From 5d5bc3e446ee50601f98ca30d4f21172d6e75e29 Mon Sep 17 00:00:00 2001 From: Silvan Jegen Date: Sat, 22 Sep 2018 20:01:40 +0200 Subject: Initial commit --- level.c | 236 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 236 insertions(+) create mode 100644 level.c (limited to 'level.c') diff --git a/level.c b/level.c new file mode 100644 index 0000000..bfa3ec1 --- /dev/null +++ b/level.c @@ -0,0 +1,236 @@ +/* + * Each of the different types of tile in the levels are numbered + * These are also the values used in the level text files + * + * All of the level tiles are stored in one image, hence the 'Rows' + * below are literally the rows there are positioned in the image. + * Have a look at tiles.png in the game's folder to see them all. + */ + +// Row 1 - main squares +#define T_WALL 0 +#define T_FLOOR 1 +#define T_SPIKE 2 +#define T_EXIT 3 +// Row two - blue button related +#define T_BLUE_BUTT_UP 4 // unpressed button +#define T_BLUE_BUTT_DOWN 5 // depressed button +#define T_BLUE_DOOR_UP 6 // door unlocked by a button +#define T_BLUE_DOOR_DOWN 7 // door locked and impassible +// Row three - yellow button related +#define T_YELL_BUTT_UP 8 +#define T_YELL_BUTT_DOWN 9 +#define T_YELL_DOOR_UP 10 +#define T_YELL_DOOR_DOWN 11 +// Row four - red lever/switch related +#define T_RED_SWITCH_ON 12 +#define T_RED_SWITCH_OFF 13 +#define T_RED_DOOR_UP 14 +#define T_RED_DOOR_DOWN 15 + +// An echidna is one of the monsters +// The structure is define here in level.c so it can be loaded from the level files +struct echidna +{ + int xpos, ypos; // Position on map + int face; // Which of the echidna pictures to use + + int mode; // As described at the top of the document + + int this_echidna_exists; // When this is equal to 1, the echidna is alive and on the level + + // These movement directions are used in the AI code + signed int move_x; + signed int move_y; + // ditto here + signed int check_x; + signed int check_y; + +}; + +/* The level structure is passed to the rendering module, so everything that needs to be seen + * on-screen is also stored here as well + * + * Eg: + * - player position + * - resource locations ( graphics ) + */ +struct level_struct +{ + + char squares[SCREEN_WIDTH_SQUARES][SCREEN_HEIGHT_SQUARES]; // Squares of the level + + // Player details + int player_face; // Picture number ( player has 4 different looks ) + int px, py; // Player X and Y position, on the tiles + int sx, sy; // Player X and Y starting positions + + // Resources + SDL_Surface * surf_entities; // Player and echidna pictures + SDL_Surface * surf_tiles; // Level tiles/squares + + // A various selection of losing screens + SDL_Surface * surf_losingscreens[5]; + + // The screen to display when the game ends + SDL_Surface * surf_winning_screen; + + // Up to ten echidnas + struct echidna echidnas[10]; + +}; + + + +/* eat_until_newline will 'eat' one character at a time from a file until it detects it has + * finished a line, then stops. This is used to make sure a line of text in the level files + * has been finished before we move on to the next */ +void eat_until_newline( FILE *currentfile ) +{ + char letter='a'; + while ( letter != '\n' ) // The '\n' represents the invisible line ending characters (either CRLF or LF) + { + // Every time a character is read, the current position inside of the file is also moved forward + // one character + letter = fgetc( currentfile ); + } +} + + + +// Load the graphics used in levels +void level_load_resources( struct level_struct *level ) +{ + // Load the images for things into their own 'surfaces' + level->surf_entities = IMG_Load( "entities.png" ); + level->surf_tiles = IMG_Load( "tiles.png" ); + + // Do the same for the losing screens + level->surf_losingscreens[0] = IMG_Load("failscreen_01.png"); + level->surf_winning_screen = IMG_Load("winningscreen.png"); + +} + + + +// level_load will load a level from a text file into a level_struct +void level_load( int level_number, struct level_struct *level ) +{ + + // Create the level's actual filename from its number + char levelname[20]; + sprintf( levelname, "level_%02d.level", level_number ); + + // Attempt to open the file + FILE *levelfile = fopen( levelname, "r"); // r = reading mode + + + // Check if the file loaded, quit program if this has failed + if ( levelfile == NULL ) + { + // For some reason the file cannot be accessed + // This could be because it does not exist or we don't have permission to open it + + fprintf(stderr, "Error: Could not open level file %d, perhaps it is somewhere else or does not exist?\n", level_number ); + fprintf(stderr, "Exiting... \n\n" ); + + exit(1); + } + + // First we need to skip the first line of the file, which is dedicated to title, author etc information + eat_until_newline( levelfile ); + + // The second line contains the starting position of the player + fscanf( levelfile, "%d %d", &level->sx, &level->sy ); + eat_until_newline(levelfile); + + printf("Loading level %s, player at position: %d %d\n", levelname, level->sx, level->sy ); + + /* Ieterate through the file and load the squares into the level's structure + * Each row/line in the file represents a row of squares in the level + * Each square is represented in the rows by a number from 0 to 255 + * Open up one of the level files with a text editor to study its structure further + */ + + /* WARNING: This code assumes the file is structured correctly in the first place! + * The game will behave in an unexpected manner if the level files are not perfect! + */ + + int row, column; // Current position + + for ( row=0; row < SCREEN_HEIGHT_SQUARES; row++ ) + { + for ( column=0; column < SCREEN_WIDTH_SQUARES; column++ ) + { + /* we read each two letter number into a three letter character array ( string ) + * the third character is used to represent the end or 'termination' of the string + */ + char tempstring[3]; + fgets( tempstring, 3, levelfile ); + + // atoi() is a standard C function used to covert a string of numbers in character + // form into an actual number ( integer ) + level->squares[column][row] = atoi( tempstring ); + } + + // We need to make sure that we finish the current line of numbers/characters in the + // level file, and are up to the next, else bad things may happen + eat_until_newline( levelfile ); + } + + /* Now start loading the echidna positions + * Every line after the main level tile body is an echidna + * The format for each line is: + * xpos ypos face + * Where each of them is a number, face being a number from 0 to 3 choosing the particular face of the echidna + */ + + int ech_no; // Echidna number + + for ( ech_no = 0; ech_no < 10; ech_no++ ) + { + level->echidnas[ech_no].this_echidna_exists = 0; + level->echidnas[ech_no].mode = 1; // Start in hunt mode + + // Now load the echidna values in + if ( fscanf( levelfile, "%d %d %d", &level->echidnas[ech_no].xpos, &level->echidnas[ech_no].ypos, &level->echidnas[ech_no].face ) == 3 ) + { + // When fscanf returns a number other than '3' ( which is how many numbers we are reading per line ) + // we know there are no more lines in the file and we should stop, hence the == 3 + level->echidnas[ech_no].this_echidna_exists = 1; + + printf("Echidna loaded at x:%d y:%d\n", level->echidnas[ech_no].xpos, level->echidnas[ech_no].ypos ); + } + } + + +} + + + +// Replace every tile in the level of firsttype with secondtype +// Useful for eg opening doors +void level_replace_tiles( struct level_struct *currentlevel, char firsttype, char secondtype ) +{ + int tilex, tiley; // Where we are up to + + for ( tiley=0; tiley < SCREEN_WIDTH_SQUARES; tiley++ ) + { + for ( tilex=0; tilex < SCREEN_WIDTH_SQUARES; tilex++ ) + { + if ( currentlevel->squares[tilex][tiley] == firsttype ) currentlevel->squares[tilex][tiley] = secondtype; + } + } +} + + + + + + + + + + + + -- cgit v1.2.1-18-gbd029