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865 lines
21 KiB
C
865 lines
21 KiB
C
//Chase NES game by Shiru (shiru@mail.ru) 01'12
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//Feel free to do anything you want with this code, consider it Public Domain
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//This game is an example for my article Programming NES games in C
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//include the library
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#include "neslib.h"
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#include <string.h>
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//#link "famitone2.s"
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//#link "music.s"
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//#link "sounds.s"
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// CHR data
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//#resource "tileset.chr"
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//#link "tileset.s"
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//include nametables for all the screens such as title or game over
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#include "title_nam.h"
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#include "level_nam.h"
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#include "gameover_nam.h"
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#include "welldone_nam.h"
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//include nametables for levels
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#include "level1_nam.h"
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#include "level2_nam.h"
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#include "level3_nam.h"
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#include "level4_nam.h"
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#include "level5_nam.h"
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//game uses 12:4 fixed point calculations for enemy movements
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#define FP_BITS 4
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//max size of the game map
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#define MAP_WDT 16
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#define MAP_WDT_BIT 4
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#define MAP_HGT 13
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//macro for calculating map offset from screen space, as
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//the map size is smaller than screen to save some memory
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#define MAP_ADR(x,y) ((((y)-2)<<MAP_WDT_BIT)|(x))
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//size of a map tile
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#define TILE_SIZE 16
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#define TILE_SIZE_BIT 4
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//movement directions, match to the gamepad buttons bits to
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//simplify some things
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#define DIR_NONE 0
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#define DIR_LEFT PAD_LEFT
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#define DIR_RIGHT PAD_RIGHT
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#define DIR_UP PAD_UP
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#define DIR_DOWN PAD_DOWN
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//tile numbers for certain things in the game map
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//i.e. which object corresponds to a character in the tileset
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#define TILE_PLAYER 0x10
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#define TILE_ENEMY1 0x11
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#define TILE_ENEMY2 0x12
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#define TILE_ENEMY3 0x13
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#define TILE_WALL 0x40
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#define TILE_EMPTY 0x44
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#define TILE_ITEM 0x45
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//number of levels in the game
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#define LEVELS_ALL 5
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//numbers for screens that are displayed by the same function as the
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//level number
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#define SCREEN_GAMEOVER (LEVELS_ALL+0)
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#define SCREEN_WELLDONE (LEVELS_ALL+1)
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//total number of moving characters on the screen
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#define PLAYER_MAX 4
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//sound effect numbers, it is easier to use meaningful defines than
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//remember actual numbers of the effects
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#define SFX_START 0
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#define SFX_ITEM 1
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#define SFX_RESPAWN1 2
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#define SFX_RESPAWN2 3
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//sub songs numbers in the music.ftm
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#define MUSIC_LEVEL 0
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#define MUSIC_GAME 1
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#define MUSIC_CLEAR 2
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#define MUSIC_GAME_OVER 3
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#define MUSIC_WELL_DONE 4
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#define MUSIC_LOSE 5
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//palettes data
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//all the palettes are designed in NES Screen Tool, then copy/pasted here
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//with Palettes/Put C data to clipboard function
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/*{pal:"nes",layout:"nes"}*/
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const unsigned char palGame1[16]={ 0x0f,0x11,0x32,0x30,0x0f,0x1c,0x2c,0x3c,0x0f,0x09,0x27,0x38,0x0f,0x11,0x21,0x31 };
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/*{pal:"nes",layout:"nes"}*/
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const unsigned char palGame2[16]={ 0x0f,0x11,0x32,0x30,0x0f,0x11,0x21,0x31,0x0f,0x07,0x27,0x38,0x0f,0x13,0x23,0x33 };
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/*{pal:"nes",layout:"nes"}*/
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const unsigned char palGame3[16]={ 0x0f,0x11,0x32,0x30,0x0f,0x15,0x25,0x35,0x0f,0x05,0x27,0x38,0x0f,0x13,0x23,0x33 };
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/*{pal:"nes",layout:"nes"}*/
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const unsigned char palGame4[16]={ 0x0f,0x11,0x32,0x30,0x0f,0x19,0x29,0x39,0x0f,0x0b,0x27,0x38,0x0f,0x17,0x27,0x37 };
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/*{pal:"nes",layout:"nes"}*/
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const unsigned char palGame5[16]={ 0x0f,0x11,0x32,0x30,0x0f,0x16,0x26,0x36,0x0f,0x07,0x27,0x38,0x0f,0x18,0x28,0x38 };
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/*{pal:"nes",layout:"nes"}*/
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const unsigned char palGameSpr[16]={ 0x0f,0x0f,0x29,0x30,0x0f,0x0f,0x26,0x30,0x0f,0x0f,0x24,0x30,0x0f,0x0f,0x21,0x30 };
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/*{pal:"nes",layout:"nes"}*/
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const unsigned char palTitle[16]={ 0x0f,0x0f,0x0f,0x0f,0x0f,0x1c,0x2c,0x3c,0x0f,0x12,0x22,0x32,0x0f,0x14,0x24,0x34 };
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//metasprites
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const unsigned char sprPlayer[]={
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0,-1,0x49,0,
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8,-1,0x4a,0,
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0, 7,0x4b,0,
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8, 7,0x4c,0,
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128
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};
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const unsigned char sprEnemy1[]={
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0,-1,0x4d,1,
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8,-1,0x4e,1,
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0, 7,0x4f,1,
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8, 7,0x50,1,
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128
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};
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const unsigned char sprEnemy2[]={
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0,-1,0x4d,2,
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8,-1,0x4e,2,
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0, 7,0x4f,2,
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8, 7,0x50,2,
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128
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};
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const unsigned char sprEnemy3[]={
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0,-1,0x4d,3,
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8,-1,0x4e,3,
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0, 7,0x4f,3,
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8, 7,0x50,3,
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128
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};
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//list of metasprites
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const unsigned char* const sprListPlayer[]={ sprPlayer,sprEnemy1,sprEnemy2,sprEnemy3 };
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//list of the levels, include pointer to the packed nametable of the level,
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//and pointer to the associated palette
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const unsigned char* const levelList[LEVELS_ALL*2]={
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level1_nam,palGame1,
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level2_nam,palGame2,
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level3_nam,palGame3,
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level4_nam,palGame3,
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level5_nam,palGame3
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};
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//preinitialized update list used during the gameplay
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const unsigned char updateListData[]={
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0x28,0x00,TILE_EMPTY, //these four entries are used to clear
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0x28,0x00,TILE_EMPTY, //the level tile after an item is collected
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0x28,0x00,TILE_EMPTY,
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0x28,0x00,TILE_EMPTY,
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0x20,0x4f,0x10, //these three entires are used to display
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0x20,0x50,0x10, //number of the collected items
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0x20,0x51,0x10,
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NT_UPD_EOF
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};
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//a nametable string with the game stats, created in NES Screen Tool
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//and copy/pasted here with Shift+C
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const unsigned char statsStr[27]={
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0x2c,0x25,0x36,0x25,0x2c,0x1a,0x00,0x00,0x27,
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0x25,0x2d,0x33,0x1a,0x00,0x00,0x00,0x0f,0x00,
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0x00,0x00,0x00,0x2c,0x29,0x36,0x25,0x33,0x1a
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};
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//list of screens such as level number, game over, and well done
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//contains pointers to the packed nametables
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const unsigned char* screenList[3]={ level_nam,gameover_nam,welldone_nam };
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//list of sub songs for corresponding screens
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const unsigned char screenMusicList[3]={MUSIC_LEVEL,MUSIC_GAME_OVER,MUSIC_WELL_DONE};
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//large 1-5 numbers nametable definitons, 2x3 tiles each
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//numbers were drawn one next to the other in NES Screen Tool,
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//then that part of nametable was copy/pasted here with Shift+C
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//here they are orderded as
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// top row of 11 22 33 44 55
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//middle row of 11 22 33 44 55
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//bottom row of 11 22 33 44 55
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const unsigned char largeNums[10*3]={
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0x7a,0x7b,0x7c,0x7d,0x7c,0x7d,0x7e,0x7f,0x80,0x81,
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0x86,0x7b,0x87,0x88,0x89,0x8a,0x8b,0x8c,0x8d,0x7d,
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0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x7f,0x94,0x95
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};
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//array for game map, contains walls, empty spaces, and items
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static unsigned char map[MAP_WDT*MAP_HGT];
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//put all the subsequent global vars into zeropage, to make code faster and shorter
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#pragma bss-name(push,"ZEROPAGE")
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#pragma data-name(push,"ZEROPAGE")
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//set of general purpose global vars that are used everywhere in the program
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//this makes code faster and shorter, although not very convinent and readable
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static unsigned char i,j;
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static unsigned char ptr,spr;
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static unsigned char px,py;
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static unsigned char wait;
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static unsigned int i16;
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static int iy,dy;
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//this array is used to determine movement directions for enemies
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static unsigned char dir[4];
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//this array is used to convert nametable into game map, row by row
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static unsigned char nameRow[32];
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//number of moving characters on current level
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static unsigned char player_all;
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//character variables
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static unsigned int player_x [PLAYER_MAX];
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static unsigned int player_y [PLAYER_MAX];
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static unsigned char player_dir [PLAYER_MAX];
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static int player_cnt [PLAYER_MAX];
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static unsigned int player_speed[PLAYER_MAX];
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static unsigned char player_wait [PLAYER_MAX];
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//number of items on current level, total and collected
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static unsigned char items_count;
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static unsigned char items_collected;
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//game state variables
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static unsigned char game_level;
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static unsigned char game_lives;
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//game state flags, they are 0 or 1
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static unsigned char game_done;
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static unsigned char game_paused;
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static unsigned char game_clear;
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//system vars used everywhere as well
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static unsigned char frame_cnt;
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static unsigned char bright;
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//update list
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static unsigned char update_list[7*3+1];
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//smoothly fade current bright to the given value
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//in case when to=0 it also stops the music,
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//turns the display off, reset vram update and scroll
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void pal_fade_to(unsigned to)
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{
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if(!to) music_stop();
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while(bright!=to)
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{
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delay(4);
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if(bright<to) ++bright; else --bright;
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pal_bright(bright);
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}
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if(!bright)
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{
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ppu_off();
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set_vram_update(NULL);
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scroll(0,0);
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}
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}
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//show title screen
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void title_screen(void)
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{
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scroll(-8,240);//title is aligned to the color attributes, so shift it a bit to the right
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vram_adr(NAMETABLE_A);
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vram_unrle(title_nam);
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vram_adr(NAMETABLE_C);//clear second nametable, as it is visible in the jumping effect
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vram_fill(0,1024);
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pal_bg(palTitle);
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pal_bright(4);
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ppu_on_bg();
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delay(20);//delay just to make it look better
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iy=240<<FP_BITS;
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dy=-8<<FP_BITS;
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frame_cnt=0;
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wait=160;
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bright=4;
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while(1)
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{
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ppu_wait_frame();
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scroll(-8,iy>>FP_BITS);
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if(pad_trigger(0)&PAD_START) break;
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iy+=dy;
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if(iy<0)
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{
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iy=0;
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dy=-dy>>1;
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}
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if(dy>(-8<<FP_BITS)) dy-=2;
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if(wait)
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{
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--wait;
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}
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else
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{
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pal_col(2,(frame_cnt&32)?0x0f:0x20);//blinking press start text
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++frame_cnt;
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}
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}
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scroll(-8,0);//if start is pressed, show the title at whole
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sfx_play(SFX_START,0);
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for(i=0;i<16;++i)//and blink the text faster
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{
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pal_col(2,i&1?0x0f:0x20);
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delay(4);
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}
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pal_fade_to(0);
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}
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//show level intro, game over, or well done screen
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void show_screen(unsigned char num)
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{
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scroll(-4,0); //all the screens are misaligneg horizontally by half of a tile
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if(num<LEVELS_ALL) spr=0; else spr=num-LEVELS_ALL+1;//get offset in the screens list
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vram_adr(NAMETABLE_A);
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vram_unrle(screenList[spr]);
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if(!spr)//if it is the level screen, print large number
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{
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j=num<<1;
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i16=0x2194;//position of the number in the nametable
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for(i=0;i<3;++i)
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{
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vram_adr(i16);
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vram_put(largeNums[j]);
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vram_put(largeNums[j+1]);
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j+=10;
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i16+=32;
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}
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}
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i16=(num==SCREEN_GAMEOVER)?0x1525:0x1121;//two colors for flashing text in LSB and MSB
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frame_cnt=0;
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pal_col(2,i16&0xff);//this palette entry is used for flashing text
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pal_col(3,0x30);
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pal_col(6,0x30);
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ppu_on_bg();
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pal_fade_to(4);
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music_play(screenMusicList[spr]);
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if(!spr)//if it is the level screen, just wait one second
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{
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delay(50);
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}
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else//otherwise wait for Start button and display flashing text
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{
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while(1)
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{
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ppu_wait_frame();
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pal_col(2,frame_cnt&2?i16&0xff:i16>>8);
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if(pad_trigger(0)&PAD_START) break;
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++frame_cnt;
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}
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}
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pal_fade_to(0);
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}
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//set up a move in the specified direction if there is no wall
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void player_move(unsigned char id,unsigned char dir)
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{
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px=player_x[id]>>(TILE_SIZE_BIT+FP_BITS);
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py=player_y[id]>>(TILE_SIZE_BIT+FP_BITS);
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switch(dir)
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{
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case DIR_LEFT: --px; break;
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case DIR_RIGHT: ++px; break;
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case DIR_UP: --py; break;
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case DIR_DOWN: ++py; break;
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}
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if(map[MAP_ADR(px,py)]==TILE_WALL) return;
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player_cnt[id]=TILE_SIZE<<FP_BITS;
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player_dir[id]=dir;
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}
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//print a 1-3 digit decimal number into VRAM
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void put_num(unsigned int adr,unsigned int num,unsigned char len)
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{
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vram_adr(adr);
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if(len>2) vram_put(0x10+num/100);
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if(len>1) vram_put(0x10+num/10%10);
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vram_put(0x10+num%10);
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}
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//the main gameplay code
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void game_loop(void)
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{
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oam_clear();
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i=game_level<<1;
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vram_adr(NAMETABLE_A);
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vram_unrle(levelList[i]); //unpack level nametable
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vram_adr(NAMETABLE_A+0x0042);
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vram_write((unsigned char*)statsStr,27); //add game stats string
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pal_bg(levelList[i+1]); //set up background palette
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pal_spr(palGameSpr); //set up sprites palette
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player_all=0;
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items_count=0;
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items_collected=0;
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//this loop reads the level nametable back from VRAM, row by row,
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//constructs game map, removes spawn points from the nametable,
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//and writes back to the VRAM
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i16=NAMETABLE_A+0x0080;
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ptr=0;
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wait=0;
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for(i=2;i<MAP_HGT+2;++i)
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{
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vram_adr(i16);
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vram_read(nameRow,32);
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vram_adr(i16);
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for(j=0;j<MAP_WDT<<1;j+=2)
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{
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spr=nameRow[j];
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switch(spr)
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{
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case TILE_PLAYER://player
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case TILE_ENEMY1://enemies
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case TILE_ENEMY2:
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case TILE_ENEMY3:
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player_dir [player_all]=DIR_NONE;
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player_x [player_all]=(j<<3)<<FP_BITS;
|
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player_y [player_all]=(i<<4)<<FP_BITS;
|
|
player_cnt [player_all]=0;
|
|
player_wait [player_all]=16+((spr-TILE_PLAYER)<<4);
|
|
player_speed[player_all]=(spr==TILE_PLAYER)?2<<FP_BITS:10+((spr-TILE_ENEMY1)<<1);
|
|
++player_all;
|
|
wait+=16;
|
|
spr=TILE_EMPTY;
|
|
break;
|
|
|
|
case TILE_ITEM:
|
|
++items_count;
|
|
break;
|
|
}
|
|
|
|
map[ptr++]=spr;
|
|
|
|
vram_put(spr);
|
|
vram_put(nameRow[j+1]);
|
|
}
|
|
|
|
i16+=64;
|
|
}
|
|
|
|
//setup update list
|
|
|
|
memcpy(update_list,updateListData,sizeof(updateListData));
|
|
|
|
set_vram_update(update_list);
|
|
|
|
//put constant game stats numbers, that aren't updated during level
|
|
|
|
put_num(NAMETABLE_A+0x0048,game_level+1,1);
|
|
put_num(NAMETABLE_A+0x0053,items_count,3);
|
|
put_num(NAMETABLE_A+0x005d,game_lives-1,1);
|
|
|
|
//enable display
|
|
|
|
ppu_on_all();
|
|
|
|
game_done=FALSE;
|
|
game_paused=FALSE;
|
|
game_clear=FALSE;
|
|
|
|
bright=0;
|
|
frame_cnt=0;
|
|
|
|
while(!game_done)
|
|
{
|
|
//construct OAM from object parameters
|
|
|
|
spr=(player_all-1)<<4;
|
|
|
|
for(i=0;i<player_all;++i)
|
|
{
|
|
py=player_y[i]>>FP_BITS;
|
|
|
|
if(player_wait[i])
|
|
{
|
|
if(player_wait[i]>=16||player_wait[i]&2) py=240;
|
|
}
|
|
|
|
oam_meta_spr(player_x[i]>>FP_BITS,py,spr,sprListPlayer[i]);
|
|
spr-=16;
|
|
}
|
|
|
|
//wait for next frame
|
|
//it is here and not at beginning of the loop because you need
|
|
//to update OAM for the very first frame, and you also need to do that
|
|
//right after object parameters were changed, so either OAM update should
|
|
//be in a function that called before the loop and at the end of the loop,
|
|
//or wait for NMI should be placed there
|
|
//otherwise you would have situation update-wait-display, i.e.
|
|
//one frame delay between action and display of its result
|
|
|
|
ppu_wait_frame();
|
|
|
|
++frame_cnt;
|
|
|
|
//slowly fade virtual brightness to needed value,
|
|
//which is max for gameplay or half for pause
|
|
|
|
if(!(frame_cnt&3))
|
|
{
|
|
if(!game_paused&&bright<4) ++bright;
|
|
if( game_paused&&bright>2) --bright;
|
|
|
|
pal_bright(bright);
|
|
}
|
|
|
|
//poll the gamepad in the trigger mode
|
|
|
|
i=pad_trigger(0);
|
|
|
|
//it start was released and then pressed, toggle pause mode
|
|
|
|
if(i&PAD_START)
|
|
{
|
|
game_paused^=TRUE;
|
|
music_pause(game_paused);
|
|
}
|
|
|
|
//don't process anything in pause mode, just display latest game state
|
|
|
|
if(game_paused) continue;
|
|
|
|
//CHR bank switching animation with different speed for background and sprites
|
|
|
|
bank_bg((frame_cnt>>4)&1);
|
|
bank_spr((frame_cnt>>3)&1);
|
|
|
|
//a counter that does not allow objects to move while spawn animation plays
|
|
|
|
if(wait)
|
|
{
|
|
--wait;
|
|
|
|
if(!wait) music_play(MUSIC_GAME);//start the music when all the objects spawned
|
|
}
|
|
|
|
//check for level completion condition
|
|
|
|
if(items_collected==items_count)
|
|
{
|
|
music_play(MUSIC_CLEAR);
|
|
game_done=TRUE;
|
|
game_clear=TRUE;
|
|
}
|
|
|
|
//process all the objects
|
|
//player and enemies are the same type of object in this game,
|
|
//to make code simpler and shorter, but generally they need to be
|
|
//different kind of objects
|
|
|
|
for(i=0;i<player_all;++i)
|
|
{
|
|
//per-object spawn animation counter, it counts fron N to 16 to 0
|
|
//needed because objects spawn in sequence, not all at once
|
|
|
|
if(player_wait[i])
|
|
{
|
|
if(player_wait[i]==16) sfx_play(i?SFX_RESPAWN2:SFX_RESPAWN1,i);
|
|
--player_wait[i];
|
|
continue;
|
|
}
|
|
|
|
if(wait) continue; //don't process object movements if spawn animation is running
|
|
|
|
//check collision of an enemy object with player object
|
|
//NOT logic is used here, check http://gendev.spritesmind.net/page-collide.html
|
|
|
|
if(i)
|
|
{
|
|
if(!((player_x[i]+(4 <<FP_BITS))>=(player_x[0]+(12<<FP_BITS))||
|
|
(player_x[i]+(12<<FP_BITS))< (player_x[0]+(4 <<FP_BITS))||
|
|
(player_y[i]+(4 <<FP_BITS))>=(player_y[0]+(12<<FP_BITS))||
|
|
(player_y[i]+(12<<FP_BITS))< (player_y[0]+(4 <<FP_BITS))))
|
|
{
|
|
//if an enemy touch the player, quit the game loop
|
|
|
|
if(!game_clear)
|
|
{
|
|
music_play(MUSIC_LOSE);
|
|
game_done=TRUE;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
//if movement counter is not zero, process the movement
|
|
|
|
if(player_cnt[i])
|
|
{
|
|
switch(player_dir[i])
|
|
{
|
|
case DIR_RIGHT: player_x[i]+=player_speed[i]; break;
|
|
case DIR_LEFT: player_x[i]-=player_speed[i]; break;
|
|
case DIR_DOWN: player_y[i]+=player_speed[i]; break;
|
|
case DIR_UP: player_y[i]-=player_speed[i]; break;
|
|
}
|
|
|
|
player_cnt[i]-=player_speed[i];
|
|
|
|
//if move from one tile to another is over, realign the object to tile grid
|
|
//it is needed because when it moves with non-integer speed, it could
|
|
//overrun the destination tile a little bit, and thus can't take a turn properly
|
|
|
|
if(player_cnt[i]<=0)
|
|
{
|
|
if(player_cnt[i]<0) //overrun
|
|
{
|
|
player_cnt[i]=0;
|
|
|
|
//0xff is a coordinate mask that leaves only integer tile offeset
|
|
//it is 8:4:4 here, where 8 is integer tile coordinate,
|
|
//first 4 is offset in the tile, which is 16 pixels wide,
|
|
//and second 4 is fixed point resolution
|
|
|
|
player_x[i]=(player_x[i]&0xff00)+(player_dir[i]==DIR_LEFT?0x100:0);
|
|
player_y[i]=(player_y[i]&0xff00)+(player_dir[i]==DIR_UP ?0x100:0);
|
|
}
|
|
|
|
//it is is the player object, check if there is an item in the new tile
|
|
if(!i)
|
|
{
|
|
i16=MAP_ADR((player_x[i]>>(TILE_SIZE_BIT+FP_BITS)),
|
|
(player_y[i]>>(TILE_SIZE_BIT+FP_BITS)));
|
|
|
|
if(map[i16]==TILE_ITEM)
|
|
{
|
|
map[i16]=TILE_EMPTY; //mark as collected in the game map
|
|
|
|
sfx_play(SFX_ITEM,2);
|
|
++items_collected;
|
|
|
|
//get address of the tile in the nametable
|
|
|
|
i16=NAMETABLE_A+0x0080+(((player_y[i]>>(TILE_SIZE_BIT+FP_BITS))-2)<<6)|
|
|
((player_x[i]>>(TILE_SIZE_BIT+FP_BITS))<<1);
|
|
|
|
//replace it with empty tile through the update list
|
|
|
|
update_list[0]=i16>>8;
|
|
update_list[1]=i16&255;
|
|
update_list[3]=update_list[0];
|
|
update_list[4]=update_list[1]+1;
|
|
i16+=32;
|
|
update_list[6]=i16>>8;
|
|
update_list[7]=i16&255;
|
|
update_list[9]=update_list[6];
|
|
update_list[10]=update_list[7]+1;
|
|
|
|
//update number of collected items in the game stats
|
|
|
|
update_list[14]=0x10+items_collected/100;
|
|
update_list[17]=0x10+items_collected/10%10;
|
|
update_list[20]=0x10+items_collected%10;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if(!player_cnt[i]) //movement to the next tile is done, set up new movement
|
|
{
|
|
if(!i) //this is the player, process controls
|
|
{
|
|
//get gamepad state, it was previously polled with pad_trigger
|
|
|
|
j=pad_state(0);
|
|
|
|
//this is a tricky part to make controls more predictable
|
|
//when you press two directions at once, sliding by a wall
|
|
//to take turn into a passage on the side
|
|
//this piece of code gives current direction lower priority
|
|
//through testing it first
|
|
//bits in player_dir var are matching to the buttons bits
|
|
|
|
if(j&player_dir[0])
|
|
{
|
|
j&=~player_dir[0]; //remove the direction from further check
|
|
player_move(i,player_dir[0]); //change the direction
|
|
}
|
|
|
|
//now continue control processing as usual
|
|
|
|
if(j&PAD_LEFT) player_move(i,DIR_LEFT);
|
|
if(j&PAD_RIGHT) player_move(i,DIR_RIGHT);
|
|
if(j&PAD_UP) player_move(i,DIR_UP);
|
|
if(j&PAD_DOWN) player_move(i,DIR_DOWN);
|
|
}
|
|
else //this is an enemy, run AI
|
|
{
|
|
//the AI is very simple
|
|
//first we create list of all directions that are possible to take
|
|
//excluding the direction that is opposite to previous one
|
|
|
|
i16=MAP_ADR((player_x[i]>>8),(player_y[i]>>8));
|
|
ptr=player_dir[i];
|
|
j=0;
|
|
|
|
if(ptr!=DIR_RIGHT&&map[i16-1]!=TILE_WALL) dir[j++]=DIR_LEFT;
|
|
if(ptr!=DIR_LEFT &&map[i16+1]!=TILE_WALL) dir[j++]=DIR_RIGHT;
|
|
if(ptr!=DIR_DOWN &&map[i16-MAP_WDT]!=TILE_WALL) dir[j++]=DIR_UP;
|
|
if(ptr!=DIR_UP &&map[i16+MAP_WDT]!=TILE_WALL) dir[j++]=DIR_DOWN;
|
|
|
|
//randomly select a possible direction
|
|
|
|
player_move(i,dir[rand8()%j]);
|
|
|
|
//if there was more than one possible direction,
|
|
//i.e. it is a branch and not a corridor,
|
|
//attempt to move towards the player
|
|
|
|
if(j>1)
|
|
{
|
|
if(ptr!=DIR_DOWN &&player_y[0]<player_y[i]) player_move(i,DIR_UP);
|
|
if(ptr!=DIR_UP &&player_y[0]>player_y[i]) player_move(i,DIR_DOWN);
|
|
if(ptr!=DIR_RIGHT&&player_x[0]<player_x[i]) player_move(i,DIR_LEFT);
|
|
if(ptr!=DIR_LEFT &&player_x[0]>player_x[i]) player_move(i,DIR_RIGHT);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
delay(100);
|
|
pal_fade_to(0);
|
|
}
|
|
|
|
|
|
|
|
//this is where the program starts
|
|
extern const void sound_data[];
|
|
extern const void music_data[];
|
|
|
|
void main(void)
|
|
{
|
|
famitone_init(&music_data);
|
|
sfx_init(&sound_data);
|
|
nmi_set_callback(famitone_update);
|
|
|
|
while(1)//infinite loop, title-gameplay
|
|
{
|
|
title_screen();
|
|
|
|
game_level=0;
|
|
game_lives=4;
|
|
|
|
while(game_lives&&game_level<LEVELS_ALL)//loop for gameplay
|
|
{
|
|
show_screen(game_level);
|
|
|
|
game_loop();
|
|
|
|
if(game_clear) ++game_level; else --game_lives;
|
|
}
|
|
|
|
show_screen(!game_lives?SCREEN_GAMEOVER:SCREEN_WELLDONE);//show game results
|
|
}
|
|
} |