diff options
Diffstat (limited to 'libdimension/dimension/object.h')
| -rw-r--r-- | libdimension/dimension/object.h | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/libdimension/dimension/object.h b/libdimension/dimension/object.h index f633a2d..cef1acb 100644 --- a/libdimension/dimension/object.h +++ b/libdimension/dimension/object.h @@ -41,8 +41,6 @@ typedef struct dmnsn_intersection { const dmnsn_interior *interior; } dmnsn_intersection; -dmnsn_vector dmnsn_transform_normal(dmnsn_matrix trans, dmnsn_vector normal); - /* Forward-declare dmnsn_object */ typedef struct dmnsn_object dmnsn_object; @@ -89,4 +87,20 @@ void dmnsn_delete_object(dmnsn_object *object); void dmnsn_object_init(dmnsn_object *object); +/* Useful function to transform a normal vector */ +DMNSN_INLINE dmnsn_vector +dmnsn_transform_normal(dmnsn_matrix trans, dmnsn_vector normal) +{ + return dmnsn_vector_normalize( + dmnsn_vector_sub( + dmnsn_transform_vector(trans, normal), + /* Optimized form of dmnsn_transform_vector(trans, dmnsn_zero) */ + dmnsn_vector_div( + dmnsn_new_vector(trans.n[0][3], trans.n[1][3], trans.n[2][3]), + trans.n[3][3] + ) + ) + ); +} + #endif /* DIMENSION_OBJECT_H */ |