feat: barycentric interpolation for normals

rendertarget.hpp

@@ -11,6 +11,7 @@ class Rendertarget {
 
     Rendertarget(int width, int height) : width(width), height(height) {
         pixels = new decimal[width * height * 3];
+        depth = new decimal[width * height];
     }
 
     void set(int x, int y, vec3 val) {
@@ -25,8 +26,17 @@ class Rendertarget {
             (*val)[i] = pixels[start + i];
         }
     }
+    decimal getDepth(int x, int y) { return depth[width * y + x]; }
+    void setDepth(int x, int y, decimal val) { depth[width * y + x] = val; }
+
+    void clearDepth() {
+        for (int i = 0; i < width * height; i++) {
+            depth[i].i = std::numeric_limits<int32_t>::max();
+        }
+    }
 
     decimal *pixels;
+    decimal *depth;
 };
 
 #endif