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8bitworkshop/presets/coleco/common.c
2018-12-07 17:24:27 -05:00

126 lines
2.3 KiB
C

#include <stdlib.h>
#include <string.h>
#include <cv.h>
#include <cvu.h>
#include "common.h"
volatile uint_fast8_t vint_counter;
void vint_handler(void) {
vint_counter++;
}
const unsigned char reverse_lookup[16] = {
0x0, 0x8, 0x4, 0xc, 0x2, 0xa, 0x6, 0xe, 0x1, 0x9, 0x5, 0xd, 0x3, 0xb, 0x7, 0xf, };
byte reverse_bits(byte n) {
return (reverse_lookup[n&0b1111] << 4) | reverse_lookup[n>>4];
}
void flip_sprite_patterns(word dest, const byte* patterns, word len) {
word i;
for (i=0; i<len; i++) {
cvu_voutb(reverse_bits(*patterns++), dest++ ^ 16); // swap left/right chars
}
}
void clrscr() {
cvu_vmemset(IMAGE, 0, COLS*ROWS);
}
word getimageaddr(byte x, byte y) {
return IMAGE + y*COLS + x;
}
byte getchar(byte x, byte y) {
return cvu_vinb(getimageaddr(x,y));
}
void putchar(byte x, byte y, byte attr) {
cvu_voutb(attr, getimageaddr(x,y));
}
void putstring(byte x, byte y, const char* string) {
while (*string) {
putchar(x++, y, CHAR(*string++));
}
}
void delay(byte i) {
while (i--) {
wait_vsync();
}
}
byte rndint(byte a, byte b) {
return ((byte)rand() % (b-a+1)) + a;
}
void memset_safe(void* _dest, char ch, word size) {
byte* dest = _dest;
while (size--) {
*dest++ = ch;
}
}
char in_rect(byte x, byte y, byte x0, byte y0, byte w, byte h) {
return ((byte)(x-x0) < w && (byte)(y-y0) < h); // unsigned
}
void draw_bcd_word(byte x, byte y, word bcd) {
byte j;
x += 3;
for (j=0; j<4; j++) {
putchar(x, y, CHAR('0'+(bcd&0xf)));
x--;
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;
}
void vdp_setup() {
cv_set_screen_active(false);
cv_set_screen_mode(CV_SCREENMODE_STANDARD);
cv_set_image_table(IMAGE);
cv_set_character_pattern_t(PATTERN);
cv_set_color_table(COLOR);
cv_set_sprite_pattern_table(SPRITE_PATTERNS);
cv_set_sprite_attribute_table(SPRITES);
cv_set_sprite_big(true);
}
void set_shifted_pattern(const byte* src, word dest, byte shift) {
byte y;
for (y=0; y<8; y++) {
byte a = src[y+8];
byte b = src[y];
cvu_voutb(a>>shift, dest);
cvu_voutb(b>>shift | a<<(8-shift), dest+8);
cvu_voutb(b<<(8-shift), dest+16);
dest++;
}
}