Path: blob/master/BizHawk.Emulation.Cores/Consoles/Sega/SMS/VDP.ModeTMS.cs
2 views
// Contains rendering functions for legacy TMS9918 modes.
using System;
namespace BizHawk.Emulation.Cores.Sega.MasterSystem
{
public partial class VDP
{
int[] PaletteTMS9918 = new int[]
{
unchecked((int)0xFF000000),
unchecked((int)0xFF000000),
unchecked((int)0xFF47B73B),
unchecked((int)0xFF7CCF6F),
unchecked((int)0xFF5D4EFF),
unchecked((int)0xFF8072FF),
unchecked((int)0xFFB66247),
unchecked((int)0xFF5DC8ED),
unchecked((int)0xFFD76B48),
unchecked((int)0xFFFB8F6C),
unchecked((int)0xFFC3CD41),
unchecked((int)0xFFD3DA76),
unchecked((int)0xFF3E9F2F),
unchecked((int)0xFFB664C7),
unchecked((int)0xFFCCCCCC),
unchecked((int)0xFFFFFFFF)
};
void RenderBackgroundM0(bool show)
{
if (ScanLine >= FrameHeight)
return;
if (DisplayOn == false)
{
Array.Clear(FrameBuffer, ScanLine * 256, 256);
return;
}
int yc = ScanLine / 8;
int yofs = ScanLine % 8;
int FrameBufferOffset = ScanLine * 256;
int PatternNameOffset = TmsPatternNameTableBase + (yc * 32);
int ScreenBGColor = PaletteTMS9918[Registers[7] & 0x0F];
for (int xc = 0; xc < 32; xc++)
{
int pn = VRAM[PatternNameOffset++];
int pv = VRAM[PatternGeneratorBase + (pn * 8) + yofs];
int colorEntry = VRAM[ColorTableBase + (pn / 8)];
int fgIndex = (colorEntry >> 4) & 0x0F;
int bgIndex = colorEntry & 0x0F;
int fgColor = fgIndex == 0 ? ScreenBGColor : PaletteTMS9918[fgIndex];
int bgColor = bgIndex == 0 ? ScreenBGColor : PaletteTMS9918[bgIndex];
FrameBuffer[FrameBufferOffset++] = show ? (((pv & 0x80) > 0) ? fgColor : bgColor) : 0;
FrameBuffer[FrameBufferOffset++] = show ? (((pv & 0x40) > 0) ? fgColor : bgColor) : 0;
FrameBuffer[FrameBufferOffset++] = show ? (((pv & 0x20) > 0) ? fgColor : bgColor) : 0;
FrameBuffer[FrameBufferOffset++] = show ? (((pv & 0x10) > 0) ? fgColor : bgColor) : 0;
FrameBuffer[FrameBufferOffset++] = show ? (((pv & 0x08) > 0) ? fgColor : bgColor) : 0;
FrameBuffer[FrameBufferOffset++] = show ? (((pv & 0x04) > 0) ? fgColor : bgColor) : 0;
FrameBuffer[FrameBufferOffset++] = show ? (((pv & 0x02) > 0) ? fgColor : bgColor) : 0;
FrameBuffer[FrameBufferOffset++] = show ? (((pv & 0x01) > 0) ? fgColor : bgColor) : 0;
}
}
void RenderBackgroundM2(bool show)
{
if (ScanLine >= FrameHeight)
return;
if (DisplayOn == false)
{
Array.Clear(FrameBuffer, ScanLine * 256, 256);
return;
}
int yrow = ScanLine / 8;
int yofs = ScanLine % 8;
int FrameBufferOffset = ScanLine * 256;
int PatternNameOffset = TmsPatternNameTableBase + (yrow * 32);
int PatternGeneratorOffset = (((Registers[4] & 4) << 11) & 0x2000);// +((yrow / 8) * 0x100);
int ColorOffset = (ColorTableBase & 0x2000);// +((yrow / 8) * 0x100);
int ScreenBGColor = PaletteTMS9918[Registers[7] & 0x0F];
for (int xc = 0; xc < 32; xc++)
{
int pn = VRAM[PatternNameOffset++] + ((yrow / 8) * 0x100);
int pv = VRAM[PatternGeneratorOffset + (pn * 8) + yofs];
int colorEntry = VRAM[ColorOffset + (pn * 8) + yofs];
int fgIndex = (colorEntry >> 4) & 0x0F;
int bgIndex = colorEntry & 0x0F;
int fgColor = fgIndex == 0 ? ScreenBGColor : PaletteTMS9918[fgIndex];
int bgColor = bgIndex == 0 ? ScreenBGColor : PaletteTMS9918[bgIndex];
FrameBuffer[FrameBufferOffset++] = show ? (((pv & 0x80) > 0) ? fgColor : bgColor) : 0;
FrameBuffer[FrameBufferOffset++] = show ? (((pv & 0x40) > 0) ? fgColor : bgColor) : 0;
FrameBuffer[FrameBufferOffset++] = show ? (((pv & 0x20) > 0) ? fgColor : bgColor) : 0;
FrameBuffer[FrameBufferOffset++] = show ? (((pv & 0x10) > 0) ? fgColor : bgColor) : 0;
FrameBuffer[FrameBufferOffset++] = show ? (((pv & 0x08) > 0) ? fgColor : bgColor) : 0;
FrameBuffer[FrameBufferOffset++] = show ? (((pv & 0x04) > 0) ? fgColor : bgColor) : 0;
FrameBuffer[FrameBufferOffset++] = show ? (((pv & 0x02) > 0) ? fgColor : bgColor) : 0;
FrameBuffer[FrameBufferOffset++] = show ? (((pv & 0x01) > 0) ? fgColor : bgColor) : 0;
}
}
void RenderTmsSprites(bool show)
{
if (ScanLine >= FrameHeight || DisplayOn == false)
return;
if (EnableDoubledSprites == false)
RenderTmsSpritesStandard(show);
else
RenderTmsSpritesDouble(show);
}
void RenderTmsSpritesStandard(bool show)
{
Array.Clear(ScanlinePriorityBuffer, 0, 256);
Array.Clear(SpriteCollisionBuffer, 0, 256);
bool LargeSprites = EnableLargeSprites;
int SpriteSize = 8;
if (LargeSprites) SpriteSize *= 2;
const int OneCellSize = 8;
int NumSpritesOnScanline = 0;
for (int i = 0; i < 32; i++)
{
int SpriteBase = TmsSpriteAttributeBase + (i * 4);
int y = VRAM[SpriteBase++];
int x = VRAM[SpriteBase++];
int Pattern = VRAM[SpriteBase++];
int Color = VRAM[SpriteBase];
if (y == 208) break; // terminator sprite
if (y > 224) y -= 256; // sprite Y wrap
y++; // inexplicably, sprites start on Y+1
if (y > ScanLine || y + SpriteSize <= ScanLine) continue; // sprite is not on this scanline
if ((Color & 0x80) > 0) x -= 32; // Early Clock adjustment
if (++NumSpritesOnScanline == 5)
{
StatusByte &= 0xE0; // Clear FS0-FS4 bits
StatusByte |= (byte)i; // set 5th sprite index
StatusByte |= 0x40; // set overflow bit
break;
}
if (LargeSprites) Pattern &= 0xFC; // 16x16 sprites forced to 4-byte alignment
int SpriteLine = ScanLine - y;
// pv contains the VRAM byte holding the pattern data for this character at this scanline.
// each byte contains the pattern data for each the 8 pixels on this line.
// the bit-shift further down on PV pulls out the relevant horizontal pixel.
byte pv = VRAM[SpritePatternGeneratorBase + (Pattern * 8) + SpriteLine];
for (int xp = 0; xp < SpriteSize && x + xp < 256; xp++)
{
if (x + xp < 0) continue;
if (LargeSprites && xp == OneCellSize)
pv = VRAM[SpritePatternGeneratorBase + (Pattern * 8) + SpriteLine + 16];
if (Color != 0 && (pv & (1 << (7 - (xp & 7)))) > 0)
{
if (SpriteCollisionBuffer[x + xp] != 0)
StatusByte |= 0x20; // Set sprite collision flag
if (ScanlinePriorityBuffer[x + xp] == 0)
{
ScanlinePriorityBuffer[x + xp] = 1;
SpriteCollisionBuffer[x + xp] = 1;
if (show)
FrameBuffer[(ScanLine * 256) + x + xp] = PaletteTMS9918[Color & 0x0F];
}
}
}
}
}
void RenderTmsSpritesDouble(bool show)
{
Array.Clear(ScanlinePriorityBuffer, 0, 256);
Array.Clear(SpriteCollisionBuffer, 0, 256);
bool LargeSprites = EnableLargeSprites;
int SpriteSize = 8;
if (LargeSprites) SpriteSize *= 2;
SpriteSize *= 2; // because sprite magnification
const int OneCellSize = 16; // once 8-pixel cell, doubled, will take 16 pixels
int NumSpritesOnScanline = 0;
for (int i = 0; i < 32; i++)
{
int SpriteBase = TmsSpriteAttributeBase + (i * 4);
int y = VRAM[SpriteBase++];
int x = VRAM[SpriteBase++];
int Pattern = VRAM[SpriteBase++];
int Color = VRAM[SpriteBase];
if (y == 208) break; // terminator sprite
if (y > 224) y -= 256; // sprite Y wrap
y++; // inexplicably, sprites start on Y+1
if (y > ScanLine || y + SpriteSize <= ScanLine) continue; // sprite is not on this scanline
if ((Color & 0x80) > 0) x -= 32; // Early Clock adjustment
if (++NumSpritesOnScanline == 5)
{
StatusByte &= 0xE0; // Clear FS0-FS4 bits
StatusByte |= (byte)i; // set 5th sprite index
StatusByte |= 0x40; // set overflow bit
break;
}
if (LargeSprites) Pattern &= 0xFC; // 16x16 sprites forced to 4-byte alignment
int SpriteLine = ScanLine - y;
SpriteLine /= 2; // because of sprite magnification
byte pv = VRAM[SpritePatternGeneratorBase + (Pattern * 8) + SpriteLine];
for (int xp = 0; xp < SpriteSize && x + xp < 256; xp++)
{
if (x + xp < 0) continue;
if (LargeSprites && xp == OneCellSize)
pv = VRAM[SpritePatternGeneratorBase + (Pattern * 8) + SpriteLine + 16];
if (Color != 0 && (pv & (1 << (7 - ((xp / 2) & 7)))) > 0) // xp/2 is due to sprite magnification
{
if (SpriteCollisionBuffer[x + xp] != 0)
StatusByte |= 0x20; // Set sprite collision flag
if (ScanlinePriorityBuffer[x + xp] == 0)
{
ScanlinePriorityBuffer[x + xp] = 1;
SpriteCollisionBuffer[x + xp] = 1;
if (show)
FrameBuffer[(ScanLine * 256) + x + xp] = PaletteTMS9918[Color & 0x0F];
}
}
}
}
}
}
}