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8bitworkshop/presets/apple2/cosmic.c
2018-08-13 16:53:31 -04:00

601 lines
21 KiB
C

#include <string.h>
#include <conio.h>
#include <apple2.h>
// type aliases for byte/signed byte/unsigned 16-bit
typedef unsigned char byte;
typedef signed char sbyte;
typedef unsigned short word;
// peeks, pokes, and strobes
#define POKE(addr,val) (*(unsigned char*) (addr) = (val))
#define POKEW(addr,val) (*(unsigned*) (addr) = (val))
#define PEEK(addr) (*(unsigned char*) (addr))
#define PEEKW(addr) (*(unsigned*) (addr))
#define STROBE(addr) __asm__ ("sta %w", addr)
// speaker click
#define CLICK STROBE(0xc030)
/// HIRES LOOKUP TABLE
#define VHEIGHT 192 // number of scanlines
#define VBWIDTH 40 // number of bytes per scanline
#define PIXWIDTH 280 // 7 pixels per byte
#define LUT(x) (byte*)(0x2000|x)
// starting address of each scanline
static byte* const vidmem[VHEIGHT] = {
LUT(0x0000), LUT(0x0400), LUT(0x0800), LUT(0x0c00), LUT(0x1000), LUT(0x1400), LUT(0x1800), LUT(0x1c00),
LUT(0x0080), LUT(0x0480), LUT(0x0880), LUT(0x0c80), LUT(0x1080), LUT(0x1480), LUT(0x1880), LUT(0x1c80),
LUT(0x0100), LUT(0x0500), LUT(0x0900), LUT(0x0d00), LUT(0x1100), LUT(0x1500), LUT(0x1900), LUT(0x1d00),
LUT(0x0180), LUT(0x0580), LUT(0x0980), LUT(0x0d80), LUT(0x1180), LUT(0x1580), LUT(0x1980), LUT(0x1d80),
LUT(0x0200), LUT(0x0600), LUT(0x0a00), LUT(0x0e00), LUT(0x1200), LUT(0x1600), LUT(0x1a00), LUT(0x1e00),
LUT(0x0280), LUT(0x0680), LUT(0x0a80), LUT(0x0e80), LUT(0x1280), LUT(0x1680), LUT(0x1a80), LUT(0x1e80),
LUT(0x0300), LUT(0x0700), LUT(0x0b00), LUT(0x0f00), LUT(0x1300), LUT(0x1700), LUT(0x1b00), LUT(0x1f00),
LUT(0x0380), LUT(0x0780), LUT(0x0b80), LUT(0x0f80), LUT(0x1380), LUT(0x1780), LUT(0x1b80), LUT(0x1f80),
LUT(0x0028), LUT(0x0428), LUT(0x0828), LUT(0x0c28), LUT(0x1028), LUT(0x1428), LUT(0x1828), LUT(0x1c28),
LUT(0x00a8), LUT(0x04a8), LUT(0x08a8), LUT(0x0ca8), LUT(0x10a8), LUT(0x14a8), LUT(0x18a8), LUT(0x1ca8),
LUT(0x0128), LUT(0x0528), LUT(0x0928), LUT(0x0d28), LUT(0x1128), LUT(0x1528), LUT(0x1928), LUT(0x1d28),
LUT(0x01a8), LUT(0x05a8), LUT(0x09a8), LUT(0x0da8), LUT(0x11a8), LUT(0x15a8), LUT(0x19a8), LUT(0x1da8),
LUT(0x0228), LUT(0x0628), LUT(0x0a28), LUT(0x0e28), LUT(0x1228), LUT(0x1628), LUT(0x1a28), LUT(0x1e28),
LUT(0x02a8), LUT(0x06a8), LUT(0x0aa8), LUT(0x0ea8), LUT(0x12a8), LUT(0x16a8), LUT(0x1aa8), LUT(0x1ea8),
LUT(0x0328), LUT(0x0728), LUT(0x0b28), LUT(0x0f28), LUT(0x1328), LUT(0x1728), LUT(0x1b28), LUT(0x1f28),
LUT(0x03a8), LUT(0x07a8), LUT(0x0ba8), LUT(0x0fa8), LUT(0x13a8), LUT(0x17a8), LUT(0x1ba8), LUT(0x1fa8),
LUT(0x0050), LUT(0x0450), LUT(0x0850), LUT(0x0c50), LUT(0x1050), LUT(0x1450), LUT(0x1850), LUT(0x1c50),
LUT(0x00d0), LUT(0x04d0), LUT(0x08d0), LUT(0x0cd0), LUT(0x10d0), LUT(0x14d0), LUT(0x18d0), LUT(0x1cd0),
LUT(0x0150), LUT(0x0550), LUT(0x0950), LUT(0x0d50), LUT(0x1150), LUT(0x1550), LUT(0x1950), LUT(0x1d50),
LUT(0x01d0), LUT(0x05d0), LUT(0x09d0), LUT(0x0dd0), LUT(0x11d0), LUT(0x15d0), LUT(0x19d0), LUT(0x1dd0),
LUT(0x0250), LUT(0x0650), LUT(0x0a50), LUT(0x0e50), LUT(0x1250), LUT(0x1650), LUT(0x1a50), LUT(0x1e50),
LUT(0x02d0), LUT(0x06d0), LUT(0x0ad0), LUT(0x0ed0), LUT(0x12d0), LUT(0x16d0), LUT(0x1ad0), LUT(0x1ed0),
LUT(0x0350), LUT(0x0750), LUT(0x0b50), LUT(0x0f50), LUT(0x1350), LUT(0x1750), LUT(0x1b50), LUT(0x1f50),
LUT(0x03d0), LUT(0x07d0), LUT(0x0bd0), LUT(0x0fd0), LUT(0x13d0), LUT(0x17d0), LUT(0x1bd0), LUT(0x1fd0)
};
// divide-by 7 table
const byte DIV7[256] = {
0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4,
4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 9,
9, 9, 9, 9, 9, 9,10,10,10,10,10,10,10,11,11,11,11,11,11,11,12,12,12,12,12,12,12,13,13,13,13,13,
13,13,14,14,14,14,14,14,14,15,15,15,15,15,15,15,16,16,16,16,16,16,16,17,17,17,17,17,17,17,18,18,
18,18,18,18,18,19,19,19,19,19,19,19,20,20,20,20,20,20,20,21,21,21,21,21,21,21,22,22,22,22,22,22,
22,23,23,23,23,23,23,23,24,24,24,24,24,24,24,25,25,25,25,25,25,25,26,26,26,26,26,26,26,27,27,27,
27,27,27,27,28,28,28,28,28,28,28,29,29,29,29,29,29,29,30,30,30,30,30,30,30,31,31,31,31,31,31,31,
32,32,32,32,32,32,32,33,33,33,33,33,33,33,34,34,34,34,34,34,34,35,35,35,35,35,35,35,36,36,36,36};
// modulo-by-7 table
const byte MOD7[256] = {
0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3,
4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0,
1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4,
5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1,
2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5,
6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2,
3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6,
0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3};
// bitmask table
const byte BIT7[7] = { 1, 2, 4, 8, 16, 32, 64 };
#pragma static-locals(on)
/// SOUND FUNCTIONS
void tone(byte period, byte dur, sbyte mod) {
word i;
while (dur--) {
for (i=0; i<period; i++) ;
CLICK;
period += mod;
}
}
/// GRAPHICS FUNCTIONS
void clrscr() {
STROBE(0xc052); // turn off mixed-mode
STROBE(0xc054); // page 1
STROBE(0xc057); // hi-res
STROBE(0xc050); // set graphics mode
memset((byte*)0x2000, 0, 0x2000); // clear page 1
}
void xor_vline(byte x, byte y1, byte y2) {
byte xb = DIV7[x]; // divide x by 7
byte mask = BIT7[MOD7[x]]; // lookup bitmask for remainder
byte y;
for (y=y1; y<=y2; y++) {
byte* dest = &vidmem[y][xb]; // lookup dest. address
*dest ^= mask; // XOR mask with destination
}
}
void xor_pixel(byte x, byte y) {
xor_vline(x, y, y); // draw line with 1-pixel height
}
typedef enum {
OP_DRAW, OP_XOR, OP_ERASE
} GraphicsOperation;
byte render_sprite(const byte* src, byte x, byte y, byte op) {
byte i,j;
byte w = *src++; // get width from 1st byte of sprite
byte h = *src++; // get height from 2nd byte of sprite
byte xb = DIV7[x]; // xb = x DIV 7
byte xs = MOD7[x]; // xs = x MOD 7
byte result = 0; // result (used only with XOR)
for (j=0; j<h; j++) {
byte* dest = &vidmem[y++][xb]; // lookup video address
byte rest = 0; // rest = leftover bits
for (i=0; i<w; i++) {
byte data = *src++; // get next sprite byte
byte next = (data << xs) | rest; // shift and OR with leftover
// compute graphics operation, write to dest
switch (op) {
case OP_DRAW: *dest++ = next; break;
case OP_XOR: result |= (*dest++ ^= next); break;
case OP_ERASE: *dest++ &= ~next; break;
}
rest = data >> (7-xs); // save leftover bits
}
// compute final byte operation
switch (op) {
case OP_DRAW: *dest = rest; break;
case OP_XOR: result |= (*dest ^= rest); break;
case OP_ERASE: *dest &= ~rest; break;
}
}
return result;
}
void draw_sprite(const byte* src, byte x, byte y) {
render_sprite(src, x, y, OP_DRAW);
}
// XOR returns non-zero if any pixels were overlapped
byte xor_sprite(const byte* src, byte x, byte y) {
return render_sprite(src, x, y, OP_XOR);
}
void erase_sprite(const byte* src, byte x, byte y) {
render_sprite(src, x, y, OP_ERASE);
}
// clear just sets all bytes to 0, and is fast
void clear_sprite(const byte* src, byte x, byte y) {
byte i,j;
byte w = *src++;
byte h = *src++;
byte xb = DIV7[x];
for (j=0; j<h; j++) {
byte* dest = &vidmem[y++][xb];
for (i=0; i<=w; i++) {
dest[i] = 0;
}
}
}
// FONT FUNCTIONS
#define LOCHAR 0x20 // lowest character value in font
#define HICHAR 0x7f // highest character value in font
const byte font8x8[HICHAR-LOCHAR+1][8] = {/*{w:8,h:8,bpp:1,count:96}*/
{ 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 }, { 0x18,0x18,0x18,0x18,0x00,0x00,0x18,0x00 }, { 0x66,0x66,0x66,0x00,0x00,0x00,0x00,0x00 }, { 0x66,0x66,0xff,0x66,0xff,0x66,0x66,0x00 }, { 0x18,0x7c,0x06,0x3c,0x60,0x3e,0x18,0x00 }, { 0x46,0x66,0x30,0x18,0x0c,0x66,0x62,0x00 }, { 0x3c,0x66,0x3c,0x1c,0xe6,0x66,0xfc,0x00 }, { 0x60,0x30,0x18,0x00,0x00,0x00,0x00,0x00 }, { 0x30,0x18,0x0c,0x0c,0x0c,0x18,0x30,0x00 }, { 0x0c,0x18,0x30,0x30,0x30,0x18,0x0c,0x00 }, { 0x00,0x66,0x3c,0xff,0x3c,0x66,0x00,0x00 }, { 0x00,0x18,0x18,0x7e,0x18,0x18,0x00,0x00 }, { 0x00,0x00,0x00,0x00,0x00,0x18,0x18,0x0c }, { 0x00,0x00,0x00,0x7e,0x00,0x00,0x00,0x00 }, { 0x00,0x00,0x00,0x00,0x00,0x18,0x18,0x00 }, { 0x00,0xc0,0x60,0x30,0x18,0x0c,0x06,0x00 }, { 0x3c,0x66,0x76,0x6e,0x66,0x66,0x3c,0x00 }, { 0x18,0x18,0x1c,0x18,0x18,0x18,0x7e,0x00 }, { 0x3c,0x66,0x60,0x30,0x0c,0x06,0x7e,0x00 }, { 0x3c,0x66,0x60,0x38,0x60,0x66,0x3c,0x00 }, { 0x60,0x70,0x78,0x66,0xfe,0x60,0x60,0x00 }, { 0x7e,0x06,0x3e,0x60,0x60,0x66,0x3c,0x00 }, { 0x3c,0x66,0x06,0x3e,0x66,0x66,0x3c,0x00 }, { 0x7e,0x66,0x30,0x18,0x18,0x18,0x18,0x00 }, { 0x3c,0x66,0x66,0x3c,0x66,0x66,0x3c,0x00 }, { 0x3c,0x66,0x66,0x7c,0x60,0x66,0x3c,0x00 }, { 0x00,0x00,0x18,0x00,0x00,0x18,0x00,0x00 }, { 0x00,0x00,0x18,0x00,0x00,0x18,0x18,0x0c }, { 0x70,0x18,0x0c,0x06,0x0c,0x18,0x70,0x00 }, { 0x00,0x00,0x7e,0x00,0x7e,0x00,0x00,0x00 }, { 0x0e,0x18,0x30,0x60,0x30,0x18,0x0e,0x00 }, { 0x3c,0x66,0x60,0x30,0x18,0x00,0x18,0x00 }, { 0x3c,0x66,0x76,0x76,0x06,0x46,0x3c,0x00 }, { 0x18,0x3c,0x66,0x7e,0x66,0x66,0x66,0x00 }, { 0x3e,0x66,0x66,0x3e,0x66,0x66,0x3e,0x00 }, { 0x3c,0x66,0x06,0x06,0x06,0x66,0x3c,0x00 }, { 0x1e,0x36,0x66,0x66,0x66,0x36,0x1e,0x00 }, { 0x7e,0x06,0x06,0x1e,0x06,0x06,0x7e,0x00 }, { 0x7e,0x06,0x06,0x1e,0x06,0x06,0x06,0x00 }, { 0x3c,0x66,0x06,0x76,0x66,0x66,0x3c,0x00 }, { 0x66,0x66,0x66,0x7e,0x66,0x66,0x66,0x00 }, { 0x3c,0x18,0x18,0x18,0x18,0x18,0x3c,0x00 }, { 0x78,0x30,0x30,0x30,0x30,0x36,0x1c,0x00 }, { 0x66,0x36,0x1e,0x0e,0x1e,0x36,0x66,0x00 }, { 0x06,0x06,0x06,0x06,0x06,0x06,0x7e,0x00 }, { 0xc6,0xee,0xfe,0xd6,0xc6,0xc6,0xc6,0x00 }, { 0x66,0x6e,0x7e,0x7e,0x76,0x66,0x66,0x00 }, { 0x3c,0x66,0x66,0x66,0x66,0x66,0x3c,0x00 }, { 0x3e,0x66,0x66,0x3e,0x06,0x06,0x06,0x00 }, { 0x3c,0x66,0x66,0x66,0x66,0x3c,0x70,0x00 }, { 0x3e,0x66,0x66,0x3e,0x1e,0x36,0x66,0x00 }, { 0x3c,0x66,0x06,0x3c,0x60,0x66,0x3c,0x00 }, { 0x7e,0x18,0x18,0x18,0x18,0x18,0x18,0x00 }, { 0x66,0x66,0x66,0x66,0x66,0x66,0x3c,0x00 }, { 0x66,0x66,0x66,0x66,0x66,0x3c,0x18,0x00 }, { 0xc6,0xc6,0xc6,0xd6,0xfe,0xee,0xc6,0x00 }, { 0x66,0x66,0x3c,0x18,0x3c,0x66,0x66,0x00 }, { 0x66,0x66,0x66,0x3c,0x18,0x18,0x18,0x00 }, { 0x7e,0x60,0x30,0x18,0x0c,0x06,0x7e,0x00 }, { 0x3c,0x0c,0x0c,0x0c,0x0c,0x0c,0x3c,0x00 }, { 0x00,0x06,0x0c,0x18,0x30,0x60,0xc0,0x00 }, { 0x3c,0x30,0x30,0x30,0x30,0x30,0x3c,0x00 }, { 0x00,0x18,0x3c,0x7e,0x18,0x18,0x18,0x18 }, { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xff }, { 0x06,0x0c,0x18,0x00,0x00,0x00,0x00,0x00 }, { 0x00,0x00,0x3c,0x60,0x7c,0x66,0x7c,0x00 }, { 0x00,0x06,0x06,0x3e,0x66,0x66,0x3e,0x00 }, { 0x00,0x00,0x3c,0x06,0x06,0x06,0x3c,0x00 }, { 0x00,0x60,0x60,0x7c,0x66,0x66,0x7c,0x00 }, { 0x00,0x00,0x3c,0x66,0x7e,0x06,0x3c,0x00 }, { 0x00,0x70,0x18,0x7c,0x18,0x18,0x18,0x00 }, { 0x00,0x00,0x7c,0x66,0x66,0x7c,0x60,0x3e }, { 0x00,0x06,0x06,0x3e,0x66,0x66,0x66,0x00 }, { 0x00,0x18,0x00,0x1c,0x18,0x18,0x3c,0x00 }, { 0x00,0x60,0x00,0x60,0x60,0x60,0x60,0x3c }, { 0x00,0x06,0x06,0x36,0x1e,0x36,0x66,0x00 }, { 0x00,0x1c,0x18,0x18,0x18,0x18,0x3c,0x00 }, { 0x00,0x00,0x66,0xfe,0xfe,0xd6,0xc6,0x00 }, { 0x00,0x00,0x3e,0x66,0x66,0x66,0x66,0x00 }, { 0x00,0x00,0x3c,0x66,0x66,0x66,0x3c,0x00 }, { 0x00,0x00,0x3e,0x66,0x66,0x3e,0x06,0x06 }, { 0x00,0x00,0x7c,0x66,0x66,0x7c,0x60,0x60 }, { 0x00,0x00,0x3e,0x66,0x06,0x06,0x06,0x00 }, { 0x00,0x00,0x7c,0x06,0x3c,0x60,0x3e,0x00 }, { 0x00,0x18,0x7e,0x18,0x18,0x18,0x70,0x00 }, { 0x00,0x00,0x66,0x66,0x66,0x66,0x7c,0x00 }, { 0x00,0x00,0x66,0x66,0x66,0x3c,0x18,0x00 }, { 0x00,0x00,0xc6,0xd6,0xfe,0x7c,0x6c,0x00 }, { 0x00,0x00,0x66,0x3c,0x18,0x3c,0x66,0x00 }, { 0x00,0x00,0x66,0x66,0x66,0x7c,0x30,0x1e }, { 0x00,0x00,0x7e,0x30,0x18,0x0c,0x7e,0x00 }, { 0x38,0x0c,0x0c,0x06,0x0c,0x0c,0x38,0x00 }, { 0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18 }, { 0x1c,0x30,0x30,0x60,0x30,0x30,0x1c,0x00 }, { 0x00,0x4c,0x32,0x00,0x00,0x00,0x00,0x00 }, { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 },
};
// draw character from column 0..39, row 0..23
void draw_char(char ch, byte col, byte row) {
byte i;
const byte* src = &font8x8[(ch-LOCHAR)][0];
byte y = row*8;
for (i=0; i<8; i++) {
byte* dest = &vidmem[y++][col];
*dest = *src;
src += 1;
}
}
// draw string starting at row/col (vert 1 = draw vertical)
void draw_string(const char* str, byte col, byte row, byte vert) {
do {
byte ch = *str++;
if (!ch) break;
draw_char(ch, col, row);
if (vert) row++; else col++;
} while (1);
}
// draw 4-digit BCD word
void draw_bcd_word(word bcd, byte col, byte row, byte vert) {
byte j;
if (vert) row+=3; else col+=3; // move to rightmost digit
for (j=0; j<4; j++) {
draw_char('0'+(bcd&0xf), col, row);
if (vert) row--; else col--;
bcd >>= 4;
}
}
// add two 4-digit BCD words
word bcd_add(word a, word b) {
word result;
__asm__ ("sed"); // set decimal (BCD) mode
result = a+b;
__asm__ ("cld"); // clear BCD mode
return result;
}
//
// GAME GRAPHICS
//
const byte player_bitmap[] =
{3,16,/*{w:24,h:16,bpp:1}*/0x00,0x00,0x00,0x00,0x18,0x00,0x00,0x3C,0x00,0x04,0x18,0x20,0x04,0x18,0x20,0x0C,0x3C,0x30,0x3C,0x3C,0x3C,0xCC,0xE7,0x33,0x0C,0x66,0x30,0xC4,0xE7,0x23,0x34,0xE7,0x2C,0x0C,0x7E,0x30,0xCC,0xFF,0x33,0x3C,0x18,0x3C,0x0C,0x18,0x30,0x04,0x18,0x20};
const byte bomb_bitmap[] =
{1,5,/*{w:8,h:5,bpp:1}*/0x88,0x55,0x77,0x55,0x88};
const byte bullet_bitmap[] =
{1,5,/*{w:8,h:5,bpp:1}*/0x14,0x28,0x14,0x14,0x28};
const byte enemy1_bitmap[] =
{2,16,/*{w:16,h:16,bpp:1}*/0x00,0x00,0x70,0x38,0xF8,0x7C,0xFC,0xFC,0xFE,0xFC,0xFE,0xFF,0xFC,0xFF,0xF8,0x7F,0xF0,0x3F,0x88,0x47,0xF0,0x3F,0xF0,0x3F,0xD0,0x2F,0x8C,0xC7,0x48,0x48,0x80,0x04};
const byte enemy2_bitmap[] =
{2,16,/*{w:16,h:16,bpp:1}*/0x00,0x00,0x30,0x0C,0x14,0x28,0x2E,0x74,0x08,0x10,0x20,0x04,0xE0,0x07,0xD0,0x0B,0xB0,0x0D,0xB2,0x4D,0x19,0x98,0x8E,0x71,0x82,0x41,0xB1,0x8D,0x59,0x9A,0x4A,0x52};
const byte enemy3_bitmap[] =
{2,16,/*{w:16,h:16,bpp:1}*/0x00,0x00,0x00,0x00,0x04,0x20,0x05,0xA0,0x05,0xA0,0x25,0xA4,0xA7,0xE5,0xF7,0xEF,0xF7,0xEF,0xFE,0x7F,0xFC,0x3F,0xBC,0x3D,0xE4,0x27,0x20,0x00,0x00,0x00,0x00,0x00};
const byte enemy4_bitmap[] =
{2,16,/*{w:16,h:16,bpp:1}*/0x00,0x00,0x00,0x00,0xF0,0x0F,0xF8,0x1F,0xD8,0x1B,0xF8,0x1F,0xF8,0x1F,0xF8,0x1F,0xF0,0x0F,0xA8,0x15,0xCC,0x33,0xE8,0x17,0x66,0x66,0x33,0xCC,0x61,0x86,0x40,0x02};
const byte* const enemy_bitmaps[4] = {
enemy1_bitmap,
enemy2_bitmap,
enemy3_bitmap,
enemy4_bitmap
};
//
// GAME CODE
//
byte attract;
word score;
byte lives;
#define MAXLIVES 5
byte player_x;
byte bullet_x;
byte bullet_y;
byte bomb_x;
byte bomb_y;
typedef struct {
byte x,y;
const byte* shape; // need const here
} Enemy;
#define MAX_ENEMIES 28
Enemy enemies[MAX_ENEMIES];
byte enemy_index;
byte num_enemies;
typedef struct {
int right:1;
int down:1;
} MarchMode;
MarchMode this_mode, next_mode;
void draw_lives() {
byte i;
byte n = lives;
byte y = 18;
byte x = VBWIDTH-1;
for (i=0; i<MAXLIVES; i++) {
draw_char(i<n?'*':' ', x, y++);
}
}
void draw_score() {
byte x = VBWIDTH-1;
byte y = 10;
draw_bcd_word(score, x, y, 1);
}
void draw_bunker(byte x, byte y, byte y2, byte h, byte w) {
byte i,a,b;
for (i=0; i<h; i++) {
a = y-y2-i*2;
b = y-i;
xor_vline(x+i, a, b);
xor_vline(x+h*2+w-i-1, a, b);
}
for (i=0; i<w; i++) {
xor_vline(x+h+i, a, b);
}
}
void draw_playfield() {
byte i;
clrscr();
draw_string("PLAYER 1", VBWIDTH-1, 0, 1);
draw_score();
draw_lives();
for (i=0; i<VBWIDTH-4; i++)
vidmem[191][i] = (i&1) ? 0x55 : 0x2a;
draw_bunker(20, 165, 15, 15, 20);
draw_bunker(160, 165, 15, 15, 20);
}
void add_score(word pts) {
if (attract) return;
score = bcd_add(score, pts);
draw_score();
}
void xor_player_derez() {
byte i,j;
byte x = player_x+13;
byte y = 190;
byte* rand = (byte*) &clrscr; // use code as random #'s
for (j=1; j<=0x1f; j++) {
for (i=0; i<50; i++) {
signed char xx = x + (*rand++ & 0x1f) - 15;
signed char yy = y - (*rand++ & j);
xor_pixel(xx, yy);
if ((xx & 0x1f) > j) { CLICK; }
}
}
}
void destroy_player() {
xor_player_derez(); // xor derez pattern
xor_sprite(player_bitmap, player_x, 192-17); // erase ship via xor
xor_player_derez(); // xor 2x to erase derez pattern
player_x = 0xff;
lives--;
}
void init_enemies() {
byte i,x,y,bm;
x=0;
y=10;
bm=0;
for (i=0; i<MAX_ENEMIES; i++) {
Enemy* e = &enemies[i];
e->x = x;
e->y = y;
e->shape = enemy_bitmaps[bm];
x += 29;
if (x >= 200) {
x = 0;
y += 20;
bm++;
}
}
enemy_index = 0;
num_enemies = MAX_ENEMIES;
this_mode.right = 1;
this_mode.down = 0;
next_mode.right = 1;
next_mode.down = 0;
}
void delete_enemy(Enemy* e) {
clear_sprite(e->shape, e->x, e->y);
memmove(e, e+1, sizeof(Enemy)*(enemies-e+MAX_ENEMIES-1));
num_enemies--; // update_next_enemy() will check enemy_index
tone(1,10,10);
}
void update_next_enemy() {
Enemy* e;
if (enemy_index >= num_enemies) {
enemy_index = 0;
memcpy(&this_mode, &next_mode, sizeof(this_mode));
tone(220+num_enemies,3,1);
}
e = &enemies[enemy_index];
clear_sprite(e->shape, e->x, e->y);
if (this_mode.down) {
e->y += 4;
// if too close to ground, end game
if (e->y > 170) {
destroy_player();
lives = 0;
}
next_mode.down = 0;
} else {
if (this_mode.right) {
e->x += 2;
if (e->x >= 255-16) {
next_mode.down = 1;
next_mode.right = 0;
}
} else {
e->x -= 2;
if (e->x == 0) {
next_mode.down = 1;
next_mode.right = 1;
}
}
}
draw_sprite(e->shape, e->x, e->y);
enemy_index++;
}
char in_rect(Enemy* e, byte x, byte y, byte w, byte h) {
byte ew = e->shape[0]*8;
byte eh = e->shape[1];
return (x >= e->x-w && x <= e->x+ew && y >= e->y-h && y <= e->y+eh);
}
Enemy* find_enemy_at(byte x, byte y) {
byte i;
for (i=0; i<num_enemies; i++) {
Enemy* e = &enemies[i];
if (in_rect(e, x, y, 0, 2)) {
return e;
}
}
return NULL;
}
void check_bullet_hit(byte x, byte y) {
Enemy* e = find_enemy_at(x,y);
if (e) {
delete_enemy(e);
add_score(0x25);
}
}
void fire_bullet() {
bullet_x = player_x + 13;
bullet_y = 192-22;
xor_sprite(bullet_bitmap, bullet_x, bullet_y); // draw
}
void move_bullet() {
byte leftover = xor_sprite(bullet_bitmap, bullet_x, bullet_y); // erase
if (leftover || bullet_y < 10) {
clear_sprite(bullet_bitmap, bullet_x, bullet_y);
check_bullet_hit(bullet_x, bullet_y+2);
bullet_y = 0;
} else {
bullet_y -= 4;
tone(bullet_y,3,0);
xor_sprite(bullet_bitmap, bullet_x, bullet_y); // draw
}
}
void drop_bomb() {
Enemy* e = &enemies[enemy_index];
bomb_x = e->x + 7;
bomb_y = e->y + 16;
xor_sprite(bomb_bitmap, bomb_x, bomb_y);
}
void move_bomb() {
byte leftover = xor_sprite(bomb_bitmap, bomb_x, bomb_y); // erase
if (bomb_y > 192-12) {
bomb_y = 0;
} else if (leftover) {
erase_sprite(bomb_bitmap, bomb_x, bomb_y); // erase bunker
if (bomb_y > 192-22) {
// player was hit (probably)
destroy_player();
}
bomb_y = 0;
} else {
bomb_y += 3;
xor_sprite(bomb_bitmap, bomb_x, bomb_y);
}
}
byte frame;
signed char player_dir = 0;
void move_player() {
if (attract) {
if (bullet_y == 0) fire_bullet();
player_dir = 0;
} else {
char key;
// handle keyboard
if (kbhit()) {
key = cgetc();
switch (key) {
case 8: // left arrow
player_dir = player_dir < 0 ? 0 : -2;
break;
case 21: // right arrow
player_dir = player_dir > 0 ? 0 : 2;
break;
case ' ': // space
if (bullet_y == 0) {
fire_bullet();
}
break;
}
}
}
// move player
if (player_dir < 0 && player_x > 0)
player_x += player_dir;
else if (player_dir > 0 && player_x < 255-28)
player_x += player_dir;
draw_sprite(player_bitmap, player_x, 192-17);
}
void play_round() {
draw_playfield();
player_x = VHEIGHT/2-8;
bullet_y = 0;
bomb_y = 0;
frame = 0;
while (player_x != 0xff && num_enemies) {
move_player();
if (bullet_y) {
move_bullet();
}
update_next_enemy();
if (frame & 1) {
if (bomb_y == 0) {
drop_bomb();
} else {
move_bomb();
}
}
frame++;
}
}
void init_game() {
score = 0;
lives = 5;
}
void game_over_msg() {
byte i;
byte x=11;
byte y=10;
for (i=0; i<50; i++) {
draw_string(" *************** ", x, y+0, 0);
draw_string("*** ***", x, y+1, 0);
draw_string("** GAME OVER **", x, y+2, 0);
draw_string("*** ***", x, y+3, 0);
draw_string(" *************** ", x, y+4, 0);
}
}
void play_game() {
attract = 0;
init_game();
init_enemies();
while (lives) {
play_round();
if (num_enemies == 0) {
init_enemies();
}
}
game_over_msg();
}
void attract_mode() {
attract = 1;
while (1) {
init_enemies();
play_round();
}
}
void main() {
// NOTE: initializers don't get run, so we init here
while (1) {
//attract_mode();
play_game();
}
}