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Kristian Høgsberg012a0072010-10-26 00:02:20 -04001/*
2 * Copyright © 2010 Kristian Høgsberg
3 *
4 * Permission to use, copy, modify, distribute, and sell this software and its
5 * documentation for any purpose is hereby granted without fee, provided that
6 * the above copyright notice appear in all copies and that both that copyright
7 * notice and this permission notice appear in supporting documentation, and
8 * that the name of the copyright holders not be used in advertising or
9 * publicity pertaining to distribution of the software without specific,
10 * written prior permission. The copyright holders make no representations
11 * about the suitability of this software for any purpose. It is provided "as
12 * is" without express or implied warranty.
13 *
14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
20 * OF THIS SOFTWARE.
21 */
22
23#include <stdint.h>
24#include <stdio.h>
25#include <stdlib.h>
26#include <string.h>
27#include <time.h>
28#include <fcntl.h>
29#include <unistd.h>
30#include <math.h>
31#include <time.h>
32#include <cairo.h>
33#include <glib.h>
34
Pekka Paalanen50719bc2011-11-22 14:18:50 +020035#include <wayland-client.h>
Kristian Høgsberg012a0072010-10-26 00:02:20 -040036#include "window.h"
37
38struct smoke {
39 struct display *display;
40 struct window *window;
Kristian Høgsberg75bc6672012-01-10 09:43:58 -050041 struct widget *widget;
Kristian Høgsberg012a0072010-10-26 00:02:20 -040042 cairo_surface_t *surface;
43 int x, y, width, height;
44 int offset, current;
45 struct { float *d, *u, *v; } b[2];
46};
47
Kristian Høgsberg012a0072010-10-26 00:02:20 -040048static void diffuse(struct smoke *smoke, uint32_t time,
49 float *source, float *dest)
50{
Kristian Høgsberg012a0072010-10-26 00:02:20 -040051 float *s, *d;
52 int x, y, k, stride;
53 float t, a = 0.0002;
54
55 stride = smoke->width;
56
57 for (k = 0; k < 5; k++) {
58 for (y = 1; y < smoke->height - 1; y++) {
59 s = source + y * stride;
60 d = dest + y * stride;
61 for (x = 1; x < smoke->width - 1; x++) {
62 t = d[x - 1] + d[x + 1] +
63 d[x - stride] + d[x + stride];
64 d[x] = (s[x] + a * t) / (1 + 4 * a) * 0.995;
65 }
66 }
67 }
68}
69
70static void advect(struct smoke *smoke, uint32_t time,
71 float *uu, float *vv, float *source, float *dest)
72{
Kristian Høgsberg012a0072010-10-26 00:02:20 -040073 float *s, *d;
74 float *u, *v;
Bryce Harrington40269a62010-11-19 12:15:36 -080075 int x, y, stride;
Kristian Høgsberg012a0072010-10-26 00:02:20 -040076 int i, j;
77 float px, py, fx, fy;
78
79 stride = smoke->width;
80
81 for (y = 1; y < smoke->height - 1; y++) {
82 d = dest + y * stride;
83 u = uu + y * stride;
84 v = vv + y * stride;
85
86 for (x = 1; x < smoke->width - 1; x++) {
87 px = x - u[x];
88 py = y - v[x];
89 if (px < 0.5)
90 px = 0.5;
91 if (py < 0.5)
92 py = 0.5;
93 if (px > smoke->width - 0.5)
94 px = smoke->width - 0.5;
95 if (py > smoke->height - 0.5)
96 py = smoke->height - 0.5;
97 i = (int) px;
98 j = (int) py;
99 fx = px - i;
100 fy = py - j;
101 s = source + j * stride + i;
102 d[x] = (s[0] * (1 - fx) + s[1] * fx) * (1 - fy) +
103 (s[stride] * (1 - fx) + s[stride + 1] * fx) * fy;
104 }
105 }
106}
107
108static void project(struct smoke *smoke, uint32_t time,
109 float *u, float *v, float *p, float *div)
110{
111 int x, y, k, l, s;
Bryce Harrington40269a62010-11-19 12:15:36 -0800112 float h;
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400113
114 h = 1.0 / smoke->width;
115 s = smoke->width;
116 memset(p, 0, smoke->height * smoke->width);
117 for (y = 1; y < smoke->height - 1; y++) {
118 l = y * s;
119 for (x = 1; x < smoke->width - 1; x++) {
120 div[l + x] = -0.5 * h * (u[l + x + 1] - u[l + x - 1] +
121 v[l + x + s] - v[l + x - s]);
122 p[l + x] = 0;
123 }
124 }
125
126 for (k = 0; k < 5; k++) {
127 for (y = 1; y < smoke->height - 1; y++) {
128 l = y * s;
129 for (x = 1; x < smoke->width - 1; x++) {
130 p[l + x] = (div[l + x] +
131 p[l + x - 1] +
132 p[l + x + 1] +
133 p[l + x - s] +
134 p[l + x + s]) / 4;
135 }
136 }
137 }
138
139 for (y = 1; y < smoke->height - 1; y++) {
140 l = y * s;
141 for (x = 1; x < smoke->width - 1; x++) {
142 u[l + x] -= 0.5 * (p[l + x + 1] - p[l + x - 1]) / h;
143 v[l + x] -= 0.5 * (p[l + x + s] - p[l + x - s]) / h;
144 }
145 }
146}
147
148static void render(struct smoke *smoke)
149{
Bryce Harrington40269a62010-11-19 12:15:36 -0800150 unsigned char *dest;
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400151 int x, y, width, height, stride;
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400152 float *s;
153 uint32_t *d, c, a;
154
155 dest = cairo_image_surface_get_data (smoke->surface);
156 width = cairo_image_surface_get_width (smoke->surface);
157 height = cairo_image_surface_get_height (smoke->surface);
158 stride = cairo_image_surface_get_stride (smoke->surface);
159
160 for (y = 1; y < height - 1; y++) {
161 s = smoke->b[smoke->current].d + y * smoke->height;
162 d = (uint32_t *) (dest + y * stride);
163 for (x = 1; x < width - 1; x++) {
164 c = (int) (s[x] * 800);
165 if (c > 255)
166 c = 255;
167 a = c;
168 if (a < 0x33)
169 a = 0x33;
170 d[x] = (a << 24) | (c << 16) | (c << 8) | c;
171 }
172 }
173}
174
175static void
Kristian Høgsberga8d1fa72011-08-23 18:14:06 -0400176frame_callback(void *data, struct wl_callback *callback, uint32_t time)
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400177{
Kristian Høgsberga8d1fa72011-08-23 18:14:06 -0400178 static const struct wl_callback_listener listener = {
179 frame_callback,
180 };
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400181 struct smoke *smoke = data;
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400182
183 diffuse(smoke, time / 30, smoke->b[0].u, smoke->b[1].u);
184 diffuse(smoke, time / 30, smoke->b[0].v, smoke->b[1].v);
185 project(smoke, time / 30,
186 smoke->b[1].u, smoke->b[1].v,
187 smoke->b[0].u, smoke->b[0].v);
188 advect(smoke, time / 30,
189 smoke->b[1].u, smoke->b[1].v,
190 smoke->b[1].u, smoke->b[0].u);
191 advect(smoke, time / 30,
192 smoke->b[1].u, smoke->b[1].v,
193 smoke->b[1].v, smoke->b[0].v);
194 project(smoke, time / 30,
195 smoke->b[0].u, smoke->b[0].v,
196 smoke->b[1].u, smoke->b[1].v);
197
198 diffuse(smoke, time / 30, smoke->b[0].d, smoke->b[1].d);
199 advect(smoke, time / 30,
200 smoke->b[0].u, smoke->b[0].v,
201 smoke->b[1].d, smoke->b[0].d);
202
203 render(smoke);
204
Kristian Høgsberga8d1fa72011-08-23 18:14:06 -0400205 if (callback)
206 wl_callback_destroy(callback);
207
Benjamin Franzkebde55ec2011-03-07 15:08:09 +0100208 display_surface_damage(smoke->display, smoke->surface,
209 0, 0, smoke->width, smoke->height);
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400210 window_damage(smoke->window, 0, 0, smoke->width, smoke->height);
Kristian Høgsberga8d1fa72011-08-23 18:14:06 -0400211
212 callback = wl_surface_frame(window_get_wl_surface(smoke->window));
213 wl_callback_add_listener(callback, &listener, smoke);
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400214}
215
216static int
Kristian Høgsberg87a57bb2012-01-09 10:34:35 -0500217smoke_motion_handler(struct widget *widget, struct input *input,
218 uint32_t time, int32_t x, int32_t y, void *data)
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400219{
220 struct smoke *smoke = data;
221 int i, i0, i1, j, j0, j1, k, d = 5;
222
Kristian Høgsberg87a57bb2012-01-09 10:34:35 -0500223 if (x - d < 1)
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400224 i0 = 1;
225 else
Kristian Høgsberg87a57bb2012-01-09 10:34:35 -0500226 i0 = x - d;
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400227 if (i0 + 2 * d > smoke->width - 1)
228 i1 = smoke->width - 1;
229 else
230 i1 = i0 + 2 * d;
231
Kristian Høgsberg87a57bb2012-01-09 10:34:35 -0500232 if (y - d < 1)
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400233 j0 = 1;
234 else
Kristian Høgsberg87a57bb2012-01-09 10:34:35 -0500235 j0 = y - d;
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400236 if (j0 + 2 * d > smoke->height - 1)
237 j1 = smoke->height - 1;
238 else
239 j1 = j0 + 2 * d;
240
241 for (i = i0; i < i1; i++)
242 for (j = j0; j < j1; j++) {
243 k = j * smoke->width + i;
244 smoke->b[0].u[k] += 256 - (random() & 512);
245 smoke->b[0].v[k] += 256 - (random() & 512);
246 smoke->b[0].d[k] += 1;
247 }
248
249 return POINTER_HAND1;
250}
251
252int main(int argc, char *argv[])
253{
254 struct timespec ts;
255 struct smoke smoke;
256 struct display *d;
Bryce Harrington40269a62010-11-19 12:15:36 -0800257 int size;
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400258
Kristian Høgsberg9de79a92011-08-24 11:09:53 -0400259 d = display_create(&argc, &argv, NULL);
Yuval Fledele9f5e362010-11-22 21:34:19 +0200260 if (d == NULL) {
261 fprintf(stderr, "failed to create display: %m\n");
262 return -1;
263 }
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400264
265 smoke.x = 200;
266 smoke.y = 200;
267 smoke.width = 200;
268 smoke.height = 200;
269 smoke.display = d;
Kristian Høgsberg009ac0a2012-01-31 15:24:48 -0500270 smoke.window = window_create(d);
Kristian Høgsberg75bc6672012-01-10 09:43:58 -0500271 smoke.widget = window_add_widget(smoke.window, &smoke);
Kristian Høgsberg248c1b62011-01-21 18:03:15 -0500272 window_set_title(smoke.window, "smoke");
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400273
274 window_set_buffer_type(smoke.window, WINDOW_BUFFER_TYPE_SHM);
275 clock_gettime(CLOCK_MONOTONIC, &ts);
276 srandom(ts.tv_nsec);
277 smoke.offset = random();
278
279 smoke.current = 0;
280 size = smoke.height * smoke.width;
281 smoke.b[0].d = calloc(size, sizeof(float));
282 smoke.b[0].u = calloc(size, sizeof(float));
283 smoke.b[0].v = calloc(size, sizeof(float));
284 smoke.b[1].d = calloc(size, sizeof(float));
285 smoke.b[1].u = calloc(size, sizeof(float));
286 smoke.b[1].v = calloc(size, sizeof(float));
287
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400288 window_create_surface(smoke.window);
289 smoke.surface = window_get_surface(smoke.window);
290
291 window_flush(smoke.window);
292
Kristian Høgsberg75bc6672012-01-10 09:43:58 -0500293 widget_set_motion_handler(smoke.widget, smoke_motion_handler);
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400294
295 window_set_user_data(smoke.window, &smoke);
Kristian Høgsberga8d1fa72011-08-23 18:14:06 -0400296 frame_callback(&smoke, NULL, 0);
Kristian Høgsberg012a0072010-10-26 00:02:20 -0400297 display_run(d);
298
299 return 0;
300}