<canvas width="600" height="400"> </canvas>
<script>
var pantalla = document.querySelector("canvas");
var pincel = pantalla.getContext("2d");
pincel.fillStyle = "grey";
pincel.fillRect(0,0,600,400);
var colores = ["blue","red", "green"];
var indiceColorActual = 0;
function dibujarCirculo(evento) {
var x = evento.pageX - pantalla.offsetLeft;
var y = evento.pageY - pantalla.offsetTop;
pincel.fillStyle = colores[indiceColorActual];
pincel.beginPath();
pincel.arc(x,y,10,0,2*3.14);
pincel.fill();
console.log(x + " , " + y);
}
pantalla.onclick = dibujarCirculo;
function alterarColor() {
indiceColorActual++;
if(indiceColorActual>= colores.lenght) {
indiceColorActual = 0;
}
return false;
}
pantalla.oncontextmenu = alterarColor;
</script>