bugfixes, adjusted famec timing

[picodrive.git] / Pico / PicoFrameHints.c

diff --git a/Pico/PicoFrameHints.c b/Pico/PicoFrameHints.c
index 562229f..91959d8 100644 (file)
--- a/Pico/PicoFrameHints.c
+++ b/Pico/PicoFrameHints.c
@@ -22,7 +22,7 @@
     else { \
       cnt = SekCyclesDone() - z80startCycle; \
       cnt = (cnt>>1)-(cnt>>5); \
-      if (cnt > (z80_cycles)) cnt = z80_cycles; \
+      if (cnt < 0 || cnt > (z80_cycles)) cnt = z80_cycles; \
       Pico.m.z80Run |= 2; \
       z80CycleAim+=cnt; \
     } \
@@ -54,10 +54,20 @@
 static int PicoFrameHints(void)
 {
   struct PicoVideo *pv=&Pico.video;
-  int lines,y,lines_vis = 224,total_z80 = 0,z80CycleAim = 0,line_sample;
-  int skip=PicoSkipFrame || (PicoOpt&0x10);
+  int lines, y, lines_vis = 224, total_z80 = 0, z80CycleAim = 0, line_sample, skip;
   int hint; // Hint counter
 
+  if ((PicoOpt&0x10) && !PicoSkipFrame) {
+    // draw a frame just after vblank in alternative render mode
+    // yes, this will cause 1 frame lag, but this is inaccurate mode anyway.
+    PicoFrameFull();
+#ifdef DRAW_FINISH_FUNC
+    DRAW_FINISH_FUNC();
+#endif
+    skip = 1;
+  }
+  else skip=PicoSkipFrame;
+
   if (Pico.m.pal) {
     //cycles_68k = (int) ((double) OSC_PAL  /  7 / 50 / 312 + 0.4); // should compile to a constant (488)
     //cycles_z80 = (int) ((double) OSC_PAL  / 15 / 50 / 312 + 0.4); // 228
@@ -139,6 +149,11 @@ static int PicoFrameHints(void)
 #endif
   }
 
+#ifdef DRAW_FINISH_FUNC
+  if (!skip)
+    DRAW_FINISH_FUNC();
+#endif
+
   // V-int line (224 or 240)
   Pico.m.scanline=(short)y;
 
@@ -219,10 +234,6 @@ static int PicoFrameHints(void)
 #endif
   }
 
-  // draw a frame just after vblank in alternative render mode
-  if (!PicoSkipFrame && (PicoOpt&0x10))
-    PicoFrameFull();
-
   return 0;
 }