Hillshade renderer speed improvements #7411
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While working on OpenCL stuff I've got an advice from Nyall and Even regarding some speed improvement used by GDAL DEM, and here they are. According to my measurements the speed gain is roughly: + 20% for unidirectional + 70% for multi directional
| @@ -264,6 +304,13 @@ QgsRasterBlock *QgsHillshadeRenderer::block( int bandNo, const QgsRectangle &ext | |||
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| #ifdef QGISDEBUG | |||
| QgsMessageLog::logMessage( QStringLiteral( "CPU Rendering time for hillshade (%2 x %3 ): %4 ms" ) | |||
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This should probably also depend on the rendering debug option being enabled.
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@m-kuhn do you mean settings.value( QStringLiteral( "Map/logCanvasRefreshEvent" ), false ).toBool() ?
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Nice! |
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Nice -- while we're at it, I'm wondering whether we should add a "help/tip" label into the renderer's widget panel, which would state: "To avoid visual artifacts, set the zoomed in resambling to bilinear, and insure the project's CRS matches that of your raster". The project CRS part if needed, the zoomed in resambling method is disabled for reprojected rasters. The tip label is to help people hitting the issue/limitation below: |
@nirvn - let's move that discussion out of this PR. It's not related so shouldn't hold back this one. |
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@nyalldawson , sounds good. |
This reverts commit 0ac35a6.
While working on OpenCL stuff I've got an advice
from Nyall and Even regarding some speed improvement
used by GDAL DEM, and here they are.
According to my measurements the speed gain is roughly: