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: 1.3 $
  16  * $Author: bradleyb $
  17  * $Date: 2001-10-31 03:54:50 $
  18  *
  19  * Instancing routines
  20  *
  21  * $Log: not supported by cvs2svn $
  22  * Revision 1.2  2001/01/31 15:17:48  bradleyb
  23  * Makefile and conf.h fixes
  24  *
  25  * Revision 1.1.1.1  2001/01/19 03:29:58  bradleyb
  26  * Import of d2x-0.0.8
  27  *
  28  * Revision 1.1.1.1  1999/06/14 21:57:45  donut
  29  * Import of d1x 1.37 source.
  30  *
  31  * Revision 1.2  1995/06/12  12:36:57  allender
  32  * fixed bug where g3_start_instance_angles recursively called itself
  33  *
  34  * Revision 1.1  1995/05/05  08:51:27  allender
  35  * Initial revision
  36  *
  37  * Revision 1.1  1995/04/17  06:43:29  matt
  38  * Initial revision
  39  *
  40  *
  41  */
  42
  43 #ifdef HAVE_CONFIG_H
  44 #include <conf.h>
  45 #endif
  46
  47 #ifdef RCS
  48 static char rcsid[] = "$Id: instance.c,v 1.3 2001-10-31 03:54:50 bradleyb Exp $";
  49 #endif
  50
  51 #include <stdlib.h>
  52 #include "error.h"
  53
  54 #include "3d.h"
  55 #include "globvars.h"
  56
  57 #define MAX_INSTANCE_DEPTH      5
  58
  59 struct instance_context {
  60         vms_matrix m;
  61         vms_vector p;
  62 } instance_stack[MAX_INSTANCE_DEPTH];
  63
  64 int instance_depth = 0;
  65
  66 //instance at specified point with specified orientation
  67 //if matrix==NULL, don't modify matrix.  This will be like doing an offset
  68 void g3_start_instance_matrix(vms_vector *pos,vms_matrix *orient)
  69 {
  70         vms_vector tempv;
  71         vms_matrix tempm,tempm2;
  72
  73 #ifdef D1XD3D
  74         Win32_start_instance_matrix (pos, orient);
  75 #endif
  76
  77         Assert(instance_depth<MAX_INSTANCE_DEPTH);
  78
  79         instance_stack[instance_depth].m = View_matrix;
  80         instance_stack[instance_depth].p = View_position;
  81         instance_depth++;
  82
  83         //step 1: subtract object position from view position
  84
  85         vm_vec_sub(&tempv,&View_position,pos);
  86
  87
  88         if (orient) {
  89
  90                 //step 2: rotate view vector through object matrix
  91
  92                 vm_vec_rotate(&View_position,&tempv,orient);
  93
  94                 //step 3: rotate object matrix through view_matrix (vm = ob * vm)
  95
  96                 vm_copy_transpose_matrix(&tempm2,orient);
  97
  98                 vm_matrix_x_matrix(&tempm,&tempm2,&View_matrix);
  99                 View_matrix = tempm;
 100         }
 101 }
 102
 103
 104 //instance at specified point with specified orientation
 105 //if angles==NULL, don't modify matrix.  This will be like doing an offset
 106 void g3_start_instance_angles(vms_vector *pos,vms_angvec *angles)
 107 {
 108         vms_matrix tm;
 109
 110         if (angles==NULL) {
 111                 g3_start_instance_matrix(pos,NULL);
 112                 return;
 113         }
 114
 115         vm_angles_2_matrix(&tm,angles);
 116
 117         g3_start_instance_matrix(pos,&tm);
 118
 119 }
 120
 121
 122 //pops the old context
 123 void g3_done_instance()
 124 {
 125 #ifdef D1XD3D
 126         Win32_done_instance ();
 127 #endif
 128
 129         instance_depth--;
 130
 131         Assert(instance_depth >= 0);
 132
 133         View_position = instance_stack[instance_depth].p;
 134         View_matrix = instance_stack[instance_depth].m;
 135 }
 136
 137