diff options
| -rw-r--r-- | src/util.c | 10 |
1 files changed, 10 insertions, 0 deletions
@@ -27,6 +27,14 @@ #include "compositor.h" +/* + * Matrices are stored in column-major order, that is the array indices are: + * 0 4 8 12 + * 1 5 9 13 + * 2 6 10 14 + * 3 7 11 15 + */ + WL_EXPORT void weston_matrix_init(struct weston_matrix *matrix) { @@ -37,6 +45,7 @@ weston_matrix_init(struct weston_matrix *matrix) memcpy(matrix, &identity, sizeof identity); } +/* m <- n * m, that is, m is multiplied on the LEFT. */ WL_EXPORT void weston_matrix_multiply(struct weston_matrix *m, const struct weston_matrix *n) { @@ -76,6 +85,7 @@ weston_matrix_scale(struct weston_matrix *matrix, GLfloat x, GLfloat y, GLfloat weston_matrix_multiply(matrix, &scale); } +/* v <- m * v */ WL_EXPORT void weston_matrix_transform(struct weston_matrix *matrix, struct weston_vector *v) { |