#include <string.h>

typedef unsigned char byte;
typedef unsigned short word;

byte __at (0xc000) palette[16];
byte __at (0xc800) input0;
byte __at (0xc802) input1;
byte __at (0xc804) input2;
byte __at (0xc900) rom_select;
byte __at (0xcb00) video_counter;
byte __at (0xcbff) watchdog0x39;
byte __at (0xcc00) nvram[0x400];

// blitter flags
#define SRCSCREEN 0x1
#define DSTSCREEN 0x2
#define ESYNC 0x4
#define FGONLY 0x8
#define SOLID 0x10
#define RSHIFT 0x20
#define EVENONLY 0x40
#define ODDONLY 0x80

struct {
  byte flags;
  byte solid;
  word sstart;
  word dstart;
  byte width;
  byte height;
} __at (0xca00) blitter;

byte __at (0x0) vidmem[128][304]; // 256x304x4bpp video memory

void main();

// start routine @ 0x0
// set stack pointer, enable interrupts
void start() {
__asm
        LD      SP,#0xc000
        DI
__endasm;
        main();
}

const byte palette_data[16] = {
  0x00, 0x03, 0x19, 0x50, 0x52, 0x07, 0x1f, 0x37, 0xe0, 0xa4, 0xfd, 0xff, 0x00, 0x00, 0x00, 0x00, };

const byte sprite_data[] = {
8,128,
0x00,0x09,0x99,0x00,0x00,0x99,0x90,0x00,
0x00,0x94,0x94,0x90,0x09,0x49,0x49,0x00,
0x04,0x49,0x49,0x90,0x09,0x94,0x94,0x90,
0x94,0x99,0x94,0x90,0x09,0x49,0x99,0x49,
0x99,0x99,0x49,0x93,0x39,0x94,0x99,0x99,
0x04,0x49,0x99,0x94,0x49,0x99,0x94,0x90,
0x00,0x94,0x94,0x43,0x34,0x49,0x49,0x00,
0x00,0x09,0x43,0x94,0x49,0x34,0x90,0x00,
0x00,0x90,0x00,0x39,0x93,0x00,0x09,0x00,
0x00,0x09,0x83,0x33,0x33,0x33,0x90,0x00,
0x00,0x09,0x32,0x23,0x32,0x23,0x90,0x00,
0x00,0x03,0x03,0x23,0x82,0x30,0x30,0x00,
0x03,0x30,0x00,0x33,0x33,0x00,0x03,0x30,
0x00,0x30,0x03,0x00,0x00,0x30,0x03,0x00,
0x00,0x00,0x00,0x30,0x03,0x00,0x00,0x00,
0x00,0x00,0x00,0x40,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x01,0x10,0x00,0x00,0x00,
0x00,0x00,0x00,0x11,0x11,0x00,0x00,0x00,
0x00,0x00,0x00,0x01,0x10,0x00,0x00,0x00,
0x00,0x00,0x00,0x01,0x10,0x00,0x00,0x00,
0x00,0x11,0x10,0x01,0x10,0x01,0x11,0x00,
0x11,0x00,0x10,0x11,0x11,0x01,0x00,0x11,
0x10,0x00,0x11,0x11,0x11,0x11,0x00,0x01,
0x10,0x00,0x00,0x11,0x11,0x00,0x00,0x01,
0x00,0x01,0x10,0x11,0x41,0x01,0x10,0x00,
0x00,0x10,0x11,0x11,0x11,0x11,0x01,0x00,
0x01,0x00,0x00,0x51,0x15,0x00,0x00,0x10,
0x01,0x00,0x01,0x10,0x01,0x10,0x00,0x10,
0x01,0x00,0x10,0x00,0x00,0x01,0x00,0x10,
0x00,0x10,0x01,0x00,0x00,0x10,0x01,0x00,
0x00,0x10,0x00,0x00,0x00,0x00,0x01,0x00,
0x00,0x01,0x10,0x00,0x00,0x01,0x10,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0xbb,0xbb,0x00,0x00,0x00,
0x00,0x00,0x00,0xbb,0xbb,0x00,0x00,0x00,
0x00,0x00,0xbb,0xbb,0xbb,0xbb,0x00,0x00,
0x00,0x0b,0x4b,0xbb,0xbb,0xb4,0xb0,0x00,
0x00,0x0b,0x44,0xbb,0xbb,0x49,0xb0,0x00,
0x00,0xbb,0x99,0x4b,0xb4,0x99,0xbb,0x00,
0x00,0x4b,0xb9,0x9b,0xb4,0x4b,0xb4,0x00,
0x00,0x04,0xbb,0x4b,0xb9,0xbb,0x40,0x00,
0x00,0x00,0x4b,0xbb,0xbb,0xb4,0x00,0x00,
0x11,0x00,0x0b,0xbb,0xbb,0xb0,0x00,0x11,
0x10,0x10,0x0b,0x41,0x14,0xb0,0x01,0x01,
0x10,0x00,0x05,0x11,0x11,0x50,0x00,0x01,
0x01,0x00,0x01,0x51,0x15,0x10,0x00,0x10,
0x00,0x10,0x01,0x10,0x01,0x10,0x01,0x00,
0x01,0x01,0x10,0x10,0x01,0x01,0x10,0x10,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x22,0x00,0x00,0x22,0x00,0x00,
0x00,0x20,0x20,0x00,0x00,0x02,0x02,0x00,
0x02,0x22,0x12,0x00,0x00,0x21,0x22,0x20,
0x00,0x02,0x11,0x00,0x00,0x11,0x20,0x00,
0x00,0x00,0x02,0x11,0x11,0x20,0x00,0x00,
0x00,0x00,0x02,0x22,0x22,0x20,0x00,0x00,
0x00,0x00,0x21,0x22,0x22,0x12,0x00,0x00,
0x00,0x00,0x22,0x12,0x21,0x22,0x00,0x00,
0x02,0x00,0x22,0x12,0x21,0x22,0x00,0x20,
0x20,0x02,0x21,0x11,0x11,0x12,0x20,0x02,
0x02,0x22,0x15,0x12,0x21,0x51,0x22,0x20,
0x02,0x11,0x15,0x52,0x25,0x51,0x11,0x20,
0x20,0x00,0x22,0x12,0x21,0x22,0x00,0x02,
0x20,0x02,0x20,0x20,0x02,0x02,0x20,0x02,
0x02,0x02,0x00,0x20,0x02,0x00,0x20,0x20,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x04,0x04,0x04,0x00,
0x00,0x00,0x00,0x00,0x44,0x44,0x44,0x40,
0x00,0x00,0x04,0x04,0x49,0x49,0x99,0x44,
0x00,0x00,0x44,0x44,0x99,0x94,0x44,0x40,
0x00,0x04,0x49,0x99,0x94,0x49,0x99,0x40,
0x00,0x44,0x99,0x94,0x49,0x99,0x44,0x00,
0x04,0x49,0x44,0x99,0x99,0x44,0x00,0x00,
0x04,0x44,0x00,0x49,0x44,0x40,0x00,0x00,
0x04,0x40,0x00,0x04,0x00,0x00,0x00,0x00,
0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x60,0x00,0x00,0x00,0x00,0x06,0x00,
0x60,0x60,0x00,0x00,0x00,0x00,0x06,0x06,
0x60,0x60,0x50,0x00,0x00,0x05,0x06,0x06,
0x60,0x60,0x06,0x00,0x00,0x60,0x06,0x06,
0x66,0x60,0x06,0x06,0x60,0x60,0x06,0x66,
0x66,0x60,0x66,0x66,0x66,0x66,0x06,0x66,
0x66,0x60,0x6b,0x6b,0xb6,0xb6,0x06,0x66,
0x06,0x66,0x66,0xb6,0x6b,0x66,0x66,0x60,
0x00,0x67,0x66,0x66,0x66,0x66,0x66,0x00,
0x00,0x11,0x11,0x66,0x66,0x11,0x11,0x00,
0x01,0x11,0x21,0x11,0x11,0x12,0x11,0x10,
0x00,0x10,0x01,0x01,0x10,0x10,0x01,0x00,
0x00,0x10,0x11,0x00,0x00,0x11,0x01,0x00,
0x00,0x00,0x10,0x00,0x00,0x01,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x11,0x11,0x11,0x11,0x00,0x00,
0x00,0x01,0x61,0x11,0x21,0x12,0x10,0x00,
0x00,0x11,0x12,0x11,0x61,0x11,0x11,0x00,
0x00,0x11,0x71,0x21,0x61,0x17,0x11,0x00,
0x00,0x11,0x77,0x11,0x12,0x77,0x11,0x00,
0x00,0x11,0x17,0x17,0x71,0x72,0x11,0x00,
0x00,0x16,0x21,0x78,0x87,0x11,0x11,0x00,
0x00,0x01,0x81,0x88,0x88,0x18,0x10,0x00,
0x00,0x08,0x18,0x58,0x85,0x81,0x80,0x00,
0x00,0x88,0x01,0x88,0x88,0x10,0x88,0x00,
0x00,0x08,0x07,0x78,0x87,0x70,0x80,0x00,
0x08,0x80,0x07,0x80,0x08,0x70,0x08,0x80,
0x88,0x00,0x88,0x00,0x00,0x88,0x00,0x88,
0x80,0x00,0x08,0x80,0x08,0x80,0x00,0x08,
0x00,0x00,0x00,0x80,0x08,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0xaa,0x00,0x00,0xaa,0x00,0x00,
0x00,0x00,0xa0,0x0a,0xa0,0x0a,0x00,0x00,
0x0a,0xaa,0xa4,0xaa,0xaa,0x3a,0xaa,0xa0,
0x00,0x0a,0x3a,0x9a,0xa9,0xa3,0xa0,0x00,
0x00,0x0a,0xaa,0x99,0xa4,0xaa,0xa0,0x00,
0x00,0x0a,0xaa,0x99,0x94,0xaa,0xa0,0x00,
0x00,0xaa,0x33,0xaa,0xaa,0x43,0xaa,0x00,
0x0a,0x3a,0xaa,0x3a,0xa3,0xaa,0xa3,0xa0,
0x00,0xaa,0xaa,0x30,0x03,0xaa,0xaa,0x00,
0x00,0x0a,0xa0,0x30,0x03,0x0a,0xa0,0x00,
0x00,0xa3,0xa0,0x00,0x00,0x0a,0x4a,0x00,
0x00,0xaa,0xa0,0x00,0x00,0x0a,0xaa,0x00,
0x00,0x0a,0xa0,0x00,0x00,0x0a,0xa0,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
};

inline word swapw(word j) {
  return ((j << 8) | (j >> 8));
}

// x1: 0-151
// y1: 0-255
inline void blit_solid(byte x1, byte y1, byte w, byte h, byte color) {
  blitter.width = w^4;
  blitter.height = h^4;
  blitter.dstart = x1+y1*256; // swapped
  blitter.solid = color;
  blitter.flags = DSTSCREEN|SOLID;
}

inline void blit_copy(byte x1, byte y1, byte w, byte h, const byte* data) {
  blitter.width = w^4;
  blitter.height = h^4;
  blitter.sstart = swapw((word)data);
  blitter.dstart = x1+y1*256; // swapped
  blitter.solid = 0;
  blitter.flags = DSTSCREEN|FGONLY;
}

inline void blit_copy_solid(byte x1, byte y1, byte w, byte h, const byte* data, byte solid) {
  blitter.width = w^4;
  blitter.height = h^4;
  blitter.sstart = swapw((word)data);
  blitter.dstart = x1+y1*256; // swapped
  blitter.solid = solid;
  blitter.flags = DSTSCREEN|FGONLY|SOLID;
}

inline void draw_sprite(const byte* data, byte x, byte y) {
  blitter.width = data[0]^4;
  blitter.height = data[1]^4;
  blitter.sstart = swapw((word)(data+2));
  blitter.dstart = x+y*256; // swapped
  blitter.solid = 0;
  blitter.flags = DSTSCREEN|FGONLY;
}

void main() {
  byte y = 0;
  byte i;
  blit_solid(0, 0, 255, 255, 0);
  memcpy(palette, palette_data, 16);
  draw_sprite(sprite_data, 20, 20);
  while (1) {
    for (i=0; i<8; i++) {
      byte xpos = 40+i*12;
      const byte* sprdata = sprite_data+2+i*8*16;
      blit_copy_solid(xpos, y-1, 8, 16, sprdata, 0);
      blit_copy(xpos, y, 8, 16, sprdata);
    }
    y++;
    watchdog0x39 = 0x39;
  }
}