int GdBeginDr(Drauing *drawing, GpBox *damage, int landscape)
{
int needToRedraw= 0;
Engine *eng;
if (damage) {
/* If drawing has incurred damage, report damage to ALL engines
interested in the drawing (not just active engines). */
for (eng=GpNextEngine(0) ; eng ; eng=GpNextEngine(eng))
if (eng->drawing==drawing) GpDamage(eng, drawing, damage);
}
/* Loop on active engines to alert them that drawing is coming. */
for (eng=GpNextActive(0) ; eng ; eng=GpNextActive(eng)) {
if (eng->drawing!=drawing) {
/* This engine is not marked as interested in this drawing.
Mark it, and reset damaged and lastDrawn flags so that no
elements will be inhibited. */
eng->drawing= drawing;
eng->lastDrawn= -1;
eng->damaged= 0;
if (landscape != eng->landscape) {
eng->landscape= landscape;
/* This change will be detected and acted upon by the first call
to the ChangeMap method (GpSetTrans). */
}
/* The semantics here are subtle --
After a ClearDrawing, GdDetach zeroes eng->drawing in order to
communicate that the drawing has been cleared. Thus, the code
gets here on a GdDraw after the drawing has been cleared, so
the time has come to carry out the deferred clearing of this
engine's plotting surface. */
GpClear(eng, CONDITIONALLY);
needToRedraw= 1;
} else if (eng->damaged) {
/* This engine was interested in the drawing, which has been
damaged. Clear damaged area in preparation for repair work.
(This is redundant if the damage was due to an X windows
expose event, but the resulting inefficiency is very small.) */
eng->ClearArea(eng, &eng->damage);
needToRedraw= 1;
} else if (eng->lastDrawn<drawing->nElements-1) {
needToRedraw= 1;
}
}
gdNowRendering= gdMaxRendered= -1;
return needToRedraw;
}
void GhHCP(void)
{
Engine *hcp= currentDevice<0? 0 : ghDevices[currentDevice].hcp;
if (!hcp) hcp= hcpDefault;
if (!hcp) return;
GpPreempt(hcp);
if (gdraw_hook) gdraw_hook(hcp, 4);
GdDraw(0);
/* NB- must be very careful not to Preempt twice with GdDrawLegends */
if (ghDevices[currentDevice].doLegends) GdDrawLegends(0);
GpClear(0, ALWAYS);
GpFlush(0);
if (gdraw_hook) gdraw_hook(hcp, 5);
GpPreempt(0);
}
void GhFMA(void)
{
Engine *display;
Engine *hcp= 0;
if (currentDevice<0) return;
display= ghDevices[currentDevice].display;
if (animateOn && !display) animateOn= 0;
if (hcpOn) {
hcp= ghDevices[currentDevice].hcp;
if (!hcp) hcp= hcpDefault;
if (hcp) GpActivate(hcp);
}
if (gdraw_hook) gdraw_hook(display, 2);
GdDraw(1);
if (hcpOn && hcp && ghDevices[currentDevice].doLegends)
GdDrawLegends(hcp);
if (animateOn) GxStrobe(display, 1);
GpFlush(0);
if (animateOn!=1) GdClear(0);
else GdClearSystem();
if (gdraw_hook) gdraw_hook(display, 3);
if (hcpOn && hcp) {
GpClear(hcp, CONDITIONALLY);
GpDeactivate(hcp);
}
ghDevices[currentDevice].fmaCount++;
if (++fmaCount > 100) { /* clean house once in a while */
fmaCount= 0;
GaFreeScratch();
}
}