// select matrix
vgSeti(VG_MATRIX_MODE, VG_MATRIX_PATH_USER_TO_SURFACE);

// it must generate an error code
vgLoadMatrix(NULL);
writeInt(f, vgGetError(), "vgLoadMatrix(NULL)");

// VG_NO_ERROR must be generated
vgLoadMatrix(m);
writeInt(f, vgGetError(), "vgLoadMatrix(m)");

// it must generate an error code
vgGetMatrix(NULL);
writeInt(f, vgGetError(), "vgGetMatrix(NULL)");

// VG_NO_ERROR must be generated
vgGetMatrix(m);
writeInt(f, vgGetError(), "vgGetMatrix(m)");

// it must generate an error code
vgMultMatrix(NULL);
writeInt(f, vgGetError(), "vgMultMatrix(NULL)");

// VG_NO_ERROR must be generated
vgMultMatrix(m);
writeInt(f, vgGetError(), "vgMultMatrix(m)");