matrix:
GdipCreateMatrix
GdipCreateMatrix2
GdipDeleteMatrix
GdipGetMatrixElements
GdipInvertMatrix
GdipResetWorldTransform
GdipRotateMatrix
GdipRotateWorldTransform
GdipScaleMatrix
GdipScaleTextureTransform
GdipSetMatrixElements
GdipShearMatrix
GdipTranslateMatrix
GdipTranslateWorldTransform
GDI+: rotating images using matrix transformations