// Copyright 2008 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#include <type_traits>

#include "Common/CommonFuncs.h"
#include "Common/CommonTypes.h"
#include "VideoCommon/VertexLoader.h"
#include "VideoCommon/VertexLoader_TextCoord.h"
#include "VideoCommon/VertexLoaderManager.h"
#include "VideoCommon/VertexLoaderUtils.h"

template <int N>
void LOG_TEX();

template <>
void LOG_TEX<1>()
{
	// warning: mapping buffer should be disabled to use this
	// PRIM_LOG("tex: %f, ", ((float*)g_vertex_manager_write_ptr)[-1]);
}

template <>
void LOG_TEX<2>()
{
	// warning: mapping buffer should be disabled to use this
	// PRIM_LOG("tex: %f %f, ", ((float*)g_vertex_manager_write_ptr)[-2], ((float*)g_vertex_manager_write_ptr)[-1]);
}

static void TexCoord_Read_Dummy(VertexLoader* loader)
{
	loader->m_tcIndex++;
}

template <typename T>
float TCScale(T val, float scale)
{
	return val * scale;
}

template <>
float TCScale(float val, float scale)
{
	return val;
}

template <typename T, int N>
void TexCoord_ReadDirect(VertexLoader* loader)
{
	auto const scale = loader->m_tcScale[loader->m_tcIndex];
	DataReader dst(g_vertex_manager_write_ptr, nullptr);
	DataReader src(g_video_buffer_read_ptr, nullptr);

	for (int i = 0; i != N; ++i)
		dst.Write(TCScale(src.Read<T>(), scale));

	g_vertex_manager_write_ptr = dst.GetPointer();
	g_video_buffer_read_ptr = src.GetPointer();
	LOG_TEX<N>();

	++loader->m_tcIndex;
}

template <typename I, typename T, int N>
void TexCoord_ReadIndex(VertexLoader* loader)
{
	static_assert(std::is_unsigned<I>::value, "Only unsigned I is sane!");

	auto const index = DataRead<I>();
	auto const data = reinterpret_cast<const T*>(VertexLoaderManager::cached_arraybases[ARRAY_TEXCOORD0 + loader->m_tcIndex]
	                + (index * g_main_cp_state.array_strides[ARRAY_TEXCOORD0 + loader->m_tcIndex]));
	auto const scale = loader->m_tcScale[loader->m_tcIndex];
	DataReader dst(g_vertex_manager_write_ptr, nullptr);

	for (int i = 0; i != N; ++i)
		dst.Write(TCScale(Common::FromBigEndian(data[i]), scale));

	g_vertex_manager_write_ptr = dst.GetPointer();
	LOG_TEX<N>();
	++loader->m_tcIndex;
}

static TPipelineFunction tableReadTexCoord[4][8][2] = {
	{
		{nullptr, nullptr,},
		{nullptr, nullptr,},
		{nullptr, nullptr,},
		{nullptr, nullptr,},
		{nullptr, nullptr,},
	},
	{
		{TexCoord_ReadDirect<u8, 1>,  TexCoord_ReadDirect<u8, 2>,},
		{TexCoord_ReadDirect<s8, 1>,   TexCoord_ReadDirect<s8, 2>,},
		{TexCoord_ReadDirect<u16, 1>, TexCoord_ReadDirect<u16, 2>,},
		{TexCoord_ReadDirect<s16, 1>,  TexCoord_ReadDirect<s16, 2>,},
		{TexCoord_ReadDirect<float, 1>,  TexCoord_ReadDirect<float, 2>,},
	},
	{
		{TexCoord_ReadIndex<u8, u8, 1>,  TexCoord_ReadIndex<u8, u8, 2>,},
		{TexCoord_ReadIndex<u8, s8, 1>,   TexCoord_ReadIndex<u8, s8, 2>,},
		{TexCoord_ReadIndex<u8, u16, 1>, TexCoord_ReadIndex<u8, u16, 2>,},
		{TexCoord_ReadIndex<u8, s16, 1>,  TexCoord_ReadIndex<u8, s16, 2>,},
		{TexCoord_ReadIndex<u8, float, 1>,  TexCoord_ReadIndex<u8, float, 2>,},
	},
	{
		{TexCoord_ReadIndex<u16, u8, 1>,  TexCoord_ReadIndex<u16, u8, 2>,},
		{TexCoord_ReadIndex<u16, s8, 1>,   TexCoord_ReadIndex<u16, s8, 2>,},
		{TexCoord_ReadIndex<u16, u16, 1>, TexCoord_ReadIndex<u16, u16, 2>,},
		{TexCoord_ReadIndex<u16, s16, 1>,  TexCoord_ReadIndex<u16, s16, 2>,},
		{TexCoord_ReadIndex<u16, float, 1>,  TexCoord_ReadIndex<u16, float, 2>,},
	},
};

static int tableReadTexCoordVertexSize[4][8][2] = {
	{
		{0, 0,}, {0, 0,}, {0, 0,}, {0, 0,}, {0, 0,},
	},
	{
		{1, 2,}, {1, 2,}, {2, 4,}, {2, 4,}, {4, 8,},
	},
	{
		{1, 1,}, {1, 1,}, {1, 1,}, {1, 1,}, {1, 1,},
	},
	{
		{2, 2,}, {2, 2,}, {2, 2,}, {2, 2,}, {2, 2,},
	},
};

unsigned int VertexLoader_TextCoord::GetSize(u64 _type, unsigned int _format, unsigned int _elements)
{
	return tableReadTexCoordVertexSize[_type][_format][_elements];
}

TPipelineFunction VertexLoader_TextCoord::GetFunction(u64 _type, unsigned int _format, unsigned int _elements)
{
	return tableReadTexCoord[_type][_format][_elements];
}

TPipelineFunction VertexLoader_TextCoord::GetDummyFunction()
{
	return TexCoord_Read_Dummy;
}