** Draw simple shapes into a Typed Array as a 2d image.**

Four funcitons are exported:

• drawBox(buffer, width, x, y, h, w, rot, color, rop)
• drawCircle(buffer, width, x, y, rad, color, rop)
• drawPolygon(buffer, width, points, color, rop)
• drawEllipse(buffer, width, x, y, h, w, rot, color, rop)

Arguments:

• buffer - a TypedArray of data to draw into.
• width - the width of the first dimension buffer.
• x, y - center position of the shape to draw.
• h, w - height and width of the shape.
• color - value or "color" to draw.
• rop - raster operation to perform, either set or add. If undefined "set" is the default.