Incremental rendering of features does not work when render cache is used

[qgib]

Author Name: Jeremy Palmer (@palmerj)
Original Redmine Issue: 2038
Affected QGIS version: master
Redmine category:map_canvas

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r11831 introduced the feature to cache rendering whenever possible. However this new functionality has disabled the number of features to draw before updating the display.

[qgib]

Author Name: Giovanni Manghi (@gioman)

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confirmed also under linux with trunk. Is this on purpose?

[qgib]

Author Name: Steven Mizuno (Steven Mizuno)

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Actually, it is partially working on the initial rendering - after a layer is drawn, it is displayed. This appears to be an unintended consequence.

However, the point of caching is to speed up redrawing the map if it is not necessary to re-render a layer, as when a layer is disabled/enabled for view and the extent hasn't changed, so I don't see a reason for incremental drawing at all.

I would recommend when render caching is enabled, incremental drawing not be used during rendering and be disabled in Settings|Options to indicate that it is not available.

[qgib]

Author Name: Giovanni Manghi (@gioman)

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• fixed_version_id was changed from Version 1.7.0 to Version 1.7.4

[qgib]

Author Name: Paolo Cavallini (@pcav)

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• crashes_corrupts_data was configured as 0
• version was configured as master
• fixed_version_id was changed from Version 1.7.4 to Version 1.8.0

[qgib]

Author Name: Paolo Cavallini (@pcav)

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• fixed_version_id was changed from Version 1.8.0 to Version 2.0.0

[qgib]

Author Name: Nathan Woodrow (@NathanW2)

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2.4 now has multithreading so this should no longer be a issue.

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• assigned_to_id removed nobody
• resolution was configured as fixed/implemented
• status_id was changed from Open to Closed
• pull_request_patch_supplied was configured as 0