persp_project(3)                Allegro manual                persp_project(3)



NAME
       persp_project, persp_project_f - Projects a 3d point into 2d screen
       space. Allegro game programming library.

SYNOPSIS
       #include <allegro.h>


       void persp_project(fixed x, fixed y, fixed z, fixed *xout, fixed
       *yout);

       void persp_project_f(float x, float y, float z, float *xout, float
       *yout);

DESCRIPTION
       Projects the 3d point (x, y, z) into 2d screen space, storing the
       result in (*xout, *yout) and using the scaling parameters previously
       set by calling set_projection_viewport(). This function projects from
       the normalized viewing pyramid, which has a camera at the origin and
       facing along the positive z axis. The x axis runs left/right, y runs
       up/down, and z increases with depth into the screen. The camera has a
       90 degree field of view, ie. points on the planes x=z and -x=z will map
       onto the left and right edges of the screen, and the planes y=z and
       -y=z map to the top and bottom of the screen. If you want a different
       field of view or camera location, you should transform all your objects
       with an appropriate viewing matrix, eg. to get the effect of panning
       the camera 10 degrees to the left, rotate all your objects 10 degrees
       to the right.




SEE ALSO
       set_projection_viewport(3), get_camera_matrix(3), ex3d(3), exstars(3)



Allegro                          version 4.2.3                persp_project(3)
