Render double-width-res tiles from Background Mode 5 as half-width tiles. This makes the menu text in Secret of Mana readable.

Sprites in Background Mode 5 are still messed up. At least they're at the right X coordinate, roughly...

4 files changed, 230 insertions, 14 deletions

diff --git a/source/gfx.cpp b/source/gfx.cpp
index 611ec0a..59ff71a 100644
--- a/source/gfx.cpp
+++ b/source/gfx.cpp
@@ -173,6 +173,11 @@ void DrawTile (uint32 Tile, uint32 Offset, uint32 StartLine,
 void DrawClippedTile (uint32 Tile, uint32 Offset,
 		      uint32 StartPixel, uint32 Width,
 		      uint32 StartLine, uint32 LineCount);
+void DrawTileHalfWidth (uint32 Tile, uint32 Offset, uint32 StartLine,
+	       uint32 LineCount);
+void DrawClippedTileHalfWidth (uint32 Tile, uint32 Offset,
+		      uint32 StartPixel, uint32 Width,
+		      uint32 StartLine, uint32 LineCount);
 void DrawTilex2 (uint32 Tile, uint32 Offset, uint32 StartLine,
 		 uint32 LineCount);
 void DrawClippedTilex2 (uint32 Tile, uint32 Offset,
@@ -193,6 +198,11 @@ void DrawTile16 (uint32 Tile, uint32 Offset, uint32 StartLine,
 void DrawClippedTile16 (uint32 Tile, uint32 Offset,
 		        uint32 StartPixel, uint32 Width,
 		        uint32 StartLine, uint32 LineCount);
+void DrawTile16HalfWidth (uint32 Tile, uint32 Offset, uint32 StartLine,
+	         uint32 LineCount);
+void DrawClippedTile16HalfWidth (uint32 Tile, uint32 Offset,
+		        uint32 StartPixel, uint32 Width,
+		        uint32 StartLine, uint32 LineCount);
 void DrawTile16x2 (uint32 Tile, uint32 Offset, uint32 StartLine,
 		   uint32 LineCount);
 void DrawClippedTile16x2 (uint32 Tile, uint32 Offset,
@@ -392,8 +402,16 @@ bool8 S9xGraphicsInit ()
 	DrawTilePtr = DrawTile16;
 	DrawClippedTilePtr = DrawClippedTile16;
 	DrawLargePixelPtr = DrawLargePixel16;
-	DrawHiResTilePtr= DrawTile16;
-	DrawHiResClippedTilePtr = DrawClippedTile16;
+	if (Settings.SupportHiRes)
+	{
+		DrawHiResTilePtr= DrawTile16;
+		DrawHiResClippedTilePtr = DrawClippedTile16;
+	}
+	else
+	{
+		DrawHiResTilePtr= DrawTile16HalfWidth;
+		DrawHiResClippedTilePtr = DrawClippedTile16HalfWidth;
+	}
 	GFX.PPL = GFX.Pitch >> 1;
 	GFX.PPLx2 = GFX.Pitch;
 #ifndef FOREVER_16_BIT
@@ -403,8 +421,16 @@ bool8 S9xGraphicsInit ()
 	DrawTilePtr = DrawTile;
 	DrawClippedTilePtr = DrawClippedTile;
 	DrawLargePixelPtr = DrawLargePixel;
-	DrawHiResTilePtr = DrawTile;
-	DrawHiResClippedTilePtr = DrawClippedTile;
+	if (Settings.SupportHiRes)
+	{
+		DrawHiResTilePtr= DrawTile;
+		DrawHiResClippedTilePtr = DrawClippedTile;
+	}
+	else
+	{
+		DrawHiResTilePtr= DrawTileHalfWidth;
+		DrawHiResClippedTilePtr = DrawClippedTileHalfWidth;
+	}
 	GFX.PPL = GFX.Pitch;
 	GFX.PPLx2 = GFX.Pitch * 2;
     }
@@ -635,11 +661,13 @@ void S9xStartScreenRefresh ()
 			{
 				IPPU.RenderedScreenWidth = 512;
 				IPPU.DoubleWidthPixels = TRUE;
+				IPPU.HalfWidthPixels = FALSE;
 			}
 			else
 			{
 				IPPU.RenderedScreenWidth = 256;
 				IPPU.DoubleWidthPixels = FALSE;
+				IPPU.HalfWidthPixels = FALSE;
 			}
 
 			if (IPPU.Interlace)
@@ -673,11 +701,20 @@ void S9xStartScreenRefresh ()
 				GFX.PPLx2 = GFX.PPL << 1;
 			}
 		}
+		else if (!Settings.SupportHiRes && (PPU.BGMode == 5))
+		{
+			// Secret of Mana displays menus with mode 5.
+			// Make them readable.
+			IPPU.DoubleWidthPixels = FALSE;
+			IPPU.HalfWidthPixels = TRUE;
+			IPPU.DoubleHeightPixels = FALSE;
+		}
 		else
 		{
 		    IPPU.RenderedScreenWidth = 256;
 		    IPPU.RenderedScreenHeight = PPU.ScreenHeight;
 		    IPPU.DoubleWidthPixels = FALSE;
+		    IPPU.HalfWidthPixels = FALSE;
     	    IPPU.DoubleHeightPixels = FALSE;
 		    {
 				GFX.Pitch2 = GFX.Pitch = GFX.RealPitch;
@@ -820,7 +857,6 @@ void S9xEndScreenRefresh ()
     }
 #endif
 
-		
     if (CPU.SRAMModified)
     {
 		S9xAutoSaveSRAM ();
@@ -852,9 +888,18 @@ inline void SelectTileRenderer (bool8 normal)
 {
     if (normal)
     {
-		DrawTilePtr = DrawTile16;
-		DrawClippedTilePtr = DrawClippedTile16;
-		DrawLargePixelPtr = DrawLargePixel16;
+		if (IPPU.HalfWidthPixels)
+		{
+			DrawTilePtr = DrawTile16HalfWidth;
+			DrawClippedTilePtr = DrawClippedTile16HalfWidth;
+			DrawLargePixelPtr = DrawLargePixel16;
+		}
+		else
+		{
+			DrawTilePtr = DrawTile16;
+			DrawClippedTilePtr = DrawClippedTile16;
+			DrawLargePixelPtr = DrawLargePixel16;
+		}
     }
     else
     {
@@ -1257,6 +1302,69 @@ if(Settings.BGLayering) {
 #endif
 		}
 	}
+	else if (!Settings.SupportHiRes)
+	{
+		if (PPU.BGMode == 5)
+		{
+			// Bah, OnMain is never used except to determine if calling
+			// SelectTileRenderer is necessary. So let's hack it to false here
+			// to stop SelectTileRenderer from being called when it causes
+			// problems.
+			OnMain = FALSE;
+			GFX.PixSize = 1; // half width - maybe? [Neb]
+			if (IPPU.HalfWidthPixels)
+			{
+#ifndef FOREVER_16_BIT
+				if (Settings.SixteenBit)
+				{
+#endif
+					DrawTilePtr = DrawTile16HalfWidth;
+					DrawClippedTilePtr = DrawClippedTile16HalfWidth;
+#ifndef FOREVER_16_BIT
+				}
+				else
+				{
+					DrawTilePtr = DrawTileHalfWidth;
+					DrawClippedTilePtr = DrawClippedTileHalfWidth;
+				}
+#endif
+			}
+			else
+			{
+#ifndef FOREVER_16_BIT
+				if (Settings.SixteenBit)
+				{
+#endif
+					DrawTilePtr = DrawTile16;
+					DrawClippedTilePtr = DrawClippedTile16;
+#ifndef FOREVER_16_BIT
+				}
+				else
+				{
+					DrawTilePtr = DrawTile;
+					DrawClippedTilePtr = DrawClippedTile;
+				}
+#endif
+			}
+		}
+		else
+		{
+#ifndef FOREVER_16_BIT
+			if (Settings.SixteenBit)
+			{
+#endif
+				DrawTilePtr = DrawTile16;
+				DrawClippedTilePtr = DrawClippedTile16;
+#ifndef FOREVER_16_BIT
+			}
+			else
+			{
+				DrawTilePtr = DrawTile;
+				DrawClippedTilePtr = DrawClippedTile;
+			}
+#endif
+		}
+	}
 	GFX.Z1 = D + 2;
 
 	for(uint32 Y=GFX.StartY, Offset=Y*GFX.PPL; Y<=GFX.EndY; Y++, Offset+=GFX.PPL){
@@ -2066,7 +2174,7 @@ static void DrawBackgroundMode5 (uint32 /* BGMODE */, uint32 bg, uint8 Z1, uint8
 					Count = 8 - Offset;
 					if (Count > Width)
 						Count = Width;
-					s -= Offset;
+					s -= Offset >> 1;
 					Tile = READ_2BYTES (t);
 					GFX.Z1 = GFX.Z2 = depths [(Tile & 0x2000) >> 13];
 					
@@ -2123,14 +2231,14 @@ static void DrawBackgroundMode5 (uint32 /* BGMODE */, uint32 bg, uint8 Z1, uint8
 					else if (Quot == 127)
 						t = b1;
 					Quot++;
-					s += 8;
+					s += (IPPU.HalfWidthPixels ? 4 : 8);
 				}
 				
 				// Middle, unclipped tiles
 				Count = Width - Count;
 				int Middle = Count >> 3;
 				Count &= 7;
-				for (int C = Middle; C > 0; s += 8, Quot++, C--)
+				for (int C = Middle; C > 0; s += (IPPU.HalfWidthPixels ? 4 : 8), Quot++, C--)
 				{
 					Tile = READ_2BYTES(t);
 					GFX.Z1 = GFX.Z2 = depths [(Tile & 0x2000) >> 13];
@@ -2279,11 +2387,13 @@ static void DrawBackground (uint32 BGMode, uint32 bg, uint8 Z1, uint8 Z2)
 		
     case 5:
     case 6: // XXX: is also offset per tile.
-		if (Settings.SupportHiRes)
-		{
+//		if (Settings.SupportHiRes)
+//		{
+			if (!Settings.SupportHiRes)
+				SelectTileRenderer(TRUE /* normal */);
 			DrawBackgroundMode5 (BGMode, bg, Z1, Z2);
 			return;
-		}
+//		}
 		break;
     }
     CHECK_SOUND();
diff --git a/source/ppu.cpp b/source/ppu.cpp
index 44dbece..91e16a0 100644
--- a/source/ppu.cpp
+++ b/source/ppu.cpp
@@ -2615,6 +2615,7 @@ static void CommonPPUReset ()
 	IPPU.Interlace = FALSE;
 	IPPU.InterlaceSprites = FALSE;
 	IPPU.DoubleWidthPixels = FALSE;
+	IPPU.HalfWidthPixels = FALSE;
 	IPPU.DoubleHeightPixels = FALSE;
 	IPPU.RenderedScreenWidth = SNES_WIDTH;
 	IPPU.RenderedScreenHeight = SNES_HEIGHT;
diff --git a/source/ppu.h b/source/ppu.h
index 065ad5f..f55421a 100644
--- a/source/ppu.h
+++ b/source/ppu.h
@@ -140,6 +140,7 @@ struct InternalPPU {
     bool8  Interlace;
     bool8  InterlaceSprites;
     bool8  DoubleWidthPixels;
+    bool8  HalfWidthPixels;
     int    RenderedScreenHeight;
     int    RenderedScreenWidth;
     uint32 Red [256];
diff --git a/source/tile.cpp b/source/tile.cpp
index 008ef33..4fb9de0 100644
--- a/source/tile.cpp
+++ b/source/tile.cpp
@@ -249,6 +249,37 @@ static void WRITE_4PIXELS_FLIPPED (uint32 Offset, uint8 *Pixels, uint16 *ScreenC
 		}
 	}
 }
+static void WRITE_4PIXELS_HALFWIDTH (uint32 Offset, uint8 *Pixels, uint16 *ScreenColors)
+{
+	uint8 Pixel;
+	uint8 *Screen = GFX.S + Offset;
+	uint8 *Depth = GFX.DB + Offset;
+
+	for (uint8 N = 0; N < 4; N += 2)
+	{
+		if (GFX.Z1 > Depth [N] && (Pixel = Pixels[N]))
+		{
+			Screen [N >> 1] = (uint8) ScreenColors [Pixel];
+			Depth [N >> 1] = GFX.Z2;
+		}
+	}
+}
+
+static void WRITE_4PIXELS_FLIPPED_HALFWIDTH (uint32 Offset, uint8 *Pixels, uint16 *ScreenColors)
+{
+	uint8 Pixel;
+	uint8 *Screen = GFX.S + Offset;
+	uint8 *Depth = GFX.DB + Offset;
+
+	for (uint8 N = 0; N < 4; N += 2)
+	{
+		if (GFX.Z1 > Depth [N] && (Pixel = Pixels[2 - N]))
+		{
+			Screen [N >> 1] = (uint8) ScreenColors [Pixel];
+			Depth [N >> 1] = GFX.Z2;
+		}
+	}
+}
 
 static void WRITE_4PIXELSx2 (uint32 Offset, uint8 *Pixels, uint16 *ScreenColors)
 {
@@ -335,6 +366,27 @@ void DrawClippedTile (uint32 Tile, uint32 Offset,
     RENDER_CLIPPED_TILE(WRITE_4PIXELS, WRITE_4PIXELS_FLIPPED, 4)
 }
 
+void DrawTileHalfWidth (uint32 Tile, uint32 Offset, uint32 StartLine,
+	       uint32 LineCount)
+{
+    TILE_PREAMBLE
+
+    register uint8 *bp;
+
+    RENDER_TILE(WRITE_4PIXELS_HALFWIDTH, WRITE_4PIXELS_FLIPPED_HALFWIDTH, 2)
+}
+
+void DrawClippedTileHalfWidth (uint32 Tile, uint32 Offset,
+		      uint32 StartPixel, uint32 Width,
+		      uint32 StartLine, uint32 LineCount)
+{
+    TILE_PREAMBLE
+    register uint8 *bp;
+
+    TILE_CLIP_PREAMBLE
+    RENDER_CLIPPED_TILE(WRITE_4PIXELS_HALFWIDTH, WRITE_4PIXELS_FLIPPED_HALFWIDTH, 2)
+}
+
 void DrawTilex2 (uint32 Tile, uint32 Offset, uint32 StartLine,
 		 uint32 LineCount)
 {
@@ -423,6 +475,38 @@ static void WRITE_4PIXELS16_FLIPPED (uint32 Offset, uint8 *Pixels, uint16 *Scree
 	}
 }
 
+static void WRITE_4PIXELS16_HALFWIDTH (uint32 Offset, uint8 *Pixels, uint16 *ScreenColors)
+{
+	uint8  Pixel;
+	uint16 *Screen = (uint16 *) GFX.S + Offset;
+	uint8  *Depth = GFX.DB + Offset;
+
+	for (uint8 N = 0; N < 4; N += 2)
+	{
+		if (GFX.Z1 > Depth [N] && (Pixel = Pixels[N]))
+		{
+			Screen [N >> 1] = ScreenColors [Pixel];
+			Depth [N >> 1] = GFX.Z2;
+		}
+	}
+}
+
+static void WRITE_4PIXELS16_FLIPPED_HALFWIDTH (uint32 Offset, uint8 *Pixels, uint16 *ScreenColors)
+{
+	uint8  Pixel;
+	uint16 *Screen = (uint16 *) GFX.S + Offset;
+	uint8  *Depth = GFX.DB + Offset;
+
+	for (uint8 N = 0; N < 4; N += 2)
+	{
+		if (GFX.Z1 > Depth [N] && (Pixel = Pixels[2 - N]))
+		{
+			Screen [N >> 1] = ScreenColors [Pixel];
+			Depth [N >> 1] = GFX.Z2;
+		}
+	}
+}
+
 static void WRITE_4PIXELS16x2 (uint32 Offset, uint8 *Pixels, uint16 *ScreenColors)
 {
 	uint8  Pixel;
@@ -570,6 +654,26 @@ void DrawClippedTile16 (uint32 Tile, uint32 Offset,
     RENDER_CLIPPED_TILE(WRITE_4PIXELS16, WRITE_4PIXELS16_FLIPPED, 4)
 }
 
+void DrawTile16HalfWidth (uint32 Tile, uint32 Offset, uint32 StartLine,
+		   uint32 LineCount)
+{
+    TILE_PREAMBLE
+    register uint8 *bp;
+
+    RENDER_TILE(WRITE_4PIXELS16_HALFWIDTH, WRITE_4PIXELS16_FLIPPED_HALFWIDTH, 2)
+}
+
+void DrawClippedTile16HalfWidth (uint32 Tile, uint32 Offset,
+			uint32 StartPixel, uint32 Width,
+			uint32 StartLine, uint32 LineCount)
+{
+    TILE_PREAMBLE
+    register uint8 *bp;
+
+    TILE_CLIP_PREAMBLE
+    RENDER_CLIPPED_TILE(WRITE_4PIXELS16_HALFWIDTH, WRITE_4PIXELS16_FLIPPED_HALFWIDTH, 2)
+}
+
 void DrawTile16x2 (uint32 Tile, uint32 Offset, uint32 StartLine,
 		   uint32 LineCount)
 {