[Qgis-developer] How to color a raster with a color table with values From - To?

[SupportLists]

Hi,

I am using QGIS API to develop a custom application. Currently I'm using 
QgsRasterLayer::PalettedColor + QgsRasterLayer::ColorRampShader  + 
QgsColorRampShader::ColorRampItem to render a raster using a specific 
color map.

Now, I need to render the raster with a colormap using value From - To 
however, ColorRampItem struct only accepts one value. Is there another 
way around? Or, its it possible to create user defined DrawingStyles and 
ColorShadingAlgorithms? If so how?

Any help is very much appreciated.

Regards,
Carlos.