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

#include "Common/Assert.h"
#include "Common/CommonTypes.h"

#include "VideoCommon/DataReader.h"
#include "VideoCommon/VertexLoader.h"
#include "VideoCommon/VertexLoader_Color.h"
#include "VideoCommon/VertexLoader_Normal.h"
#include "VideoCommon/VertexLoader_Position.h"
#include "VideoCommon/VertexLoader_TextCoord.h"
#include "VideoCommon/VertexLoaderManager.h"
#include "VideoCommon/VertexLoaderUtils.h"
#include "VideoCommon/VideoCommon.h"

// This pointer is used as the source/dst for all fixed function loader calls
u8* g_video_buffer_read_ptr;
u8* g_vertex_manager_write_ptr;

static void PosMtx_ReadDirect_UByte(VertexLoader* loader)
{
	u32 posmtx = DataRead<u8>() & 0x3f;
	if (loader->m_counter < 3)
		VertexLoaderManager::position_matrix_index[loader->m_counter] = posmtx;
	DataWrite<u32>(posmtx);
	PRIM_LOG("posmtx: %d, ", posmtx);
}

static void TexMtx_ReadDirect_UByte(VertexLoader* loader)
{
	loader->m_curtexmtx[loader->m_texmtxread] = DataRead<u8>() & 0x3f;

	PRIM_LOG("texmtx%d: %d, ", loader->m_texmtxread, loader->m_curtexmtx[loader->m_texmtxread]);
	loader->m_texmtxread++;
}

static void TexMtx_Write_Float(VertexLoader* loader)
{
	DataWrite(float(loader->m_curtexmtx[loader->m_texmtxwrite++]));
}

static void TexMtx_Write_Float2(VertexLoader* loader)
{
	DataWrite(0.f);
	DataWrite(float(loader->m_curtexmtx[loader->m_texmtxwrite++]));
}

static void TexMtx_Write_Float3(VertexLoader* loader)
{
	DataWrite(0.f);
	DataWrite(0.f);
	DataWrite(float(loader->m_curtexmtx[loader->m_texmtxwrite++]));
}

static void SkipVertex(VertexLoader* loader)
{
	if (loader->m_vertexSkip)
	{
		// reset the output buffer
		g_vertex_manager_write_ptr -= loader->m_native_vtx_decl.stride;

		loader->m_skippedVertices++;
	}
}

VertexLoader::VertexLoader(const TVtxDesc &vtx_desc, const VAT &vtx_attr)
: VertexLoaderBase(vtx_desc, vtx_attr)
{
	VertexLoader_Normal::Init();

	CompileVertexTranslator();

	// generate frac factors
	m_posScale = 1.0f / (1U << m_VtxAttr.PosFrac);
	for (int i = 0; i < 8; i++)
		m_tcScale[i] = 1.0f / (1U << m_VtxAttr.texCoord[i].Frac);
}

void VertexLoader::CompileVertexTranslator()
{
	m_VertexSize = 0;
	const TVtxAttr &vtx_attr = m_VtxAttr;

	// Reset pipeline
	m_numPipelineStages = 0;

	// Colors
	const u64 col[2] = { m_VtxDesc.Color0, m_VtxDesc.Color1 };
	// TextureCoord
	const u64 tc[8] = {
		m_VtxDesc.Tex0Coord, m_VtxDesc.Tex1Coord, m_VtxDesc.Tex2Coord, m_VtxDesc.Tex3Coord,
		m_VtxDesc.Tex4Coord, m_VtxDesc.Tex5Coord, m_VtxDesc.Tex6Coord, m_VtxDesc.Tex7Coord
	};

	u32 components = 0;

	// Position in pc vertex format.
	int nat_offset = 0;

	// Position Matrix Index
	if (m_VtxDesc.PosMatIdx)
	{
		WriteCall(PosMtx_ReadDirect_UByte);
		components |= VB_HAS_POSMTXIDX;
		m_native_vtx_decl.posmtx.components = 4;
		m_native_vtx_decl.posmtx.enable = true;
		m_native_vtx_decl.posmtx.offset = nat_offset;
		m_native_vtx_decl.posmtx.type = VAR_UNSIGNED_BYTE;
		m_native_vtx_decl.posmtx.integer = true;
		nat_offset += 4;
		m_VertexSize += 1;
	}

	if (m_VtxDesc.Tex0MatIdx) { m_VertexSize += 1; components |= VB_HAS_TEXMTXIDX0; WriteCall(TexMtx_ReadDirect_UByte); }
	if (m_VtxDesc.Tex1MatIdx) { m_VertexSize += 1; components |= VB_HAS_TEXMTXIDX1; WriteCall(TexMtx_ReadDirect_UByte); }
	if (m_VtxDesc.Tex2MatIdx) { m_VertexSize += 1; components |= VB_HAS_TEXMTXIDX2; WriteCall(TexMtx_ReadDirect_UByte); }
	if (m_VtxDesc.Tex3MatIdx) { m_VertexSize += 1; components |= VB_HAS_TEXMTXIDX3; WriteCall(TexMtx_ReadDirect_UByte); }
	if (m_VtxDesc.Tex4MatIdx) { m_VertexSize += 1; components |= VB_HAS_TEXMTXIDX4; WriteCall(TexMtx_ReadDirect_UByte); }
	if (m_VtxDesc.Tex5MatIdx) { m_VertexSize += 1; components |= VB_HAS_TEXMTXIDX5; WriteCall(TexMtx_ReadDirect_UByte); }
	if (m_VtxDesc.Tex6MatIdx) { m_VertexSize += 1; components |= VB_HAS_TEXMTXIDX6; WriteCall(TexMtx_ReadDirect_UByte); }
	if (m_VtxDesc.Tex7MatIdx) { m_VertexSize += 1; components |= VB_HAS_TEXMTXIDX7; WriteCall(TexMtx_ReadDirect_UByte); }

	// Write vertex position loader
	WriteCall(VertexLoader_Position::GetFunction(m_VtxDesc.Position, m_VtxAttr.PosFormat, m_VtxAttr.PosElements));

	m_VertexSize += VertexLoader_Position::GetSize(m_VtxDesc.Position, m_VtxAttr.PosFormat, m_VtxAttr.PosElements);
	int pos_elements = m_VtxAttr.PosElements + 2;
	m_native_vtx_decl.position.components = pos_elements;
	m_native_vtx_decl.position.enable = true;
	m_native_vtx_decl.position.offset = nat_offset;
	m_native_vtx_decl.position.type = VAR_FLOAT;
	m_native_vtx_decl.position.integer = false;
	nat_offset += pos_elements * sizeof(float);

	// Normals
	if (m_VtxDesc.Normal != NOT_PRESENT)
	{
		m_VertexSize += VertexLoader_Normal::GetSize(m_VtxDesc.Normal,
			m_VtxAttr.NormalFormat, m_VtxAttr.NormalElements, m_VtxAttr.NormalIndex3);

		TPipelineFunction pFunc = VertexLoader_Normal::GetFunction(m_VtxDesc.Normal,
			m_VtxAttr.NormalFormat, m_VtxAttr.NormalElements, m_VtxAttr.NormalIndex3);

		if (pFunc == nullptr)
		{
			PanicAlert("VertexLoader_Normal::GetFunction(%i %i %i %i) returned zero!",
				(u32)m_VtxDesc.Normal, m_VtxAttr.NormalFormat,
				m_VtxAttr.NormalElements, m_VtxAttr.NormalIndex3);
		}
		WriteCall(pFunc);

		for (int i = 0; i < (vtx_attr.NormalElements ? 3 : 1); i++)
		{
			m_native_vtx_decl.normals[i].components = 3;
			m_native_vtx_decl.normals[i].enable = true;
			m_native_vtx_decl.normals[i].offset = nat_offset;
			m_native_vtx_decl.normals[i].type = VAR_FLOAT;
			m_native_vtx_decl.normals[i].integer = false;
			nat_offset += 12;
		}

		components |= VB_HAS_NRM0;
		if (m_VtxAttr.NormalElements == 1)
			components |= VB_HAS_NRM1 | VB_HAS_NRM2;
	}

	for (int i = 0; i < 2; i++)
	{
		m_native_vtx_decl.colors[i].components = 4;
		m_native_vtx_decl.colors[i].type = VAR_UNSIGNED_BYTE;
		m_native_vtx_decl.colors[i].integer = false;
		switch (col[i])
		{
		case NOT_PRESENT:
			break;
		case DIRECT:
			switch (m_VtxAttr.color[i].Comp)
			{
			case FORMAT_16B_565:  m_VertexSize += 2; WriteCall(Color_ReadDirect_16b_565); break;
			case FORMAT_24B_888:  m_VertexSize += 3; WriteCall(Color_ReadDirect_24b_888); break;
			case FORMAT_32B_888x: m_VertexSize += 4; WriteCall(Color_ReadDirect_32b_888x); break;
			case FORMAT_16B_4444: m_VertexSize += 2; WriteCall(Color_ReadDirect_16b_4444); break;
			case FORMAT_24B_6666: m_VertexSize += 3; WriteCall(Color_ReadDirect_24b_6666); break;
			case FORMAT_32B_8888: m_VertexSize += 4; WriteCall(Color_ReadDirect_32b_8888); break;
			default: _assert_(0); break;
			}
			break;
		case INDEX8:
			m_VertexSize += 1;
			switch (m_VtxAttr.color[i].Comp)
			{
			case FORMAT_16B_565:  WriteCall(Color_ReadIndex8_16b_565); break;
			case FORMAT_24B_888:  WriteCall(Color_ReadIndex8_24b_888); break;
			case FORMAT_32B_888x: WriteCall(Color_ReadIndex8_32b_888x); break;
			case FORMAT_16B_4444: WriteCall(Color_ReadIndex8_16b_4444); break;
			case FORMAT_24B_6666: WriteCall(Color_ReadIndex8_24b_6666); break;
			case FORMAT_32B_8888: WriteCall(Color_ReadIndex8_32b_8888); break;
			default: _assert_(0); break;
			}
			break;
		case INDEX16:
			m_VertexSize += 2;
			switch (m_VtxAttr.color[i].Comp)
			{
			case FORMAT_16B_565:  WriteCall(Color_ReadIndex16_16b_565); break;
			case FORMAT_24B_888:  WriteCall(Color_ReadIndex16_24b_888); break;
			case FORMAT_32B_888x: WriteCall(Color_ReadIndex16_32b_888x); break;
			case FORMAT_16B_4444: WriteCall(Color_ReadIndex16_16b_4444); break;
			case FORMAT_24B_6666: WriteCall(Color_ReadIndex16_24b_6666); break;
			case FORMAT_32B_8888: WriteCall(Color_ReadIndex16_32b_8888); break;
			default: _assert_(0); break;
			}
			break;
		}
		// Common for the three bottom cases
		if (col[i] != NOT_PRESENT)
		{
			components |= VB_HAS_COL0 << i;
			m_native_vtx_decl.colors[i].offset = nat_offset;
			m_native_vtx_decl.colors[i].enable = true;
			nat_offset += 4;
		}
	}

	// Texture matrix indices (remove if corresponding texture coordinate isn't enabled)
	for (int i = 0; i < 8; i++)
	{
		m_native_vtx_decl.texcoords[i].offset = nat_offset;
		m_native_vtx_decl.texcoords[i].type = VAR_FLOAT;
		m_native_vtx_decl.texcoords[i].integer = false;

		const int format = m_VtxAttr.texCoord[i].Format;
		const int elements = m_VtxAttr.texCoord[i].Elements;

		if (tc[i] != NOT_PRESENT)
		{
			_assert_msg_(VIDEO, DIRECT <= tc[i] && tc[i] <= INDEX16, "Invalid texture coordinates!\n(tc[i] = %d)", (u32)tc[i]);
			_assert_msg_(VIDEO, FORMAT_UBYTE <= format && format <= FORMAT_FLOAT, "Invalid texture coordinates format!\n(format = %d)", format);
			_assert_msg_(VIDEO, 0 <= elements && elements <= 1, "Invalid number of texture coordinates elements!\n(elements = %d)", elements);

			components |= VB_HAS_UV0 << i;
			WriteCall(VertexLoader_TextCoord::GetFunction(tc[i], format, elements));
			m_VertexSize += VertexLoader_TextCoord::GetSize(tc[i], format, elements);
		}

		if (components & (VB_HAS_TEXMTXIDX0 << i))
		{
			m_native_vtx_decl.texcoords[i].enable = true;
			if (tc[i] != NOT_PRESENT)
			{
				// if texmtx is included, texcoord will always be 3 floats, z will be the texmtx index
				m_native_vtx_decl.texcoords[i].components = 3;
				nat_offset += 12;
				WriteCall(m_VtxAttr.texCoord[i].Elements ? TexMtx_Write_Float : TexMtx_Write_Float2);
			}
			else
			{
				m_native_vtx_decl.texcoords[i].components = 3;
				nat_offset += 12;
				WriteCall(TexMtx_Write_Float3);
			}
		}
		else
		{
			if (tc[i] != NOT_PRESENT)
			{
				m_native_vtx_decl.texcoords[i].enable = true;
				m_native_vtx_decl.texcoords[i].components = vtx_attr.texCoord[i].Elements ? 2 : 1;
				nat_offset += 4 * (vtx_attr.texCoord[i].Elements ? 2 : 1);
			}
		}

		if (tc[i] == NOT_PRESENT)
		{
			// if there's more tex coords later, have to write a dummy call
			int j = i + 1;
			for (; j < 8; ++j)
			{
				if (tc[j] != NOT_PRESENT)
				{
					WriteCall(VertexLoader_TextCoord::GetDummyFunction()); // important to get indices right!
					break;
				}
			}
			// tricky!
			if (j == 8 && !((components & VB_HAS_TEXMTXIDXALL) & (VB_HAS_TEXMTXIDXALL << (i + 1))))
			{
				// no more tex coords and tex matrices, so exit loop
				break;
			}
		}
	}

	// indexed position formats may skip a the vertex
	if (m_VtxDesc.Position & 2)
	{
		WriteCall(SkipVertex);
	}

	m_native_components = components;
	m_native_vtx_decl.stride = nat_offset;
}

void VertexLoader::WriteCall(TPipelineFunction func)
{
	m_PipelineStages[m_numPipelineStages++] = func;
}

int VertexLoader::RunVertices(DataReader src, DataReader dst, int count)
{
	g_vertex_manager_write_ptr = dst.GetPointer();
	g_video_buffer_read_ptr = src.GetPointer();

	m_numLoadedVertices += count;
	m_skippedVertices = 0;

	for (m_counter = count - 1; m_counter >= 0; m_counter--)
	{
		m_tcIndex = 0;
		m_colIndex = 0;
		m_texmtxwrite = m_texmtxread = 0;
		for (int i = 0; i < m_numPipelineStages; i++)
			m_PipelineStages[i](this);
		PRIM_LOG("\n");
	}

	return count - m_skippedVertices;
}
