1 /* $Id: instance.c,v 1.5 2004-08-28 23:17:45 schaffner Exp $ */
3 THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
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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
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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
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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.
30 #define MAX_INSTANCE_DEPTH 5
32 struct instance_context {
35 } instance_stack[MAX_INSTANCE_DEPTH];
37 int instance_depth = 0;
39 //instance at specified point with specified orientation
40 //if matrix==NULL, don't modify matrix. This will be like doing an offset
41 void g3_start_instance_matrix(vms_vector *pos,vms_matrix *orient)
44 vms_matrix tempm,tempm2;
47 Win32_start_instance_matrix (pos, orient);
50 Assert(instance_depth<MAX_INSTANCE_DEPTH);
52 instance_stack[instance_depth].m = View_matrix;
53 instance_stack[instance_depth].p = View_position;
56 //step 1: subtract object position from view position
58 vm_vec_sub(&tempv,&View_position,pos);
63 //step 2: rotate view vector through object matrix
65 vm_vec_rotate(&View_position,&tempv,orient);
67 //step 3: rotate object matrix through view_matrix (vm = ob * vm)
69 vm_copy_transpose_matrix(&tempm2,orient);
71 vm_matrix_x_matrix(&tempm,&tempm2,&View_matrix);
77 //instance at specified point with specified orientation
78 //if angles==NULL, don't modify matrix. This will be like doing an offset
79 void g3_start_instance_angles(vms_vector *pos,vms_angvec *angles)
84 g3_start_instance_matrix(pos,NULL);
88 vm_angles_2_matrix(&tm,angles);
90 g3_start_instance_matrix(pos,&tm);
95 //pops the old context
96 void g3_done_instance()
99 Win32_done_instance ();
104 Assert(instance_depth >= 0);
106 View_position = instance_stack[instance_depth].p;
107 View_matrix = instance_stack[instance_depth].m;