path: root/Source/Plugins/Plugin_VideoOGL/Src/OpcodeDecoding.cpp

// Copyright (C) 2003-2008 Dolphin Project.

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License 2.0 for more details.

// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/

// Official SVN repository and contact information can be found at
// http://code.google.com/p/dolphin-emu/

//DL facts:
//	Ikaruga uses NO display lists!
//  Zelda WW uses TONS of display lists
//  Zelda TP uses almost 100% display lists except menus (we like this!)

// Note that it IS NOT POSSIBLE to precompile display lists! You can compile them as they are
// and hope that the vertex format doesn't change, though, if you do it just when they are 
// called. The reason is that the vertex format affects the sizes of the vertices.

#include "Globals.h"
#include "OpcodeDecoding.h"
#include "VertexLoader.h"
#include "VertexShaderManager.h"
#include "TextureMngr.h"

#include "BPStructs.h"
#include "DataReader.h"

#define CMDBUFFER_SIZE 1024*1024
void Decode();

extern u8 FAKE_PeekFifo8(u32 _uOffset);
extern u16 FAKE_PeekFifo16(u32 _uOffset);
extern u32 FAKE_PeekFifo32(u32 _uOffset);
extern int FAKE_GetFifoSize();

CDataReader_Fifo g_fifoReader;

void ExecuteDisplayList(u32 address, u32 size)
{
    IDataReader* pOldReader = g_pDataReader;

    //address &= 0x01FFFFFF; // phys address
    CDataReader_Memory memoryReader(address);
    g_pDataReader = &memoryReader;

    while((memoryReader.GetReadAddress() - address) < size)
    {
        Decode();
    }
    INCSTAT(stats.numDListsAlive);
    // reset to the old reader
    g_pDataReader = pOldReader;
}

inline u8 PeekFifo8(u32 _uOffset)
{
    return FAKE_PeekFifo8(_uOffset);
}

inline u16 PeekFifo16(u32 _uOffset)
{
    return FAKE_PeekFifo16(_uOffset);
}

inline u32 PeekFifo32(u32 _uOffset)
{
    return FAKE_PeekFifo32(_uOffset);
}


bool FifoCommandRunnable(void)
{
    u32 iBufferSize = FAKE_GetFifoSize();
    if (iBufferSize == 0)
        return false;

    u8 Cmd = PeekFifo8(0);	
    u32 iCommandSize = 0;

    switch(Cmd)
    {
    case GX_NOP:
        // Hm, this means that we scan over nop streams pretty slowly...
        iCommandSize = 1;
        break;

    case GX_LOAD_CP_REG:
        iCommandSize = 6;
        break;

    case GX_LOAD_INDX_A:
    case GX_LOAD_INDX_B:
    case GX_LOAD_INDX_C:
    case GX_LOAD_INDX_D:
        iCommandSize = 5;
        break;

    case GX_CMD_CALL_DL:	
        iCommandSize = 9;
        break;

    case 0x44:
        iCommandSize = 1;
        // zelda 4 swords calls it and checks the metrics registers after that
        break;

    case GX_CMD_INVL_VC: // invalid vertex cache - no parameter?
        iCommandSize = 1;
        break;

    case GX_LOAD_BP_REG:	
        iCommandSize = 5;
        break;

    case GX_LOAD_XF_REG:
        {
            // check if we can read the header
            if (iBufferSize >= 5) {				
                iCommandSize = 1 + 4;
                u32 Cmd2 = PeekFifo32(1);
                int dwTransferSize = ((Cmd2>>16)&15) + 1;
                iCommandSize += dwTransferSize * 4;				
            }
            else {
                return false;
            }			
        }
        break;

    default:
        if (Cmd&0x80)
        {				
            // check if we can read the header
            if (iBufferSize >= 3) {
                iCommandSize = 1 + 2;
                u16 numVertices = PeekFifo16(1);
                VertexLoader& vtxLoader = g_VertexLoaders[Cmd & GX_VAT_MASK];
                iCommandSize += numVertices * vtxLoader.ComputeVertexSize();
            }
            else {				
                return false;
            }
        }
        else {
            char szTemp[512];
            sprintf(szTemp, "Error: Unknown Opcode (0x%x)", Cmd);
            SysMessage(szTemp);
            g_VideoInitialize.pLog(szTemp, TRUE);
        }
        break;
    }
    
    if (iCommandSize > iBufferSize)
        return false;

    INFO_LOG("OP detected: Cmd 0x%x  size %i  buffer %i",Cmd, iCommandSize, iBufferSize);

    return true;
}

void Decode(void)
{
    int Cmd = g_pDataReader->Read8();
    switch(Cmd)
    {
    case GX_NOP:
        break;

    case GX_LOAD_CP_REG: //0x08
        {
            u32 SubCmd = g_pDataReader->Read8();
            u32 Value = g_pDataReader->Read32();
            VertexManager::LoadCPReg(SubCmd,Value);
        }
        break;

    case GX_LOAD_XF_REG:
        {
            u32 Cmd2 = g_pDataReader->Read32();
            
            int dwTransferSize = ((Cmd2>>16)&15) + 1;
            DWORD dwAddress = Cmd2 & 0xFFFF;
            static u32 pData[16];
            for (int i=0; i<dwTransferSize; i++)
                pData[i] = g_pDataReader->Read32();
            VertexShaderMngr::LoadXFReg(dwTransferSize,dwAddress,pData);
        }
        break;

    case GX_LOAD_INDX_A: //used for position matrices
        VertexShaderMngr::LoadIndexedXF(g_pDataReader->Read32(),0xC);
        break;
    case GX_LOAD_INDX_B: //used for normal matrices
        VertexShaderMngr::LoadIndexedXF(g_pDataReader->Read32(),0xD);
        break;
    case GX_LOAD_INDX_C: //used for postmatrices
        VertexShaderMngr::LoadIndexedXF(g_pDataReader->Read32(),0xE);
        break;
    case GX_LOAD_INDX_D: //used for lights
        VertexShaderMngr::LoadIndexedXF(g_pDataReader->Read32(),0xF);
        break;

    case GX_CMD_CALL_DL:
        {
            u32 dwAddr  = g_pDataReader->Read32();
            u32 dwCount = g_pDataReader->Read32();
            ExecuteDisplayList(dwAddr, dwCount);
        }			
        break;

    case 0x44:
        // zelda 4 swords calls it and checks the metrics registers after that
        break;

    case GX_CMD_INVL_VC:// Invalidate	(vertex cache?)	
        DebugLog("Invalidate	(vertex cache?)");
        break;

    case GX_LOAD_BP_REG: //0x61
        {
            u32 cmd = g_pDataReader->Read32();
            LoadBPReg(cmd);
        }
        break;

    // draw primitives 
    default:
        if (Cmd&0x80)
        {			
            // load vertices
            u16 numVertices = g_pDataReader->Read16();			
            if( numVertices > 0 ) {
                g_VertexLoaders[Cmd & GX_VAT_MASK].RunVertices((Cmd & GX_PRIMITIVE_MASK) >> GX_PRIMITIVE_SHIFT, numVertices);
            }
        }
        else
        {
            // char szTmp[256];
            //sprintf(szTmp, "Illegal command %02x (at %08x)",Cmd,g_pDataReader->GetPtr());
            //g_VideoInitialize.pLog(szTmp);
            //MessageBox(0,szTmp,"GFX ERROR",0);
            // _assert_msg_(0,szTmp,"");
            break;
        }
        break;
    }
}

void OpcodeDecoder_Init()
{	
    g_pDataReader = &g_fifoReader;
}


void OpcodeDecoder_Shutdown()
{
}

void OpcodeDecoder_Run()
{
    // just a small check
    if (g_pDataReader != &g_fifoReader) {
        SysMessage("very strange");
    }

    DVSTARTPROFILE();

    while (FifoCommandRunnable())
    {
        Decode();
    }
}