etc
This commit is contained in:
zeromus
parent
5ad3aeeea4
commit
37b36dc8c0
456
src/ppu.cpp
456
src/ppu.cpp
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@ -1805,283 +1805,285 @@ int FCEUX_PPU_Loop(int skip) {
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goto finish;
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}
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//vblank
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PPU_status |= 0x80;
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if(VBlankON) TriggerNMI();
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{
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//vblank
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PPU_status |= 0x80;
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if(VBlankON) TriggerNMI();
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//TRICKY:
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//even though the timing doc says that every scanline is 1364 except for the first dummy scanline,
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//i need these to be 1360 in order to get marble madness and pirates! to work.
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runppu(20*1360);
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//TRICKY:
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//even though the timing doc says that every scanline is 1364 except for the first dummy scanline,
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//i need these to be 1360 in order to get marble madness and pirates! to work.
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runppu(20*1360);
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//no longer in vblank
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PPU_status &= ~0x80;
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//fceu cleared the spritehit and spriteoverflow flags at the same time.. it is reasonable here. or, it is resaonable at vblank interrupt time
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PPU_status &= ~0x40;
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PPU_status &= ~0x20;
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//no longer in vblank
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PPU_status &= ~0x80;
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//fceu cleared the spritehit and spriteoverflow flags at the same time.. it is reasonable here. or, it is resaonable at vblank interrupt time
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PPU_status &= ~0x40;
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PPU_status &= ~0x20;
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//----------
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//this early out caused metroid to fail to boot. I am leaving it here as a reminder of what not to do
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//if(!PPUON) {
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// runppu(kLineTime*242);
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// goto finish;
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//}
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//----------
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//----------
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//this early out caused metroid to fail to boot. I am leaving it here as a reminder of what not to do
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//if(!PPUON) {
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// runppu(kLineTime*242);
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// goto finish;
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//}
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//----------
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//There are 2 conditions that update all 5 PPU scroll counters with the
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//contents of the latches adjacent to them. The first is after a write to
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//2006/2. The second, is at the beginning of scanline 20, when the PPU starts
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//rendering data for the first time in a frame (this update won't happen if
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//all rendering is disabled via 2001.3 and 2001.4).
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//There are 2 conditions that update all 5 PPU scroll counters with the
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//contents of the latches adjacent to them. The first is after a write to
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//2006/2. The second, is at the beginning of scanline 20, when the PPU starts
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//rendering data for the first time in a frame (this update won't happen if
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//all rendering is disabled via 2001.3 and 2001.4).
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if(PPUON)
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ppur.install_latches();
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if(PPUON)
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ppur.install_latches();
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uint8 oams[2][8][7];
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int oamcounts[2]={0,0};
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int oamslot=0;
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int oamcount;
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uint8 oams[2][8][7];
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int oamcounts[2]={0,0};
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int oamslot=0;
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int oamcount;
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//capture the initial xscroll
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int xscroll = ppur.fh;
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//capture the initial xscroll
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int xscroll = ppur.fh;
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//render 241 scanlines (including 1 dummy at beginning)
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for(int sl=0;sl<241;sl++) {
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int yp = sl-1;
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//render 241 scanlines (including 1 dummy at beginning)
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for(int sl=0;sl<241;sl++) {
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int yp = sl-1;
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if(sl != 0) {
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FCEUD_UpdatePPUView(scanline=yp,1);
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FCEUD_UpdateNTView(scanline=yp,1);
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}
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//twiddle the oam buffers
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int scanslot = oamslot^1;
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int renderslot = oamslot;
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oamslot ^= 1;
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oamcount = oamcounts[renderslot];
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//the main scanline rendering loop:
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//32 times, we will fetch a tile and then render 8 pixels.
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//two of those tiles were read in the last scanline.
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for(int xt=0;xt<32;xt++) {
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bgdata.main[xt+2].Read(true);
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//ok, we're also going to draw here.
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//unless we're on the first dummy scanline
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if(sl != 0) {
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int xstart = xt<<3;
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oamcount = oamcounts[renderslot];
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uint8 *target=XBuf+(yp<<8)+xstart;
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uint8 *ptr = target;
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int rasterpos = xstart;
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FCEUD_UpdatePPUView(scanline=yp,1);
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FCEUD_UpdateNTView(scanline=yp,1);
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}
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//check all the conditions that can cause things to render in these 8px
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bool renderspritenow = SpriteON && rendersprites && (xt>0 || SpriteLeft8);
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bool renderbgnow = ScreenON && renderbg && (xt>0 || BGLeft8);
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//twiddle the oam buffers
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int scanslot = oamslot^1;
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int renderslot = oamslot;
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oamslot ^= 1;
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for(int xp=0;xp<8;xp++,rasterpos++) {
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oamcount = oamcounts[renderslot];
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//the main scanline rendering loop:
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//32 times, we will fetch a tile and then render 8 pixels.
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//two of those tiles were read in the last scanline.
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for(int xt=0;xt<32;xt++) {
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bgdata.main[xt+2].Read(true);
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//bg pos is different from raster pos due to its offsetability.
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//so adjust for that here
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int bgpos = rasterpos + xscroll;
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int bgpx = bgpos&7;
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int bgtile = bgpos>>3;
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uint8 pixel=0, pixelcolor;
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//ok, we're also going to draw here.
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//unless we're on the first dummy scanline
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if(sl != 0) {
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int xstart = xt<<3;
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oamcount = oamcounts[renderslot];
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uint8 *target=XBuf+(yp<<8)+xstart;
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uint8 *ptr = target;
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int rasterpos = xstart;
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//generate the BG data
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if(renderbgnow)
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{
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uint8* pt = bgdata.main[bgtile].pt;
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pixel = ((pt[0]>>(7-bgpx))&1) | (((pt[1]>>(7-bgpx))&1)<<1) | bgdata.main[bgtile].at;
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}
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pixelcolor = PALRAM[pixel];
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//check all the conditions that can cause things to render in these 8px
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bool renderspritenow = SpriteON && rendersprites && (xt>0 || SpriteLeft8);
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bool renderbgnow = ScreenON && renderbg && (xt>0 || BGLeft8);
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//look for a sprite to be drawn
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if(renderspritenow) {
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bool havepixel = false;
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for(int s=0;s<oamcount;s++) {
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uint8* oam = oams[renderslot][s];
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int x = oam[3];
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if(rasterpos>=x && rasterpos<x+8) {
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//build the pixel.
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//fetch the LSB of the patterns
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uint8 spixel = oam[4]&1;
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spixel |= (oam[5]&1)<<1;
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for(int xp=0;xp<8;xp++,rasterpos++) {
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//shift down the patterns so the next pixel is in the LSB
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oam[4] >>= 1;
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oam[5] >>= 1;
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//bg pos is different from raster pos due to its offsetability.
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//so adjust for that here
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int bgpos = rasterpos + xscroll;
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int bgpx = bgpos&7;
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int bgtile = bgpos>>3;
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uint8 pixel=0, pixelcolor;
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//bail out if we already have a pixel from a higher priority sprite
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if(havepixel) continue;
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//generate the BG data
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if(renderbgnow)
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{
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uint8* pt = bgdata.main[bgtile].pt;
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pixel = ((pt[0]>>(7-bgpx))&1) | (((pt[1]>>(7-bgpx))&1)<<1) | bgdata.main[bgtile].at;
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}
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pixelcolor = PALRAM[pixel];
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//transparent pixel bailout
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if(spixel==0) continue;
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//look for a sprite to be drawn
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if(renderspritenow) {
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bool havepixel = false;
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for(int s=0;s<oamcount;s++) {
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uint8* oam = oams[renderslot][s];
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int x = oam[3];
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if(rasterpos>=x && rasterpos<x+8) {
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//build the pixel.
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//fetch the LSB of the patterns
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uint8 spixel = oam[4]&1;
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spixel |= (oam[5]&1)<<1;
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//spritehit:
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//1. is it sprite#0?
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//2. is the bg pixel nonzero?
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//then, it is spritehit.
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if(oam[6] == 0 && pixel != 0)
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PPU_status |= 0x40;
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//shift down the patterns so the next pixel is in the LSB
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oam[4] >>= 1;
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oam[5] >>= 1;
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havepixel = true;
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//bail out if we already have a pixel from a higher priority sprite
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if(havepixel) continue;
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//priority handling
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if(oam[2]&0x20) {
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//behind background:
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if((pixel&3)!=0) continue;
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//transparent pixel bailout
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if(spixel==0) continue;
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//spritehit:
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//1. is it sprite#0?
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//2. is the bg pixel nonzero?
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//then, it is spritehit.
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if(oam[6] == 0 && pixel != 0)
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PPU_status |= 0x40;
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havepixel = true;
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//priority handling
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if(oam[2]&0x20) {
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//behind background:
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if((pixel&3)!=0) continue;
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}
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//bring in the palette bits and palettize
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spixel |= (oam[2]&3)<<2;
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pixelcolor = PALRAM[0x10+spixel];
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}
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//bring in the palette bits and palettize
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spixel |= (oam[2]&3)<<2;
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pixelcolor = PALRAM[0x10+spixel];
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}
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}
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//fceu rendering system requires that this be set
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//(so that it knows there is a valid pixel there?)
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pixelcolor |= 0x80;
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*ptr++ = pixelcolor;
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}
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}
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}
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//look for sprites (was supposed to run concurrent with bg rendering)
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oamcounts[scanslot] = 0;
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oamcount=0;
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int spriteHeight = Sprite16?16:8;
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for(int i=0;i<64;i++) {
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uint8* spr = SPRAM+i*4;
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if(yp >= spr[0] && yp < spr[0]+spriteHeight) {
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//if we already have 8 sprites, then this new one causes an overflow,
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//set the flag and bail out.
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if(oamcount == 8) {
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PPU_status |= 0x20;
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break;
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}
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//fceu rendering system requires that this be set
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//(so that it knows there is a valid pixel there?)
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pixelcolor |= 0x80;
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*ptr++ = pixelcolor;
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//just copy some bytes into the internal sprite buffer
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for(int j=0;j<4;j++)
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oams[scanslot][oamcount][j] = spr[j];
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//note that we stuff the oam index into [6].
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//i need to turn this into a struct so we can have fewer magic numbers
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oams[scanslot][oamcount][6] = (uint8)i;
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oamcount++;
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}
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}
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}
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oamcounts[scanslot] = oamcount;
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//look for sprites (was supposed to run concurrent with bg rendering)
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oamcounts[scanslot] = 0;
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oamcount=0;
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int spriteHeight = Sprite16?16:8;
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for(int i=0;i<64;i++) {
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uint8* spr = SPRAM+i*4;
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if(yp >= spr[0] && yp < spr[0]+spriteHeight) {
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//if we already have 8 sprites, then this new one causes an overflow,
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//set the flag and bail out.
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if(oamcount == 8) {
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PPU_status |= 0x20;
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break;
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//todo - think about clearing oams to a predefined value to force deterministic behavior
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//fetch sprite patterns
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for(int s=0;s<8;s++) {
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if(s==1 && sl != 0) {
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//begin hblank!
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//the screen is always behind the ppu operation so we need to wait a little longer before triggering it
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//NOTE: SMB3 is very sensitive about this timing, for the statusbar
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if(PPUON) {
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if(GameHBIRQHook)
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GameHBIRQHook();
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} else {
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int zzz=9;
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}
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}
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//just copy some bytes into the internal sprite buffer
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for(int j=0;j<4;j++)
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oams[scanslot][oamcount][j] = spr[j];
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//note that we stuff the oam index into [6].
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//i need to turn this into a struct so we can have fewer magic numbers
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oams[scanslot][oamcount][6] = (uint8)i;
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oamcount++;
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}
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}
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oamcounts[scanslot] = oamcount;
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uint8* oam = oams[scanslot][s];
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uint32 line = yp - oam[0];
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if(oam[2]&0x80) //vflip
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line = spriteHeight-line-1;
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//todo - think about clearing oams to a predefined value to force deterministic behavior
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uint32 patternNumber = oam[1];
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uint32 patternAddress;
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//fetch sprite patterns
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for(int s=0;s<8;s++) {
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if(s==1 && sl != 0) {
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//begin hblank!
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//the screen is always behind the ppu operation so we need to wait a little longer before triggering it
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//NOTE: SMB3 is very sensitive about this timing, for the statusbar
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if(PPUON) {
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if(GameHBIRQHook)
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GameHBIRQHook();
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//8x16 sprite handling:
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if(Sprite16) {
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uint32 bank = (patternNumber&1)<<12;
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patternNumber = patternNumber&~1;
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patternNumber |= (line>>3);
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patternAddress = (patternNumber<<4) | bank;
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} else {
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int zzz=9;
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patternAddress = (patternNumber<<4) | (SpAdrHI<<9);
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}
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//offset into the pattern for the current line.
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//tricky: tall sprites have already had lines>8 taken care of by getting a new pattern number above.
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//so we just need the line offset for the second pattern
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patternAddress += line&7;
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//garbage nametable fetches
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runppu(kFetchTime);
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runppu(kFetchTime);
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//pattern table fetches
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RefreshAddr = patternAddress;
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oam[4] = FFCEUX_PPURead(RefreshAddr);
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runppu(kFetchTime);
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RefreshAddr += 8;
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oam[5] = FFCEUX_PPURead(RefreshAddr);
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runppu(kFetchTime);
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//hflip
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if(!(oam[2]&0x40)) {
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oam[4] = bitrevlut[oam[4]];
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oam[5] = bitrevlut[oam[5]];
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}
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}
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uint8* oam = oams[scanslot][s];
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uint32 line = yp - oam[0];
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if(oam[2]&0x80) //vflip
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line = spriteHeight-line-1;
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// FV is clocked by the PPU's horizontal blanking impulse, and therefore will increment every scanline.
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//well, according to my tests, maybe at the end of hblank.
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//but where is the end of hblank?
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//well, i imagine it needs to be before the BG fetches for the next line.
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if(PPUON && sl != 0)
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ppur.increment_vs();
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uint32 patternNumber = oam[1];
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uint32 patternAddress;
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//so.. this is the end of hblank. latch horizontal scroll values
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if(PPUON && sl != 0)
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ppur.install_h_latches();
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//8x16 sprite handling:
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if(Sprite16) {
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uint32 bank = (patternNumber&1)<<12;
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patternNumber = patternNumber&~1;
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patternNumber |= (line>>3);
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patternAddress = (patternNumber<<4) | bank;
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} else {
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patternAddress = (patternNumber<<4) | (SpAdrHI<<9);
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}
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//capture the next xscroll
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xscroll = ppur.fh;
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//offset into the pattern for the current line.
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//tricky: tall sprites have already had lines>8 taken care of by getting a new pattern number above.
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//so we just need the line offset for the second pattern
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patternAddress += line&7;
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//fetch BG: two tiles for next line
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for(int xt=0;xt<2;xt++)
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bgdata.main[xt].Read(true);
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//garbage nametable fetches
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//I'm unclear of the reason why this particular access to memory is made.
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//The nametable address that is accessed 2 times in a row here, is also the
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//same nametable address that points to the 3rd tile to be rendered on the
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//screen (or basically, the first nametable address that will be accessed when
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//the PPU is fetching background data on the next scanline).
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//(not implemented yet)
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runppu(kFetchTime);
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runppu(kFetchTime);
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//pattern table fetches
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RefreshAddr = patternAddress;
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oam[4] = FFCEUX_PPURead(RefreshAddr);
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runppu(kFetchTime);
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RefreshAddr += 8;
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oam[5] = FFCEUX_PPURead(RefreshAddr);
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runppu(kFetchTime);
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//hflip
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if(!(oam[2]&0x40)) {
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oam[4] = bitrevlut[oam[4]];
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oam[5] = bitrevlut[oam[5]];
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}
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//After memory access 170, the PPU simply rests for 4 cycles (or the
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//equivelant of half a memory access cycle) before repeating the whole
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//pixel/scanline rendering process. If the scanline being rendered is the very
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//first one on every second frame, then this delay simply doesn't exist.
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if(sl==0 && idleSynch==0)
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{}
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||||
else
|
||||
runppu(4);
|
||||
}
|
||||
|
||||
idleSynch ++;
|
||||
if(idleSynch==2) idleSynch = 0;
|
||||
|
||||
// FV is clocked by the PPU's horizontal blanking impulse, and therefore will increment every scanline.
|
||||
//well, according to my tests, maybe at the end of hblank.
|
||||
//but where is the end of hblank?
|
||||
//well, i imagine it needs to be before the BG fetches for the next line.
|
||||
if(PPUON && sl != 0)
|
||||
ppur.increment_vs();
|
||||
//idle for one line
|
||||
//why 1360? see the note up top at vblank
|
||||
runppu(1360);
|
||||
|
||||
//so.. this is the end of hblank. latch horizontal scroll values
|
||||
if(PPUON && sl != 0)
|
||||
ppur.install_h_latches();
|
||||
framectr++;
|
||||
|
||||
//capture the next xscroll
|
||||
xscroll = ppur.fh;
|
||||
|
||||
//fetch BG: two tiles for next line
|
||||
for(int xt=0;xt<2;xt++)
|
||||
bgdata.main[xt].Read(true);
|
||||
|
||||
//I'm unclear of the reason why this particular access to memory is made.
|
||||
//The nametable address that is accessed 2 times in a row here, is also the
|
||||
//same nametable address that points to the 3rd tile to be rendered on the
|
||||
//screen (or basically, the first nametable address that will be accessed when
|
||||
//the PPU is fetching background data on the next scanline).
|
||||
//(not implemented yet)
|
||||
runppu(kFetchTime);
|
||||
runppu(kFetchTime);
|
||||
|
||||
|
||||
//After memory access 170, the PPU simply rests for 4 cycles (or the
|
||||
//equivelant of half a memory access cycle) before repeating the whole
|
||||
//pixel/scanline rendering process. If the scanline being rendered is the very
|
||||
//first one on every second frame, then this delay simply doesn't exist.
|
||||
if(sl==0 && idleSynch==0)
|
||||
{}
|
||||
else
|
||||
runppu(4);
|
||||
}
|
||||
|
||||
idleSynch ++;
|
||||
if(idleSynch==2) idleSynch = 0;
|
||||
|
||||
//idle for one line
|
||||
//why 1360? see the note up top at vblank
|
||||
runppu(1360);
|
||||
|
||||
framectr++;
|
||||
|
||||
|
||||
finish:
|
||||
FCEU_PutImage();
|
||||
|
|
|
|||
Loading…
Reference in New Issue