Provided by: libfontconfig-doc_2.15.0-2.3ubuntu1_all 

NAME
FcMatrixRotate - Rotate a matrix
SYNOPSIS
#include <fontconfig/fontconfig.h>
void FcMatrixRotate (FcMatrix *matrix, double cos, double sin);
DESCRIPTION
FcMatrixRotate rotates matrix by the angle who's sine is sin and cosine is cos. This is done by
multiplying by the matrix:
cos -sin
sin cos
Fontconfig 2.15.0 04 July 2025 FcMatrixRotate(3)