early generation code (possible infinite loop)

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <tice.h>

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <graphx.h>
#include <keypadc.h>
#include <debug.h>

#include "structs.h"

/* Put your function prototypes here */
void mapgen(void);
void genrooms(void);
void randroom(int,int,int,int);
bool placeroom(int,int);
bool doesroomfit(int,int,int,int);
void mazeworm(void);
void drawmap(void);

/* Put all your globals here */
int _x;
int _y;
int offset = 10;
int xmin = 0;
int xmax = 30;
int ymin = 0;
int ymax = 20;
int treecolor = 0x03;
int floorcolor = 0xFF;
int wallcolor = 0xE0;
int min_w = 3;
int min_h = 3;
int max_w=10;
int max_h=10;
int num_rcands;
int room_x;
int room_y;
int room_w;
int room_h;

room_t r[600];

int map[30][20];

void main(void) {
    gfx_Begin();

    mapgen();
    drawmap();

    do {
        kb_Scan();
    } while (!(kb_Data[6] & kb_Clear));

    gfx_End();
}

/* Put other functions here */
void drawmap() {
    gfx_FillScreen(0x00);
    for (_x=xmin;_x<xmax;_x++){
        for (_y=ymin;_y<ymax;_y++){
            if (map[_x][_y] == 1){
                gfx_SetColor(wallcolor);
            }
            else if (map[_x][_y] == 0){
                gfx_SetColor(floorcolor);
            }
            gfx_SetTextXY((_x*8)+offset,(_y*8)+offset);
            gfx_PrintStringXY("o",(_x*8)+offset,(_y*8)+offset);
        }
    }
}

void mapgen() {
    genrooms();
    //mazeworm();
    //placeflags();
}

void genrooms() {
    int fmax=10;
    int rmax=10;
    max_w = 10;
    max_h = 10;
    randroom(min_w,max_w,min_h,max_h);
    do {
        if (placeroom(room_w, room_h)) {
            rmax--;
        }
        else {
            fmax--;
        }
    } while (fmax > 0 || rmax > 0);
}

void randroom(int mn_w,int mx_w,int mn_h,int mx_h) {
    room_w = randInt(mn_w,mx_w);
    room_h = randInt(mn_h,mx_h);
}

bool placeroom(int w,int h) {
    int r_x;
    int r_y;
    int R;
    int rp_x;
    int rp_y;
    int mx;
    int my;
    num_rcands = 0;
    for (r_x=xmin;r_x<(xmax-w);r_x++){
        for (r_y=ymin;r_y<(ymax-h);r_y++){
            if (doesroomfit(r_x,r_y,w,h)) {
                r[num_rcands].x=r_x;
                r[num_rcands].y=r_y;
                r[num_rcands].w=w;
                r[num_rcands].h=h;
                num_rcands++;
            }
        }
    }
    if (num_rcands==0){
        return false;
    }
    R=randInt(0,num_rcands);
    for (rp_x=r[R].x;rp_x<(r[R].x+r[R].w);rp_x++){
        for (rp_y=r[R].y;rp_y<(r[R].y+r[R].h);rp_y++){
            mx=r[R].x;
            my=r[R].y;
            map[mx][my]=0;
        }
    }
    return true;
}

bool doesroomfit(int x,int y,int w,int h) {
    int r_x;
    int r_y;
    for (r_x=(x-1);r_x<x+(w+1);r_x++){
        for (r_y=(y-1);r_y<y+(h+1);r_y++){
            if (map[r_x][r_y]==0){
                if (w>=h) {
                    max_w--;
                }
                else {
                    max_h--;
                }
                return false;
            }
        }
    }
    return true;
}