Does MetaFun provide some macro to draw oriented paths? I would like it to basically add a small arrow *in the middle* of the path? Such a macro draworiented somepath somespecs ; would have to act like drawarrow firsthalf(somepath) somespecs ; draw secondhalf(somepath) somespecs ; Is it available already, or should I roll my own? -- Giuseppe "Oblomov" Bilotta
Wednesday, November 16, 2005 Giuseppe Bilotta wrote:
Does MetaFun provide some macro to draw oriented paths? I would like it to basically add a small arrow *in the middle* of the path? Such a macro
draworiented somepath somespecs ;
would have to act like
drawarrow firsthalf(somepath) somespecs ; draw secondhalf(somepath) somespecs ;
Is it available already, or should I roll my own?
Hm. I came up with def draworiented expr c = path _c_ ; _c_ := c ; do_draworiented enddef ; def do_draworiented text t = draw _c_ t ; drawarrow subpath(0, length(_c_)/2) of _c_ ; enddef; which works, although I have to do draworiented (reverse p1) Is there an easy way to have it work with draworiented reverse p1 ? -- Giuseppe "Oblomov" Bilotta
Wednesday, November 16, 2005 Giuseppe Bilotta wrote:
Wednesday, November 16, 2005 Giuseppe Bilotta wrote:
Does MetaFun provide some macro to draw oriented paths? I would like it to basically add a small arrow *in the middle* of the path? Such a macro
draworiented somepath somespecs ;
would have to act like
drawarrow firsthalf(somepath) somespecs ; draw secondhalf(somepath) somespecs ;
Is it available already, or should I roll my own?
Hm. I came up with
def draworiented expr c = path _c_ ; _c_ := c ; do_draworiented enddef ;
def do_draworiented text t = draw _c_ t ; drawarrow subpath(0, length(_c_)/2) of _c_ ; enddef;
which works, although I have to do
draworiented (reverse p1)
Is there an easy way to have it work with
draworiented reverse p1 ?
Oh sorry it works ... however, it traces half of the curve twice. So I came up with the next: def draworiented expr c = path _c_ ; _c_ := c ; do_draworiented enddef ; def do_draworiented text t = drawarrow subpath(0, length(_c_)/2) of _c_ t ; draw subpath(length(_c_)/2, length(_c_)) of _c_ t ; enddef; This still isn't perfect, but it works. It needs a little tuning so that the arrow is more centered, and of course it could be improved to put the arrow at any arbitrary point on the path. -- Giuseppe "Oblomov" Bilotta
Giuseppe Bilotta wrote:
Wednesday, November 16, 2005 Giuseppe Bilotta wrote:
Does MetaFun provide some macro to draw oriented paths? I would like it to basically add a small arrow *in the middle* of the path? Such a macro
draworiented somepath somespecs ;
would have to act like
drawarrow firsthalf(somepath) somespecs ; draw secondhalf(somepath) somespecs ;
Is it available already, or should I roll my own?
Hm. I came up with
def draworiented expr c = path _c_ ; _c_ := c ; do_draworiented enddef ;
def do_draworiented text t = draw _c_ t ; drawarrow subpath(0, length(_c_)/2) of _c_ ; enddef;
which works, although I have to do
draworiented (reverse p1)
Is there an easy way to have it work with
draworiented reverse p1 ?
add another step (do_do_) , first pick up 'reverse p1' as expression, save that in a path variable, and then pick up the text Hans
Giuseppe Bilotta wrote:
Does MetaFun provide some macro to draw oriented paths? I would like it to basically add a small arrow *in the middle* of the path? Such a macro
draworiented somepath somespecs ;
would have to act like
drawarrow firsthalf(somepath) somespecs ; draw secondhalf(somepath) somespecs ;
Is it available already, or should I roll my own?
it's there; watch out, i just added a scaling option \starttext \setupcolors[state=start] \startMPpage vardef arrowheadonpath (expr p, s) = save autoarrows ; boolean autoarrows ; autoarrows := true ; set_ahlength(scaled ahfactor) ; % added arrowhead p if s<1 : cutafter (point (s*arclength(p)+.5ahlength) on p) fi enddef ; path p ; p := (0,0)--(10cm,10cm) ; draw p withcolor red ; ahfactor := 5 ; % default is 2.5 fill arrowheadonpath(p,.5) withcolor blue ; % try .25 currentpicture := currentpicture xsized (10cm) ; \stopMPpage \stoptext
participants (2)
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Giuseppe Bilotta -
Hans Hagen