// Mode 4 is another bitmap mode. It also has a 240×160 frame-buffer, but instead of 16bpp pixels it uses 8bpp pixels.
// These 8 bits are a palette index to the background palette located at 0500:0000 (palette 0)
private void RenderMode4Scanline()
{
byte[] vram = gba.Memory.VRam;
Color[] palette = Palettes.Palette0;
int y = CurrentScanline;
bool pixelDrawn;
bool windowing = false;
bool objVisibleOverride = true;
int windowRegion = 0;
int bgVisibleOverride = 0;
ObjController.ObjPrioritySort();
for (int x = 0; x < Screen_X_Resolution; x++)
{
pixelDrawn = false;
for (int priority = 0; priority < 4; priority++)
{
// Sprite rendering
if (DisplayControlRegister.DisplayObj &&
(!windowing || (windowing && objVisibleOverride)))
{
pixelDrawn = ObjController.RenderSpritePixel(drawBuffer, x, y, priority, windowing, windowRegion, ref bgVisibleOverride);
if (pixelDrawn)
{
break;
}
}
}
if (pixelDrawn == false)
{
// 2nd framebuffer is at 0xA000
int index = vram[((y * Screen_X_Resolution) + x)];
drawBuffer.SetPixel(x, y, palette[index]);
}
}
}
// DENNIS: the way I did threaded rendering was by caching the LCD IO registers, and updating them for the PPU whenever it started rendering the next scanline
private void RenderScanlineTextMode()
{
/*
if(frameNumber % 30 != 0)
{
return;
}
*/
/*
if (DisplayControlRegister.BgVisible(0)) Bg[0].CacheScanline();
if (DisplayControlRegister.BgVisible(1)) Bg[1].CacheScanline();
if (DisplayControlRegister.BgVisible(2)) Bg[2].CacheScanline();
if (DisplayControlRegister.BgVisible(3)) Bg[3].CacheScanline();
*/
ObjController.ObjPrioritySort();
int scanline = CurrentScanline;
bool windowing = (DisplayControlRegister.DisplayWin0 || DisplayControlRegister.DisplayWin1 || DisplayControlRegister.DisplayWin1 || DisplayControlRegister.DisplayObjWin);
//Bg[0].WaitForScanline();
//Bg[1].WaitForScanline();
//Bg[2].WaitForScanline();
//Bg[3].WaitForScanline();
// We render front to back. Once a pixel is drawn we stop going through the layers.
// TODO: In order to do blending we may need to go through all the layers for each pixel
#if ParallelizeScanline
var paritioner = Partitioner.Create(0, LcdController.Screen_X_Resolution, 80);
var result = Parallel.ForEach(paritioner, (range) =>
{
for (int x = range.Item1; x < range.Item2; x++)
#else
for (int x = 0; x < Screen_X_Resolution; x++)
#endif
{
int paletteIndex;
bool pixelDrawn = false;
// Windowing can disable obj's and bg's
bool objVisibleOverride = false;
int windowRegion = 0;
int bgVisibleOverride = 0; // bitmask for bg visible (from window)
if (windowing)
{
windowRegion = TileHelpers.PixelWindowRegion(x, CurrentScanline, gba);
// 0 is outside of all windows
if (windowRegion == 0)
{
objVisibleOverride = Windows[(int) Window.WindowName.WindowOut].DisplayObjs;
bgVisibleOverride = Windows[(int)Window.WindowName.WindowOut].DisplayBg0 |
Windows[(int)Window.WindowName.WindowOut].DisplayBg1 |
Windows[(int)Window.WindowName.WindowOut].DisplayBg2 |
Windows[(int)Window.WindowName.WindowOut].DisplayBg3;
}
// Window 0 takes priority over window 1. We don't need to check if the point is within both areas as it is done in the function call above
else if((windowRegion & (int)TileHelpers.WindowRegion.Window0) != 0)
{
objVisibleOverride = Windows[(int)Window.WindowName.Window0].DisplayObjs;
bgVisibleOverride = Windows[(int)Window.WindowName.Window0].DisplayBg0 |
Windows[(int)Window.WindowName.Window0].DisplayBg1 |
Windows[(int)Window.WindowName.Window0].DisplayBg2 |
Windows[(int)Window.WindowName.Window0].DisplayBg3;
}
else if ((windowRegion & (int)TileHelpers.WindowRegion.Window1) != 0)
{
objVisibleOverride = Windows[(int)Window.WindowName.Window1].DisplayObjs;
bgVisibleOverride = Windows[(int)Window.WindowName.Window1].DisplayBg0 |
Windows[(int)Window.WindowName.Window1].DisplayBg1 |
Windows[(int)Window.WindowName.Window1].DisplayBg2 |
Windows[(int)Window.WindowName.Window1].DisplayBg3;
}
}
else
{
objVisibleOverride = true;
bgVisibleOverride = 0;
}
// Start at the top priority, if something draws to the pixel, we can early out and stop processing this pixel
// Highest priority (0) is drawn at the front. Lower priorities can be obscured
for (int priority = 0; priority < 4; priority++)
{
// Sprite rendering
// If a sprite has the same priority as a bg, the sprite is drawn on top, therefore we check sprites first
if (DisplayControlRegister.DisplayObj &&
(!windowing || (windowing && objVisibleOverride)))
{
pixelDrawn = ObjController.RenderSpritePixel(drawBuffer, x, scanline, priority, windowing, windowRegion, ref bgVisibleOverride);
if (pixelDrawn)
{
break;
}
}
// No Sprite occupied this pixel, move on to backgrounds
// Bg Rendering
// Find the backgrounds with this priority
// In case of same priority, BG0 has highest (drawn at front)
for (int bgSelect = 0; bgSelect < 4; bgSelect++)
{
if (Bg[bgSelect].CntRegister.Priority != priority ||
DisplayControlRegister.BgVisible(Bg[bgSelect].BgNumber) == false ||
(windowing && ((bgVisibleOverride & (1 << bgSelect)) == 0)))
{
continue;
}
/*
if(Bg[2].AffineMode && bgSelect == 1)
{
continue;
}
*/
if (Bg[bgSelect].AffineMode)
{
paletteIndex = Bg[bgSelect].PixelValueAffine(x, scanline);
}
else
{
paletteIndex = Bg[bgSelect].PixelValue(x, scanline);
}
// TODO: If we need to blend then get the pixels we need to blend here
/*
lock (Bg[bgSelect].ScanlineData)
{
paletteIndex = Bg[bgSelect].ScanlineData[x];
}
*/
// Pal 0 == Transparent
if (paletteIndex == 0)
{
continue;
}
drawBuffer.SetPixel(x, scanline, Palettes.Palette0[paletteIndex]);
pixelDrawn = true;
// Once a pixel has been drawn, no need to check other BG's
break;
}
if(pixelDrawn)
{
break;
}
}
// If nothing is drawn then default to backdrop colour
if (pixelDrawn == false)
{
drawBuffer.SetPixel(x, scanline, Palettes.Palette0[0]);
}
}
#if ParallelizeScanline
}); // Parallel.For
//while (result.IsCompleted == false) ;
#endif
}