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NES: Fix more then 8 sprites per scanline

This commit is contained in:
alyosha-tas 2017-01-27 18:34:56 -05:00 committed by GitHub
parent 37a44c2b17
commit dd19a69b6c
1 changed files with 112 additions and 9 deletions
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121
BizHawk.Emulation.Cores/Consoles/Nintendo/NES/PPU.run.cs
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@ -37,7 +37,6 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
public int yp;
public int target;
public int spriteHeight;
public int o_bug; // this is incramented when checks for sprite overflow start, mirroring a hardware bug
public byte[] soam = new byte[512]; // in a real nes, this would only be 32, but we wish to allow more then 8 sprites per scanline
public bool reg_2001_color_disable_latch; // the value used here is taken
@ -196,7 +195,6 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
soam_m_index_aux = 0;
oam_index_aux = 0;
oam_index = 0;
o_bug = 0;
is_even_cycle = true;
sprite_eval_write = true;
sprite_zero_go = false;
@ -254,12 +252,10 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
{
if (oam_index == 64)
{
oam_index_aux = 0;
oam_index = 0;
sprite_eval_write = false;
}
if (is_even_cycle)
if (is_even_cycle && oam_index<64)
{
read_value = OAM[oam_index * 4 + soam_m_index];
@ -322,14 +318,16 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
oam_index = oam_index_aux;
}
}
}
//////////////////////////////////////////////////
//Sprite Evaluation End
//////////////////////////////////////////////////
//process the current clock's worth of bg data fetching
//this needs to be split into 8 pieces or else exact sprite 0 hitting wont work due to the cpu not running while the sprite renders below
if (reg_2001.show_obj || reg_2001.show_bg)
@ -433,7 +431,31 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
Read_bgdata(ref bgdata[xt + 2]);
// normally only 8 sprites are allowed, but with a particular setting we can have more then that
// this extra bit is here because the actual loop doesn't have enough time to scann all sprites if there are more then 8
if (nes.Settings.AllowMoreThanEightSprites)
{
while (oam_index_aux < 64)
{
//look for sprites
soam[soam_index * 4] = OAM[oam_index_aux * 4];
read_value_aux = OAM[oam_index_aux * 4];
if (yp >= read_value_aux && yp < read_value_aux + spriteHeight)
{
soam[soam_index * 4 + 1] = OAM[oam_index_aux * 4 + 1];
soam[soam_index * 4 + 2] = OAM[oam_index_aux * 4 + 2];
soam[soam_index * 4 + 3] = OAM[oam_index_aux * 4 + 3];
soam_index++;
oam_index_aux++;
}
else
{
oam_index_aux++;
}
}
}
soam_index_prev = soam_index;
if (soam_index_prev > 8 && !nes.Settings.AllowMoreThanEightSprites)
soam_index_prev = 8;
@ -453,7 +475,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
bound = 8;
}
for (int s = 0; s < bound; s++)
for (int s = 0; s < 8; s++)
{
//if this is a real sprite sprite, then it is not above the 8 sprite limit.
//this is how we support the no 8 sprite limit feature.
@ -461,7 +483,6 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
//this could be handy for the debugging tools also
bool realSprite = (s < 8);
bool junksprite = (!reg_2001.PPUON);
bool extra_sprite = (s >= 8);
t_oam[s].oam_y = soam[s * 4];
t_oam[s].oam_ind = soam[s * 4 + 1];
@ -493,7 +514,9 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
//garbage nametable fetches + scroll resets
int garbage_todo = 2;
ppubus_read(ppur.get_ntread(), true, true);
if (reg_2001.PPUON)
{
if (sl == 0 && ppur.status.cycle == 304)
@ -526,6 +549,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
garbage_todo = 0;
}
}
if (realSprite)
{
for (int i = 0; i < garbage_todo; i++)
@ -602,6 +626,85 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
} // sprite pattern fetch loop
//now do the same for extra sprites, but without any cycles run
if (bound>8)
{
for (int s = 8; s < bound; s++)
{
bool junksprite = (!reg_2001.PPUON);
t_oam[s].oam_y = soam[s * 4];
t_oam[s].oam_ind = soam[s * 4 + 1];
t_oam[s].oam_attr = soam[s * 4 + 2];
t_oam[s].oam_x = soam[s * 4 + 3];
int line = yp - t_oam[s].oam_y;
if ((t_oam[s].oam_attr & 0x80) != 0) //vflip
line = spriteHeight - line - 1;
int patternNumber = t_oam[s].oam_ind;
int patternAddress;
//8x16 sprite handling:
if (reg_2000.obj_size_16)
{
int bank = (patternNumber & 1) << 12;
patternNumber = patternNumber & ~1;
patternNumber |= (line >> 3) & 1;
patternAddress = (patternNumber << 4) | bank;
}
else
patternAddress = (patternNumber << 4) | (reg_2000.obj_pattern_hi << 12);
//offset into the pattern for the current line.
//tricky: tall sprites have already had lines>8 taken care of by getting a new pattern number above.
//so we just need the line offset for the second pattern
patternAddress += line & 7;
//garbage nametable fetches + scroll resets
int garbage_todo = 2;
ppubus_read(ppur.get_ntread(), true, false);
for (int i = 0; i < garbage_todo; i++)
{
if (i == 0)
{
read_value = t_oam[s].oam_y;
}
else
{
read_value = t_oam[s].oam_ind;
}
}
ppubus_read(ppur.get_atread(), true, false); //at or nt?
read_value = t_oam[s].oam_attr;
read_value = t_oam[s].oam_x;
int addr = patternAddress;
t_oam[s].patterns_0 = ppubus_read(addr, true, false);
read_value = t_oam[s].oam_x;
addr += 8;
t_oam[s].patterns_1 = ppubus_read(addr, true, false);
read_value = t_oam[s].oam_x;
// hflip
if ((t_oam[s].oam_attr & 0x40) == 0)
{
t_oam[s].patterns_0 = BitReverse.Byte8[t_oam[s].patterns_0];
t_oam[s].patterns_1 = BitReverse.Byte8[t_oam[s].patterns_1];
}
} // sprite pattern fetch loop
}
ppuphase = PPUPHASE.BG;
// fetch BG: two tiles for next line