add heightmap:resize(int, int, str)

src/maths/Heightmap.hpp

@@ -5,6 +5,12 @@
 
 #include "typedefs.hpp"
 
+enum class InterpolationType {
+    NEAREST,
+    LINEAR,
+    CUBIC,
+};
+
 class Heightmap {
     std::vector<float> buffer;
     uint width, height;
@@ -14,8 +20,13 @@ public:
         buffer.resize(width*height);
     }
 
+    Heightmap(uint width, uint height, std::vector<float> buffer) 
+    : width(width), height(height), buffer(std::move(buffer)) {}
+
     ~Heightmap() = default;
 
+    void resize(uint width, uint height, InterpolationType interpolation);
+
     uint getWidth() const {
         return width;
     }