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PPU add windowing

This commit is contained in:
alyosha-tas 2017-09-04 17:36:26 -04:00 committed by GitHub
parent 042fd6ddaa
commit 666e284e03
1 changed files with 176 additions and 5 deletions
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181
BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/PPU.cs
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@ -78,6 +78,15 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
public int sprite_ordered_index;
public int bottom_index;
// windowing state
public int window_counter;
public bool window_pre_render;
public bool window_started;
public int window_tile_inc;
public int window_y_tile;
public int window_x_tile;
public int window_y_tile_inc;
public byte ReadReg(int addr)
{
byte ret = 0;
@ -318,6 +327,13 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
LY_inc = 1;
Core.in_vblank = false;
VBL_INT = false;
// special note here, the y coordiate of the window is kept if the window is deactivated
// meaning it will pick up where it left off if re-enabled later
// so we don't reset it in the scanline loop
window_y_tile = 0;
window_y_tile_inc = 0;
window_started = false;
}
Core.cpu.LY = LY;
@ -325,6 +341,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
if (LY==144)
{
Core.in_vblank = true;
}
}
}
@ -460,6 +477,18 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
fetch_sprite = false;
no_sprites = false;
window_pre_render = false;
if (window_started && LCDC.Bit(5))
{
window_y_tile_inc++;
if (window_y_tile_inc==8)
{
window_y_tile_inc = 0;
window_y_tile++;
}
}
window_started = false;
// calculate the row number of the tiles to be fetched
y_tile = ((int)Math.Floor((float)(scroll_y + LY) / 8)) % 32;
@ -468,8 +497,39 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
no_sprites = true;
}
}
// before anything else, we have to check if windowing is in effect
if (LCDC.Bit(5) && !window_started && LY >= window_y && pixel_counter >= window_x - 7)
{
/*
Console.Write(LY);
Console.Write(" ");
Console.Write(window_y);
Console.Write(" ");
Console.Write(window_y_tile_inc);
Console.Write(" ");
Console.WriteLine(scroll_y);
*/
if (pixel_counter == 0 && window_x <= 7)
{
// if the window starts at zero, we still do the first access to the BG
// but then restart all over again at the window
window_pre_render = true;
}
else
{
// otherwise, just restart the whole process as if starting BG again
window_pre_render = true;
read_case = 4;
window_counter = 0;
}
if (!pre_render && !fetch_sprite)
window_x_tile = (int)Math.Floor((float)(pixel_counter - (window_x - 7)) / 8);
window_tile_inc = 0;
window_started = true;
}
if (!pre_render && !fetch_sprite && !window_pre_render)
{
// start by fetching all the sprites that need to be fetched
if (!no_sprites)
@ -600,11 +660,15 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
}
else
{
read_case = 1;
if (!pre_render)
{
tile_inc++;
}
read_case = 1;
if (window_pre_render)
{
read_case = 4;
}
}
}
break;
@ -687,18 +751,110 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
}
else
{
read_case = 0;
if (window_started)
{
read_case = 4;
}
else
{
read_case = 0;
}
latch_new_data = true;
}
if (window_started) { window_counter++; }
break;
case 4: // read from window data
if ((window_counter % 2) == 0)
{
temp_fetch = window_y_tile * 32 + (window_x_tile + window_tile_inc) % 32;
tile_byte = LCDC.Bit(6) ? Core.BG_map_2[temp_fetch] : Core.BG_map_1[temp_fetch];
}
else
{
if (!window_pre_render)
{
window_tile_inc++;
}
read_case = 6;
}
window_counter++;
break;
case 6: // read from tile graphics (for the window)
if ((window_counter % 2) == 0)
{
y_scroll_offset = (window_y_tile_inc) % 8;
if (LCDC.Bit(4))
{
tile_data[0] = Core.CHR_RAM[tile_byte * 16 + y_scroll_offset * 2];
}
else
{
// same as before except now tile byte represents a signed byte
if (tile_byte.Bit(7))
{
tile_byte -= 256;
}
tile_data[0] = Core.CHR_RAM[0x1000 + tile_byte * 16 + y_scroll_offset * 2];
}
}
else
{
read_case = 7;
}
window_counter++;
break;
case 7: // read from tile graphics (for the window)
if ((window_counter % 2) == 0)
{
y_scroll_offset = (window_y_tile_inc) % 8;
if (LCDC.Bit(4))
{
// if LCDC somehow changed between the two reads, make sure we have a positive number
if (tile_byte < 0)
{
tile_byte += 256;
}
tile_data[1] = Core.CHR_RAM[tile_byte * 16 + y_scroll_offset * 2 + 1];
}
else
{
// same as before except now tile byte represents a signed byte
if (tile_byte.Bit(7) && tile_byte > 0)
{
tile_byte -= 256;
}
tile_data[1] = Core.CHR_RAM[0x1000 + tile_byte * 16 + y_scroll_offset * 2 + 1];
}
}
else
{
if (window_pre_render)
{
// here we set up rendering
window_pre_render = false;
render_offset = 0;
render_counter = -1;
latch_counter = 0;
read_case = 4;
}
else
{
read_case = 3;
}
}
window_counter++;
break;
case 8: // done reading, we are now in phase 0
@ -794,7 +950,15 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
stat_line = false;
stat_line_old = false;
}
window_counter = 0;
window_pre_render = false;
window_started = false;
window_tile_inc = 0;
window_y_tile = 0;
window_x_tile = 0;
window_y_tile_inc = 0;
}
public void process_sprite()
{
@ -917,6 +1081,13 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
ser.Sync("sprite_ordered_index", ref sprite_ordered_index);
ser.Sync("bottom_index", ref bottom_index);
ser.Sync("window_counter", ref window_counter);
ser.Sync("window_pre_render", ref window_pre_render);
ser.Sync("window_started", ref window_started);
ser.Sync("window_tile_inc", ref window_tile_inc);
ser.Sync("window_y_tile", ref window_y_tile);
ser.Sync("window_x_tile", ref window_x_tile);
ser.Sync("window_y_tile_inc", ref window_y_tile_inc);
}
}
}