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WIP: gb: LCD 4-bit work
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Signed-off-by: Mahyar Koshkouei <mk@deltabeard.com>
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@deltabeard
deltabeard committed Nov 14, 2022
1 parent 4494140 commit 7dbc700
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Showing 2 changed files with 34 additions and 14 deletions.
21 changes: 17 additions & 4 deletions examples/benchmark/peanut_benchmark.c
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Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,8 @@
# define ENABLE_LCD 1
#endif

#define PEANUT_GB_HIGH_LCD_ACCURACY 1

/* Sound is disabled for this project. */
#define ENABLE_SOUND 0

Expand Down Expand Up @@ -118,17 +120,28 @@ static void gb_error(const enum gb_error_e gb_err, const uint16_t val, void *pri
abort();
}

//#include <assert.h>
#if ENABLE_LCD
/**
* Draws scanline into framebuffer.
*/
static void lcd_draw_line(const uint8_t pixels[160], const uint_fast8_t line, void *priv)
static void lcd_draw_line(const uint8_t pixels[160], const uint8_t line, void *priv)
{
struct priv_t *p = priv;
const uint16_t palette[] = { 0x7FFF, 0x5294, 0x294A, 0x0000 };
const uint16_t palette[12] = {
0x7FFF, 0x5294, 0x294A, 0x0000,
0x7FFF, 0x5294, 0x294A, 0x0000,
0x7FFF, 0x5294, 0x294A, 0x0000
};

for (unsigned int x = 0; x < LCD_WIDTH; x++)
p->fb[line][x] = palette[pixels[x] & 3];
for (int x = 0; x < LCD_WIDTH; x++)
{
if(pixels[x] >= 12)
__assume(0);

//assert(pixels[x] < PEANUT_GB_ARRAYSIZE(palette));
p->fb[line][x] = palette[pixels[x]];
}
}
#endif

Expand Down
27 changes: 17 additions & 10 deletions peanut_gb.h
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Original file line number Diff line number Diff line change
Expand Up @@ -447,16 +447,16 @@ struct count_s
* Bit mask for whether a pixel is OBJ0, OBJ1, or BG. Each may have a different
* palette when playing a DMG game on CGB.
*/
#define LCD_PALETTE_OBJ 0x10
#define LCD_PALETTE_BG 0x20
#define LCD_PALETTE_OBJ 0x04
#define LCD_PALETTE_BG 0x08
/**
* Bit mask for the two bits listed above.
* LCD_PALETTE_ALL == 0b00 --> OBJ0
* LCD_PALETTE_ALL == 0b01 --> OBJ1
* LCD_PALETTE_ALL == 0b10 --> BG
* LCD_PALETTE_ALL == 0b11 --> NOT POSSIBLE
*/
#define LCD_PALETTE_ALL 0x30
#define LCD_PALETTE_ALL 0x0C
#endif

/**
Expand Down Expand Up @@ -597,7 +597,9 @@ struct gb_s
uint8_t gb_bios_enable : 1;
#endif
uint8_t gb_frame : 1; /* New frame drawn. */
#if ENABLE_LCD
uint8_t lcd_blank : 1;
#endif

struct cpu_registers_s cpu_reg;
struct count_s counter;
Expand Down Expand Up @@ -636,7 +638,7 @@ struct gb_s
* guaranteed to be between 0-144 inclusive.
*/
void (*lcd_draw_line)(const uint8_t* pixels,
const uint_fast8_t line, void *priv);
const uint8_t line, void *priv);
} display;
#endif

Expand Down Expand Up @@ -946,7 +948,9 @@ void __gb_write(struct gb_s *gb, const uint_fast16_t addr, const uint8_t val)
(val & LCDC_ENABLE))
{
gb->counter.lcd_count = 0;
#if ENABLE_LCD
gb->lcd_blank = 1;
#endif
}

gb->hram_io[IO_LCDC] = val;
Expand Down Expand Up @@ -1513,8 +1517,7 @@ void __gb_draw_line(struct gb_s *gb)

#if !PEANUT_GB_HIGH_LCD_ACCURACY
/* If sprite isn't on this line, continue. */
if(gb->hram_io[IO_LY +
(gb->hram_io[IO_LCDC] & LCDC_OBJ_SIZE ? 0 : 8) >= OY ||
if(gb->hram_io[IO_LY] + (gb->hram_io[IO_LCDC] & LCDC_OBJ_SIZE ? 0 : 8) >= OY ||
gb->hram_io[IO_LY] + 16 < OY)
continue;
#endif
Expand Down Expand Up @@ -1576,7 +1579,7 @@ void __gb_draw_line(struct gb_s *gb)
? gb->display.sp_palette[c + 4]
: gb->display.sp_palette[c];
/* Set pixel palette (OBJ0 or OBJ1). */
pixels[disp_x] |= (OF & OBJ_PALETTE);
pixels[disp_x] |= ((OF >> 2) & OBJ_PALETTE);
/* Deselect BG palette. */
pixels[disp_x] &= ~LCD_PALETTE_BG;
}
Expand Down Expand Up @@ -3351,12 +3354,12 @@ void __gb_step_cpu(struct gb_s *gb)
gb->hram_io[IO_STAT] = STAT_MODE & IO_STAT_MODE_VBLANK;
gb->gb_frame = 1;
gb->hram_io[IO_IF] |= VBLANK_INTR;
gb->lcd_blank = 0;

if(gb->hram_io[IO_STAT] & STAT_MODE_1_INTR)
gb->hram_io[IO_IF] |= LCDC_INTR;

#if ENABLE_LCD
gb->lcd_blank = 0;

/* If frame skip is activated, check if we need to draw
* the frame or skip it. */
Expand All @@ -3381,12 +3384,14 @@ void __gb_step_cpu(struct gb_s *gb)
/* Normal Line */
else if(gb->hram_io[IO_LY] < LCD_HEIGHT)
{
#if ENABLE_LCD
if(gb->hram_io[IO_LY] == 0)
{
/* Clear Screen */
gb->display.WY = gb->hram_io[IO_WY];
gb->display.window_clear = 0;
}
#endif

gb->hram_io[IO_STAT] = STAT_MODE & IO_STAT_MODE_HBLANK;

Expand Down Expand Up @@ -3611,8 +3616,10 @@ enum gb_init_error_e gb_init(struct gb_s *gb,
gb->num_rom_banks_mask = num_rom_banks_mask[gb->gb_rom_read(bank_count_location, gb->priv)] - 1;
gb->num_ram_banks = num_ram_banks[gb->gb_rom_read(ram_size_location, gb->priv)];

#if ENABLE_LCD
gb->lcd_blank = 0;
gb->display.lcd_draw_line = NULL;
#endif

gb_reset(gb);

Expand Down Expand Up @@ -3646,7 +3653,7 @@ const char* gb_get_rom_name(struct gb_s* gb, char *title_str)
#if ENABLE_LCD
void gb_init_lcd(struct gb_s *gb,
void (*lcd_draw_line)(const uint8_t *pixels,
const uint_fast8_t line, void *priv))
const uint8_t line, void *priv))
{
gb->display.lcd_draw_line = lcd_draw_line;

Expand Down Expand Up @@ -3766,7 +3773,7 @@ void gb_reset(struct gb_s *gb);
#if ENABLE_LCD
void gb_init_lcd(struct gb_s *gb,
void (*lcd_draw_line)(const uint8_t *pixels,
const uint_fast8_t line, void *priv));
const uint8_t line, void *priv));
#endif

/**
Expand Down

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