[GRASS-dev] [GRASS GIS] #2403: cairo driver fails to create surface

[GRASS GIS]

#2403: cairo driver fails to create surface
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 Reporter:  martinl                     |       Owner:  martinl    
     Type:  defect                      |      Status:  assigned   
 Priority:  major                       |   Milestone:  7.0.0      
Component:  Display                     |     Version:  unspecified
 Keywords:  cairo, resolution, surface  |    Platform:  Linux      
      Cpu:  x86-64                      |  
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Comment(by glynn):

 Replying to [comment:8 martinl]:

 > Could you please review attachment:cairo_down_sampling.diff which do
 down-sampling for Cairo in similar as already does PNG driver?

 The main issue was that it neglected the inner Y loop when up-scaling.

 r63582 makes the cairo driver behave almost identically to the PNG driver.

 For reasons which I've been unable to determine so far, the result is one
 destination pixel wider than with the PNG driver.

 Ultimately, the code should be modified to use an intermediate surface
 which has the same dimensions as the destination rectangle, to avoid the
 overhead of copying the (empty) borders.

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Ticket URL: <http://trac.osgeo.org/grass/ticket/2403#comment:9>
GRASS GIS <http://grass.osgeo.org>