​

nunits = 20;

​

//global constants

let space;

let maze;

let rightborder, downboarder;

let rows, columns;

let heroRow,heroCol,heroDir;

​

// utility functions

​

function initArray(rows, columns, value){

  //create a dynamic array of size rows x columns and fill it with values

  let a = new Array(rows);

  for (var i=0;i<a.length;i++){

    a[i] = new Array(columns);

    for (var j=0;j<a[i].length;j++){

      a[i][j] = value;

    }

  }

  return a

}

​

function rand(maxval){

  return ~~(Math.random()*maxval);

}

​

// maze generation

function generateMaze(){

  i = rand(rows);

  j = rand(columns);

  visited = initArray(rows,columns,0);

  mazeiter(i,j,visited);

}

​

function mazeiter(r,c,visited){

  visited[r][c] = 1;

  while (true){

    neighbours = [];

    if (r>0){

      if (visited[r-1][c]==0){

        neighbours[neighbours.length] = [r-1,c];

      }

    }

    if (c>0){

      if (visited[r][c-1]==0){

        neighbours[neighbours.length] = [r,c-1];

      }

    }

    if (r<rows-1){

      if (visited[r+1][c]==0){

        neighbours[neighbours.length] = [r+1,c];

      }

    }

    if (c<columns-1){

      if (visited[r][c+1]==0){

        neighbours[neighbours.length] = [r,c+1];

      }

    }

    if (neighbours.length>0){

      index = rand(neighbours.length);

      [nr,nc] = neighbours[index];

      if (r==nr){

        rightborder[r][min(c,nc)] = 0;

      }

      if (c==nc){

        downborder[min(r,nr)][c] = 0;

      }

      mazeiter(nr,nc,visited);

    }

    else {

      break;

    }

  }

}

​

// drawing functions

function topleftpoint(row, col){

  return [col*space,row*space]

}

function toprightpoint(row, col){

  return [(col+1)*space, row*space]

}

function bottomleftpoint(row, col){

  return [col*space, (row+1)*space]

}

function bottomrightpoint(row, col){

  return [(col+1)*space, (row+1)*space]

}

function middlepoint(row, col){

  return [col*space + space/2, row*space+space/2]

}

function drawBorder(){

  [x1,y1] = topleftpoint(0,0);

  [x2,y2] = toprightpoint(0,columns-1);

  [x3,y3] = bottomrightpoint(rows-1, columns-1);

  [x4,y4] = bottomleftpoint(rows-1,0)

  strokeWeight(space/4);

  stroke(0,0,255);

  line(x1,y1,x2,y2)

  line(x2,y2,x3,y3)

  line(x3,y3,x4,y4)

  line(x4,y4,x1,y1)

}

function drawMaze(){

  stroke(0);

  strokeWeight(max(space/8,1));

  for (var i=0;i<rows;i++){

    for (var j=0;j<columns;j++){

      if (rightborder[i][j]==1){

        [x1,y1] = toprightpoint(i,j);

        [x2, y2] = bottomrightpoint(i,j);

        line(x1,y1,x2,y2)

      }

      if (downborder[i][j]==1){

        [x1,y1] = bottomleftpoint(i,j);

        [x2,y2] = bottomrightpoint(i,j);

        line(x1,y1,x2,y2);

      }

    }

  }

​

}

function drawHero(){

  // directions 0: top 1: bottom 2: left 3: right

  [x,y] = middlepoint(heroRow,heroCol);

  stroke(0);

  strokeWeight(max(space/20,1));

  fill(70,100,170)

  if (heroDir==0){

    x1 = x-space/8;

    x2 = x+space/8;

    y1 = y-space/2.5;

    y2 = y-space/2.5;

  }

  if (heroDir==1){

    x1 = x-space/8;

    x2 = x+space/8;

    y1 = y+space/2.5;

    y2 = y+space/2.5;

  }

  if (heroDir==2){

    x1 = x-space/2.5;

    x2 = x-space/2.5;

    y1 = y-space/8;

    y2 = y+space/8;

  }

  if (heroDir==3){

    x1 = x+space/2.5;

    x2 = x+space/2.5;

    y1 = y-space/8;

    y2 = y+space/8;

  }

  triangle(x,y,x1,y1, x2,y2);

  fill(200,120,10)

  circle(x,y,space/2.5)

}

​

// game functions

function heroGoLeft(){

  heroDir = 2;

  if (heroCol>0){

    if (rightborder[heroRow][heroCol-1]==0){

      heroCol = heroCol-1;

    }

  }

}

​

function heroGoRight(){

  heroDir=3;

  if (heroCol<columns-1){

    if (rightborder[heroRow][heroCol]==0){

      heroCol = heroCol+1;

    }

  }

}

​

function heroGoUp(){

  heroDir=0;

  if (heroRow>0){

    if (downborder[heroRow-1][heroCol]==0){

      heroRow = heroRow-1;

    }

  }

}

​

function heroGoDown(){

  heroDir=1;

  if (heroRow<rows-1){

    if (downborder[heroRow][heroCol]==0){

      heroRow = heroRow+1;

    }

  }

}

​

//pygame functions

function setup() {

  createCanvas(windowWidth, windowHeight);

  // determine maze constants

  var dimension = min(windowWidth, windowHeight);

  space = dimension/nunits;

  // rows go vertically and columns go horizontally

  rows = ~~(windowHeight/space);

  columns =  ~~(windowWidth/space);

  maze = initArray(rows, columns, 0);

  rightborder = initArray(rows, columns, 1);

  downborder = initArray(rows, columns, 1);

  generateMaze();

  heroRow = rand(rows);

  heroCol = rand(columns);

  heroDir = 0;

}

​

function draw() {

  background(220);

  drawMaze();

  drawBorder();

  drawHero();

}

​

function keyPressed(){

  if (keyCode == LEFT_ARROW){

    heroGoLeft()

  }

  if (keyCode == RIGHT_ARROW){

    heroGoRight()

  }

  if (keyCode == UP_ARROW){

    heroGoUp()

  }

  if (keyCode == DOWN_ARROW){

    heroGoDown()

  }

}