The memoir class - The UK TeX Archive

D. PICTURESand [Far90]; no doubt there are more recent sources available and there is a brief reviewin [Wil04a].Figure D.5 shows two of these curves. The figure was produced by the code below.\begin{figure}\setlength{\unitlength}{1mm}\centering\begin{picture}(100,100)\thicklines % first curve\qbezier(10,50)(50,90)(50,50)\thinlines % draw lines joining control points\put(10,50){\line(1,1){40}}\put(50,90){\line(0,-1){40}}% label control points\put(10,45){\makebox(0,0)[t]{\texttt{(10,50)}}}\put(50,95){\makebox(0,0)[b]{\texttt{(50,90)}}}\put(55,50){\makebox(0,0)[l]{\texttt{(50,50)}}}\thicklines % second curve\qbezier[25](50,50)(50,10)(90,50)\thinlines % draw lines joining control points% \put(50,50){\line(0,-1){40}}% \put(50,10){\line(1,1){40}}% label control points\put(50,5){\makebox(0,0)[t]{\texttt{(50,10)}}}\put(90,55){\makebox(0,0)[b]{\texttt{(90,50)}}}\end{picture}\setlength{\unitlength}{1pt}\caption{Two Bezier curves}\label{lpicf:bez}\end{figure}The three points used to specify the position and shape of the Bezier curve are calledcontrol points. The curve starts at the first control point and is tangent to the line joining thefirst and second control points. The curve stops at the last control point and is tangent tothe line joining the last two control points.In Figure D.5 the lines joining the control points for the first curve have been drawn in.The locations of all the control points for the two curves are labeled.The second Bezier curve is the same shape as the first one, but rotated 180 degrees.The first control point of this curve is the same as the last control point of the first curve.This means that the two curves are joind at this point. The line, although it is not drawn,connecting the first two control points of the second curve is in the same direction as theline joining the last two control points of the first curve. This means that the two curvesare also tangent at the point where they join. By stringing together several Bezier curvesyou can draw quite complex curved shapes.426\qbeziermax