gistfile1.coffee

canvas = document.getElementById("canvas");
field = document.getElementById("field");
robot = document.getElementById("robot");
goal = document.getElementById("goal");

ctx = canvas.getContext("2d");

mkImagePattern = (img) -> ctx.createPattern(img, 'repeat');

# fills canvas with a field pattern
paintField = () -> 
    imagePattern = mkImagePattern(field)
    ctx.rect(0, 0, canvas.width, canvas.height)
    ctx.fillStyle = imagePattern
    ctx.fill();        

# draws the robot robot with a certain degree of rotation
drawRobot = (degrees) ->
    image = robot
    ctx.save();
    ctx.translate(canvas.width/2,canvas.height/2);
    ctx.rotate(degrees*Math.PI/180);
    #ctx.drawImage(robot,-robot.width/2,-robot.width/2);
    ctx.drawImage(robot,0,0);
    ctx.restore();

robot.angles = 0

paint = () ->
    paintField()    
    ctx.drawImage(goal,250,250)    
    robot.position = {x: canvas.width/2, y: canvas.height/2} 

    drawRobot(robot.angles);
    robot.angles += 1
    if (robot.angles >= 360)
        robot.angles = 0

moveRobotTo = (pos) ->
    robot.target = pos
    
callbackHandler = undefined

###
# Optimize the repaint frequency 
# See http://www.w3.org/TR/animation-timing/
### 
requestID = 0

# for compatibility
requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || 
    window.webkitRequestAnimationFrame || window.msRequestAnimationFrame;
cancelAnimationFrame = window.cancelAnimationFrame || window.mozCancelAnimationFrame;

start = () ->
    repaint = (timestamp) -> 
        paint()
        requestID = requestAnimationFrame(repaint);

    requestID = requestAnimationFrame(repaint);

stop = () -> 
    if (requestID)
        cancelAnimationFrame(requestID);
    requestId = 0;

start()