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
33 #include <wayland-client.h>
37 struct display *display;
38 struct window *window;
39 struct widget *widget;
43 struct { float *d, *u, *v; } b[2];
46 static void diffuse(struct smoke *smoke, uint32_t time,
47 float *source, float *dest)
53 stride = smoke->width;
55 for (k = 0; k < 5; k++) {
56 for (y = 1; y < smoke->height - 1; y++) {
57 s = source + y * stride;
58 d = dest + y * stride;
59 for (x = 1; x < smoke->width - 1; x++) {
60 t = d[x - 1] + d[x + 1] +
61 d[x - stride] + d[x + stride];
62 d[x] = (s[x] + a * t) / (1 + 4 * a) * 0.995;
68 static void advect(struct smoke *smoke, uint32_t time,
69 float *uu, float *vv, float *source, float *dest)
77 stride = smoke->width;
79 for (y = 1; y < smoke->height - 1; y++) {
80 d = dest + y * stride;
84 for (x = 1; x < smoke->width - 1; x++) {
91 if (px > smoke->width - 0.5)
92 px = smoke->width - 0.5;
93 if (py > smoke->height - 0.5)
94 py = smoke->height - 0.5;
99 s = source + j * stride + i;
100 d[x] = (s[0] * (1 - fx) + s[1] * fx) * (1 - fy) +
101 (s[stride] * (1 - fx) + s[stride + 1] * fx) * fy;
106 static void project(struct smoke *smoke, uint32_t time,
107 float *u, float *v, float *p, float *div)
112 h = 1.0 / smoke->width;
114 memset(p, 0, smoke->height * smoke->width);
115 for (y = 1; y < smoke->height - 1; y++) {
117 for (x = 1; x < smoke->width - 1; x++) {
118 div[l + x] = -0.5 * h * (u[l + x + 1] - u[l + x - 1] +
119 v[l + x + s] - v[l + x - s]);
124 for (k = 0; k < 5; k++) {
125 for (y = 1; y < smoke->height - 1; y++) {
127 for (x = 1; x < smoke->width - 1; x++) {
128 p[l + x] = (div[l + x] +
137 for (y = 1; y < smoke->height - 1; y++) {
139 for (x = 1; x < smoke->width - 1; x++) {
140 u[l + x] -= 0.5 * (p[l + x + 1] - p[l + x - 1]) / h;
141 v[l + x] -= 0.5 * (p[l + x + s] - p[l + x - s]) / h;
146 static void render(struct smoke *smoke, cairo_surface_t *surface)
149 int x, y, width, height, stride;
153 dest = cairo_image_surface_get_data(surface);
154 width = cairo_image_surface_get_width(surface);
155 height = cairo_image_surface_get_height(surface);
156 stride = cairo_image_surface_get_stride(surface);
158 for (y = 1; y < height - 1; y++) {
159 s = smoke->b[smoke->current].d + y * smoke->height;
160 d = (uint32_t *) (dest + y * stride);
161 for (x = 1; x < width - 1; x++) {
162 c = (int) (s[x] * 800);
168 d[x] = (a << 24) | (c << 16) | (c << 8) | c;
174 frame_callback(void *data, struct wl_callback *callback, uint32_t time)
176 struct smoke *smoke = data;
178 window_schedule_redraw(smoke->window);
182 wl_callback_destroy(callback);
185 static const struct wl_callback_listener listener = {
190 redraw_handler(struct widget *widget, void *data)
192 struct smoke *smoke = data;
193 uint32_t time = smoke->time;
194 struct wl_callback *callback;
195 cairo_surface_t *surface;
197 diffuse(smoke, time / 30, smoke->b[0].u, smoke->b[1].u);
198 diffuse(smoke, time / 30, smoke->b[0].v, smoke->b[1].v);
199 project(smoke, time / 30,
200 smoke->b[1].u, smoke->b[1].v,
201 smoke->b[0].u, smoke->b[0].v);
202 advect(smoke, time / 30,
203 smoke->b[1].u, smoke->b[1].v,
204 smoke->b[1].u, smoke->b[0].u);
205 advect(smoke, time / 30,
206 smoke->b[1].u, smoke->b[1].v,
207 smoke->b[1].v, smoke->b[0].v);
208 project(smoke, time / 30,
209 smoke->b[0].u, smoke->b[0].v,
210 smoke->b[1].u, smoke->b[1].v);
212 diffuse(smoke, time / 30, smoke->b[0].d, smoke->b[1].d);
213 advect(smoke, time / 30,
214 smoke->b[0].u, smoke->b[0].v,
215 smoke->b[1].d, smoke->b[0].d);
217 surface = window_get_surface(smoke->window);
219 render(smoke, surface);
221 window_damage(smoke->window, 0, 0, smoke->width, smoke->height);
223 cairo_surface_destroy(surface);
225 callback = wl_surface_frame(window_get_wl_surface(smoke->window));
226 wl_callback_add_listener(callback, &listener, smoke);
227 wl_surface_commit(window_get_wl_surface(smoke->window));
231 smoke_motion_handler(struct smoke *smoke, float x, float y)
233 int i, i0, i1, j, j0, j1, k, d = 5;
239 if (i0 + 2 * d > smoke->width - 1)
240 i1 = smoke->width - 1;
248 if (j0 + 2 * d > smoke->height - 1)
249 j1 = smoke->height - 1;
253 for (i = i0; i < i1; i++)
254 for (j = j0; j < j1; j++) {
255 k = j * smoke->width + i;
256 smoke->b[0].u[k] += 256 - (random() & 512);
257 smoke->b[0].v[k] += 256 - (random() & 512);
258 smoke->b[0].d[k] += 1;
263 mouse_motion_handler(struct widget *widget, struct input *input,
264 uint32_t time, float x, float y, void *data)
266 smoke_motion_handler(data, x, y);
272 touch_motion_handler(struct widget *widget, struct input *input,
273 uint32_t time, int32_t id, float x, float y, void *data)
275 smoke_motion_handler(data, x, y);
279 resize_handler(struct widget *widget,
280 int32_t width, int32_t height, void *data)
282 struct smoke *smoke = data;
285 widget_set_size(smoke->widget, smoke->width, smoke->height);
288 int main(int argc, char *argv[])
295 d = display_create(&argc, argv);
297 fprintf(stderr, "failed to create display: %m\n");
304 smoke.window = window_create(d);
305 smoke.widget = window_add_widget(smoke.window, &smoke);
306 window_set_title(smoke.window, "smoke");
308 window_set_buffer_type(smoke.window, WINDOW_BUFFER_TYPE_SHM);
309 clock_gettime(CLOCK_MONOTONIC, &ts);
313 size = smoke.height * smoke.width;
314 smoke.b[0].d = calloc(size, sizeof(float));
315 smoke.b[0].u = calloc(size, sizeof(float));
316 smoke.b[0].v = calloc(size, sizeof(float));
317 smoke.b[1].d = calloc(size, sizeof(float));
318 smoke.b[1].u = calloc(size, sizeof(float));
319 smoke.b[1].v = calloc(size, sizeof(float));
321 widget_set_motion_handler(smoke.widget, mouse_motion_handler);
322 widget_set_touch_motion_handler(smoke.widget, touch_motion_handler);
323 widget_set_resize_handler(smoke.widget, resize_handler);
324 widget_set_redraw_handler(smoke.widget, redraw_handler);
326 window_set_user_data(smoke.window, &smoke);
328 widget_schedule_resize(smoke.widget, smoke.width, smoke.height);
332 widget_destroy(smoke.widget);
333 window_destroy(smoke.window);