# Color Grapher

## Instructions

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To draw a picture, write a javascript function in the text box below. This function will be called for every pixel and will be given four arguments: x, y, d and a. The first two correspond to the Cartesian coordinates of the point; the latter two are the polar coordinates with d being the distance to the center and a being the angle.

The origin is the center of the drawing area; the angle is in radians, going counter-clockwise from the x-axis. Basically, this works exactly as it would in a math class.

In addition to the pixel’s position, the function will have height and width accessible. These correspond to the height and width of the drawing area; if the area is resized, they will change.

The function should return a Color. This can be done by calling return new Color(r, g, b); at the very end of the function where r, g and b correspond to the red, green and blue channels of the color respectively.

For convenience, all of the properties of the Math class are available without needing to reference Math. That is, instead of calling Math.cos, you can just use cos.

Here is a simple example of a function that can be used here, which creates an interesting pattern:

function (x, y, d, a) {
var r = cos(round(x / 10, 0)) * 256;
var g = sin(round(y / 10, 0)) * 256;
var b = random() * d;

return new Color(r, g, b);
}

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This only works on browsers supporting pixel manipulation using canvas.