[C/C++] Frage zu "tile based maps"?

#include <allegro.h>
#include <stdio.h>
#include <ctype.h>
#include <time.h>
#include <stdlib.h>

const int MAP_W = 40;
const int MAP_H = 30;
const int TILE_W = 20;
const int TILE_H = 20;
const int hero_images = 4;

char char2tile[] ="201RLUDP";


void setupMap(char*, int);
void drawTile(char, char, int, int, int);
void drawMap(char*, BITMAP*, BITMAP*);

class mand { //Mandliposition bestimmen
private:
 int x;
 int y;
public:
 void screengroesse(int h) {
 y = h - (h - 13*20);
 x = 0;
 }
 int posx() {return(x);}
 int posy() {return(y);}
};

int main(int argc, char **argv) {

//Klassen deklarieren
mand mandli;


char tileMapStr[MAP_W * MAP_H+1] = 
"1111111111111111111111111111111111111111"
"1PPP000000010000000000000PP10000000PPPP1"
"1PPP0000000100000000000000010000000PPPP1"
"1000000000011110000000000001000000000001"
"1000000000000010000000000001000000000000"
"10000000000000L0000000000001000000000001"
"1000000000000010000000000001000000000001"
"1000000000011110000000000001000000000001"
"1000000000010000000000000001000000000001"
"1000000000010000000000000001000000000001"
"100000000001PP00000000000001000000000001"
"11111D111111111111000000000111111D111111"
"1000000000000000010000000001PP0000000001"
"0000000000000000010000000001P00000000001"
"10000000000000PPP11111U11111000000000001"
"10000000000000PPP10000000001000000000001"
"1111111111111111110000000001000000000001"
"1111111111111111110000000001000000000001"
"1111111111111111110000000001000000000001"
"111111111111111111000000000L000000000001"
"11111111111111111100000000P10000000000P1"
"1111111111111111110000000PP1111111111111"
"111111111111111111000000PPP1111111111111"
"1111111111111111111111111111111111111111"
"1111111111111111111111111111111111111111"
"1111111111111111111111111111111111111111"
"2222222222222222222222222222222222222222"
"2222222222222222222222222222222222222222"
"2222222222222222222222222222222222222222";

allegro_init();
install_keyboard();

set_color_depth(24);
if (set_gfx_mode(GFX_AUTODETECT_WINDOWED,800,600,0,0) < 0) {
 allegro_message("Unable to set graphic mode!");
 exit(0);
}
// Loading Bitamps
BITMAP *tiles = load_bitmap("bausteine2.bmp", NULL);
BITMAP *doublebuffer = create_bitmap(SCREEN_W,SCREEN_H);
BITMAP *herobitmaps[hero_images];

//Loading Hero Bitmaps
char *filename[] = {"hero_up.bmp","hero_down.bmp","hero_left.bmp","hero_right.bmp"};
for(int i = 0; i < hero_images; i++) {
 herobitmaps[i] = load_bitmap(filename[i], NULL);
}
setupMap(tileMapStr, MAP_W*MAP_H);

mandli.screengroesse(SCREEN_H);
int changeimage = 3;
int x = mandli.posx();
int y = mandli.posy();

while(!key[KEY_ESC]) 
{
 if(key[KEY_DOWN]) {
 y+=1;
 changeimage = 1;}
 if(key[KEY_UP]) {
 y-=1;
 changeimage = 0;}
 if(key[KEY_LEFT]) {
 x-=0;
 changeimage = 2;}
 if(key[KEY_RIGHT]) {
 x+=1;
 changeimage = 3;}

 //Level zeichen
 drawMap(tileMapStr, tiles, doublebuffer);
 
 //Mandli zeichnen
 draw_sprite(doublebuffer,herobitmaps[changeimage],x,y);

 //Doublebuffer
 blit(doublebuffer,screen,0,0,0,0,SCREEN_W,SCREEN_H);
}

return(0);

}END_OF_MAIN()

void setupMap(char *map, int size) {
 for (int a=0; a < size; a++) {
 for (int tile=0; char2tile[tile]; ++tile) {
 if (map[a] == char2tile[tile]) {
 map[a] = tile;
 break;
 }
 }
 }
}

void drawTile(BITMAP *dest, BITMAP *tile, int index, int x, int y) {
 blit(tile, dest, index * TILE_W, 0, x, y, TILE_W, TILE_H);
}

void drawMap(char* map, BITMAP *tiles, BITMAP *doublebuffer) {
 int pos = 0;
 for (int y=0; y < MAP_H; ++y) {
 for (int x=0; x < MAP_W; ++x) {
 drawTile(doublebuffer, tiles, map[pos], x*TILE_W, y*TILE_H);
 ++pos;
 }
 }
}