bool DMA::doOAMTransfer()
{
int t_c = static_cast<int>(m_vecDMATransfers[OAMDMA].size());
if (t_c > 0)
{
ITexture* pTexture = getTexture(OAMDMA, 0);
if (NULL == pTexture)
{
return false;
}
uint32_t* pTextureData;
int iStride;
if (false == pTexture->getBuffer(pTextureData, iStride))
{
return false;
}
for (int iLoop = 0; iLoop < t_c; ++iLoop)
{
const DMATransfer& dmaTransfer = m_vecDMATransfers[OAMDMA][iLoop];
if (NULL == dmaTransfer.pSource)
{
continue;
}
else
{
if (-1 == dmaTransfer.iHeight)
{
doDMATransfer(pTexture, dmaTransfer.pSource, pTextureData, iStride, dmaTransfer.iStartTile, dmaTransfer.iWidth, OAMDMA);
}
else
{
doDMATransfer(pTexture, dmaTransfer.pSource, pTextureData, iStride, dmaTransfer.iStartTile, dmaTransfer.iWidth, dmaTransfer.iHeight,
OAMDMA);
}
}
}
pTexture->releaseBuffer();
}
m_vecDMATransfers[OAMDMA].clear();
return true;
}
void writeByte(struct gameboy * gameboy, uint16_t address, uint8_t data)
{
//0000-8000 is read only
if (address < CARTRIDGE_SIZE){
handleBankWrite(gameboy, address, data);
}
//anything written to echo RAM should be written to work RAM.
else if ((address >= ECHO_RAM_START_UPPER) && (address < ECHO_RAM_END_UPPER)){
gameboy->memory.mem[address] = data;
gameboy->memory.mem[address - ECHO_OFFSET] = data;
}
else if ((address >= ECHO_RAM_START_LOWER) && (address < ECHO_RAM_END_LOWER)){
gameboy->memory.mem[address] = data;
gameboy->memory.mem[address + ECHO_OFFSET] = data;
}
else if ((address >= RESTRICTED_START) && (address < RESTRICTED_END)){
//printf("sp: %x\n", gameboy->cpu.sp);
//printf("WriteMemory: address %x is within restricted memory %x - %x\n", address, RESTRICTED_START, RESTRICTED_END);
// fprintf(stderr, "WriteMemory: address %x is within restricted memory %x - %x\n", address, RESTRICTED_START, RESTRICTED_END);
//printDebugTrace(gameboy);
}
else if (address == TMC){
//the game is trying to change the timer controller
int currentFreq = getTimerFrequency(gameboy);
gameboy->memory.mem[TMC] = data;
int newFreq = getTimerFrequency(gameboy);
if (newFreq != currentFreq){
initialiseTimerCounter(gameboy);
}
}
else if (address == DIV_REG){
//any writes to the divider register resets it to 0
gameboy->memory.mem[DIV_REG] = 0;
}
else if (address == DMA_ADDRESS){
doDMATransfer(gameboy, data);
}
else if (address == CONTROL_REG){
gameboy->screen.control = data;
}
else if (address == CURRENT_SCANLINE){
//printf("resetting scanline\n");
gameboy->screen.currentScanline = 0;
}
else if (address == STATUS_REG){
gameboy->screen.status = data;
}
else {
gameboy->memory.mem[address] = data;
}
}
bool DMA::doBGTransfer()
{
int t_c = static_cast<int>(m_vecDMATransfers[BGDMA].size());
int iCurrentBG = -1;
if (t_c > 0)
{
qsort(&m_vecDMATransfers[BGDMA][0], m_vecDMATransfers[BGDMA].size(), sizeof(DMATransfer*), dmaSort);
ITexture* pTexture = NULL;
uint32_t* pTextureData = NULL;
int iStride;
for (int iLoop = 0; iLoop < t_c; ++iLoop)
{
const DMATransfer& dmaTransfer = m_vecDMATransfers[BGDMA][iLoop];
if (dmaTransfer.iBG != iCurrentBG)
{
iCurrentBG = dmaTransfer.iBG;
if (pTexture != NULL)
{
pTexture->releaseBuffer();
}
pTexture = getTexture(BGDMA, dmaTransfer.iBG);
if (NULL == pTexture)
{
return false;
}
if (false == pTexture->getBuffer(pTextureData, iStride))
{
return false;
}
}
ASSERT_LOG(pTexture != NULL && pTextureData != NULL, "Texture wasn't set");
if (NULL == dmaTransfer.pSource)
{
doVRAMClear(pTextureData, iStride, dmaTransfer.iStartTile, dmaTransfer.iWidth, dmaTransfer.iHeight, BGDMA);
}
else
{
if (-1 == dmaTransfer.iHeight)
{
doDMATransfer(pTexture, dmaTransfer.pSource, pTextureData, iStride, dmaTransfer.iStartTile, dmaTransfer.iWidth, BGDMA);
}
else
{
doDMATransfer(pTexture, dmaTransfer.pSource, pTextureData, iStride, dmaTransfer.iStartTile, dmaTransfer.iWidth, dmaTransfer.iHeight,
BGDMA);
}
}
}
if (pTexture != NULL)
{
pTexture->releaseBuffer();
}
}
m_vecDMATransfers[BGDMA].clear();
return true;
}
