MapGenerator.js

function convert2Dto1D(x, y, size){
    return (y * size) + x;
}

class MapGenerator {


    constructor() {
        this.size = 21;
    }

    //// 2 dimension coordinates to 1 dimension


    generateMap(id, scene) {
        var map;
        
        var walls = [];

        var map_content = [];
        let playerSpawnX = 0, playerSpawnY=0;

        // create ground 
        var geometry = new THREE.PlaneGeometry( this.size, this.size );
        var material = new THREE.MeshBasicMaterial( {color: 0x000000, side: THREE.DoubleSide} );
        var plane = new THREE.Mesh( geometry, material );
        scene.add(plane);
        plane.position.z -= 0.5;

        // send http request
        fetch("/get/map/"+id+"/", { headers: { "Content-Type": "text/plain; charset=utf-8" }})
            .then(res => res.json()) // parse response as JSON
            .then(response => {

                // copy response to array
                for (let i = 0; i < this.size*this.size; i++) {
                    map_content.push(response[i]);
                }

                // loop through map content in 2 dimension to prepare to position walls in ground
                let i = 0;
                let offsetX, offsetY, wallWidth, wallHeight, wallPosX, wallPosY;
                for (let y = 0; y < this.size; y++) {
                    for (let x = 0; x < this.size; x++) {
                        i = convert2Dto1D(x,y,this.size);
                        
                        switch (map_content[i]){ // 
                            case "WALL":
                                offsetX = 1;
                                offsetY = 1;
                                wallWidth = 1;
                                wallHeight = 1;
                                wallPosX = x;
                                wallPosY = y;
                            
                                map_content[i] = '' ; //empty the box to prevent from creating 2 walls at the same spot
                                
                                // check for a horizontal line of wall
                                while (map_content[convert2Dto1D(x + offsetX, y,this.size)] == 'WALL' & x + offsetX < this.size){
                                    map_content[convert2Dto1D(x + offsetX, y,this.size)] = '';
                                    wallWidth++;
                                    offsetX++;
                                }

                                //check for a vertical line of wall only if it was not a horizonatl wall
                                while (wallWidth <= 1 & map_content[convert2Dto1D(x, y + offsetY,this.size)] == 'WALL' & y + offsetY < this.size){
                                    map_content[convert2Dto1D(x, y + offsetY,this.size)] = ''
                                    wallHeight++;
                                    offsetY++;
                                }

                                //create wall object
                                var geometry = new THREE.BoxGeometry( wallWidth, wallHeight ,0.6);
                                var material = new THREE.MeshBasicMaterial( {color: 0x0000FF} );
                                var wall = new THREE.Mesh( geometry, material );
                                // re-position coreectly
                                wall.position.x = wallPosX - (this.size)/2 + wallWidth/2;
                                wall.position.y = wallPosY - (this.size)/2 + wallHeight /2;
                                // add to scene
                                scene.add(wall);
                                walls.push(wall);
                                break;

                            case "FOOD":
                                break;

                            case "S_FOOD":
                                break;

                            case "FOOD":
                                break;

                            case "SPAWN_P":
                                playerSpawnX = x;
                                playerSpawnY = y;
                                break;

                        }
                    }
                }
                
            })
            .catch(err => {
                alert(err);
            });      
        
        return [plane, walls, [playerSpawnX, playerSpawnY]];
    }
}