diff options
| author | Silvan Jegen <s.jegen@gmail.com> | 2018-09-22 20:01:40 +0200 |
|---|---|---|
| committer | Silvan Jegen <s.jegen@gmail.com> | 2018-09-22 20:05:53 +0200 |
| commit | 5d5bc3e446ee50601f98ca30d4f21172d6e75e29 (patch) | |
| tree | abdbe68d23373c095e2d50b2cd8f15af40dfdb65 /level.c | |
Initial commit
Diffstat (limited to 'level.c')
| -rw-r--r-- | level.c | 236 |
1 files changed, 236 insertions, 0 deletions
@@ -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;
+ }
+ }
+}
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