display(0),
core(core),
frames_rendered(0),
+ cycles_until_next_update(0),
+ mode(2),
display_mode(NORMAL)
{
SDL_Init(SDL_INIT_VIDEO);
u8 GBVideo::read_VRAM (int addr) const
{
- int STAT = core->memory.read(GBIO::STAT);
+ int STAT = core->memory.IO.ports[GBIO::I_STAT];
if ((STAT & 3) == 3)
return 0xFF; // VRAM access disabled
else
u8 GBVideo::read_OAM (int addr) const
{
- int STAT = core->memory.read(GBIO::STAT);
+ int STAT = core->memory.IO.ports[GBIO::I_STAT];
if ((STAT & 3) >= 2)
return 0xFF; // OAM access disabled
else
void GBVideo::write_VRAM(int addr, u8 value)
{
- int STAT = core->memory.read(GBIO::STAT);
+ int STAT = core->memory.IO.ports[GBIO::I_STAT];
if ((STAT & 3) == 3)
return; // VRAM access disabled
else
void GBVideo::write_OAM (int addr, u8 value)
{
- int STAT = core->memory.read(GBIO::STAT);
+ int STAT = core->memory.IO.ports[GBIO::I_STAT];
if ((STAT & 3) >= 2)
return; // OAM access disabled
else
// mode 0 starts at 252, 708, 1164...
// vblank starts at 65664
- u32 *pixels = static_cast<u32*>(display->pixels);
- u32 pixels_per_line = display->pitch/display->format->BytesPerPixel;
+ if (cycles_until_next_update == 0)
+ {
+ int STAT = core->memory.IO.ports[GBIO::I_STAT];
+ int LYC = core->memory.IO.ports[GBIO::I_LYC];
+ int LY = core->memory.IO.ports[GBIO::I_LY];
- int LCDC = core->memory.read(GBIO::LCDC);
- int STAT = core->memory.read(GBIO::STAT);
- int LYC = core->memory.read(GBIO::LYC);
+ switch (mode)
+ {
+ case 0:
+ // HBlank (preserve bits 2-6, mode = 0)
+ STAT = (STAT&0xFC);
+ if (check_bit(STAT, 3))
+ {
+ logger.trace("Requesting IRQ_LCD_STAT -- HBLANK");
+ core->irq(GameBoy::IRQ_LCD_STAT);
+ }
+ cycles_until_next_update = 204;
+ if (LY == 143)
+ mode = 1;
+ else
+ mode = 2;
+ break;
+ case 1:
+ if (LY == 144)
+ {
+ logger.trace("Requesting IRQ_VBLANK");
+ core->irq(GameBoy::IRQ_VBLANK);
- int t = core->cycle_count % 70224;
- int hline_t=-1;
- int LY = t/456;
+ if (check_bit(STAT,4))
+ {
+ logger.trace("Requesting IRQ_LCD_STAT -- VBLANK");
+ core->irq(GameBoy::IRQ_LCD_STAT);
+ }
+ SDL_Flip(display);
+ frames_rendered++;
+ char buf[50];
+ sprintf(buf, "%d", frames_rendered);
+ SDL_WM_SetCaption(buf, 0);
- if (t >= 65664)
- {
- if (t == 65664)
- {
- logger.trace("Requesting IRQ_VBLANK");
- core->irq(GameBoy::IRQ_VBLANK);
+ // preserve bits 3-6, set mode to 1 (VBlank) and coincidence to 0
+ STAT = (STAT&0xF8) | 1;
+ }
+ cycles_until_next_update = 456;
+ if (LY == 153)
+ mode = 2;
+ else
+ mode = 1;
+ break;
+ case 2: {
+ if (LY == LYC)
+ {
+ STAT = set_bit(STAT, 2); // set coincidence flag
+ if (check_bit(STAT, 6))
+ {
+ logger.trace("Requesting IRQ_LCD_STAT -- LY = LYC = ", LY, " EI=", int(core->memory.IE),
+ " IME =", int(core->IME));
+ core->irq(GameBoy::IRQ_LCD_STAT);
+ }
+ }
- if (check_bit(STAT,4))
- {
- logger.trace("Requesting IRQ_LCD_STAT -- VBLANK");
- core->irq(GameBoy::IRQ_LCD_STAT);
+ if (check_bit(STAT, 5))
+ {
+ logger.trace("Requesting IRQ_LCD_STAT -- Mode 2");
+ core->irq(GameBoy::IRQ_LCD_STAT);
+ }
+
+ // preserve bits 2-6, set mode 2
+ STAT = (STAT&0xFC) | 2;
+ cycles_until_next_update = 80;
+ mode = 3;
+ break;
}
- SDL_Flip(display);
- frames_rendered++;
- char buf[50];
- sprintf(buf, "%d", frames_rendered);
- SDL_WM_SetCaption(buf, 0);
+ case 3:
+ draw();
+ // preserve bits 2-6, set mode 3
+ STAT = (STAT&0xFC) | 3;
+ cycles_until_next_update = 172;
+ mode = 0;
+ break;
}
-
- // preserve bits 3-6, set mode to 1 (VBlank) and coincidence to 0
- STAT = (STAT&0xF8) | 1;
- }
- else
- {
- hline_t = t%456;
- if (hline_t == 0 && LY == LYC)
+
+ if (mode == 1 || mode == 2)
{
- STAT = set_bit(STAT, 2); // set coincidence flag
- if (hline_t == 0 && check_bit(STAT, 6))
- {
- logger.trace("Requesting IRQ_LCD_STAT -- LY = LYC = ", LY, " EI=", int(core->memory.read(0xFFFF)),
- " IME =", int(core->IME));
- core->irq(GameBoy::IRQ_LCD_STAT);
- }
+ LY = (LY+1)%154;
+ logger.trace(LY);
+ core->memory.IO.ports[GBIO::I_LY] = LY;
}
- if (hline_t < 80)
- {
- if (hline_t == 0 && check_bit(STAT, 5)) {
- logger.trace("Requesting IRQ_LCD_STAT -- Mode 2");
- core->irq(GameBoy::IRQ_LCD_STAT);
- }
- // preserve bits 2-6, set mode 2
- STAT = (STAT&0xFC) | 2;
- }
- else if (hline_t < 252)
- {
- // preserve bits 2-6, set mode 3
- STAT = (STAT&0xFC) | 3;
- }
- else
- {
- // HBlank (preserve bits 2-6, mode = 0)
- STAT = (STAT&0xFC);
- if (hline_t == 252 && check_bit(STAT, 3))
- {
- logger.trace("Requesting IRQ_LCD_STAT -- HBLANK");
- core->irq(GameBoy::IRQ_LCD_STAT);
- }
- }
-
+ core->memory.IO.ports[GBIO::I_STAT] = STAT;
}
-
- core->memory.write(GBIO::LY, LY);
- core->memory.write(GBIO::STAT, STAT);
- if (display_mode == NORMAL)
+ --cycles_until_next_update;
+ return;
+}
+
+void GBVideo::draw()
+{
+ u32 *pixels = static_cast<u32*>(display->pixels);
+ u32 pixels_per_line = display->pitch/display->format->BytesPerPixel;
+
+ int LCDC = core->memory.IO.ports[GBIO::I_LCDC];
+ int LY = core->memory.IO.ports[GBIO::I_LY];
+
+ if (LY < 144 && display_mode == NORMAL)
{
// Draw the background
// Draw at hline_t == 80, when the app cannot write to neither VRAM nor OAM
- if (hline_t == 80)
+ int BGP = core->memory.IO.ports[GBIO::I_BGP];
+ int pallette[4];
+ pallette[0] = BGP & 3;
+ pallette[1] = (BGP>>2) & 3;
+ pallette[2] = (BGP>>4) & 3;
+ pallette[3] = (BGP>>6) & 3;
+
+ if (check_bit(LCDC, 0)) // is BG display active?
{
- int BGP = core->memory.read(GBIO::BGP);
- int pallette[4];
- pallette[0] = BGP & 3;
- pallette[1] = (BGP>>2) & 3;
- pallette[2] = (BGP>>4) & 3;
- pallette[3] = (BGP>>6) & 3;
-
- if (check_bit(LCDC, 0)) // is BG display active?
+ u16 tile_map_addr = check_bit(LCDC,3) ? 0x1C00 : 0x1800;
+ u16 tile_data_addr = check_bit(LCDC,4) ? 0x0000 : 0x0800;
+ int tile_data_base = (tile_data_addr == 0x0800) ? -128 : 0;
+
+ // (vx , vy ) -> position of the pixel in the 256x256 bg
+ // (map_x , map_y ) -> map coordinates of the current tile
+ // (tile_x, tile_y) -> position of the pixel in the tile
+ int SCX = core->memory.IO.ports[GBIO::I_SCX];
+ int SCY = core->memory.IO.ports[GBIO::I_SCY];
+ int vy = (LY + SCY) % 256;
+ int map_y = vy / 8;
+ int tile_y = vy % 8;
+ for (int x=0; x<160; x++)
{
- u16 tile_map_addr = check_bit(LCDC,3) ? 0x1C00 : 0x1800;
- u16 tile_data_addr = check_bit(LCDC,4) ? 0x0000 : 0x0800;
- int tile_data_base = (tile_data_addr == 0x0800) ? -128 : 0;
+ int vx = (x+SCX) % 256;
+ int map_x = vx/8;
+
+ if (LY == 0)
+ logger.trace("(",map_x, ",", map_y, ")");
- // (vx , vy ) -> position of the pixel in the 256x256 bg
- // (map_x , map_y ) -> map coordinates of the current tile
- // (tile_x, tile_y) -> position of the pixel in the tile
- int SCX = core->memory.read(GBIO::SCX);
- int SCY = core->memory.read(GBIO::SCY);
- int vy = (LY + SCY) % 256;
- int map_y = vy / 8;
- int tile_y = vy % 8;
- for (int x=0; x<160; x++)
- {
- int vx = (x+SCX) % 256;
- int map_x = vx/8;
- int tile_x = 7-(vx%8);
- u8 current_tile_index = VRAM[tile_map_addr+ 32*map_y + map_x] + tile_data_base;
- u16 current_tile_addr = tile_data_addr + 16*current_tile_index;
- u8 current_row_low = VRAM[current_tile_addr+2*tile_y];
- u8 current_row_high = VRAM[current_tile_addr+2*tile_y+1];
- u32 color = colors[pallette[((current_row_high >> tile_x)&1) << 1 |
- ((current_row_low >> tile_x)&1)]];
+ int tile_x = 7-(vx%8);
+ u8 current_tile_index = VRAM[tile_map_addr+ 32*map_y + map_x] + tile_data_base;
+ u16 current_tile_addr = tile_data_addr + 16*current_tile_index;
+ u8 current_row_low = VRAM[current_tile_addr+2*tile_y];
+ u8 current_row_high = VRAM[current_tile_addr+2*tile_y+1];
+ u32 color = colors[pallette[((current_row_high >> tile_x)&1) << 1 |
+ ((current_row_low >> tile_x)&1)]];
- pixels[2*(LY*pixels_per_line+x)] = color;
- pixels[2*(LY*pixels_per_line+x)+1] = color;
- pixels[2*(LY*pixels_per_line+x)+320] = color;
- pixels[2*(LY*pixels_per_line+x)+321] = color;
- }
+ pixels[2*(LY*pixels_per_line+x)] = color;
+ pixels[2*(LY*pixels_per_line+x)+1] = color;
+ pixels[2*(LY*pixels_per_line+x)+320] = color;
+ pixels[2*(LY*pixels_per_line+x)+321] = color;
}
- else
+ }
+ else
+ {
+ for (int x=0; x<160; x++)
{
- for (int x=0; x<160; x++)
- {
- pixels[2*(LY*pixels_per_line+x)] = colors[0];
- pixels[2*(LY*pixels_per_line+x)+1] = colors[0];
- pixels[2*(LY*pixels_per_line+x)+320] = colors[0];
- pixels[2*(LY*pixels_per_line+x)+321] = colors[0];
- }
+ pixels[2*(LY*pixels_per_line+x)] = colors[0];
+ pixels[2*(LY*pixels_per_line+x)+1] = colors[0];
+ pixels[2*(LY*pixels_per_line+x)+320] = colors[0];
+ pixels[2*(LY*pixels_per_line+x)+321] = colors[0];
}
}
}
else if (display_mode == BG_MAP)
{
- if (hline_t == 80)
+ int BGP = core->memory.IO.ports[GBIO::I_BGP];
+ int pallette[4];
+ pallette[0] = BGP & 3;
+ pallette[1] = (BGP>>2) & 3;
+ pallette[2] = (BGP>>4) & 3;
+ pallette[3] = (BGP>>6) & 3;
+ u16 tile_map_addr = check_bit(LCDC,3) ? 0x1C00 : 0x1800;
+ u16 tile_data_addr = check_bit(LCDC,4) ? 0x0000 : 0x0800;
+ int tile_data_base = (tile_data_addr == 0x0800) ? -128 : 0;
+ for (int row=0; row < 32; row++)
{
- int BGP = core->memory.read(GBIO::BGP);
- int pallette[4];
- pallette[0] = BGP & 3;
- pallette[1] = (BGP>>2) & 3;
- pallette[2] = (BGP>>4) & 3;
- pallette[3] = (BGP>>6) & 3;
- u16 tile_map_addr = check_bit(LCDC,3) ? 0x1C00 : 0x1800;
- u16 tile_data_addr = check_bit(LCDC,4) ? 0x0000 : 0x0800;
- int tile_data_base = (tile_data_addr == 0x0800) ? -128 : 0;
- for (int row=0; row < 32; row++)
+ for (int col=0; col < 32; col++)
{
- for (int col=0; col < 32; col++)
+ int ty = row*8;
+ int tx = col*8;
+ for (int y=0; y<8; y++)
{
- int ty = row*8;
- int tx = col*8;
- for (int y=0; y<8; y++)
+ for (int x=0; x<8; x++)
{
- for (int x=0; x<8; x++)
- {
- u8 tile_x = 7-x;
- u8 current_tile_index = VRAM[tile_map_addr+32*row + col] + tile_data_base;
- u16 current_tile_addr = tile_data_addr + 16*current_tile_index;
- u8 current_row_low = VRAM[current_tile_addr+2*y];
- u8 current_row_high = VRAM[current_tile_addr+2*y+1];
- u32 color = colors[pallette[((current_row_high >> tile_x)&1) << 1 |
- ((current_row_low >> tile_x)&1)]];
- pixels[320*(ty+y)+(tx+x)] = color;
- }
+ u8 tile_x = 7-x;
+ u8 current_tile_index = VRAM[tile_map_addr+32*row + col] + tile_data_base;
+ u16 current_tile_addr = tile_data_addr + 16*current_tile_index;
+ u8 current_row_low = VRAM[current_tile_addr+2*y];
+ u8 current_row_high = VRAM[current_tile_addr+2*y+1];
+ u32 color = colors[pallette[((current_row_high >> tile_x)&1) << 1 |
+ ((current_row_low >> tile_x)&1)]];
+ pixels[320*(ty+y)+(tx+x)] = color;
}
}
}
}
}
-
int GBVideo::poll_event(SDL_Event *ev)
{
return SDL_PollEvent(ev);
projects / wenboi.git / commitdiff