2 * Copyright © 2010 Kristian Høgsberg
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.
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
35 #include "wayland-client.h"
36 #include "wayland-glib.h"
40 struct display *display;
41 struct window *window;
42 cairo_surface_t *surface;
43 int x, y, width, height;
45 struct { float *d, *u, *v; } b[2];
48 static void diffuse(struct smoke *smoke, uint32_t time,
49 float *source, float *dest)
55 stride = smoke->width;
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;
70 static void advect(struct smoke *smoke, uint32_t time,
71 float *uu, float *vv, float *source, float *dest)
79 stride = smoke->width;
81 for (y = 1; y < smoke->height - 1; y++) {
82 d = dest + y * stride;
86 for (x = 1; x < smoke->width - 1; x++) {
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;
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;
108 static void project(struct smoke *smoke, uint32_t time,
109 float *u, float *v, float *p, float *div)
114 h = 1.0 / smoke->width;
116 memset(p, 0, smoke->height * smoke->width);
117 for (y = 1; y < smoke->height - 1; y++) {
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]);
126 for (k = 0; k < 5; k++) {
127 for (y = 1; y < smoke->height - 1; y++) {
129 for (x = 1; x < smoke->width - 1; x++) {
130 p[l + x] = (div[l + x] +
139 for (y = 1; y < smoke->height - 1; y++) {
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;
148 static void render(struct smoke *smoke)
151 int x, y, width, height, stride;
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);
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);
170 d[x] = (a << 24) | (c << 16) | (c << 8) | c;
176 frame_callback(void *data, uint32_t time)
178 struct smoke *smoke = data;
180 diffuse(smoke, time / 30, smoke->b[0].u, smoke->b[1].u);
181 diffuse(smoke, time / 30, smoke->b[0].v, smoke->b[1].v);
182 project(smoke, time / 30,
183 smoke->b[1].u, smoke->b[1].v,
184 smoke->b[0].u, smoke->b[0].v);
185 advect(smoke, time / 30,
186 smoke->b[1].u, smoke->b[1].v,
187 smoke->b[1].u, smoke->b[0].u);
188 advect(smoke, time / 30,
189 smoke->b[1].u, smoke->b[1].v,
190 smoke->b[1].v, smoke->b[0].v);
191 project(smoke, time / 30,
192 smoke->b[0].u, smoke->b[0].v,
193 smoke->b[1].u, smoke->b[1].v);
195 diffuse(smoke, time / 30, smoke->b[0].d, smoke->b[1].d);
196 advect(smoke, time / 30,
197 smoke->b[0].u, smoke->b[0].v,
198 smoke->b[1].d, smoke->b[0].d);
202 window_damage(smoke->window, 0, 0, smoke->width, smoke->height);
203 wl_display_frame_callback(display_get_display(smoke->display),
204 frame_callback, smoke);
208 smoke_motion_handler(struct window *window,
209 struct input *input, uint32_t time,
210 int32_t x, int32_t y,
211 int32_t surface_x, int32_t surface_y, void *data)
213 struct smoke *smoke = data;
214 int i, i0, i1, j, j0, j1, k, d = 5;
216 if (surface_x - d < 1)
220 if (i0 + 2 * d > smoke->width - 1)
221 i1 = smoke->width - 1;
225 if (surface_y - d < 1)
229 if (j0 + 2 * d > smoke->height - 1)
230 j1 = smoke->height - 1;
234 for (i = i0; i < i1; i++)
235 for (j = j0; j < j1; j++) {
236 k = j * smoke->width + i;
237 smoke->b[0].u[k] += 256 - (random() & 512);
238 smoke->b[0].v[k] += 256 - (random() & 512);
239 smoke->b[0].d[k] += 1;
242 return POINTER_HAND1;
245 int main(int argc, char *argv[])
252 d = display_create(&argc, &argv, NULL, NULL);
254 fprintf(stderr, "failed to create display: %m\n");
263 smoke.window = window_create(d, smoke.width, smoke.height);
264 window_set_title(smoke.window, "smoke");
266 window_set_buffer_type(smoke.window, WINDOW_BUFFER_TYPE_SHM);
267 clock_gettime(CLOCK_MONOTONIC, &ts);
269 smoke.offset = random();
272 size = smoke.height * smoke.width;
273 smoke.b[0].d = calloc(size, sizeof(float));
274 smoke.b[0].u = calloc(size, sizeof(float));
275 smoke.b[0].v = calloc(size, sizeof(float));
276 smoke.b[1].d = calloc(size, sizeof(float));
277 smoke.b[1].u = calloc(size, sizeof(float));
278 smoke.b[1].v = calloc(size, sizeof(float));
280 window_set_decoration(smoke.window, 0);
281 window_create_surface(smoke.window);
282 smoke.surface = window_get_surface(smoke.window);
284 window_flush(smoke.window);
286 window_set_motion_handler(smoke.window,
287 smoke_motion_handler);
289 window_set_user_data(smoke.window, &smoke);
290 wl_display_frame_callback(display_get_display(d),
291 frame_callback, &smoke);