fixed original interlaced mode desync (hack)

Makefile.wii

@@ -26,7 +26,7 @@ INCLUDES	:=	source source/m68k source/z80 source/sound source/sound/SRC source/n
 # options for code generation
 #---------------------------------------------------------------------------------
 
-CFLAGS	= -O3 -g -mrvl -Wall $(MACHDEP) -Wno-strict-aliasing $(INCLUDE) -DWORDS_BIGENDIAN -DNGC="1" -DHW_RVL
+CFLAGS	= -O3 -mrvl -Wall $(MACHDEP) -Wno-strict-aliasing $(INCLUDE) -DWORDS_BIGENDIAN -DNGC="1" -DHW_RVL
 CXXFLAGS	=	$(CFLAGS)
 
 LDFLAGS	=	$(MACHDEP) -Wl,-Map,$(notdir $@).map

source/cart_hw/eeprom.c

@@ -89,7 +89,7 @@ void eeprom_init()
   sram.custom = 0;
 
   /* look into game database */
-  while ((i<24) && (!sram.custom))
+  while ((i<25) && (!sram.custom))
   {
     if (strstr(rominfo.product,database[i].game_id) != NULL)
     {

source/ngc/gui/menu.c

@@ -1136,8 +1136,7 @@ void MainMenu ()
 
   /* Switch to menu default rendering mode (60hz or 50hz, but always 480 lines) */
   VIDEO_Configure (vmode);
-  VIDEO_ClearFrameBuffer(vmode, xfb[0], COLOR_BLACK);
+  VIDEO_ClearFrameBuffer(vmode, xfb[whichfb], COLOR_BLACK);
-  VIDEO_ClearFrameBuffer(vmode, xfb[1], COLOR_BLACK);
   VIDEO_Flush();
   VIDEO_WaitVSync();
   VIDEO_WaitVSync();
@@ -1222,11 +1221,11 @@ void MainMenu ()
   while (WPAD_ButtonsHeld(0)) WPAD_ScanPads();
 #endif
 
-  /*** Reinitialize VIDEO ***/
+  /*** Reinitialize GX ***/
-  VIDEO_ClearFrameBuffer(vmode, xfb[0], COLOR_BLACK);
+  VIDEO_ClearFrameBuffer(vmode, xfb[whichfb], COLOR_BLACK);
-  VIDEO_ClearFrameBuffer(vmode, xfb[1], COLOR_BLACK);
   VIDEO_Flush();
   VIDEO_WaitVSync();
+  VIDEO_WaitVSync();
   ogc_video__reset();
   odd_frame = 1;
 

source/ngc/ngc.c

@@ -125,16 +125,16 @@ bool fat_enabled = 0;
 
 int main (int argc, char *argv[])
 {
-  long long now, prev;
-  int RenderedFrameCount = 0;
-  int FrameCount = 0;
-
 #ifdef HW_RVL
   /* initialize Wii DVD interface first */
   DI_Close();
   DI_Init();
 #endif
 
+  long long now, prev;
+  int RenderedFrameCount = 0;
+  int FrameCount = 0;
+
   /* initialize OGC subsystems */
   ogc_video__init();
   ogc_input__init();
@@ -173,7 +173,7 @@ int main (int argc, char *argv[])
   set_history_defaults();
   history_load();
 
-  /* initialize VM */
+  /* Initialize Virtual Machine */
   init_machine ();
   
   /* load any injected rom */
@@ -183,30 +183,17 @@ int main (int argc, char *argv[])
     reloadrom ();
   }
   
-  /* show Menu first */
+  /* Show Menu */
-  ConfigRequested = 1;
+  MainMenu();
-
-  /* main emulation loop */
-  while (1)
-  {
-    /* Check for Menu request */
-    if (ConfigRequested)
-    {
-      /* stop Audio */
-      ogc_audio__stop();
-
-      /* go to Menu */
-      MainMenu ();
   ConfigRequested = 0;
 
-      /* reset frame sync */
+  /* Emulation Loop */
-      frameticker = 0;
+  while (1)
-      FrameCount = 0;
+  {
-      RenderedFrameCount = 0;
-
-      /* restart sound loop */
     ogc_audio__start();
-    }
+
+    /* this is an ugly hack to prevent VIDEO desync */
+    if (interlaced & !config.render) odd_frame = VIDEO_GetNextField()^1;
 
     if (gc_pal < 0)
     {
@@ -220,31 +207,28 @@ int main (int argc, char *argv[])
     {
       if (frameticker > 1)
       {
-        /* skip one frame */
+          /* frameskipping */
           frameticker--;
           system_frame (1);
-
-        /* update audio only */
-        ogc_audio__update();
         }
         else
         {
           /* frame sync */
-        while (frameticker < 1) usleep(1);
+        while (!frameticker) usleep(1);
 
-        /* render one frame */
+          /* frame rendering */
           system_frame (0);
           RenderedFrameCount++;
-
-        /* update audio & video */
-        ogc_audio__update();
-        ogc_video__update();
         }
 
       frameticker--;
     }
 
-    /* check rendered frame count (FPS) */
+    /* update video & audio */
+    ogc_audio__update();
+    ogc_video__update();
+
+    /* check rendered frames (FPS) */
     FrameCount++;
     if (FrameCount == vdp_rate)
     {
@@ -252,6 +236,23 @@ int main (int argc, char *argv[])
       RenderedFrameCount = 0;
       FrameCount = 0;
     }
+
+    /* Check for Menu request */
+    if (ConfigRequested)
+    {
+      /* stop Audio */
+      ogc_audio__stop();
+
+      /* go to menu */
+      MainMenu ();
+      ConfigRequested = 0;
+
+      /* reset frame sync */
+      frameticker = 0;
+      FrameCount = 0;
+      RenderedFrameCount = 0;
+
+    }
   }
 
   return 0;

source/ngc/ogc_audio.c

@@ -35,8 +35,8 @@ u8 soundbuffer[2][3840] ATTRIBUTE_ALIGN(32);
 /* Current work soundbuffer */
 int mixbuffer;
 
-/* Status of Audio playback */
+/* Current DMA status (1: DMA in progress, 0: DMA stopped) */ 
-static int AudioStarted = 0;
+static int IsPlaying  = 0;
 
 /* Current DMA length (required to be a factor of 32-bytes)
    length is calculated regarding current emulation timings:
@@ -99,12 +99,16 @@ void ogc_audio__update(void)
  ***/
 void ogc_audio__start(void)
 {
+  if (!IsPlaying)
+  {
     dma_len = vdp_pal ? 3840 : 3200;
+    memset(soundbuffer[0], 0, dma_len);
     AUDIO_InitDMA((u32) soundbuffer[0], dma_len);
     DCFlushRange(soundbuffer[0], dma_len);
     AUDIO_StartDMA();
-  AudioStarted = 1;
+    IsPlaying = 1;
     mixbuffer = 1;
+  }
 }
 
 /***
@@ -116,10 +120,6 @@ void ogc_audio__start(void)
  ***/
 void ogc_audio__stop(void)
 {
-  if (AudioStarted)
-  {
   AUDIO_StopDMA ();
-    AudioStarted = 0;
+  IsPlaying = 0;
-    memset(soundbuffer, 0, 2 * 3840);
-  }
 }

source/ngc/ogc_video.c

@@ -53,7 +53,6 @@ u8 *texturemem;        /*** Texture Data               ***/
 
 static u8 gp_fifo[DEFAULT_FIFO_SIZE] ATTRIBUTE_ALIGN (32);
 static GXTexObj texobj;
-static u8 do_copy = GX_FALSE;
 static Mtx view;
 static u32 vwidth, vheight;
 
@@ -491,7 +490,6 @@ static void gxScale(GXRModeObj *rmode)
   square[4] = square[1]  =  yscale + yshift;
   square[7] = square[10] =  -yscale + yshift;
 
-  /* flush data from cache */
   DCFlushRange (square, 32);
   GX_InvVtxCache ();
 }
@@ -621,37 +619,14 @@ void ogc_video__update()
   draw_square ();
   GX_DrawDone ();
 
-  /* postpound XFB update */
+  /* switch external framebuffers then copy EFB to XFB */
-  do_copy = GX_TRUE;
-}
-
-/* Pre-Retrace  handler 
-    synchronize XFB switch with VSYNC 
- */
-void xfb_switch(u32 cnt)
-{
-  if (!ConfigRequested)
-  {
-    /* switch external framebuffers */
   whichfb ^= 1;
+  GX_CopyDisp (xfb[whichfb], GX_TRUE);
+  GX_Flush ();
   
   /* set next XFB */
   VIDEO_SetNextFramebuffer (xfb[whichfb]);
   VIDEO_Flush ();
-  }
-}
-
-/* Post-Retrace handler 
-    synchronize XFB copy with VSYNC */
-void xfb_copy(u32 cnt)
-{
-  if (do_copy)
-  {
-    /* copy EFB to XFB */
-    GX_CopyDisp (xfb[whichfb], GX_TRUE);
-    GX_Flush ();
-    do_copy = GX_FALSE;
-  }
 }
 
 /* Initialize VIDEO subsystem */
@@ -746,10 +721,6 @@ void ogc_video__init(void)
   /* Set the framebuffer to be displayed at next VBlank */
   VIDEO_SetNextFramebuffer (xfb[0]);
 
-  /* Set Vertical Interrupt callbacks for VIDEO synchronization */
-  VIDEO_SetPreRetraceCallback(xfb_switch);
-  VIDEO_SetPostRetraceCallback(xfb_copy);
-
   /* Enable Video Interface */
   VIDEO_SetBlack (FALSE);
 

source/system.c

@@ -91,8 +91,8 @@ int system_frame (int do_skip)
     return 0;
   }
 
-  int aim_m68k    = 0;
+  uint32 aim_m68k = 0;
-  int aim_z80     = 0;
+  uint32 aim_z80  = 0;
 
   /* reset cycles counts */
   count_m68k      = 0;

source/vdp.c

@@ -1,4 +1,4 @@
-/***************************************************************************************
+  /***************************************************************************************
  *  Genesis Plus 1.2a
  *  Video Display Processor (memory handlers)
  *
@@ -73,12 +73,13 @@ uint32 dma_length;                /* Current DMA remaining bytes */
 int32 fifo_write_cnt;             /* VDP writes fifo count */
 uint32 fifo_lastwrite;            /* last VDP write cycle */
 uint8 fifo_latency;               /* VDP write cycles latency */
-uint8 odd_frame;                  /* 1: odd field , 0: even field */
+uint8 odd_frame;                  /* 1: odd field, 0: even field */
-uint8 interlaced;                 /* 1: Interlace mode 1 or 2 */
 uint8 im2_flag;                   /* 1= Interlace mode 2 is being used */
-uint8 vdp_pal;                    /* 0: NTSC, 1: PAL */
+uint8 interlaced;                 /* 1: Interlaced mode 1 or 2 */
-uint8 vdp_rate;                   /* NTSC: 60hz, PAL: 50hz */
+uint8 vdp_pal  = 0;               /* 1: PAL , 0: NTSC (default) */
-uint16 lines_per_frame;           /* NTSC: 262 lines, PAL: 313 lines */
+uint8 vdp_rate;                   /* PAL: 50hz, NTSC: 60hz */
+uint16 lines_per_frame;           /* PAL: 313 lines, NTSC: 262 lines */
+
 
 /* Tables that define the playfield layout */
 static const uint8 shift_table[] = { 6, 7, 0, 8 };
@@ -136,7 +137,7 @@ static inline void data_write(unsigned int data);
 /*--------------------------------------------------------------------------*/
 void vdp_init(void)
 {
-  /* DMA timings */
+  /* reinitialize DMA timings table */
   int i;
   for (i=0; i<4; i++)
   {
@@ -201,6 +202,7 @@ void vdp_reset(void)
 
   im2_flag = 0;
   interlaced = 0;
+  odd_frame   = 0;
 
   fifo_write_cnt = 0;
 
@@ -229,10 +231,6 @@ void vdp_reset(void)
     window_clip(1,0);
   }
 
-  /* non-interlaced display */
-  odd_frame   = 0;
-  interlaced  = 0;
-
   /* default latency */
   fifo_latency = 27;
 }