compositor: drop inverse matrix from weston_transform
Remove the inverse matrix member from struct weston_transform. It is
easier (and probably faster, too) to create and store only forward
transformation matrices in a list, multiply them once, and then invert
the final matrix, rather than creating both forward and inverse
matrices, and multiplying both.
Add a stub for the 4x4 matrix inversion function.
Signed-off-by: Pekka Paalanen <ppaalanen@gmail.com>
diff --git a/src/matrix.h b/src/matrix.h
index f149d87..2c3285a 100644
--- a/src/matrix.h
+++ b/src/matrix.h
@@ -43,4 +43,8 @@
void
weston_matrix_transform(struct weston_matrix *matrix, struct weston_vector *v);
+int
+weston_matrix_invert(struct weston_matrix *inverse,
+ const struct weston_matrix *matrix);
+
#endif /* WESTON_MATRIX_H */