MipMap.h

#pragma once

#include <type_traits>

#include "Mipmapable.h"

template <typename T>
struct isMipmapable : std::conditional<std::is_base_of<Mipmapable<T>,T>::value,
    std::true_type, std::false_type>::type {};

template <typename T, typename = void> class MipMap;

template <typename T>
class MipMap<T, typename std::enable_if<isMipmapable<T>::value, void>::type>
{
public:
    MipMap::MipMap(T* topMap, const int levels) {
        if (levels < 1)
            THROW("There must be at least 1 mipmap level.");
        mipMapLevels = levels;
        mipMaps = (T**) malloc(sizeof(T*) * mipMapLevels);
        mipMaps[0] = topMap;
        for (int i = 1; i < mipMapLevels; i++) {
            mipMaps[i] = NULL;
        }
    }

    MipMap::~MipMap(void) {
        for (int i = 1; i < mipMapLevels; i++) {
            delete mipMaps[i];
        }
        delete mipMaps;
    }

    void assertMipMaps() {
        for (int i = 1; i < mipMapLevels; i++) {
            if (mipMaps[i] == NULL) {
                mipMaps[i] = mipMaps[i - 1]->makeMipMap();
            }
        }
    }

    int getMipMapCount() {
        return mipMapLevels;
    }

    void setMipMap(T* mipMap, int level) {
        if (level < 0 || level >= mipMapLevels)
            THROW("Level must be between 0 and " << (mipMapLevels - 1) << " for this mipmap.");
        if (mipMaps[level] != NULL)
            delete mipMaps[level];
        mipMaps[level] = mipMap;
    }

private:
    T** mipMaps;
    int mipMapLevels;
};