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PbezierTangent

processing

Calculates the tangent of a point on a Bezier curve. There's a good definition of tangent on Wikipedia.

Link to original Processing doc

PbezierTangent is available since version 1.0.0.

See also

Signatures

Examples

// @preview image //draw tangents along the curve 300 200 '2D3' PGraphics 255 Pbackground 16 PtextSize 50 'x1' STORE 50 'y1' STORE 200 'x2' STORE 130 'y2' STORE 100 'cx1' STORE 40 'cy1' STORE 110 'cx2' STORE 140 'cy2' STORE 4 PstrokeWeight $x1 $y1 Ppoint //first anchor $x2 $y2 Ppoint //second anchor 2 PstrokeWeight $x1 $y1 $cx1 $cy1 Pline $x2 $y2 $cx2 $cy2 Pline 2 PstrokeWeight 0xffff0000 Pstroke $x1 $y1 $cx1 $cy1 $cx2 $cy2 $x2 $y2 Pbezier 0 10 <% 10.0 / 't' STORE $x1 $cx1 $cx2 $x2 $t PbezierPoint 'x' STORE $y1 $cy1 $cy2 $y2 $t PbezierPoint 'y' STORE $x1 $cx1 $cx2 $x2 $t PbezierTangent 'tx' STORE $y1 $cy1 $cy2 $y2 $t PbezierTangent 'ty' STORE $ty $tx ATAN2 PI 2.0 / - 'angle' STORE 0xff009f00 Pstroke $x $y $x $angle COS 12 * + $y $angle SIN 12 * + Pline 0x9f009f00 Pfill PnoStroke 'CENTER' PellipseMode $x $y 5 5 Pellipse %> FOR Pencode