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# Bezier curve

 P: n/a Hi all I want to draw a line as if it were being drawn in real-time by a person. To save lots of data I think that storing 4 points in memory and drawing a bezier curve would be efficient. What I need to know is, how can I determine each of the required pixel positions so that I may loop through them and draw them onto a canvas over a timespan of (for example) 1 second? Thankyou! Pete Nov 11 '07 #1
2 Replies

 P: n/a http://www.moshplant.com/direct-or/bezier/ will give you the math, given the four points. To draw the curve in real time, start at the point with the smallest x coordinate, and calculate y for each pixel, as you increment the x coordinate by one. Stop when you reach the point with the largest x coordinate. A Google search on "Bezier curve" will give you many useful links. "Peter Morris"

 P: n/a That site had just what I needed, thanks :-) private Point GetBezierPoint(float t, Point p0, Point p1, Point p2, Point p3) { float cx = 3 * (p1.X - p0.X); float bx = 3 * (p2.X - p1.X) - cx; float ax = p3.X - p0.X - cx - bx; float cy = 3 * (p1.Y - p0.Y); float by = 3 * (p2.Y - p1.Y) - cy; float ay = p3.Y - p0.Y - cy - by; float tCubed = t * t * t; float tSquared = t * t; float resultX = (ax * tCubed) + (bx * tSquared) + (cx * t) + p0.X; float resultY = (ay * tCubed) + (by * tSquared) + (cy * t) + p0.Y; return new Point((int)resultX, (int)resultY); } Pete Nov 11 '07 #3

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