improved HBLANK flag occurence timing (fixes Mega Turrican Sky level)

improved emulation of CRAM writes during HBLANK
improved Wii RESET button behavior ("true" MD soft-reset)

source/genesis.c

@@ -149,10 +149,6 @@ void gen_reset(uint32 hard_reset)
   }
 
   resetline   = -1;
-#ifdef NGC
-  /* register SOFTRESET */
-  SYS_SetResetCallback(set_softreset);
-#endif
 
   /* reset CPUs */
   m68k_pulse_reset();

source/gx/gx_input.c

@@ -157,14 +157,20 @@ static void pad_config(int chan, int max_keys)
 
 static void pad_update(s8 chan, u8 i)
 {
-  /* get PAD status */
+  /* PAD status */
+  u16 p = PAD_ButtonsHeld(chan);
   s8 x  = PAD_StickX (chan);
   s8 y  = PAD_StickY (chan);
-  u16 p = PAD_ButtonsHeld(chan);
 
-  /* Soft RESET */
+  if (p & PAD_TRIGGER_Z)
-  if ((p & PAD_TRIGGER_L) && (p & PAD_TRIGGER_Z))
   {
+    /* Menu Request */
+    ConfigRequested = 1;
+    return;
+  }
+  else if ((p & PAD_TRIGGER_L) && (p & PAD_TRIGGER_Z))
+  {
+    /* Soft RESET */
     set_softreset();
   }
 
@@ -428,13 +434,19 @@ static void wpad_update(s8 chan, u8 i, u32 exp)
   /* WPAD data */
   WPADData *data = WPAD_Data(chan);
 
-  /* WPAD buttons */
+  /* WPAD held buttons */
   u32 p = data->btns_h;
 
-  /* Soft RESET */
+  if ((p & WPAD_BUTTON_HOME) || (p & WPAD_CLASSIC_BUTTON_HOME))
-  if (((p & WPAD_CLASSIC_BUTTON_PLUS) && (p & WPAD_CLASSIC_BUTTON_MINUS)) ||
-      ((p & WPAD_BUTTON_PLUS) && (p & WPAD_BUTTON_MINUS)))
   {
+    /* Menu Request */
+    ConfigRequested = 1;
+    return;
+  }
+  else if (((p & WPAD_BUTTON_PLUS) && (p & WPAD_BUTTON_MINUS)) ||
+           ((p & WPAD_CLASSIC_BUTTON_PLUS) && (p & WPAD_CLASSIC_BUTTON_MINUS)))
+  {
+    /* Soft RESET */
     set_softreset();
   }
 
@@ -712,18 +724,11 @@ void gx_input_UpdateEmu(void)
   WPAD_ScanPads();
 #endif
 
-  /* Menu Request */
-  if (PAD_ButtonsHeld(0) & PAD_TRIGGER_Z)
-  {
-    ConfigRequested = 1;
-    return;
-  }
-
 #ifdef HW_RVL
-  if ((WPAD_ButtonsHeld(0) & WPAD_BUTTON_HOME) || (WPAD_ButtonsHeld(0) & WPAD_CLASSIC_BUTTON_HOME))
+  if (SYS_ResetButtonDown())
   {
-    ConfigRequested = 1;
+    /* Soft RESET */
-    return;
+    set_softreset();
   }
 #endif
 

source/gx/gx_input.h

@@ -34,9 +34,6 @@
 /* Genesis controller keys */
 #define MAX_KEYS 8
 
-/* Genesis Plus wrapper */
-#define update_input() gx_input_UpdateEmu()
-
 /* Key configuration structure */
 typedef struct 
 {

source/gx/osd.h

@@ -38,6 +38,8 @@
 #define VERSION "version 1.3.XG"
 #endif
 
+#define osd_input_Update() gx_input_UpdateEmu()
+
 /* globals */
 extern void error(char *format, ...);
 extern void ClearGGCodes();

source/system.c

@@ -257,7 +257,7 @@ int system_frame (int do_skip)
 {
   if (!gen_running)
   {
-    update_input();
+    osd_input_Update();
     return 0;
   }
 
@@ -318,10 +318,6 @@ int system_frame (int do_skip)
     /* Soft Reset ? */
     if (line == reset)
     {
-#ifdef NGC
-      /* wait for RESET button to be released */
-      while (SYS_ResetButtonDown());
-#endif
       /* Pro Action Replay (switch at "Trainer" position) */
       if (config.lock_on == TYPE_AR)
         datel_reset(0);
@@ -344,9 +340,10 @@ int system_frame (int do_skip)
       }
 
       /* HINT will be triggered on next line, approx. 36 cycles before VDP starts line rendering      */
-      /* during this period, any VRAM/CRAM/VSRAM writes should NOT be taken in account before next line */
+      /* during this period, any VRAM or VSRAM writes should NOT be taken in account before next line */
-      /* as a result, current line is shortened */
+      /* as a result, line is rendered immediately after HINT and current line is shortened           */
-      /* fix Lotus 1, Lotus 2 RECS, Striker, Zero the Kamikaze Squirell */
+      /* CRAM and VDP register writes that could occur during HBLANK are handled separately           */
+      /* fix Lotus 1, Lotus 2 RECS, Striker, Skitchin, Zero the Kamikaze Squirell                     */
       if ((line < vdp_height) && (h_counter == 0)) aim_m68k -= 36;
 
       /* update DMA timings */
@@ -359,7 +356,7 @@ int system_frame (int do_skip)
         if ((line < end_line) && (!do_skip)) render_line(line, 1);
 
         /* update inputs (doing this here fix Warriors of Eternal Sun) */
-        update_input();
+        osd_input_Update();
 
         /* set VBLANK flag */
         status |= 0x08;

source/vdp.c

@@ -430,8 +430,8 @@ unsigned int vdp_ctrl_r(void)
   /* display OFF: VBLANK flag is set */
   if (!(reg[1] & 0x40)) temp |= 0x8; 
 
-  /* HBLANK flag (Sonic 3 and Sonic 2 "VS Modes", Lemmings 2) */
+  /* HBLANK flag (Sonic 3 and Sonic 2 "VS Modes", Lemmings 2, Mega Turrican) */
-  if ((count_m68k <= (line_m68k + 84)) || (count_m68k > (line_m68k + m68cycles_per_line))) temp |= 0x4;
+  if ((count_m68k <= (line_m68k + 84)) || (count_m68k > (line_m68k + m68cycles_per_line - 36))) temp |= 0x4;
 
   /* clear pending flag */
   pending = 0;
@@ -616,6 +616,13 @@ static inline void data_w(unsigned int data)
         *p = data;
         if (index) color_update (index, *p);
         if (border == index) color_update (0x00, *p);
+
+        /* CRAM modified during HBLANK */
+        if (!(status & 8) && (reg[1]&0x40) && (count_m68k <= (line_m68k + 84)))
+        {
+          /* remap current line (Striker) */
+          remap_buffer(v_counter,bitmap.viewport.w + 2*bitmap.viewport.x);
+        }
       }
       break;
     }
@@ -691,14 +698,18 @@ static inline void reg_w(unsigned int r, unsigned int d)
         if (vdp_pal) vctab = (d & 8) ? vc_pal_240 : vc_pal_224;
       }
 
-      /* Display activated/blanked during Horizontal Blanking */
+      /* Display enabled/blanked during "Horizontal Blanking" */
       if (((d&0x40) != (reg[1]&0x40)) && !(status & 8))
       {
         if (count_m68k <= (hint_m68k + 120))
         {
-          /* Redraw the current line :
+          /* Fixes the following games :
-            - Legend of Galahad, Lemmings 2, Nigel Mansell's World Championship Racing (set display OFF)
+            - Legend of Galahad, Lemmings 2, Nigel Mansell's World Championship Racing (display OFF)
-            - Deadly Moves aka Power Athlete (set display ON)
+            - Deadly Moves, Power Athlete (display ON)
+          */
+          /* NB: This is not entirely correct since we are a little too tolerant with the HBLANK period limits
+                 while still redrawing the whole line. This is done because some games appear to write this
+                 register outside HBLANK: on real hardware, the line would appear partially blanked.
            */
           reg[1] = d;
           render_line(v_counter, 0);
@@ -745,7 +756,7 @@ static inline void reg_w(unsigned int r, unsigned int d)
         /* background color modified during Horizontal Blanking */
         if (!(status & 8) && (count_m68k <= (line_m68k + 84)))
         {
-          /* remap current line (see Road Rash I,II,III) */
+          /* remap entire line (see Road Rash I,II,III) */
           reg[7] = d;
           remap_buffer(v_counter,bitmap.viewport.w + 2*bitmap.viewport.x);
         }