More backports for PPU and video

libretro · Jan 10, 2024 · bf612c2 · bf612c2
1 parent 64e3962
commit bf612c2
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Showing 3 changed files with 26 additions and 13 deletions.
diff --git a/src/nsf.c b/src/nsf.c
@@ -267,6 +267,7 @@ int NSFLoad(FCEUFILE *fp) {
 
 	GameInterface = NSFGI;
 
+#if 0
 	FCEU_printf("NSF Loaded.  File information:\n\n");
 	FCEU_printf(" Name:       %s\n Artist:     %s\n Copyright:  %s\n\n", NSFHeader.SongName, NSFHeader.Artist, NSFHeader.Copyright);
 	if (NSFHeader.SoundChip) {
@@ -284,11 +285,11 @@ int NSFLoad(FCEUFILE *fp) {
 	FCEU_printf(" Load address:  $%04x\n Init address:  $%04x\n Play address:  $%04x\n", LoadAddr, InitAddr, PlayAddr);
 	FCEU_printf(" %s\n", (NSFHeader.VideoSystem & 1) ? "PAL" : "NTSC");
 	FCEU_printf(" Starting song:  %d / %d\n\n", NSFHeader.StartingSong, NSFHeader.TotalSongs);
+#endif
 
-	if (NSFHeader.SoundChip & 4)
-		ExWRAM = FCEU_gmalloc(32768 + 8192);
-	else
-		ExWRAM = FCEU_gmalloc(8192);
+	/* ExWRAM default size is 8192. FDS format adds additional 32K for RAM.
+	 * For simplicity for savestates and runahead, lets just use the maximum size here. */
+	ExWRAM = (uint8 *)FCEU_gmalloc(32768 + 8192);
 	return 1;
 }
 
@@ -301,8 +302,8 @@ static uint8 NSFVectorRead(uint32 A) {
 			doreset = 0; return(0x38);
 		}
 		return(X.DB);
-	} else
-		return(CartBR(A));
+	}
+	return(CartBR(A));
 }
 
 void NSF_init(void) {

diff --git a/src/ppu.c b/src/ppu.c
@@ -61,6 +61,9 @@ static uint32 ppulut1[256];
 static uint32 ppulut2[256];
 static uint32 ppulut3[128];
 
+#define RENDIS_SHOW_SPRITES    (rendis & 1)
+#define RENDIS_SHOW_BACKGROUND (rendis & 2)
+
 static void makeppulut(void) {
 	int x;
 	int y;
@@ -645,7 +648,7 @@ static void DoLine(void)
 	X6502_Run(256);
 	EndRL();
 
-	if (rendis & 2) {/* User asked to not display background data. */
+	if (RENDIS_SHOW_BACKGROUND) {/* User asked to not display background data. */
 		uint32 tem;
 		tem = PALRAM[0] | (PALRAM[0] << 8) | (PALRAM[0] << 16) | (PALRAM[0] << 24);
 		tem |= 0x40404040;
@@ -965,7 +968,7 @@ static void CopySprites(uint8 *target) {
 	if (!spork) return;
 	spork = 0;
 
-	if (rendis & 1) return;	/* User asked to not display sprites. */
+	if (RENDIS_SHOW_SPRITES) return;	/* User asked to not display sprites. */
 
    do
 	{
@@ -1048,10 +1051,19 @@ void FCEUPPU_Reset(void) {
 void FCEUPPU_Power(void) {
 	int x;
 
-	memset(NTARAM, 0x00, 0x800);
-	memset(PALRAM, 0x00, 0x20);
-	memset(UPALRAM, 0x00, 0x03);
-	memset(SPRAM, 0x00, 0x100);
+	/* initialize PPU memory regions according to settings */
+	FCEU_MemoryRand(NTARAM, 0x800);
+	FCEU_MemoryRand(PALRAM, 0x20);
+	FCEU_MemoryRand(SPRAM, 0x100);
+
+	/* palettes can only store values up to $3F, and PALRAM X4/X8/XC are mirrors of X0 for rendering purposes (UPALRAM is used for $2007 readback)*/
+	for (x = 0; x < 0x20; ++x) PALRAM[x] &= 0x3F;
+	UPALRAM[0] = PALRAM[0x04];
+	UPALRAM[1] = PALRAM[0x08];
+	UPALRAM[2] = PALRAM[0x0C];
+	PALRAM[0x0C] = PALRAM[0x08] = PALRAM[0x04] = PALRAM[0x00];
+	PALRAM[0x1C] = PALRAM[0x18] = PALRAM[0x14] = PALRAM[0x10];
+
 	FCEUPPU_Reset();
 	for (x = 0x2000; x < 0x4000; x += 8) {
 		ARead[x] = A200x;

diff --git a/src/video.c b/src/video.c
@@ -61,7 +61,7 @@ int FCEU_InitVirtualVideo(void)
       return 0;
 
    memset(XBuf, 128, 256 * (256 + extrascanlines + 8));
-   memset(XDBuf, 128, 256 * (256 + extrascanlines + 8));
+   memset(XDBuf, 0,  256 * (256 + extrascanlines + 8));
    return 1;
 }