Bezier Curves
Explore the use of cubic Bezier curves in vector graphics with Pycairo. Learn to define curves using anchor and handle points, create various curve shapes, and join multiple curves smoothly to form complex paths and splines for detailed graphics.
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We have already seen the Bezier curve in action in a previous lesson. Let’s explore it a bit more.
A Bezier curve is a commonly used curve in vector graphics. It is versatile, efficient to work with, and possesses many useful properties.
A cubic Bezier curve is the type of curve used most often and is the only one that is supported by Pycairo. It is defined by four points A, B, C, and D. Here is an example of how a Bezier curve looks:
Points A and D are called the anchors and are always located at the two ends of the curve. Points B and C are called the handles and control the basic shape of the curve. The curve will generally follow the form of the open shape ABCD.
Pycairo defines a Bezier curve with the function curve_to:
ctx.move_to(ax, ay)
ctx.curve_to(bx, by, cx, cy, dx, dy)
ctx.set_source_rgb(1, 0, 0)
ctx.set_line_width(2)
ctx.stroke()
In the code, point A is represented by the coordinates (ax, ay), point B is represented by the ...