1 /* $Id: rod.c,v 1.4 2002/07/17 21:55:19 bradleyb Exp $ */
2 /*
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.
13 */
14 /*
15 *
16 * Rod routines
17 *
18 * Old Log:
19 *
20 * Revision 1.2 1995/09/13 11:31:46 allender
21 * removed checkmuldiv in PPC implemenation
22 *
23 * Revision 1.1 1995/05/05 08:52:45 allender
24 * Initial revision
25 *
26 * Revision 1.1 1995/04/17 06:42:08 matt
27 * Initial revision
28 *
29 *
30 */
31
32 #ifdef HAVE_CONFIG_H
33 #include <conf.h>
34 #endif
35
36 #ifdef RCS
37 static char rcsid[] = "$Id: rod.c,v 1.4 2002/07/17 21:55:19 bradleyb Exp $";
38 #endif
39
40 #include "3d.h"
41 #include "globvars.h"
42 #include "fix.h"
43
44 grs_point blob_vertices[4];
45 g3s_point rod_points[4];
46 g3s_point *rod_point_list[] = {&rod_points[0],&rod_points[1],&rod_points[2],&rod_points[3]};
47
48 g3s_uvl uvl_list[4] = { { 0x0200,0x0200,0 },
49 { 0xfe00,0x0200,0 },
50 { 0xfe00,0xfe00,0 },
51 { 0x0200,0xfe00,0 }};
52
53 //compute the corners of a rod. fills in vertbuf.
calc_rod_corners(g3s_point * bot_point,fix bot_width,g3s_point * top_point,fix top_width)54 int calc_rod_corners(g3s_point *bot_point,fix bot_width,g3s_point *top_point,fix top_width)
55 {
56 vms_vector delta_vec,top,tempv,rod_norm;
57 ubyte codes_and;
58 int i;
59
60 //compute vector from one point to other, do cross product with vector
61 //from eye to get perpendiclar
62
63 vm_vec_sub(&delta_vec,&bot_point->p3_vec,&top_point->p3_vec);
64
65 //unscale for aspect
66
67 delta_vec.x = fixdiv(delta_vec.x,Matrix_scale.x);
68 delta_vec.y = fixdiv(delta_vec.y,Matrix_scale.y);
69
70 //calc perp vector
71
72 //do lots of normalizing to prevent overflowing. When this code works,
73 //it should be optimized
74
75 vm_vec_normalize(&delta_vec);
76
77 vm_vec_copy_normalize(&top,&top_point->p3_vec);
78
79 vm_vec_cross(&rod_norm,&delta_vec,&top);
80
81 vm_vec_normalize(&rod_norm);
82
83 //scale for aspect
84
85 rod_norm.x = fixmul(rod_norm.x,Matrix_scale.x);
86 rod_norm.y = fixmul(rod_norm.y,Matrix_scale.y);
87
88 //now we have the usable edge. generate four points
89
90 //top points
91
92 vm_vec_copy_scale(&tempv,&rod_norm,top_width);
93 tempv.z = 0;
94
95 vm_vec_add(&rod_points[0].p3_vec,&top_point->p3_vec,&tempv);
96 vm_vec_sub(&rod_points[1].p3_vec,&top_point->p3_vec,&tempv);
97
98 vm_vec_copy_scale(&tempv,&rod_norm,bot_width);
99 tempv.z = 0;
100
101 vm_vec_sub(&rod_points[2].p3_vec,&bot_point->p3_vec,&tempv);
102 vm_vec_add(&rod_points[3].p3_vec,&bot_point->p3_vec,&tempv);
103
104
105 //now code the four points
106
107 for (i=0,codes_and=0xff;i<4;i++)
108 codes_and &= g3_code_point(&rod_points[i]);
109
110 if (codes_and)
111 return 1; //1 means off screen
112
113 //clear flags for new points (not projected)
114
115 for (i=0;i<4;i++)
116 rod_points[i].p3_flags = 0;
117
118 return 0;
119 }
120
121 //draw a polygon that is always facing you
122 //returns 1 if off screen, 0 if drew
g3_draw_rod_flat(g3s_point * bot_point,fix bot_width,g3s_point * top_point,fix top_width)123 bool g3_draw_rod_flat(g3s_point *bot_point,fix bot_width,g3s_point *top_point,fix top_width)
124 {
125 if (calc_rod_corners(bot_point,bot_width,top_point,top_width))
126 return 0;
127
128 return g3_draw_poly(4,rod_point_list);
129
130 }
131
132 //draw a bitmap object that is always facing you
133 //returns 1 if off screen, 0 if drew
g3_draw_rod_tmap(grs_bitmap * bitmap,g3s_point * bot_point,fix bot_width,g3s_point * top_point,fix top_width,fix light)134 bool g3_draw_rod_tmap(grs_bitmap *bitmap,g3s_point *bot_point,fix bot_width,g3s_point *top_point,fix top_width,fix light)
135 {
136 if (calc_rod_corners(bot_point,bot_width,top_point,top_width))
137 return 0;
138
139 uvl_list[0].l = uvl_list[1].l = uvl_list[2].l = uvl_list[3].l = light;
140
141 return g3_draw_tmap(4,rod_point_list,uvl_list,bitmap);
142 }
143
144 #ifndef __powerc
145 int checkmuldiv(fix *r,fix a,fix b,fix c);
146 #endif
147
148 #if (!(defined(D1XD3D) || defined(OGL)))
149 //draws a bitmap with the specified 3d width & height
150 //returns 1 if off screen, 0 if drew
g3_draw_bitmap(vms_vector * pos,fix width,fix height,grs_bitmap * bm,int orientation)151 bool g3_draw_bitmap(vms_vector *pos,fix width,fix height,grs_bitmap *bm, int orientation)
152 {
153 #ifndef __powerc
154 g3s_point pnt;
155 fix t,w,h;
156
157 if (g3_rotate_point(&pnt,pos) & CC_BEHIND)
158 return 1;
159
160 g3_project_point(&pnt);
161
162 if (pnt.p3_flags & PF_OVERFLOW)
163 return 1;
164
165 if (checkmuldiv(&t,width,Canv_w2,pnt.p3_z))
166 w = fixmul(t,Matrix_scale.x);
167 else
168 return 1;
169
170 if (checkmuldiv(&t,height,Canv_h2,pnt.p3_z))
171 h = fixmul(t,Matrix_scale.y);
172 else
173 return 1;
174
175 blob_vertices[0].x = pnt.p3_sx - w;
176 blob_vertices[0].y = blob_vertices[1].y = pnt.p3_sy - h;
177 blob_vertices[1].x = blob_vertices[2].x = pnt.p3_sx + w;
178 blob_vertices[2].y = pnt.p3_sy + h;
179
180 scale_bitmap(bm,blob_vertices,0);
181
182 return 0;
183 #else
184 g3s_point pnt;
185 fix w,h;
186 double fz;
187
188 if (g3_rotate_point(&pnt,pos) & CC_BEHIND)
189 return 1;
190
191 g3_project_point(&pnt);
192
193 if (pnt.p3_flags & PF_OVERFLOW)
194 return 1;
195
196 if (pnt.p3_z == 0)
197 return 1;
198
199 fz = f2fl(pnt.p3_z);
200 w = fixmul(fl2f(((f2fl(width)*fCanv_w2) / fz)), Matrix_scale.x);
201 h = fixmul(fl2f(((f2fl(height)*fCanv_h2) / fz)), Matrix_scale.y);
202
203 blob_vertices[0].x = pnt.p3_sx - w;
204 blob_vertices[0].y = blob_vertices[1].y = pnt.p3_sy - h;
205 blob_vertices[1].x = blob_vertices[2].x = pnt.p3_sx + w;
206 blob_vertices[2].y = pnt.p3_sy + h;
207
208 scale_bitmap(bm,blob_vertices);
209
210 return 0;
211 #endif
212 }
213 #endif
214
215
216
217