def createMapSettingsFromRenderContext(ctx, baseSettings=None):
s = QgsMapSettings(baseSettings) if baseSettings else QgsMapSettings()
transform = ctx.coordinateTransform()
if transform:
s.setCrsTransformEnabled(True)
s.setDestinationCrs(transform.destCRS())
s.setExtent(ctx.extent())
s.setOutputDpi(ctx.scaleFactor() * 25.4) # ref. QgsRenderContext::fromMapSettings
if hasattr(ctx, "RenderMapTile"):
s.setFlag(QgsMapSettings.RenderMapTile, ctx.testFlag(QgsRenderContext.RenderMapTile))
if hasattr(ctx, "expressionContext"):
s.setExpressionContext(ctx.expressionContext())
return s
