improved 'normal' blitter mode, fixes flicker in PP Hammer and Spindi…

…zzy Worlds
rsn8887 · Feb 14, 2018 · ebc8f7d · ebc8f7d
1 parent 991b115
commit ebc8f7d
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Showing 2 changed files with 27 additions and 27 deletions.
diff --git a/src/blitter.cpp b/src/blitter.cpp
@@ -59,8 +59,8 @@ uae_u32 blit_masktable[BLITTER_MAX_WORDS];
 enum blitter_states bltstate;
 
 static long int blit_cyclecounter;
-// blitter_slowdown doesn't work at the moment
-//static int blit_slowdown;
+// blitter_slowdown used to cause gfx glitches in Shadow of the Beast but works now
+static int blit_slowdown;
 
 static long blit_firstline_cycles;
 static long blit_first_cycle;
@@ -545,14 +545,14 @@ void blitter_handler(void)
     return;
   }
 
-// blitter_slowdown doesn't work at the moment
-//	if (blit_slowdown > 0 && !currprefs.immediate_blits) {
-//	eventtab[ev_blitter].active = 1;
-//	eventtab[ev_blitter].oldcycles = get_cycles ();
-//	eventtab[ev_blitter].evtime = blit_slowdown * CYCLE_UNIT + get_cycles (); /* wait a little */
-//		blit_slowdown = -1;
-//		return;
-//	}
+	// blitter_slowdown used to cause gfx glitches in Shadow of the Beast but works now
+	if (!currprefs.immediate_blits && blit_slowdown > 0) {
+	eventtab[ev_blitter].active = 1;
+	eventtab[ev_blitter].oldcycles = get_cycles ();
+	eventtab[ev_blitter].evtime = blit_slowdown * CYCLE_UNIT + get_cycles (); /* wait a little */
+		blit_slowdown = -1;
+		return;
+	}
 
   blitter_doit();
 }
@@ -670,10 +670,12 @@ void do_blitter(void)
   }
 
 	bltstate = BLT_init;
-// blitter_slowdown doesn't work at the moment
-//	blit_slowdown = 0;
+	// blitter_slowdown used to cause gfx glitches in Shadow of the Beast but works now
+	if (!blitter_in_partial_mode && !currprefs.immediate_blits) {
+		blit_slowdown = 0;
+	}
 
-    if (dmaen(DMA_BLITPRI))
+	if (dmaen(DMA_BLITPRI))
         setnasty();
     else
     	unset_special (SPCFLAG_BLTNASTY);
@@ -848,9 +850,9 @@ int blitnasty (void)
 	return ccnt;
 }
 
-// blitter_slowdown doesn't work at the moment (causes gfx glitches in Shadow of the Beast)
+// blitter_slowdown used to cause gfx glitches in Shadow of the Beast but works now
 /* very approximate emulation of blitter slowdown caused by bitplane DMA */
-/*
+
 void blitter_slowdown (int ddfstrt, int ddfstop, int totalcycles, int freecycles)
 {
 	static int oddfstrt, oddfstop, ototal, ofree;
@@ -874,4 +876,3 @@ void blitter_slowdown (int ddfstrt, int ddfstop, int totalcycles, int freecycles
 		return;
 	blit_slowdown += slow;
 }
-*/
diff --git a/src/custom.cpp b/src/custom.cpp
@@ -470,16 +470,16 @@ static const int fetchstarts[] = { 3,2,1,0, 4,3,2,0, 5,4,3,0 };
 static const int fm_maxplanes[] = { 3,2,1,0, 3,3,2,0, 3,3,3,0 };
 
 static int cycle_diagram_table[3][3][9][32];
-// blitter_slowdown doesn't work at the moment (causes gfx glitches in Shadow of the Beast)
-//static int cycle_diagram_free_cycles[3][3][9];
-//static int cycle_diagram_total_cycles[3][3][9];
+// blitter_slowdown used to cause gfx glitches in Shadow of the Beast but works now
+static int cycle_diagram_free_cycles[3][3][9];
+static int cycle_diagram_total_cycles[3][3][9];
 static int *curr_diagram;
 static int cycle_sequences[3 * 8] = { 2,1,2,1,2,1,2,1, 4,2,3,1,4,2,3,1, 8,4,6,2,7,3,5,1 };
 
 static _INLINE_ void create_cycle_diagram_table(void)
 {
    int fm, res, cycle, planes, v;
-   int fetch_start, max_planes/*, freecycles*/;
+   int fetch_start, max_planes, freecycles;
    int *cycle_sequence;
 
    for (fm = 0; fm <= 2; fm++) {
@@ -489,7 +489,7 @@ static _INLINE_ void create_cycle_diagram_table(void)
          cycle_sequence = &cycle_sequences[(max_planes - 1) * 8];
          max_planes = 1 << max_planes;
          for (planes = 0; planes <= 8; planes++) {
-//            freecycles = 0;
+            freecycles = 0;
             for (cycle = 0; cycle < 32; cycle++)
                cycle_diagram_table[fm][res][planes][cycle] = -1;
             if (planes <= max_planes) {
@@ -498,13 +498,13 @@ static _INLINE_ void create_cycle_diagram_table(void)
                      v = cycle_sequence[cycle & 7];
                   } else {
                      v = 0;
-//                     freecycles++;
+                     freecycles++;
                   }
                   cycle_diagram_table[fm][res][planes][cycle] = v;
                }
             }
-//				    cycle_diagram_free_cycles[fm][res][planes] = freecycles;
-//				    cycle_diagram_total_cycles[fm][res][planes] = fetch_start;
+				    cycle_diagram_free_cycles[fm][res][planes] = freecycles;
+				    cycle_diagram_total_cycles[fm][res][planes] = fetch_start;
          }
       }
    }
@@ -3848,13 +3848,12 @@ static void hsync_handler (void)
       fetch_audio();
    }
 
-/* blitter_slowdown doesn't work at the moment (causes gfx glitches in Shadow of the Beast)
-	 if (bltstate != BLT_done && dmaen (DMA_BITPLANE) && diwstate == DIW_waiting_stop) {
+	 //blitter_slowdown used to cause gfx glitches in Shadow of the Beast but works now
+	 if (!blitter_in_partial_mode && !currprefs.immediate_blits && bltstate != BLT_done && dmaen (DMA_BITPLANE) && diwstate == DIW_waiting_stop) {
 		 blitter_slowdown (thisline_decision.plfleft, thisline_decision.plfright - (16 << fetchmode),
 			 cycle_diagram_total_cycles[fetchmode][res_bplcon0][planes_bplcon0],
 			 cycle_diagram_free_cycles[fetchmode][res_bplcon0][planes_bplcon0]);
 	 }
-*/   
 
   /* In theory only an equality test is needed here - but if a program
        goes haywire with the VPOSW register, it can cause us to miss this,