weston/clients/smoke.c

317 lines
7.8 KiB
C

/*
* Copyright © 2010 Kristian Høgsberg
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#include "config.h"
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <math.h>
#include <cairo.h>
#include <wayland-client.h>
#include "window.h"
struct smoke {
struct display *display;
struct window *window;
struct widget *widget;
int width, height;
int current;
struct { float *d, *u, *v; } b[2];
};
static void diffuse(struct smoke *smoke, uint32_t time,
float *source, float *dest)
{
float *s, *d;
int x, y, k, stride;
float t, a = 0.0002;
stride = smoke->width;
for (k = 0; k < 5; k++) {
for (y = 1; y < smoke->height - 1; y++) {
s = source + y * stride;
d = dest + y * stride;
for (x = 1; x < smoke->width - 1; x++) {
t = d[x - 1] + d[x + 1] +
d[x - stride] + d[x + stride];
d[x] = (s[x] + a * t) / (1 + 4 * a) * 0.995;
}
}
}
}
static void advect(struct smoke *smoke, uint32_t time,
float *uu, float *vv, float *source, float *dest)
{
float *s, *d;
float *u, *v;
int x, y, stride;
int i, j;
float px, py, fx, fy;
stride = smoke->width;
for (y = 1; y < smoke->height - 1; y++) {
d = dest + y * stride;
u = uu + y * stride;
v = vv + y * stride;
for (x = 1; x < smoke->width - 1; x++) {
px = x - u[x];
py = y - v[x];
if (px < 0.5)
px = 0.5;
if (py < 0.5)
py = 0.5;
if (px > smoke->width - 1.5)
px = smoke->width - 1.5;
if (py > smoke->height - 1.5)
py = smoke->height - 1.5;
i = (int) px;
j = (int) py;
fx = px - i;
fy = py - j;
s = source + j * stride + i;
d[x] = (s[0] * (1 - fx) + s[1] * fx) * (1 - fy) +
(s[stride] * (1 - fx) + s[stride + 1] * fx) * fy;
}
}
}
static void project(struct smoke *smoke, uint32_t time,
float *u, float *v, float *p, float *div)
{
int x, y, k, l, s;
float h;
h = 1.0 / smoke->width;
s = smoke->width;
memset(p, 0, smoke->height * smoke->width);
for (y = 1; y < smoke->height - 1; y++) {
l = y * s;
for (x = 1; x < smoke->width - 1; x++) {
div[l + x] = -0.5 * h * (u[l + x + 1] - u[l + x - 1] +
v[l + x + s] - v[l + x - s]);
p[l + x] = 0;
}
}
for (k = 0; k < 5; k++) {
for (y = 1; y < smoke->height - 1; y++) {
l = y * s;
for (x = 1; x < smoke->width - 1; x++) {
p[l + x] = (div[l + x] +
p[l + x - 1] +
p[l + x + 1] +
p[l + x - s] +
p[l + x + s]) / 4;
}
}
}
for (y = 1; y < smoke->height - 1; y++) {
l = y * s;
for (x = 1; x < smoke->width - 1; x++) {
u[l + x] -= 0.5 * (p[l + x + 1] - p[l + x - 1]) / h;
v[l + x] -= 0.5 * (p[l + x + s] - p[l + x - s]) / h;
}
}
}
static void render(struct smoke *smoke, cairo_surface_t *surface)
{
unsigned char *dest;
int x, y, width, height, stride;
float *s;
uint32_t *d, c, a;
dest = cairo_image_surface_get_data(surface);
width = cairo_image_surface_get_width(surface);
height = cairo_image_surface_get_height(surface);
stride = cairo_image_surface_get_stride(surface);
for (y = 1; y < height - 1; y++) {
s = smoke->b[smoke->current].d + y * smoke->height;
d = (uint32_t *) (dest + y * stride);
for (x = 1; x < width - 1; x++) {
c = (int) (s[x] * 800);
if (c > 255)
c = 255;
a = c;
if (a < 0x33)
a = 0x33;
d[x] = (a << 24) | (c << 16) | (c << 8) | c;
}
}
}
static void
redraw_handler(struct widget *widget, void *data)
{
struct smoke *smoke = data;
uint32_t time = widget_get_last_time(smoke->widget);
cairo_surface_t *surface;
diffuse(smoke, time / 30, smoke->b[0].u, smoke->b[1].u);
diffuse(smoke, time / 30, smoke->b[0].v, smoke->b[1].v);
project(smoke, time / 30,
smoke->b[1].u, smoke->b[1].v,
smoke->b[0].u, smoke->b[0].v);
advect(smoke, time / 30,
smoke->b[1].u, smoke->b[1].v,
smoke->b[1].u, smoke->b[0].u);
advect(smoke, time / 30,
smoke->b[1].u, smoke->b[1].v,
smoke->b[1].v, smoke->b[0].v);
project(smoke, time / 30,
smoke->b[0].u, smoke->b[0].v,
smoke->b[1].u, smoke->b[1].v);
diffuse(smoke, time / 30, smoke->b[0].d, smoke->b[1].d);
advect(smoke, time / 30,
smoke->b[0].u, smoke->b[0].v,
smoke->b[1].d, smoke->b[0].d);
surface = window_get_surface(smoke->window);
render(smoke, surface);
cairo_surface_destroy(surface);
widget_schedule_redraw(smoke->widget);
}
static void
smoke_motion_handler(struct smoke *smoke, float x, float y)
{
int i, i0, i1, j, j0, j1, k, d = 5;
if (x - d < 1)
i0 = 1;
else
i0 = x - d;
if (i0 + 2 * d > smoke->width - 1)
i1 = smoke->width - 1;
else
i1 = i0 + 2 * d;
if (y - d < 1)
j0 = 1;
else
j0 = y - d;
if (j0 + 2 * d > smoke->height - 1)
j1 = smoke->height - 1;
else
j1 = j0 + 2 * d;
for (i = i0; i < i1; i++)
for (j = j0; j < j1; j++) {
k = j * smoke->width + i;
smoke->b[0].u[k] += 256 - (random() & 512);
smoke->b[0].v[k] += 256 - (random() & 512);
smoke->b[0].d[k] += 1;
}
}
static int
mouse_motion_handler(struct widget *widget, struct input *input,
uint32_t time, float x, float y, void *data)
{
smoke_motion_handler(data, x, y);
return CURSOR_HAND1;
}
static void
touch_motion_handler(struct widget *widget, struct input *input,
uint32_t time, int32_t id, float x, float y, void *data)
{
smoke_motion_handler(data, x, y);
}
static void
resize_handler(struct widget *widget,
int32_t width, int32_t height, void *data)
{
struct smoke *smoke = data;
/* Don't resize me */
widget_set_size(smoke->widget, smoke->width, smoke->height);
}
int main(int argc, char *argv[])
{
struct timespec ts;
struct smoke smoke;
struct display *d;
int size;
d = display_create(&argc, argv);
if (d == NULL) {
fprintf(stderr, "failed to create display: %m\n");
return -1;
}
smoke.width = 200;
smoke.height = 200;
smoke.display = d;
smoke.window = window_create(d);
smoke.widget = window_add_widget(smoke.window, &smoke);
window_set_title(smoke.window, "smoke");
window_set_buffer_type(smoke.window, WINDOW_BUFFER_TYPE_SHM);
clock_gettime(CLOCK_MONOTONIC, &ts);
srandom(ts.tv_nsec);
smoke.current = 0;
size = smoke.height * smoke.width;
smoke.b[0].d = calloc(size, sizeof(float));
smoke.b[0].u = calloc(size, sizeof(float));
smoke.b[0].v = calloc(size, sizeof(float));
smoke.b[1].d = calloc(size, sizeof(float));
smoke.b[1].u = calloc(size, sizeof(float));
smoke.b[1].v = calloc(size, sizeof(float));
widget_set_motion_handler(smoke.widget, mouse_motion_handler);
widget_set_touch_motion_handler(smoke.widget, touch_motion_handler);
widget_set_resize_handler(smoke.widget, resize_handler);
widget_set_redraw_handler(smoke.widget, redraw_handler);
window_set_user_data(smoke.window, &smoke);
widget_schedule_resize(smoke.widget, smoke.width, smoke.height);
display_run(d);
widget_destroy(smoke.widget);
window_destroy(smoke.window);
display_destroy(d);
return 0;
}