[GRASS-dev] [GRASS GIS] #1410: scalebar displays multiples north arrows

[GRASS GIS]

#1410: scalebar displays multiples north arrows
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 Reporter:  cmbarton                     |       Owner:  grass-dev@…              
     Type:  defect                       |      Status:  new                      
 Priority:  normal                       |   Milestone:  7.0.0                    
Component:  Display                      |     Version:  svn-trunk                
 Keywords:  d.barscale, ll, north arrow  |    Platform:  All                      
      Cpu:  Unspecified                  |  
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Comment(by hamish):

 the triplicate symbols in d.barscale still happens in lat/lon locations
 with the new version of the module. The infill problem is fixed now.


 it seems to be during this code of D_symbol():
 {{{
 case S_POLYGON:
 ...
 /* again, to draw the lines */
 ...
 D_begin();
 for (k = 0; k < chain->scount; k++) {
     xp = x0 + sx * chain->sx[k];
     yp = y0 - sy * chain->sy[k];
     if (k == 0)
         D_move_abs(xp, yp);
     else
         D_cont_abs(xp, yp);
 }
 D_end();
 D_stroke();
 }}}

 which is called only once.


 adding a printf() in the loop shows the xp and yp display coords look ok:
 {{{
 xp=50.40 yp=368.00
 xp=33.40 yp=386.00
 xp=50.40 yp=316.00
 xp=68.40 yp=386.00
 xp=50.40 yp=368.00
 xp=50.40 yp=368.00
 }}}


 I tried throwing in a D_close() before the D_end(), no change.

  - It is unclear to me what D_end() does now, it appears to be a no-op?

 trying the different north_arrow= symbol options shows the problem
 manifesting itself differently through a couple different scenarios.
 My first guess would be a missing D_stroke(), but it's right there...
 so my next guess is some D_move_*() or D_pos_*() function error. It's a
 bit unclear to me when to use D_pos_*(), I tried to add some more header
 comments with what I understand about them, but some clarification would
 be appreciated as I fear spreading misinformation.

 ??


 thanks,
 Hamish

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Ticket URL: <https://trac.osgeo.org/grass/ticket/1410#comment:6>
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