The QGIS composer has an option to toggle anti-aliasing (composer-options=>rendering=>rendering-quality=>"make lines appear less jagged at the expense of some drawing performance"). The standard map renderer does not seem to have such an option.
Anti-aliasing is a visualization feature. For visual use, the anti-aliasing result is almost always 'better' than without. However, sometimes, map output may be used for other purposes: the pixel colors can be used as categories or raster values or be used to mask other maps or rasters, etc. When used for such cases, the visually intermediate pixel-values produced by anti-aliasing distort the category or pixel information.
For comparison, Geoserver has an option to disable anti-aliasing.
I have set up QGIS as a WMS server and want to somehow disable anti-aliasing in order to use the WMS output as a mask for other data.
Can I somehow configure the layer style or rendering options or WMS server output to disable anti-aliasing?