Class: QgsRasterShader

class qgis.core.QgsRasterShader

Bases: sip.wrapper

Interface for all raster shaders.

Methods

maximumValue Returns the maximum value for the raster shader.
minimumValue Returns the minimum value for the raster shader.
rasterShaderFunction
readXml Reads shader state from an XML element.
setMaximumValue Sets the maximum value for the raster shader.
setMinimumValue Sets the minimum value for the raster shader.
setRasterShaderFunction A public method that allows the user to set their own shader function.
shade Generates a new RGBA value based on one input value.
writeXml Writes shader state to an XML element.

Signals

Attributes

maximumValue(self) → float

Returns the maximum value for the raster shader.

See also

minimumValue()

minimumValue(self) → float

Returns the minimum value for the raster shader.

See also

maximumValue()

rasterShaderFunction(self) → QgsRasterShaderFunction
readXml(self, elem: QDomElement)

Reads shader state from an XML element.

setMaximumValue(self, value: float)

Sets the maximum value for the raster shader.

See also

maximumValue()

setMinimumValue(self, value: float)

Sets the minimum value for the raster shader.

See also

minimumValue()

setRasterShaderFunction(self, function: QgsRasterShaderFunction)

A public method that allows the user to set their own shader function.

Note

Raster shader takes ownership of the shader function instance

shade(self, value: float) → Tuple[bool, int, int, int, int]

Generates a new RGBA value based on one input value.

Parameters:
  • value – The original value to base a new RGBA value on
  • returnRedValue – The red component of the new RGBA value
  • returnGreenValue – The green component of the new RGBA value
  • returnBlueValue – The blue component of the new RGBA value
Returns:

  • True if the return values are valid otherwise false
  • returnAlpha: The alpha component of the new RGBA value

shade(self, redValue: float, greenValue: float, blueValue: float, alphaValue: float) -> Tuple[bool, int, int, int, int] Generates a new RGBA value based on an original RGBA value.

Parameters:
  • redValue – The red component of the original value to base a new RGBA value on
  • greenValue – The green component of the original value to base a new RGBA value on
  • blueValue – The blue component of the original value to base a new RGBA value on
  • alphaValue – The alpha component of the original value to base a new RGBA value on
  • returnRedValue – The red component of the new RGBA value
  • returnGreenValue – The green component of the new RGBA value
  • returnBlueValue – The blue component of the new RGBA value
Returns:

  • True if the return values are valid otherwise false
  • returnAlpha: The alpha component of the new RGBA value

writeXml(self, doc: QDomDocument, parent: QDomElement)

Writes shader state to an XML element.