void ldp::think_delay(unsigned int uMsDelay)
{
bool bEmulatedCpu = (get_cpu_hz(0) != 0); // whether we've got an emulated cpu
// safety check: make sure that we're not using an emulated CPU
if (bEmulatedCpu)
{
printline("think_delay() should not be used with an emulated CPU. Don't use blocking seeking maybe?");
set_quitflag();
}
// safety check: make sure pre_init has already been called so that m_start_time has been initialized
else if (!m_bPreInitCalled)
{
printline("think_delay() should not be called until pre_init() has been called.");
set_quitflag();
}
// call pre_think the same # of times that uMsDelay tells us to,
// to ensure that we aren't caught sleeping during an important event
for (unsigned int uMs = 0; uMs < uMsDelay; ++uMs)
{
pre_think();
unsigned int uElapsedMs = elapsed_ms_time(m_start_time);
// if we're ahead of where we need to be, then it's ok to stall ...
if (uElapsedMs < m_uElapsedMsSinceStart)
{
/*
string msg = "uElapsedMs is " + numstr::ToStr(uElapsedMs) + " and m_uElapsedMssinceStart is " +
numstr::ToStr(m_uElapsedMsSinceStart);
printline(msg.c_str()); // REMOVE ME
*/
MAKE_DELAY(1);
}
// otherwise we're caught up or behind, so just loop so we can make sure we're caught up
}
}
clock_t uc3_clock (void)
{
static U32 last_time=0;
static U32 overflow=0;
clock_t time;
// Get the current time.
U32 curr_time=Get_system_register(AVR32_COUNT);
// Track overflow situation. We made the assumtion here that we can detect 1 overflow situation.
// This is true if the function is called faster than the overflow time.
// For example, with a CPU at 66 MHz, you must call the function before (1<<32)/66 MHz; i.e.
// 65 seconds since the last function call.
if( curr_time<last_time )
overflow++;
// Convert the current time into absolute UC3_CLOCKS_PER_SEC ticks, given the known overflow
// situations.
time = (U64)(( ((U64)overflow<<32) | curr_time) * UC3_CLOCKS_PER_SEC) / get_cpu_hz();
// Save the time for the next function call.
last_time = curr_time;
return time;
}
static inline uint64_t ticks_to_us(uint64_t ticks)
{
return (ticks * 1000000) / get_cpu_hz();
}
void ldp::pre_think()
{
// IMPORTANT : By definition, this function must be called every millisecond to update the timer (it is called by our cpu emulation every 1 ms)
// If it cannot be called every 1 ms (if we are not emulating a cpu for example), then ldp::think_delay() can be
// (and should be) used instead of calling this function directly.
// IMPORTANT : this must be updated no matter what because vldp relies on this timer when we're paused
// START VBLANK COUNT
// at the end of this function, if vblank gets asserted, we need to call an event handler in the game class, but we
// need to do that after the frame number has been recalculated (if need be), hence the purpose of this variable.
bool bVblankAsserted = false;
++m_uElapsedMsSinceStart;
// if it's time to increase the vblank count
if (m_uElapsedMsSinceStart >= m_uMsVblankBoundary)
{
++m_uVblankCount;
// compute the next boundary
m_uMsVblankBoundary = (unsigned int) ((((Uint64) (m_uVblankCount+1)) * 1000000) / VBLANKS_PER_KILOSECOND);
// only increment the mini count if we aren't waiting for vblank to start counting frames
if (!m_bWaitingForVblankToPlay)
{
++m_uVblankMiniCount;
}
// else if we have been waiting for vblank to play, then make sure we reset the vblankminicount
else
{
// we want to start at the beginning of a new frame boundary
m_uVblankMiniCount = 0;
// we just got a vblank, so we're not waiting ...
m_bWaitingForVblankToPlay = false;
}
bVblankAsserted = true;
}
// END VBLANK COUNT
// if we're not waiting to sync up with vblank, then increase timer
// (this must be done even if we're paused so VLDP will update our video overlay)
if (!m_bWaitingForVblankToPlay)
{
++m_uElapsedMsSincePlay;
}
// If the disc is supposed to be playing then compute which frame # we're on
// IMPORTANT:
// ldp-vldp.cpp's nonblocking_seek() RELIES on this function NOT calling get_status()!!!
// Be very careful about changing this 'm_status' to a get_status()
if (m_status == LDP_PLAYING)
{
unsigned int uDiscFPKS = g_game->get_disc_fpks();
// if our frame counter is in sync with vblank, then just increment frame every 2 vblanks ...
if ((uDiscFPKS << 1) == VBLANKS_PER_KILOSECOND)
{
// if we've had 2 vblanks, then 1 frame has elapsed
if (m_uVblankMiniCount > 1)
{
increment_current_frame();
m_uVblankMiniCount = 0;
}
// else we've not had enough vblanks, so don't do anything ...
}
// else if we're not in sync with the vblank (for example if we're dragon's lair with a 24 FPS disc),
// then use the elapsed ms since play to determine if the frame has changed
else if (m_uElapsedMsSincePlay >= m_uMsFrameBoundary)
{
increment_current_frame();
// compute the next boundary
m_uMsFrameBoundary = (unsigned int) ((((Uint64) (m_uCurrentOffsetFrame+1)) * 1000000) / uDiscFPKS);
}
// else the current frame has not changed
#ifdef DEBUG
#ifndef GP2X // GP2X is slow enough that we don't want to do this safety check by default
// SAFETY CHECK
// This ensures that the number that is calculated is not far off what it should be.
// (this test is only meaningful if we are emulating a cpu, because otherwise we may deliberately
// be calling this function slower than every 1 ms, such as ffr() or vldp's internal tests )
if (get_cpu_hz(0))
{
unsigned int uElapsedMS = elapsed_ms_time(m_play_time); // compute milliseconds
unsigned int time_result = m_last_seeked_frame + m_iSkipOffsetSincePlay +
(unsigned int) ((((Uint64) uElapsedMS) * g_game->get_disc_fpks()) / 1000000);
Uint16 diff = 0;
// this isn't necessarily the same as m_uCurrentFrame due to potential skips that can occur
// (this is updated immediately, m_uCurrentFrame is updated on a time boundary)
unsigned int uCurrentFrame = m_last_seeked_frame + m_iSkipOffsetSincePlay + m_uCurrentOffsetFrame;
if (uCurrentFrame > time_result) diff = uCurrentFrame - time_result;
else diff = time_result - uCurrentFrame;
// if the difference is noticeable, then alert the developer
if (diff > 5)
{
static unsigned int last_warning = 0;
if (elapsed_ms_time(last_warning) > 1000)
{
string s = "WARNING : cycle frame is ";
s += numstr::ToStr(uCurrentFrame) + " but time frame is ";
s += numstr::ToStr(time_result) + " which has a diff of ";
s += numstr::ToStr(diff);
printline(s.c_str());
last_warning = refresh_ms_time();
}
}
}
#endif // not GP2X
#endif // DEBUG
}
// otherwise the disc is idle, so we need not change the current frame
think(); // call implementation-specific function
// If vblank was asserted, let game know about it...
// NOTE : this should probably come at the end of this function
if (bVblankAsserted)
{
// let game know about vblank ...
g_game->OnVblank();
}
}
