mirror of
https://github.com/sehugg/8bitworkshop.git
synced 2024-08-18 10:29:04 +00:00
434 lines
9.4 KiB
C
434 lines
9.4 KiB
C
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/*
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* An Astrocade port of the Cosmic Impalas game
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* described in the book
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* "Making 8-bit Arcade Games in C"
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*/
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#include <string.h>
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#include <stdlib.h>
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//#resource "astrocade.inc"
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#include "acbios.h"
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//#link "acbios.s"
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#include "aclib.h"
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//#link "aclib.s"
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#include "acextra.h"
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//#link "acextra.c"
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//#link "hdr_autostart.s"
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//
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// GAME GRAPHICS
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//
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const byte player_bitmap[2+9*3] =
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{3,9,/*{w:12,h:9,bpp:2,brev:1}*/0x00,0x00,0x00,0x00,0xFF,0x00,0x00,0x14,0x00,0x30,0x3C,0x0C,0x3A,0xBE,0xAC,0x3E,0xFF,0xBC,0x3F,0xFF,0xFC,0x37,0x7D,0xDC,0x3C,0x3C,0x3C};
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const byte bomb_bitmap[] =
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{1,3,/*{w:4,h:3,bpp:2,brev:1}*/0xF8,0x3E,0xF8};
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const byte bullet_bitmap[] =
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{1,5,/*{w:4,h:5,bpp:2,brev:1}*/0x0C,0x24,0x18,0x10,0x04};
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const byte enemy1_bitmap[18] =
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{2,8,/*{w:8,h:8,bpp:2,brev:1}*/0x22,0x88,0x2A,0xA8,0x3F,0xFC,0x37,0xDC,0x3F,0xFC,0x38,0x2C,0x30,0x0C,0x0C,0x30};
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const byte enemy2_bitmap[] =
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{2,8,/*{w:8,h:8,bpp:2,brev:1}*/0x0C,0x30,0x30,0x0C,0x17,0xE8,0x23,0xC4,0x0B,0xD0,0x2C,0x34,0x2F,0xF4,0x10,0x08};
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const byte enemy3_bitmap[] =
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{2,8,/*{w:8,h:8,bpp:2,brev:1}*/0x0F,0xC0,0x00,0xC0,0x10,0xC4,0x26,0xD8,0x27,0x98,0x26,0xD8,0x14,0x14,0x10,0x04};
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const byte enemy4_bitmap[] =
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{2,8,/*{w:8,h:8,bpp:2,brev:1}*/0x30,0x0C,0x3C,0x3C,0x0F,0xF0,0x3A,0xE8,0x3B,0xEC,0x3F,0xFC,0x30,0x0C,0x00,0x00};
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const byte mothership_bitmap[2+3*6] =
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{3,6,/*{w:12,h:6,bpp:2,brev:1}*/0x00,0x28,0x00,0x02,0xBE,0x80,0x2A,0xFF,0xA8,0x25,0x55,0x58,0x0A,0xAA,0xA0,0x02,0xAA,0x80};
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const byte explode_bitmap[18] =
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{2,8,/*{w:8,h:8,bpp:2,brev:1}*/0x40,0x44,0x10,0x40,0x06,0x81,0x0B,0xE4,0x5B,0xE0,0x02,0x81,0x04,0x10,0x10,0x44};
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const byte* const enemy_bitmaps[4] = {
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enemy1_bitmap,
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enemy2_bitmap,
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enemy3_bitmap,
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enemy4_bitmap
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};
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/*{pal:"astrocade",layout:"astrocade"}*/
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const byte palette[8] = {
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0x07, 0xD4, 0x35, 0x01,
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0x07, 0xD4, 0x35, 0x01,
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};
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#define COLOR_BUNKER 1
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#define COLOR_GROUND 2
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#define COLOR_SCORE 2
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//
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// GAME CODE
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//
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#define MAXLIVES 5
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#define PLYRHEIGHT 9
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#define ENEMY_WIDTH 8
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#define ENEMY_HEIGHT 8
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#define ENEMY_SPACING_X 14
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#define ENEMY_SPACING_Y 11
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#define ENEMY_WIDTH 8
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#define ENEMY_MARCH_X 1
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#define ENEMY_MARCH_Y 2
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#define EXPLODE_TIME 8
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typedef struct {
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byte x,y;
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const byte* shape; // need const here
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} Enemy;
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#define MAX_ENEMIES 40
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Enemy enemies[MAX_ENEMIES];
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byte enemy_index;
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byte num_enemies;
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typedef struct {
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int right:1;
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int down:1;
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} MarchMode;
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MarchMode this_mode, next_mode;
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word score;
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byte lives;
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const byte player_y = VHEIGHT-PLYRHEIGHT-1;
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byte player_x;
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byte bullet_x;
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byte bullet_y;
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byte bomb_x;
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byte bomb_y;
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byte explode_x;
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byte explode_y;
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byte explode_timer;
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void draw_lives() {
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byte i;
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byte n = lives;
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byte y = 0;
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byte x = PIXWIDTH-4*6;
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hw_xpand = XPAND_COLORS(0, COLOR_SCORE);
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for (i=0; i<MAXLIVES; i++) {
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draw_char(i<n?'|':' ', x, y, M_MOVE);
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x += 4;
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}
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}
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void draw_score() {
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byte x = 10*8;
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byte y = 0;
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hw_xpand = XPAND_COLORS(0, COLOR_SCORE);
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draw_bcd_word(score, x, y, M_MOVE);
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}
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void draw_bunker(byte x, byte y, byte y2, byte h, byte w) {
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byte i,a=0,b=0;
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for (i=0; i<h; i++) {
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a = y-y2-i*2;
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b = y-i;
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vline(x+i, a, b, COLOR_BUNKER, M_XOR);
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vline(x+h*2+w-i-1, a, b, COLOR_BUNKER, M_XOR);
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}
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for (i=0; i<w; i++) {
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vline(x+h+i, a, b, COLOR_BUNKER, M_XOR);
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}
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}
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void draw_playfield() {
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byte i;
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clrscr();
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draw_string(0, 0, COLOR_SCORE, "PLAYER 1");
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draw_score();
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draw_lives();
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for (i=0; i<PIXWIDTH; i++)
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pixel(i, VHEIGHT-1, COLOR_GROUND, M_OR);
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// TODO: const
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draw_bunker(20, 75, 5, 5, 20);
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draw_bunker(100, 75, 5, 5, 20);
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}
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void add_score(word pts) {
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score = bcd_add(score, pts);
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draw_score();
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}
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void xor_player_derez() {
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byte i,j;
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byte x = player_x+13;
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byte y = player_y+PLYRHEIGHT-1;
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byte* rand = (byte*) &xor_player_derez; // use code as random #'s
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for (j=1; j<=0xf; j++) {
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for (i=0; i<100; i++) {
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signed char xx = x + (*rand++ & 0xf) - 15;
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signed char yy = y - (*rand++ & j);
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pixel(xx, yy, *rand++, M_XOR);
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}
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}
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}
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void destroy_player() {
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xor_player_derez(); // xor derez pattern
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render_sprite(player_bitmap, player_x, player_y, M_XOR); // erase ship via xor
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xor_player_derez(); // xor 2x to erase derez pattern
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player_x = 0xff;
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lives--;
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}
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void init_enemies() {
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byte i,x,y,bm;
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x = 0;
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y = ENEMY_SPACING_Y;
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bm=0;
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for (i=0; i<MAX_ENEMIES; i++) {
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Enemy* e = &enemies[i];
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e->x = x;
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e->y = y;
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e->shape = enemy_bitmaps[bm];
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x += ENEMY_SPACING_X;
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if (x >= PIXWIDTH-ENEMY_SPACING_X*2) {
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x = 0;
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y += ENEMY_SPACING_Y;
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bm++; // TODO: can overflow
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}
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}
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enemy_index = 0;
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num_enemies = MAX_ENEMIES;
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this_mode.right = 1;
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this_mode.down = 0;
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next_mode.right = 1;
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next_mode.down = 0;
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}
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void delete_enemy(Enemy* e) {
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erase_sprite(e->shape, e->x, e->y);
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if (explode_timer == 0) {
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explode_x = e->x;
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explode_y = e->y;
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explode_timer = EXPLODE_TIME;
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}
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memmove(e, e+1, sizeof(Enemy)*(enemies-e+MAX_ENEMIES-1));
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num_enemies--; // update_next_enemy() will check enemy_index
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// TODO: enemy_index might skip updating an enemy
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}
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void update_next_enemy() {
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Enemy* e;
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if (enemy_index >= num_enemies) {
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enemy_index = 0;
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memcpy(&this_mode, &next_mode, sizeof(this_mode));
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}
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e = &enemies[enemy_index];
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if (this_mode.down) {
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erase_sprite(e->shape, e->x, e->y);
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e->y += ENEMY_MARCH_Y;
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// if too close to ground, end game
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if (e->y >= player_y) {
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destroy_player();
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lives = 0;
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}
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next_mode.down = 0;
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} else {
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if (this_mode.right) {
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e->x += ENEMY_MARCH_X;
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if (e->x >= PIXWIDTH-ENEMY_SPACING_X) {
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next_mode.down = 1;
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next_mode.right = 0;
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}
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} else {
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e->x -= ENEMY_MARCH_X;
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if (e->x == 0) {
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next_mode.down = 1;
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next_mode.right = 1;
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}
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}
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}
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render_sprite(e->shape, e->x, e->y, M_MOVE);
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enemy_index++;
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}
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char in_rect(Enemy* e, byte x, byte y, byte w, byte h) {
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byte ew = e->shape[0]*4;
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byte eh = e->shape[1];
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return (x >= e->x-w && x <= e->x+ew+w && y >= e->y-h && y <= e->y+eh+h);
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}
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Enemy* find_enemy_at(byte x, byte y) {
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byte i;
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for (i=0; i<num_enemies; i++) {
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Enemy* e = &enemies[i];
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if (in_rect(e, x, y, 4, 1)) {
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return e;
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}
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}
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return NULL;
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}
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void check_bullet_hit(byte x, byte y) {
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Enemy* e = find_enemy_at(x,y);
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if (e) {
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delete_enemy(e);
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add_score(0x25);
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}
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}
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void xor_bullet() {
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render_sprite(bullet_bitmap, bullet_x, bullet_y, M_XOR);
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}
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void fire_bullet() {
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bullet_x = player_x + 4;
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bullet_y = VHEIGHT-PLYRHEIGHT-6;
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xor_bullet();
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}
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void move_bullet() {
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byte leftover;
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xor_bullet();
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//erase_sprite(bullet_bitmap, bullet_x, bullet_y);
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hw_intst; // reset intercept counters
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bullet_y -= 2;
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xor_bullet();
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leftover = hw_intst; // any pixels leftover?
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if (leftover || bullet_y < 10) {
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erase_sprite(bullet_bitmap, bullet_x, bullet_y);
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check_bullet_hit(bullet_x, bullet_y+2);
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bullet_y = 0;
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}
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}
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void xor_bomb() {
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render_sprite(bomb_bitmap, bomb_x, bomb_y, M_XOR);
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}
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void drop_bomb() {
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byte i = rand() % num_enemies;
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Enemy* e = &enemies[i];
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// don't drop on someone else!
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if (find_enemy_at(e->x, e->y+ENEMY_HEIGHT+ENEMY_SPACING_Y+1)) {
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return;
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}
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bomb_x = e->x + ENEMY_WIDTH/4;
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bomb_y = e->y + ENEMY_HEIGHT;
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xor_bomb();
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}
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void move_bomb() {
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xor_bomb();
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if (bomb_y >= VHEIGHT-5) {
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bomb_y = 0;
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} else {
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bomb_y += 1;
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hw_intst; // reset intercept counters
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xor_bomb();
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if (hw_intst & 0xf0) { // any pixels leftover?
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erase_sprite(bomb_bitmap, bomb_x, bomb_y);
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if (bomb_y >= player_y-2) {
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// player was hit (probably)
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destroy_player();
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}
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bomb_y = 0;
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}
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}
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}
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byte frame;
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signed char player_dir = 0;
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void move_player() {
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byte mask = hw_p1ctrl;
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if (mask & 0x4) {
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if (player_x > 0)
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player_x--;
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}
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if (mask & 0x8) {
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if (player_x < PIXWIDTH-16)
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player_x++;
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}
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if (mask & 0x10) {
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if (bullet_y == 0) {
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fire_bullet();
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}
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}
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// move player
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render_sprite(player_bitmap, player_x, player_y, M_MOVE);
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}
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void animate_explosion() {
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if (--explode_timer == 0) {
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erase_sprite(explode_bitmap, explode_x, explode_y);
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} else {
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render_sprite(explode_bitmap, explode_x, explode_y, M_OR);
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}
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}
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void play_round() {
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draw_playfield();
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player_x = PIXWIDTH/2-8;
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bullet_y = 0;
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bomb_y = 0;
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explode_timer = 0;
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frame = 0;
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while (player_x != 0xff && num_enemies) {
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move_player();
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if (bullet_y) {
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move_bullet();
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}
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update_next_enemy();
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if (frame & 1) {
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if (bomb_y == 0) {
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drop_bomb();
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} else {
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move_bomb();
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}
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}
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if (explode_timer) {
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animate_explosion();
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}
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frame++;
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}
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}
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void init_game() {
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score = 0;
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lives = 5;
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}
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void game_over_msg() {
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byte i;
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byte x=16;
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byte y=10;
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hw_xpand = XPAND_COLORS(0, COLOR_SCORE);
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for (i=0; i<50; i++) {
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draw_string(x, y+0*8, COLOR_SCORE, " *************** ");
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draw_string(x, y+1*8, COLOR_SCORE, "*** ***");
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draw_string(x, y+2*8, COLOR_SCORE, "** GAME OVER **");
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draw_string(x, y+3*8, COLOR_SCORE, "*** ***");
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draw_string(x, y+4*8, COLOR_SCORE, " *************** ");
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}
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}
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void play_game() {
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init_game();
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init_enemies();
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while (lives) {
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play_round();
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if (num_enemies == 0) {
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init_enemies();
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}
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}
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game_over_msg();
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}
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void main() {
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hw_horcb = 40;
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hw_verbl = VHEIGHT*2;
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set_palette(palette);
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// NOTE: initializers don't get run, so we init here
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while (1) {
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//attract_mode();
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play_game();
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}
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}
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