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[SMS] Frameskip actually skip frames

This commit is contained in:
beirich 2011-02-24 04:39:52 +00:00
parent 24cf08dfce
commit 023fb0897a
2 changed files with 77 additions and 3 deletions
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59
BizHawk.Emulation/Consoles/Sega/SMS/VDP.Mode4.cs
View File

@ -224,6 +224,65 @@ namespace BizHawk.Emulation.Consoles.Sega
}
}
internal void ProcessSpriteCollisionForFrameskip()
{
if (DisplayOn == false) return;
int SpriteBase = SpriteAttributeTableBase;
int SpriteHeight = EnableLargeSprites ? 16 : 8;
// Clear the sprite collision buffer for this scanline
Array.Clear(SpriteCollisionBuffer, 0, 256);
// 208 is a special terminator sprite (in 192-line mode). Lets find it...
int TerminalSprite = 64;
if (FrameHeight == 192)
for (int i = 0; i < 64; i++)
{
if (VRAM[SpriteBase + i] == 208)
{
TerminalSprite = i;
break;
}
}
// Loop through these sprites and render the current scanline
int SpritesDrawnThisScanline = 0;
for (int i = TerminalSprite - 1; i >= 0; i--)
{
if (SpritesDrawnThisScanline >= 8)
StatusByte |= 0x40; // Set Overflow bit
int x = VRAM[SpriteBase + 0x80 + (i * 2)];
if (ShiftSpritesLeft8Pixels)
x -= 8;
int y = VRAM[SpriteBase + i] + 1;
if (y >= (EnableLargeSprites ? 240 : 248)) y -= 256;
if (y + SpriteHeight <= ScanLine || y > ScanLine)
continue;
int tileNo = VRAM[SpriteBase + 0x80 + (i * 2) + 1];
if (EnableLargeSprites)
tileNo &= 0xFE;
tileNo += SpriteTileBase;
int ys = ScanLine - y;
for (int xs = 0; xs < 8 && x + xs < 256; xs++)
{
byte color = PatternBuffer[(tileNo * 64) + (ys * 8) + xs];
if (color != 0 && x + xs >= 0)
{
if (SpriteCollisionBuffer[x + xs] != 0)
StatusByte |= 0x20; // Set Collision bit
SpriteCollisionBuffer[x + xs] = 1;
}
}
SpritesDrawnThisScanline++;
}
}
/// <summary>
/// Performs render buffer blanking. This includes the left-column blanking as well as Game Gear blanking if requested.
/// Should be called at the end of the frame.

21
BizHawk.Emulation/Consoles/Sega/SMS/VDP.cs
View File

@ -364,17 +364,32 @@ namespace BizHawk.Emulation.Consoles.Sega
if (TmsMode == 4)
{
// TODO: make frameskip actually skip rendering
if (render == false)
{
ProcessSpriteCollisionForFrameskip();
return;
}
RenderBackgroundCurrentLine();
if (EnableDoubledSprites)
RenderSpritesCurrentLineDoubleSize();
else
RenderSpritesCurrentLine();
} else if (TmsMode == 2) {
}
else if (TmsMode == 2)
{
if (render == false)
return;
RenderBackgroundM2();
RenderTmsSprites();
} else if (TmsMode == 0) {
}
else if (TmsMode == 0)
{
if (render == false)
return;
RenderBackgroundM0();
RenderTmsSprites();
}