1 /*
2 Copyright (c) 2005-2021 Intel Corporation
3
4 Licensed under the Apache License, Version 2.0 (the "License");
5 you may not use this file except in compliance with the License.
6 You may obtain a copy of the License at
7
8 http://www.apache.org/licenses/LICENSE-2.0
9
10 Unless required by applicable law or agreed to in writing, software
11 distributed under the License is distributed on an "AS IS" BASIS,
12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 See the License for the specific language governing permissions and
14 limitations under the License.
15 */
16
17 /*
18 The original source for this example is
19 Copyright (c) 1994-2008 John E. Stone
20 All rights reserved.
21
22 Redistribution and use in source and binary forms, with or without
23 modification, are permitted provided that the following conditions
24 are met:
25 1. Redistributions of source code must retain the above copyright
26 notice, this list of conditions and the following disclaimer.
27 2. Redistributions in binary form must reproduce the above copyright
28 notice, this list of conditions and the following disclaimer in the
29 documentation and/or other materials provided with the distribution.
30 3. The name of the author may not be used to endorse or promote products
31 derived from this software without specific prior written permission.
32
33 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
34 OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
35 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
36 ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
37 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
38 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
39 OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
40 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
41 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
42 OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
43 SUCH DAMAGE.
44 */
45
46 #include "machine.hpp"
47 #include "types.hpp"
48 #include "macros.hpp"
49 #include "vector.hpp"
50 #include "tgafile.hpp"
51 #include "trace.hpp"
52 #include "light.hpp"
53 #include "shade.hpp"
54 #include "camera.hpp"
55 #include "util.hpp"
56 #include "intersect.hpp"
57 #include "global.hpp"
58 #include "ui.hpp"
59 #include "tachyon_video.hpp"
60
61 // shared but read-only so could be private too
62 static thr_parms *all_parms;
63 static scenedef scene;
64 static int startx;
65 static int stopx;
66 static int starty;
67 static int stopy;
68 static flt jitterscale;
69 static int totaly;
70
render_one_pixel(int x,int y,unsigned int * local_mbox,unsigned int & serial,int startx,int stopx,int starty,int stopy)71 static color_t render_one_pixel(int x,
72 int y,
73 unsigned int *local_mbox,
74 unsigned int &serial,
75 int startx,
76 int stopx,
77 int starty,
78 int stopy) {
79 /* private vars moved inside loop */
80 ray primary, sample;
81 color col, avcol;
82 int R, G, B;
83 intersectstruct local_intersections;
84 int alias;
85 /* end private */
86
87 primary = camray(&scene, x, y);
88 primary.intstruct = &local_intersections;
89 primary.flags = RT_RAY_REGULAR;
90
91 serial++;
92 primary.serial = serial;
93 primary.mbox = local_mbox;
94 primary.maxdist = FHUGE;
95 primary.scene = &scene;
96 col = trace(&primary);
97
98 serial = primary.serial;
99
100 /* perform antialiasing if enabled.. */
101 if (scene.antialiasing > 0) {
102 for (alias = 0; alias < scene.antialiasing; alias++) {
103 serial++; /* increment serial number */
104 sample = primary; /* copy the regular primary ray to start with */
105 sample.serial = serial;
106
107 {
108 sample.d.x += ((std::rand() % 100) - 50) / jitterscale;
109 sample.d.y += ((std::rand() % 100) - 50) / jitterscale;
110 sample.d.z += ((std::rand() % 100) - 50) / jitterscale;
111 }
112
113 avcol = trace(&sample);
114
115 serial = sample.serial; /* update our overall serial # */
116
117 col.r += avcol.r;
118 col.g += avcol.g;
119 col.b += avcol.b;
120 }
121
122 col.r /= (scene.antialiasing + 1.0);
123 col.g /= (scene.antialiasing + 1.0);
124 col.b /= (scene.antialiasing + 1.0);
125 }
126
127 /* Handle overexposure and underexposure here... */
128 R = (int)(col.r * 255);
129 if (R > 255)
130 R = 255;
131 else if (R < 0)
132 R = 0;
133
134 G = (int)(col.g * 255);
135 if (G > 255)
136 G = 255;
137 else if (G < 0)
138 G = 0;
139
140 B = (int)(col.b * 255);
141 if (B > 255)
142 B = 255;
143 else if (B < 0)
144 B = 0;
145
146 return video->get_color(R, G, B);
147 }
148
parallel_thread(void)149 static void parallel_thread(void) {
150 // thread-local storage
151 unsigned int serial = 1;
152 unsigned int mboxsize = sizeof(unsigned int) * (max_objectid() + 20);
153 unsigned int *local_mbox = (unsigned int *)alloca(mboxsize);
154 memset(local_mbox, 0, mboxsize);
155
156 for (int y = starty; y < stopy; y++) {
157 {
158 drawing_area drawing(startx, totaly - y, stopx - startx, 1);
159 for (int x = startx; x < stopx; x++) {
160 color_t c =
161 render_one_pixel(x, y, local_mbox, serial, startx, stopx, starty, stopy);
162 drawing.put_pixel(c);
163 }
164 }
165 if (!video->next_frame())
166 return;
167 }
168 }
169
thread_trace(thr_parms * parms)170 void *thread_trace(thr_parms *parms) {
171 // shared but read-only so could be private too
172 all_parms = parms;
173 scene = parms->scene;
174 startx = parms->startx;
175 stopx = parms->stopx;
176 starty = parms->starty;
177 stopy = parms->stopy;
178 jitterscale = 40.0 * (scene.hres + scene.vres);
179 totaly = parms->scene.vres - 1;
180
181 parallel_thread();
182
183 return (nullptr);
184 }
185