#pragma once
#include <map>
#include <vector>
#include "NormalQuantizer.h"
#include "../../../core/BitHelper.h"


NormalQuantizer::NormalQuantizer(unsigned8 bits): mBits(bits)
{
	// Bits must be an even number, as there are two channels for an ONV
	assert(bits % 2 == 0);

	// Precalculate the channel mask
	unsigned32 channelStartHS = 32 - SmallNormal::BITS / 2;
	mChannelMask = BitHelper::GetHSMask<unsigned32>(channelStartHS, channelStartHS + mBits / 2);
}

std::map<SmallNormal, SmallNormal, NormalCompare>* NormalQuantizer::QuantizeMaterials(std::vector<SmallNormal> normals) const
{
	std::map<SmallNormal, SmallNormal, NormalCompare>* res = new std::map<SmallNormal, SmallNormal, NormalCompare>();
	for (const SmallNormal& normal : normals)
	{
		res->insert(std::make_pair(normal, Quantize(normal)));
	}
	if (mBits <= QUANTIZE_ALL_UP_TO)
	{
		unsigned32 maxPerChannel = 1 << (mBits / 2);
		unsigned8 shift = (SmallNormal::BITS - mBits) / 2;
		for (unsigned32 x = 0; x < maxPerChannel; x++)
			for (unsigned32 y = 0; y < maxPerChannel; y++)
			{
				SmallNormal v;
				v.SetXComponent(x << shift);
				v.SetYComponent(y << shift);
				res->insert(std::make_pair(v, v));
			}
	}
	return res;
}

SmallNormal NormalQuantizer::Quantize(const SmallNormal& normal) const
{
	SmallNormal quantized;
	quantized.SetXComponent(normal.GetXComponent() & mChannelMask);
	quantized.SetYComponent(normal.GetYComponent() & mChannelMask);
	return quantized;
}

std::string NormalQuantizer::GetQuantizerDescriptor() const
{
	return std::to_string(mBits);
}