Bug report #7461

'difference' blending mode not correctly rendered on a qgis composer map item (but exports properly)

Added by Mathieu Pellerin - nIRV about 11 years ago. Updated about 11 years ago.

Assignee:Nyall Dawson
Affected QGIS version:master Regression?:No
Operating System:all Easy fix?:No
Pull Request or Patch supplied:No Resolution:
Crashes QGIS or corrupts data:No Copied to github as #:16416


1. Open the attached QGIS project (test-blend.zip)
2. Have a look at beautiful rendering of raster heatmap (with 'difference' blend mode) over streets vector
3. Open print composer 'Composer 1'
4. Notice how the composer's map item has it all wrong, as if the raster black to white was reversed, or the layer order switched

If the user exports the composer to a PNG, the exported map is rendering properly. There's only an issue with the composer's map item preview. Also, other blend modes, like multiply, are not triggering this bug.

test-blend.zip (2.72 MB) Mathieu Pellerin - nIRV, 2013-03-27 07:02 PM

Associated revisions

Revision e6f3b2e0
Added by Nyall Dawson about 11 years ago

Draw background on painter before rendering map for composer map items (fix #7461)


#1 Updated by Nyall Dawson about 11 years ago

  • Assignee set to Nyall Dawson
  • Status changed from Open to In Progress

#2 Updated by Nyall Dawson about 11 years ago

  • Status changed from In Progress to Closed

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