ref: 88b781094d31f244b52a420330ec8049d7ca7b36
dir: /src/pt2_scopes.c/
#include <assert.h>
#include <stdint.h>
#include <stdbool.h>
#include <math.h> // modf()
#ifndef _WIN32
#include <unistd.h> // usleep()
#endif
#include "pt2_helpers.h"
#include "pt2_visuals.h"
#include "pt2_scopes.h"
#include "pt2_config.h"
// this uses code that is not entirely thread safe, but I have never had any issues so far...
static volatile bool scopesUpdatingFlag, scopesDisplayingFlag;
static hpc_t scopeHpc;
static SDL_Thread *scopeThread;
scope_t scope[PAULA_VOICES]; // global
// this is quite hackish, but fixes sample swapping issues
static int32_t getSampleSlotFromReadAddress(const int8_t *sampleReadAddress)
{
assert(song != NULL);
const int8_t *sampleData = song->sampleData;
const int32_t sampleSlotSize = config.maxSampleLength;
if (sampleData == NULL) // shouldn't really happen, but just in case
return -1;
int32_t sampleSlot = 30; // start at last slot
const int8_t *sampleBaseAddress = &sampleData[sampleSlot * sampleSlotSize];
if (sampleReadAddress == NULL || sampleReadAddress >= sampleBaseAddress+sampleSlotSize)
return -1; // out of range
for (; sampleSlot >= 0; sampleSlot--)
{
if (sampleReadAddress >= sampleBaseAddress)
break;
sampleBaseAddress -= sampleSlotSize;
}
return sampleSlot; // 0..30, or -1 if out of range
}
int32_t getSampleReadPos(int32_t ch) // used for the sampler screen
{
// cache some stuff
const scope_t *sc = &scope[ch];
const bool active = sc->active;
const int8_t *data = sc->data;
const int32_t pos = sc->pos;
const int32_t len = sc->length;
if (song == NULL || !active || data == NULL)
return -1;
/* Because the scopes work like the Paula emulation, we have a DATA
** and LENGTH variable, which are not static. This means that we have
** to get creative to get the absolute sampling position.
*/
int32_t sample = getSampleSlotFromReadAddress(data);
if (sample != editor.currSample)
return -1; // sample is not the one we're seeing in the sampler screen
const moduleSample_t *s = &song->samples[sample];
const int8_t *sampleReadAddress = &data[pos];
const int8_t *sampleBaseAddress = &song->sampleData[s->offset];
const int32_t realPos = (int32_t)(sampleReadAddress - sampleBaseAddress);
// return -1 if sample has no loop and read length is 2 (playing sample "loop" area)
const bool loopEnabled = (s->loopStart + s->loopLength) > 2;
if (!loopEnabled && len == 2)
return -1;
if (realPos < 0 || realPos >= s->length)
return -1;
return realPos;
}
void scopeSetPeriod(int32_t ch, int32_t period)
{
assert(period >= 113 && period <= 65535);
scope[ch].dDelta = (PAULA_PAL_CLK / (double)SCOPE_HZ) / period;
}
void scopeTrigger(int32_t ch) // expects data & length variables to be set already
{
volatile scope_t *sc = &scope[ch];
scope_t tempState = *sc; // cache it
if (tempState.data == NULL)
tempState.data = paulaGetNullSamplePtr();
if (tempState.length < 2)
tempState.length = 2; // for safety
tempState.dPhase = 0.0;
tempState.pos = 0;
tempState.active = true;
/* Update live scope now.
** In theory it -can- be written to in the middle of a cached read,
** then the read thread writes its own non-updated cached copy back and
** the trigger never happens. So far I have never seen it happen,
** so it's probably very rare. Yes, this is not good coding...
*/
*sc = tempState;
}
void updateScopes(void)
{
scope_t tempState;
if (editor.mod2WavOngoing)
return;
volatile scope_t *sc = scope;
scopesUpdatingFlag = true;
for (int32_t i = 0; i < PAULA_VOICES; i++, sc++)
{
tempState = *sc; // cache it
if (!tempState.active)
continue; // scope is not active
tempState.dPhase += tempState.dDelta;
const int32_t wholeSamples = (int32_t)tempState.dPhase;
tempState.dPhase -= wholeSamples;
tempState.pos += wholeSamples;
if (tempState.pos >= tempState.length)
{
// sample reached end, simulate Paula register update (sample swapping)
/* Wrap pos around one time with current length, then set new length
** and wrap around it (handles one-shot loops and sample swapping).
*/
tempState.pos -= tempState.length;
tempState.length = tempState.newLength;
if (tempState.pos >= tempState.length && tempState.length > 0)
tempState.pos %= tempState.length;
tempState.data = tempState.newData;
}
*sc = tempState; // update scope state
}
scopesUpdatingFlag = false;
}
/* This routine gets the average sample amplitude through the running scope voices.
** This gives a somewhat more stable result than getting the peak from the mixer,
** and we don't care about including filters/BLEP in the peak calculation.
*/
static void updateRealVuMeters(void)
{
scope_t tmpScope, *sc;
// sink VU-meters first
for (int32_t i = 0; i < PAULA_VOICES; i++)
{
editor.realVuMeterVolumes[i] -= 4;
if (editor.realVuMeterVolumes[i] < 0)
editor.realVuMeterVolumes[i] = 0;
}
// get peak sample data from running scope voices
sc = scope;
for (int32_t i = 0; i < PAULA_VOICES; i++, sc++)
{
tmpScope = *sc; // cache it
if (!tmpScope.active || tmpScope.data == NULL || tmpScope.volume == 0 || tmpScope.length == 0)
continue;
// amount of integer samples getting skipped every frame
const int32_t samplesToScan = (const int32_t)tmpScope.dDelta;
if (samplesToScan <= 0)
continue;
int32_t pos = tmpScope.pos;
int32_t length = tmpScope.length;
const int8_t *data = tmpScope.data;
int32_t runningAmplitude = 0;
for (int32_t x = 0; x < samplesToScan; x++)
{
int32_t amplitude = 0;
if (data != NULL)
amplitude = data[pos] * tmpScope.volume;
runningAmplitude += ABS(amplitude);
if (++pos >= length)
{
pos = 0;
/* Read cycle done, temporarily update the display data/length variables
** before the scope thread does it.
*/
data = tmpScope.newData;
length = tmpScope.newLength;
}
}
double dAvgAmplitude = runningAmplitude / (double)samplesToScan;
dAvgAmplitude *= 96.0 / (128.0 * 64.0); // normalize
int32_t vuHeight = (int32_t)(dAvgAmplitude + 0.5); // rounded
if (vuHeight > 48) // max VU-meter height
vuHeight = 48;
if ((int8_t)vuHeight > editor.realVuMeterVolumes[i])
editor.realVuMeterVolumes[i] = (int8_t)vuHeight;
}
}
void drawScopes(void)
{
volatile scope_t *sc = scope; // cache it
int32_t scopeX = 128;
const uint32_t bgColor = video.palette[PAL_BACKGRD];
const uint32_t fgColor = video.palette[PAL_QADSCP];
scopesDisplayingFlag = true;
for (int32_t i = 0; i < PAULA_VOICES; i++, sc++)
{
scope_t tmpScope = *sc; // cache it
// clear scope background
fillRect(scopeX, 55, SCOPE_WIDTH, SCOPE_HEIGHT, bgColor);
// render scope
if (tmpScope.active && tmpScope.data != NULL && tmpScope.volume != 0 && tmpScope.length > 0)
{
// render scope data
int16_t scopeData;
int32_t pos = tmpScope.pos;
int32_t length = tmpScope.length;
const int16_t volume = -(tmpScope.volume << 7);
const int8_t *data = tmpScope.data;
uint32_t *scopeDrawPtr = &video.frameBuffer[(71 * SCREEN_W) + scopeX];
for (int32_t x = 0; x < SCOPE_WIDTH; x++)
{
scopeData = 0;
if (data != NULL)
scopeData = (data[pos] * volume) >> 16;
scopeDrawPtr[(scopeData * SCREEN_W) + x] = fgColor;
pos++;
if (pos >= length)
{
pos = 0;
// read cycle done, update the drawing data/length variables
length = tmpScope.newLength;
data = tmpScope.newData;
}
}
}
else
{
// draw centered scope line
hLine(scopeX, 71, SCOPE_WIDTH, fgColor);
}
scopeX += SCOPE_WIDTH+8;
}
scopesDisplayingFlag = false;
}
static int32_t SDLCALL scopeThreadFunc(void *ptr)
{
// this is needed for scope stability (confirmed)
SDL_SetThreadPriority(SDL_THREAD_PRIORITY_HIGH);
hpc_SetDurationInHz(&scopeHpc, SCOPE_HZ);
hpc_ResetEndTime(&scopeHpc);
while (editor.programRunning)
{
if (config.realVuMeters)
updateRealVuMeters();
updateScopes();
hpc_Wait(&scopeHpc);
}
(void)ptr;
return true;
}
bool initScopes(void)
{
scopeThread = SDL_CreateThread(scopeThreadFunc, NULL, NULL);
if (scopeThread == NULL)
{
showErrorMsgBox("Couldn't create scope thread!");
return false;
}
SDL_DetachThread(scopeThread);
return true;
}
void stopScope(int32_t ch)
{
// wait for scopes to finish updating
while (scopesUpdatingFlag);
scope[ch].active = false;
// wait for scope displaying to be done (safety)
while (scopesDisplayingFlag);
}
void stopAllScopes(void)
{
// wait for scopes to finish updating
while (scopesUpdatingFlag);
for (int32_t i = 0; i < PAULA_VOICES; i++)
scope[i].active = false;
// wait for scope displaying to be done (safety)
while (scopesDisplayingFlag);
}