3d/instance.c

   1 /*
   2 THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
   3 SOFTWARE CORPORATION ("PARALLAX").  PARALLAX, IN DISTRIBUTING THE CODE TO
   4 END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
   5 ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
   6 IN USING, DISPLAYING,  AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
   7 SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
   8 FREE PURPOSES.  IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
   9 CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES.  THE END-USER UNDERSTANDS
  10 AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
  11 COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
  12 */
  13 /*
  14  * $Source: /cvs/cvsroot/d2x/3d/instance.c,v $
  15  * $Revision: 1.1.1.1 $
  16  * $Author: bradleyb $
  17  * $Date: 2001-01-19 03:29:58 $
  18  *
  19  * Instancing routines
  20  *
  21  * $Log: not supported by cvs2svn $
  22  * Revision 1.1.1.1  1999/06/14 21:57:45  donut
  23  * Import of d1x 1.37 source.
  24  *
  25  * Revision 1.2  1995/06/12  12:36:57  allender
  26  * fixed bug where g3_start_instance_angles recursively called itself
  27  *
  28  * Revision 1.1  1995/05/05  08:51:27  allender
  29  * Initial revision
  30  *
  31  * Revision 1.1  1995/04/17  06:43:29  matt
  32  * Initial revision
  33  *
  34  *
  35  */
  36
  37 #ifdef RCS
  38 static char rcsid[] = "$Id: instance.c,v 1.1.1.1 2001-01-19 03:29:58 bradleyb Exp $";
  39 #endif
  40
  41 #include <conf.h>
  42 #include <stdlib.h>
  43 #include "error.h"
  44
  45 #include "fix.h"
  46 #include "vecmat.h"
  47 #include "gr.h"
  48 #include "3d.h"
  49 #include "globvars.h"
  50
  51 #define MAX_INSTANCE_DEPTH      5
  52
  53 struct instance_context {
  54         vms_matrix m;
  55         vms_vector p;
  56 } instance_stack[MAX_INSTANCE_DEPTH];
  57
  58 int instance_depth = 0;
  59
  60 //instance at specified point with specified orientation
  61 //if matrix==NULL, don't modify matrix.  This will be like doing an offset
  62 void g3_start_instance_matrix(vms_vector *pos,vms_matrix *orient)
  63 {
  64         vms_vector tempv;
  65         vms_matrix tempm,tempm2;
  66
  67 #ifdef D1XD3D
  68         Win32_start_instance_matrix (pos, orient);
  69 #endif
  70
  71         Assert(instance_depth<MAX_INSTANCE_DEPTH);
  72
  73         instance_stack[instance_depth].m = View_matrix;
  74         instance_stack[instance_depth].p = View_position;
  75         instance_depth++;
  76
  77         //step 1: subtract object position from view position
  78
  79         vm_vec_sub(&tempv,&View_position,pos);
  80
  81
  82         if (orient) {
  83
  84                 //step 2: rotate view vector through object matrix
  85
  86                 vm_vec_rotate(&View_position,&tempv,orient);
  87
  88                 //step 3: rotate object matrix through view_matrix (vm = ob * vm)
  89
  90                 vm_copy_transpose_matrix(&tempm2,orient);
  91
  92                 vm_matrix_x_matrix(&tempm,&tempm2,&View_matrix);
  93                 View_matrix = tempm;
  94         }
  95 }
  96
  97
  98 //instance at specified point with specified orientation
  99 //if angles==NULL, don't modify matrix.  This will be like doing an offset
 100 void g3_start_instance_angles(vms_vector *pos,vms_angvec *angles)
 101 {
 102         vms_matrix tm;
 103
 104         if (angles==NULL) {
 105                 g3_start_instance_matrix(pos,NULL);
 106                 return;
 107         }
 108
 109         vm_angles_2_matrix(&tm,angles);
 110
 111         g3_start_instance_matrix(pos,&tm);
 112
 113 }
 114
 115
 116 //pops the old context
 117 void g3_done_instance()
 118 {
 119 #ifdef D1XD3D
 120         Win32_done_instance ();
 121 #endif
 122
 123         instance_depth--;
 124
 125         Assert(instance_depth >= 0);
 126
 127         View_position = instance_stack[instance_depth].p;
 128         View_matrix = instance_stack[instance_depth].m;
 129 }
 130
 131