Provided by: allegro4-doc_4.4.3.1-4.1build3_all bug

NAME

       set_projection_viewport  -  Sets  the  viewport used to scale the output of persp_project(). Allegro game
       programming library.

SYNOPSIS

       #include <allegro.h>

       void set_projection_viewport(int x, int y, int w, int h);

DESCRIPTION

       Sets the viewport used to scale the output of the persp_project() function. Pass the  dimensions  of  the
       screen  area  you  want  to  draw  onto, which will typically be 0, 0, SCREEN_W, and SCREEN_H. Also don't
       forget to pass an appropriate aspect ratio to get_camera_matrix later. The width and height  you  specify
       here  will  determine  how  big your viewport is in 3d space. So if an object in your 3D space is w units
       wide, it will fill the complete screen when you run into it (i.e., if it has a distance of 1.0 after  the
       camera  matrix  was  applied.  The  fov  and aspect-ratio parameters to get_camera_matrix also apply some
       scaling though, so this isn't always completely true). If you pass  -1/-1/2/2  as  parameters,  no  extra
       scaling will be performed by the projection.

SEE ALSO

       persp_project(3alleg4),  get_camera_matrix(3alleg4),  ex3d(3alleg4),  excamera(3alleg4), exquat(3alleg4),
       exscn3d(3alleg4), exstars(3alleg4), exzbuf(3alleg4)