pixel<T>.
Make ray3 support copy semantic.
Fix vec3 operands does not filter out vec3-vec3 as parameters.
random_uv_gen generating random unit vectors.

1 files changed, 24 insertions, 2 deletions

diff --git a/bitmap.h b/bitmap.h
index 1e35395..5b07914 100644
--- a/bitmap.h
+++ b/bitmap.h
@@ -44,8 +44,30 @@ struct pixel {
     static inline pixel<T> from_normalized(const vec3d &v3d) {
         return from_normalized(v3d.x / 2.0 + 0.5, v3d.y / 2.0 + 0.5, v3d.z / 2.0 + 0.5);
     }
+
+    static inline pixel<T> black() {
+        return pixel<T>{(T) 0, (T) 0, (T) 0};
+    }
 };
 
+template<
+        typename T,
+        typename S,
+        typename = typename std::enable_if<std::is_arithmetic<S>::value, S>::type
+>
+pixel<T> operator*(const pixel<T> &pixel, S scale) {
+    return ::pixel < T > {.r=(T) (pixel.r * scale), .g=(T) (pixel.g * scale), .b=(T) (pixel.b * scale)};
+}
+
+template<
+        typename T,
+        typename S,
+        typename = typename std::enable_if<std::is_arithmetic<S>::value, S>::type
+>
+pixel<T> operator*(S scale, const pixel <T> &pixel) {
+    return ::pixel < T > {.r=(T) (pixel.r * scale), .g=(T) (pixel.g * scale), .b=(T) (pixel.b * scale)};
+}
+
 // Mix two colors a and b. Returns a*u + b*v
 template<typename T>
 inline pixel<T> mix(const pixel<T> &a, const pixel<T> &b, double u, double v) {
@@ -93,7 +115,7 @@ public:
         bitmap<T> result{images[0].width, images[0].height};
         const auto m = images.size();
         const auto n = images[0].content.size();
-        uintmax_t acc_r, acc_g, acc_b;
+        uint_fast32_t acc_r, acc_g, acc_b;
         for (size_t i = 0; i < n; ++i) {
             acc_r = 0;
             acc_g = 0;
@@ -103,7 +125,7 @@ public:
                 acc_g += images[j].content[i].g;
                 acc_b += images[j].content[i].b;
             }
-            result.content[i] = pixel<T>{(T) (acc_r / m), (T) (acc_g / m), (T) (acc_b / m)};
+            result.content[i] = pixel<T>{(T) (1.0 * acc_r / m), (T) (1.0 * acc_g / m), (T) (1.0 * acc_b / m)};
         }
         return result;
     }