8bitworkshop/presets/astrocade/acextra.c

#include <string.h>

#include "aclib.h"
#include "acextra.h"

#pragma opt_code_speed

#define EXIT_CLIPDEST(addr) if ((((word)addr)&0xfff) >= 0xe10) return

// clear screen and set graphics mode
void clrscr(void) {
  memset(vidmem, 0, VHEIGHT*VBWIDTH); // clear page 1
}

// draw vertical line
void vline(byte x, byte y1, byte y2, byte col, byte op) {
  byte* dest = &vmagic[y1][x>>2];// destination address
  col <<= 6;			// color goes in top 2 bits
  hw_magic = M_SHIFT(x) | op;	// set magic register
  if (y2 >= VHEIGHT) y2 = VHEIGHT-1;	// clipping
  if (y1 > y2) return;
  *dest = col;
  while (++y1 <= y2) {
    dest += VBWIDTH;	// dest address to next scanline
    *dest = col;
  }
}

// render a sprite with the given graphics operation
void render_sprite(const byte* src, byte x, byte y, byte op) {
  byte i;
  byte w = *src++;	// get width from 1st byte of sprite
  byte h = *src++;	// get height from 2nd byte of sprite
  byte* dest = &vmagic[y][x>>2];// destination address
  hw_magic = M_SHIFT(x) | op;	// set magic register
  // y clipping off bottom
  if (y+h >= VHEIGHT) {
    if (y >= VHEIGHT) return;
    h = VHEIGHT-y;
  }
  // memory copy loop
  if (op != M_ERASE) {
    while (h--) {
      for (i=0; i<w; i++) {
        *dest++ = *src++;	// copy bytes
      }
      *dest = 0;		// rest of shifted byte
      dest += VBWIDTH-w;	// dest address to next scanline
    }
  // erase sprite loop
  } else {
    while (h--) {
      memset(dest, 0, w+1);	// erase bytes
      dest += VBWIDTH;		// dest address to next scanline
    }
  }
}

// FONT FUNCTIONS

const char FONT[HICHAR-LOCHAR+1][FONT_HEIGHT*FONT_BWIDTH] = {
{ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, },{ 0x00,0x00,0x00,0x20,0x20,0x20,0x00,0x20, },{ 0x00,0x00,0x50,0x50,0x50,0x00,0x00,0x00, },{ 0x00,0x00,0x00,0x50,0xF8,0x50,0xF8,0x50, },{ 0x00,0x00,0x00,0xF8,0xA0,0xF8,0x28,0xF8, },{ 0x00,0x00,0x00,0xC8,0xD0,0x20,0x58,0x98, },{ 0x00,0x00,0x00,0xE0,0xA8,0xF8,0x90,0xF8, },{ 0x00,0x00,0x40,0x40,0x40,0x00,0x00,0x00, },{ 0x00,0x00,0x30,0x20,0x20,0x20,0x20,0x20, },{ 0x00,0x00,0x60,0x20,0x20,0x20,0x20,0x20, },{ 0x00,0x00,0x00,0x20,0xA8,0x70,0xA8,0x20, },{ 0x00,0x00,0x00,0x20,0x20,0xF8,0x20,0x20, },{ 0x00,0x00,0x00,0x00,0x00,0x00,0x60,0x60, },{ 0x00,0x00,0x00,0x00,0x00,0xF8,0x00,0x00, },{ 0x00,0x00,0x00,0x00,0x00,0x00,0x60,0x60, },{ 0x00,0x00,0x00,0x08,0x10,0x20,0x40,0x80, },{ 0x00,0x00,0x00,0xF8,0x88,0xE8,0x88,0xF8, },{ 0x00,0x00,0x00,0x10,0x30,0x50,0x10,0x10, },{ 0x00,0x00,0x00,0xF8,0x08,0xF8,0x80,0xF8, },{ 0x00,0x00,0x00,0xF8,0x08,0xF8,0x08,0xF8, },{ 0x00,0x00,0x00,0x38,0x48,0x88,0xF8,0x08, },{ 0x00,0x00,0x00,0xF8,0x80,0xF8,0x08,0xF8, },{ 0x00,0x00,0x00,0xF8,0x80,0xF8,0x88,0xF8, },{ 0x00,0x00,0x00,0xF8,0x08,0x10,0x20,0x40, },{ 0x00,0x00,0x00,0xF8,0x88,0xF8,0x88,0xF8, },{ 0x00,0x00,0x00,0xF8,0x88,0xF8,0x08,0xF8, },{ 0x00,0x00,0x00,0x30,0x30,0x00,0x30,0x30, },{ 0x00,0x00,0x00,0x30,0x30,0x00,0x30,0x30, },{ 0x00,0x00,0x08,0x10,0x20,0x40,0x20,0x10, },{ 0x00,0x00,0x00,0x00,0xF8,0x00,0xF8,0x00, },{ 0x00,0x00,0x40,0x20,0x10,0x08,0x10,0x20, },{ 0x00,0x00,0x00,0xF8,0x08,0x78,0x00,0x60, },{ 0x00,0x00,0x00,0xF8,0xA8,0xB8,0x80,0xF8, },{ 0x00,0x00,0x00,0xF8,0x88,0xF8,0x88,0x88, },{ 0x00,0x00,0x00,0xF0,0x90,0xF8,0x88,0xF8, },{ 0x00,0x00,0x00,0xF8,0x80,0x80,0x80,0xF8, },{ 0x00,0x00,0x00,0xE0,0x90,0x88,0x88,0xF8, },{ 0x00,0x00,0x00,0xF8,0x80,0xF8,0x80,0xF8, },{ 0x00,0x00,0x00,0xF8,0x80,0xF8,0x80,0x80, },{ 0x00,0x00,0x00,0xF8,0x80,0xB8,0x88,0xF8, },{ 0x00,0x00,0x00,0x88,0x88,0xF8,0x88,0x88, },{ 0x00,0x00,0x00,0x40,0x40,0x40,0x40,0x40, },{ 0x00,0x00,0x00,0x08,0x08,0x88,0x88,0xF8, },{ 0x00,0x00,0x00,0x88,0x90,0xA0,0x90,0x88, },{ 0x00,0x00,0x00,0x80,0x80,0x80,0x80,0xF8, },{ 0x00,0x00,0x00,0xFE,0x92,0x92,0x92,0x92, },{ 0x00,0x00,0x00,0x88,0xC8,0xA8,0x98,0x88, },{ 0x00,0x00,0x00,0xF8,0x88,0x88,0x88,0xF8, },{ 0x00,0x00,0x00,0xF8,0x88,0x88,0xF8,0x80, },{ 0x00,0x00,0x00,0xF8,0x88,0xA8,0xA8,0xF8, },{ 0x00,0x00,0x00,0xF8,0x88,0xF8,0x90,0x88, },{ 0x00,0x00,0x00,0xF8,0x80,0xF8,0x08,0xF8, },{ 0x00,0x00,0x00,0xF8,0x20,0x20,0x20,0x20, },{ 0x00,0x00,0x00,0x88,0x88,0x88,0x88,0xF8, },{ 0x00,0x00,0x00,0x88,0x88,0x90,0xA0,0xC0, },{ 0x00,0x00,0x00,0x92,0x92,0x92,0x92,0xFE, },{ 0x00,0x00,0x00,0x88,0x50,0x20,0x50,0x88, },{ 0x00,0x00,0x00,0x88,0x88,0xF8,0x08,0xF8, },{ 0x00,0x00,0x00,0xF8,0x10,0x20,0x40,0xF8, },{ 0x00,0x00,0x38,0x20,0x20,0x20,0x20,0x20, },{ 0x00,0x00,0x00,0x80,0x40,0x20,0x10,0x08, },{ 0x00,0x00,0x70,0x10,0x10,0x10,0x10,0x10, },{ 0x00,0x00,0x00,0x20,0x50,0x88,0x00,0x00, },{ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, },{ 0x00,0x00,0x40,0x20,0x10,0x00,0x00,0x00, },{ 0x00,0x00,0x00,0xF8,0x88,0xF8,0x88,0x88, },{ 0x00,0x00,0x00,0xF0,0x90,0xF8,0x88,0xF8, },{ 0x00,0x00,0x00,0xF8,0x80,0x80,0x80,0xF8, },{ 0x00,0x00,0x00,0xE0,0x90,0x88,0x88,0xF8, },{ 0x00,0x00,0x00,0xF8,0x80,0xF8,0x80,0xF8, },{ 0x00,0x00,0x00,0xF8,0x80,0xF8,0x80,0x80, },{ 0x00,0x00,0x00,0xF8,0x80,0xB8,0x88,0xF8, },{ 0x00,0x00,0x00,0x88,0x88,0xF8,0x88,0x88, },{ 0x00,0x00,0x00,0x40,0x40,0x40,0x40,0x40, },{ 0x00,0x00,0x00,0x08,0x08,0x88,0x88,0xF8, },{ 0x00,0x00,0x00,0x88,0x90,0xA0,0x90,0x88, },{ 0x00,0x00,0x00,0x80,0x80,0x80,0x80,0xF8, },{ 0x00,0x00,0x00,0xFE,0x92,0x92,0x92,0x92, },{ 0x00,0x00,0x00,0x88,0xC8,0xA8,0x98,0x88, },{ 0x00,0x00,0x00,0xF8,0x88,0x88,0x88,0xF8, },{ 0x00,0x00,0x00,0xF8,0x88,0x88,0xF8,0x80, },{ 0x00,0x00,0x00,0xF8,0x88,0xA8,0xA8,0xF8, },{ 0x00,0x00,0x00,0xF8,0x88,0xF8,0x90,0x88, },{ 0x00,0x00,0x00,0xF8,0x80,0xF8,0x08,0xF8, },{ 0x00,0x00,0x00,0xF8,0x20,0x20,0x20,0x20, },{ 0x00,0x00,0x00,0x88,0x88,0x88,0x88,0xF8, },{ 0x00,0x00,0x00,0x88,0x88,0x90,0xA0,0xC0, },{ 0x00,0x00,0x00,0x92,0x92,0x92,0x92,0xFE, },{ 0x00,0x00,0x00,0x88,0x50,0x20,0x50,0x88, },{ 0x00,0x00,0x00,0x88,0x88,0xF8,0x08,0xF8, },{ 0x00,0x00,0x00,0xF8,0x10,0x20,0x40,0xF8, },

// draw a letter
void draw_char(byte ch, byte x, byte y, byte op) {
  const byte* src = &FONT[(ch-LOCHAR)][0];
  byte* dest = &vmagic[y][x>>2]; // destination address
  hw_magic = M_SHIFT(x) | M_XPAND | op;
  for (byte i=0; i<8; i++) {
    char b = *src++;
    EXIT_CLIPDEST(dest);
    *dest++ = b;	// expand lower nibble -> 1st byte
    *dest++ = b;	// expand upper nibble -> 2nd byte
    if (x & 3) {
      *dest++ = 0;	// leftover -> 3rd byte
      *dest = 0;	// reset upper/lower flag
    } else {
      dest++;
    }
    dest += VBWIDTH-3;	// we incremented 3 bytes for this line
  }
}

void draw_string(byte x, byte y, byte options, const char* str) {
  hw_xpand = XPAND_COLORS(0, options);
  do {
    byte ch = *str++;
    if (!ch) break;
    draw_char(ch, x, y, M_XOR);
    x += 8;
  } while (1);
}

void draw_bcd_word(word bcd, byte x, byte y, byte op) {
  byte j;
  x += 3*8;
  for (j=0; j<4; j++) {
    draw_char('0'+(bcd&0xf), x, y, op);
    x -= 8;
    bcd >>= 4;
  }
}

// add two 16-bit BCD values
word bcd_add(word a, word b) __naked {
  a; b; // to avoid warning
__asm
 	push	ix
 	ld	ix,#0
	add	ix,sp
 	ld	a,4 (ix)
 	add	a, 6 (ix)
	daa
	ld	c,a
 	ld	a,5 (ix)
 	adc	a, 7 (ix)
	daa
 	ld	b,a
 	ld	l, c
 	ld	h, b
	pop	ix
 	ret
__endasm;
}