Reference for Processing version 1.2. If you have a previous version, use the reference included with your software. If you see any errors or have suggestions, please let us know. If you prefer a more technical reference, visit the Processing Javadoc.
Name | bezierTangent() |
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Examples | noFill(); bezier(85, 20, 10, 10, 90, 90, 15, 80); int steps = 6; fill(255); for (int i = 0; i <= steps; i++) { float t = i / float(steps); // Get the location of the point float x = bezierPoint(85, 10, 90, 15, t); float y = bezierPoint(20, 10, 90, 80, t); // Get the tangent points float tx = bezierTangent(85, 10, 90, 15, t); float ty = bezierTangent(20, 10, 90, 80, t); // Calculate an angle from the tangent points float a = atan2(ty, tx); a += PI; stroke(255, 102, 0); line(x, y, cos(a)*30 + x, sin(a)*30 + y); // This follwing line of code makes a line // inverse of the above line //line(x, y, cos(a)*-30 + x, sin(a)*-30 + y); stroke(0); ellipse(x, y, 5, 5); } noFill(); bezier(85, 20, 10, 10, 90, 90, 15, 80); stroke(255, 102, 0); int steps = 16; for (int i = 0; i <= steps; i++) { float t = i / float(steps); float x = bezierPoint(85, 10, 90, 15, t); float y = bezierPoint(20, 10, 90, 80, t); float tx = bezierTangent(85, 10, 90, 15, t); float ty = bezierTangent(20, 10, 90, 80, t); float a = atan2(ty, tx); a -= HALF_PI; line(x, y, cos(a)*8 + x, sin(a)*8 + y); } |
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Description | Calculates the tangent of a point on a Bezier curve. There is a good definition of "tangent" at Wikipedia: http://en.wikipedia.org/wiki/Tangent | ||||||||||
Syntax | bezierTangent(a, b, c, d, t) |
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Parameters |
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Usage | Web & Application | ||||||||||
Related | bezier() bezierVertex() curvePoint() |