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8bitworkshop/presets/astrocade/cosmic.c
2018-12-04 17:48:04 -05:00

406 lines
9.0 KiB
C

/*
* An Astrocade port of the Cosmic Impalas game
* described in the book
* "Making 8-bit Arcade Games in C"
*/
#include <string.h>
#include "aclib.h"
//#link "aclib.c"
//#link "acheader.s"
//
// GAME GRAPHICS
//
const byte player_bitmap[] =
{3,14,/*{w:12,h:16,bpp:2,brev:1}*/0x00,0x3C,0x00,0x00,0x18,0x00,0x00,0x3C,0x00,0x00,0x18,0x00,0x04,0x18,0x20,0x0C,0x3C,0x30,0x3C,0x3C,0x3C,0x1F,0xE7,0xF4,0x1F,0x66,0xF4,0x17,0xE7,0xE4,0x17,0xE7,0xE4,0x1C,0x7E,0x34,0x1C,0xFF,0x34,0x3C,0x18,0x3C,0x0C,0x18,0x30,0x04,0x18,0x20};
const byte bomb_bitmap[] =
{1,5,/*{w:8,h:5,bpp:2,brev:1}*/0x88,0x55,0x77,0x55,0x88};
const byte bullet_bitmap[] =
{1,5,/*{w:8,h:5,bpp:2,brev:1}*/0x14,0x28,0x14,0x14,0x28};
const byte enemy1_bitmap[] =
{2,8,/*{w:16,h:8,bpp:2,brev: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[] =
{2,8,/*{w:16,h:8,bpp:2,brev: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[] =
{2,8,/*{w:16,h:8,bpp:2,brev: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[] =
{2,8,/*{w:16,h:8,bpp:2,brev: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
};
#define COLOR_BUNKER 1
#define COLOR_GROUND 2
#define COLOR_SCORE 3
//
// GAME CODE
//
#define MAXLIVES 5
#define PLYRHEIGHT 14
#define ENEMY_SPACING_X 17
#define ENEMY_SPACING_Y 11
#define ENEMY_MARCH_X 1
#define ENEMY_MARCH_Y 2
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;
byte attract;
word score;
byte lives;
const byte player_y = VHEIGHT-PLYRHEIGHT-1;
byte player_x;
byte bullet_x;
byte bullet_y;
byte bomb_x;
byte bomb_y;
void draw_lives() {
byte i;
byte n = lives;
byte y = 0;
byte x = PIXWIDTH-4*5;
hw_xpand = XPAND_COLORS(0, COLOR_SCORE);
for (i=0; i<MAXLIVES; i++) {
draw_char(i<n?'|':' ', x, y, M_MOVE);
x += 4;
}
}
void draw_score() {
byte x = 10*8;
byte y = 0;
hw_xpand = XPAND_COLORS(0, COLOR_SCORE);
draw_bcd_word(score, x, y, M_MOVE);
}
void draw_bunker(byte x, byte y, byte y2, byte h, byte w) {
byte i,a=0,b=0;
for (i=0; i<h; i++) {
a = y-y2-i*2;
b = y-i;
vline(x+i, a, b, M_XOR, COLOR_BUNKER);
vline(x+h*2+w-i-1, a, b, M_XOR, COLOR_BUNKER);
}
for (i=0; i<w; i++) {
vline(x+h+i, a, b, M_XOR, COLOR_BUNKER);
}
}
void draw_playfield() {
byte i;
clrscr();
hw_xpand = XPAND_COLORS(0, COLOR_SCORE);
draw_string("PLAYER 1", 0, 0);
draw_score();
draw_lives();
for (i=0; i<PIXWIDTH; i++)
pixel(i, VHEIGHT-1, COLOR_GROUND, M_OR);
// TODO: const
draw_bunker(20, 65, 15, 15, 20);
draw_bunker(100, 65, 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 = player_y+PLYRHEIGHT-1;
byte* rand = (byte*) &clrscr; // use code as random #'s
for (j=1; j<=0xf; j++) {
for (i=0; i<100; i++) {
signed char xx = x + (*rand++ & 0xf) - 15;
signed char yy = y - (*rand++ & j);
pixel(xx, yy, *rand++, M_XOR);
}
}
}
void destroy_player() {
xor_player_derez(); // xor derez pattern
render_sprite(player_bitmap, player_x, VHEIGHT-PLYRHEIGHT, M_XOR); // 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 = ENEMY_SPACING_Y;
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 += ENEMY_SPACING_X;
if (x >= PIXWIDTH-ENEMY_SPACING_X*2) {
x = 0;
y += ENEMY_SPACING_Y;
bm++; // TODO: can overflow
}
}
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) {
erase_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
}
void update_next_enemy() {
Enemy* e;
if (enemy_index >= num_enemies) {
enemy_index = 0;
memcpy(&this_mode, &next_mode, sizeof(this_mode));
}
e = &enemies[enemy_index];
erase_sprite(e->shape, e->x, e->y);
if (this_mode.down) {
e->y += ENEMY_MARCH_Y;
// if too close to ground, end game
if (e->y > VHEIGHT-ENEMY_SPACING_Y) {
destroy_player();
lives = 0;
}
next_mode.down = 0;
} else {
if (this_mode.right) {
e->x += ENEMY_MARCH_X;
if (e->x >= PIXWIDTH-ENEMY_SPACING_X) {
next_mode.down = 1;
next_mode.right = 0;
}
} else {
e->x -= ENEMY_MARCH_X;
if (e->x == 0) {
next_mode.down = 1;
next_mode.right = 1;
}
}
}
render_sprite(e->shape, e->x, e->y, M_XOR);
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 + 4;
bullet_y = VHEIGHT-PLYRHEIGHT-6;
render_sprite(bullet_bitmap, bullet_x, bullet_y, M_XOR); // draw
}
void move_bullet() {
byte leftover;
hw_intst; // reset intercept counters
render_sprite(bullet_bitmap, bullet_x, bullet_y, M_XOR); // erase
leftover = (hw_intst & 0xf0); // any pixels leftover?
if (leftover || bullet_y < 10) {
erase_sprite(bullet_bitmap, bullet_x, bullet_y);
check_bullet_hit(bullet_x, bullet_y+2);
bullet_y = 0;
} else {
bullet_y -= 4;
render_sprite(bullet_bitmap, bullet_x, bullet_y, M_XOR); // draw
}
}
void drop_bomb() {
Enemy* e = &enemies[enemy_index];
bomb_x = e->x + 7;
bomb_y = e->y + 16;
render_sprite(bomb_bitmap, bomb_x, bomb_y, M_XOR);
}
void move_bomb() {
hw_intst; // reset intercept counters
render_sprite(bomb_bitmap, bomb_x, bomb_y, M_XOR); // erase
if (bomb_y > VHEIGHT-12) {
bomb_y = 0;
} else if (hw_intst & 0xf0) { // any pixels leftover?
erase_sprite(bomb_bitmap, bomb_x, bomb_y); // erase bunker
if (bomb_y > VHEIGHT-23) {
// player was hit (probably)
destroy_player();
}
bomb_y = 0;
} else {
bomb_y += 3;
render_sprite(bomb_bitmap, bomb_x, bomb_y, M_XOR);
}
}
byte frame;
signed char player_dir = 0;
void move_player() {
if (attract) {
if (bullet_y == 0) fire_bullet();
player_dir = 0;
} else {
byte mask = hw_p1ctrl;
if (mask & 0x4) {
if (player_x > 0)
player_x--;
}
if (mask & 0x8) {
if (player_x < PIXWIDTH-16)
player_x++;
}
if (mask & 0x10) {
if (bullet_y == 0) {
fire_bullet();
}
}
}
// move player
render_sprite(player_bitmap, player_x, player_y, M_MOVE);
}
void play_round() {
draw_playfield();
player_x = PIXWIDTH/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=16;
byte y=10;
hw_xpand = XPAND_COLORS(0, COLOR_SCORE);
for (i=0; i<50; i++) {
draw_string(" *************** ", x, y+0*8);
draw_string("*** ***", x, y+1*8);
draw_string("** GAME OVER **", x, y+2*8);
draw_string("*** ***", x, y+3*8);
draw_string(" *************** ", x, y+4*8);
}
}
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 setup_registers() {
hw_col0r = 0x00;
hw_col1r = 0x2f;
hw_col2r = 0xef;
hw_col3r = 0xaf;
hw_horcb = 0;
hw_verbl = VHEIGHT*2;
}
void main() {
setup_registers();
// NOTE: initializers don't get run, so we init here
while (1) {
//attract_mode();
play_game();
}
}