1 /* $Id: instance.c,v 1.4 2002-07-17 21:55:19 bradleyb Exp $ */
3 THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
4 SOFTWARE CORPORATION ("PARALLAX"). PARALLAX, IN DISTRIBUTING THE CODE TO
5 END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
6 ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
7 IN USING, DISPLAYING, AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
8 SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
9 FREE PURPOSES. IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
10 CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES. THE END-USER UNDERSTANDS
11 AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
12 COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION. ALL RIGHTS RESERVED.
20 * Revision 1.2 1995/06/12 12:36:57 allender
21 * fixed bug where g3_start_instance_angles recursively called itself
23 * Revision 1.1 1995/05/05 08:51:27 allender
26 * Revision 1.1 1995/04/17 06:43:29 matt
42 #define MAX_INSTANCE_DEPTH 5
44 struct instance_context {
47 } instance_stack[MAX_INSTANCE_DEPTH];
49 int instance_depth = 0;
51 //instance at specified point with specified orientation
52 //if matrix==NULL, don't modify matrix. This will be like doing an offset
53 void g3_start_instance_matrix(vms_vector *pos,vms_matrix *orient)
56 vms_matrix tempm,tempm2;
59 Win32_start_instance_matrix (pos, orient);
62 Assert(instance_depth<MAX_INSTANCE_DEPTH);
64 instance_stack[instance_depth].m = View_matrix;
65 instance_stack[instance_depth].p = View_position;
68 //step 1: subtract object position from view position
70 vm_vec_sub(&tempv,&View_position,pos);
75 //step 2: rotate view vector through object matrix
77 vm_vec_rotate(&View_position,&tempv,orient);
79 //step 3: rotate object matrix through view_matrix (vm = ob * vm)
81 vm_copy_transpose_matrix(&tempm2,orient);
83 vm_matrix_x_matrix(&tempm,&tempm2,&View_matrix);
89 //instance at specified point with specified orientation
90 //if angles==NULL, don't modify matrix. This will be like doing an offset
91 void g3_start_instance_angles(vms_vector *pos,vms_angvec *angles)
96 g3_start_instance_matrix(pos,NULL);
100 vm_angles_2_matrix(&tm,angles);
102 g3_start_instance_matrix(pos,&tm);
107 //pops the old context
108 void g3_done_instance()
111 Win32_done_instance ();
116 Assert(instance_depth >= 0);
118 View_position = instance_stack[instance_depth].p;
119 View_matrix = instance_stack[instance_depth].m;