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 ALSOset_projection_viewport(3), get_camera_matrix(3), ex3d(3), exstars(3)Allegro version 4.4.2 persp_project(3)
