FreeBSD Manual Pages
al_use_pro...n_transform(3) Library Functions Manual al_use_pro...n_transform(3) NAME al_use_projection_transform - Allegro 5 API SYNOPSIS #include <allegro5/allegro.h> void al_use_projection_transform(const ALLEGRO_TRANSFORM *trans) DESCRIPTION Sets the projection transformation to be used for the drawing operations on the target bitmap (each bitmap maintains its own projection transforma- tion). Every drawing operation after this call will be transformed using this transformation. To return default behavior, call this function with an orthographic transform like so: ALLEGRO_TRANSFORM trans; al_identity_transform(&trans); al_orthographic_transform(&trans, 0, 0, -1.0, al_get_bitmap_width(bitmap), al_get_bitmap_height(bitmap), 1.0); al_set_target_bitmap(bitmap); al_use_projection_transform(&trans); The orthographic transformation above is the default projection transform. This function does nothing if there is no target bitmap. This function also does nothing if the bitmap is a memory bitmap (i.e. memory bitmaps al- ways use an orthographic transform like the snippet above). Note that the projection transform will be reset to default if a video bitmap is con- verted to a memory bitmap. Additionally, if the bitmap in question is the backbuffer, it's projection transformation will be reset to default if it is resized. Lastly, when you draw a memory bitmap to a video bitmap with a custom projection transform, this transformation will be ignored (i.e. it'll be as if the projection transform of the target bitmap was tem- porarily reset to default). The parameter is passed by reference as an optimization to avoid the over- head of stack copying. The reference will not be stored in the Allegro li- brary so it is safe to pass references to local variables. SINCE 5.1.9 SEE ALSO al_get_current_projection_transform(3), al_perspective_transform(3), al_or- thographic_transform(3) Allegro reference manual al_use_pro...n_transform(3)
NAME | SYNOPSIS | DESCRIPTION | SINCE | SEE ALSO
Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=al_use_projection_transform&sektion=3&manpath=FreeBSD+Ports+15.1.quarterly>