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#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <assert.h>
#include <xcb/xcb.h>
#include <xcb/shm.h>
#include <xcb/xcb_aux.h>
#include <xcb/xcb_image.h>
#define XCB_ALL_PLANES ~0
/* Needed for xcb_set_wm_protocols() */
#include <xcb/xcb_icccm.h>
#include "julia.h"
#define W_W 640
#define W_H 480
/* Parameters of the fractal */
/* double cr = -0.7927; */
/* double ci = 0.1609; */
/* double cr = 0.32; */
/* double ci = 0.043; */
/* double cr = -1.1380; */
/* double ci = -0.2403; */
/* double cr = -0.0986; */
/* double ci = -0.65186; */
/* double cr = -0.1225; */
/* double ci = 0.7449; */
double cr = -0.3380;
double ci = -0.6230;
double origin_x = -1.8;
double origin_y = -1.2;
double width = 3.6;
double height = 2.4;
/* Numbers of colors in the palette */
int cmax = 316;
static xcb_atom_t
get_atom (xcb_connection_t *connection, const char *atomName)
{
if (atomName == NULL)
return XCB_NONE;
xcb_atom_t atom = XCB_NONE;
xcb_intern_atom_reply_t *reply = xcb_intern_atom_reply(connection,
xcb_intern_atom(connection, 0, strlen(atomName), atomName), NULL);
if (reply)
{
atom = reply->atom;
free(reply);
}
return atom;
}
void
palette_julia (Data *datap)
{
xcb_alloc_color_reply_t *rep;
int i;
datap->palette = (uint32_t *)malloc (sizeof (uint32_t) * cmax);
for (i = 0 ; i < cmax ; i++)
{
if (i < 128)
rep = xcb_alloc_color_reply (datap->conn,
xcb_alloc_color (datap->conn,
datap->cmap,
i<<9, 0, 0),
0);
else if (i < 255)
rep = xcb_alloc_color_reply (datap->conn,
xcb_alloc_color (datap->conn,
datap->cmap,
65535, (i-127)<<9, 0),
0);
else
rep = xcb_alloc_color_reply (datap->conn,
xcb_alloc_color (datap->conn,
datap->cmap,
65535, 65535, (i-255)<<10),
0);
if (!rep)
datap->palette[i] = 0;
else
datap->palette[i] = rep->pixel;
free (rep);
}
}
void
draw_julia (Data *datap)
{
double zr, zi, t;
int c;
int i, j;
datap->image = xcb_image_get (datap->conn, datap->draw,
0, 0, W_W, W_H,
XCB_ALL_PLANES, datap->format);
assert(datap->image);
for (i = 0 ; i < datap->image->width ; i++)
for (j = 0 ; j < datap->image->height ; j++)
{
zr = origin_x + width * (double)i / (double)datap->image->width;
zi = origin_y + height * (double)j / (double)datap->image->height;
c = 0;
while ((zr*zr + zi*zi < 4.0) &&
(c < cmax-1))
{
t = zr;
zr = zr*zr - zi*zi + cr;
zi = 2.0*t*zi + ci;
c++;
}
xcb_image_put_pixel (datap->image,
i,j,
datap->palette[c]);
}
xcb_image_put (datap->conn, datap->draw, datap->gc, datap->image,
0, 0, 0);
}
int
main (int argc, char *argv[])
{
Data data;
xcb_screen_t *screen;
xcb_drawable_t win;
xcb_drawable_t rect;
xcb_gcontext_t bgcolor;
uint32_t mask;
uint32_t valgc[2];
uint32_t valwin[3];
xcb_rectangle_t rect_coord = { 0, 0, W_W, W_H};
int screen_num;
data.conn = xcb_connect (0, &screen_num);
screen = xcb_aux_get_screen (data.conn, screen_num);
data.depth = xcb_aux_get_depth (data.conn, screen);
win = screen->root;
data.gc = xcb_generate_id (data.conn);
mask = XCB_GC_FOREGROUND | XCB_GC_GRAPHICS_EXPOSURES;
valgc[0] = screen->black_pixel;
valgc[1] = 0; /* no graphics exposures */
xcb_create_gc (data.conn, data.gc, win, mask, valgc);
bgcolor = xcb_generate_id (data.conn);
mask = XCB_GC_FOREGROUND | XCB_GC_GRAPHICS_EXPOSURES;
valgc[0] = screen->white_pixel;
valgc[1] = 0; /* no graphics exposures */
xcb_create_gc (data.conn, bgcolor, win, mask, valgc);
data.draw = xcb_generate_id (data.conn);
mask = XCB_CW_BACK_PIXEL | XCB_CW_EVENT_MASK | XCB_CW_DONT_PROPAGATE;
valwin[0] = screen->white_pixel;
valwin[1] = XCB_EVENT_MASK_BUTTON_PRESS | XCB_EVENT_MASK_EXPOSURE;
valwin[2] = XCB_EVENT_MASK_BUTTON_PRESS;
xcb_create_window (data.conn, 0,
data.draw,
screen->root,
0, 0, W_W, W_H,
10,
XCB_WINDOW_CLASS_INPUT_OUTPUT,
screen->root_visual,
mask, valwin);
xcb_map_window (data.conn, data.draw);
rect = xcb_generate_id (data.conn);
xcb_create_pixmap (data.conn, data.depth,
rect, data.draw,
W_W, W_H);
xcb_poly_fill_rectangle(data.conn, rect, bgcolor, 1, &rect_coord);
xcb_map_window (data.conn, data.draw);
data.format = XCB_IMAGE_FORMAT_Z_PIXMAP;
data.cmap = xcb_generate_id (data.conn);
xcb_create_colormap (data.conn,
XCB_COLORMAP_ALLOC_NONE,
data.cmap,
data.draw,
screen->root_visual);
palette_julia (&data);
xcb_atom_t deleteWindowAtom = get_atom(data.conn, "WM_DELETE_WINDOW");
/* Listen to X client messages in order to be able to pickup
the "delete window" message that is generated for example
when someone clicks the top-right X button within the window
manager decoration (or when user hits ALT-F4). */
xcb_set_wm_protocols (data.conn, data.draw, 1, &deleteWindowAtom);
xcb_flush (data.conn);
bool finished = false;
while (!finished)
{
xcb_generic_event_t *e;
if (e = xcb_wait_for_event(data.conn))
{
switch (e->response_type & 0x7f)
{
case XCB_EXPOSE:
{
xcb_copy_area(data.conn, rect, data.draw, bgcolor,
0, 0, 0, 0, W_W, W_H);
draw_julia (&data);
xcb_flush (data.conn);
break;
}
case XCB_CLIENT_MESSAGE:
{
if (((xcb_client_message_event_t *)e)->data.data32[0] == deleteWindowAtom)
{
finished = true;
}
break;
}
case XCB_BUTTON_PRESS:
{
finished = true;
break;
}
}
free (e);
}
}
if (data.palette)
free (data.palette);
if (data.image)
xcb_image_destroy (data.image);
xcb_disconnect (data.conn);
return 0;
}
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