FreeBSD Manual Pages
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 re- sult 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 ap- propriate 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 4.4.3 persp_project(3)
NAME | SYNOPSIS | DESCRIPTION | SEE ALSO
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