nuklear/demo/x11/main.c

/* nuklear - v1.00 - public domain */
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <time.h>
#include <sys/time.h>
#include <unistd.h>
#include <math.h>

#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xresource.h>

#define DTIME       20
#define WINDOW_WIDTH 800
#define WINDOW_HEIGHT 600

#define NK_INCLUDE_FIXED_TYPES
#define NK_INCLUDE_DEFAULT_ALLOCATOR
#include "nuklear_xlib.h"
#include "nuklear_xlib.c"

typedef struct XWindow XWindow;
struct XWindow {
    Display *dpy;
    Window root;
    Visual *vis;
    Colormap cmap;
    XWindowAttributes attr;
    XSetWindowAttributes swa;
    Window win;
    int screen;
    XFont *font;
    unsigned int width;
    unsigned int height;
};

static void
die(const char *fmt, ...)
{
    va_list ap;
    va_start(ap, fmt);
    vfprintf(stderr, fmt, ap);
    va_end(ap);
    fputs("\n", stderr);
    exit(EXIT_FAILURE);
}

static void*
xcalloc(size_t siz, size_t n)
{
    void *ptr = calloc(siz, n);
    if (!ptr) die("Out of memory\n");
    return ptr;
}

static long
timestamp(void)
{
    struct timeval tv;
    if (gettimeofday(&tv, NULL) < 0) return 0;
    return (long)((long)tv.tv_sec * 1000 + (long)tv.tv_usec/1000);
}

static void
sleep_for(long t)
{
    struct timespec req;
    const time_t sec = (int)(t/1000);
    const long ms = t - (sec * 1000);
    req.tv_sec = sec;
    req.tv_nsec = ms * 1000000L;
    while(-1 == nanosleep(&req, &req));
}

int
main(void)
{
    long dt;
    long started;
    int running = 1;
    XWindow xw;
    struct nk_context *ctx;

    /* X11 */
    memset(&xw, 0, sizeof xw);
    xw.dpy = XOpenDisplay(NULL);
    xw.root = DefaultRootWindow(xw.dpy);
    xw.screen = XDefaultScreen(xw.dpy);
    xw.vis = XDefaultVisual(xw.dpy, xw.screen);
    xw.cmap = XCreateColormap(xw.dpy,xw.root,xw.vis,AllocNone);
    xw.swa.colormap = xw.cmap;
    xw.swa.event_mask =
        ExposureMask | KeyPressMask | KeyReleaseMask |
        ButtonPress | ButtonReleaseMask| ButtonMotionMask |
        Button1MotionMask | Button3MotionMask | Button4MotionMask | Button5MotionMask|
        PointerMotionMask | KeymapStateMask;
    xw.win = XCreateWindow(xw.dpy, xw.root, 0, 0, WINDOW_WIDTH, WINDOW_HEIGHT, 0,
        XDefaultDepth(xw.dpy, xw.screen), InputOutput,
        xw.vis, CWEventMask | CWColormap, &xw.swa);
    XStoreName(xw.dpy, xw.win, "X11");
    XMapWindow(xw.dpy, xw.win);
    XGetWindowAttributes(xw.dpy, xw.win, &xw.attr);
    xw.width = (unsigned int)xw.attr.width;
    xw.height = (unsigned int)xw.attr.height;


    /* GUI */
    xw.font = nk_xfont_create(xw.dpy, "fixed");
    ctx = nk_xlib_init(xw.font, xw.dpy, xw.screen, xw.win, xw.width, xw.height);
    while (running)
    {
        /* Input */
        XEvent evt;
        started = timestamp();
        nk_input_begin(ctx);
        while (XCheckWindowEvent(xw.dpy, xw.win, xw.swa.event_mask, &evt)){
            if (XFilterEvent(&evt, xw.win)) continue;
            nk_xlib_handle_event(xw.dpy, xw.screen, xw.win, &evt);
        }
        nk_input_end(ctx);

        /* GUI */
        {struct nk_panel layout;
        if (nk_begin(ctx, &layout, "Demo", nk_rect(50, 50, 200, 300),
            NK_WINDOW_BORDER|NK_WINDOW_MOVABLE|NK_WINDOW_SCALABLE|
            NK_WINDOW_CLOSABLE|NK_WINDOW_MINIMIZABLE|NK_WINDOW_TITLE))
        {
            enum {EASY, HARD};
            static int op = EASY;
            static int property = 20;

            nk_layout_row_static(ctx, 30, 80, 1);
            if (nk_button_label(ctx, "button", NK_BUTTON_DEFAULT))
                fprintf(stdout, "button pressed\n");
            nk_layout_row_dynamic(ctx, 30, 2);
            if (nk_option_label(ctx, "easy", op == EASY)) op = EASY;
            if (nk_option_label(ctx, "hard", op == HARD)) op = HARD;
            nk_layout_row_dynamic(ctx, 22, 1);
            nk_property_int(ctx, "Compression:", 0, &property, 100, 10, 1);
            nk_layout_row_dynamic(ctx, 100, 1);
        }
        nk_end(ctx);}
        if (nk_window_is_closed(ctx, "Demo")) break;

        /* Draw */
        XClearWindow(xw.dpy, xw.win);
        nk_xlib_render(xw.win, nk_rgb(30,30,30));
        XFlush(xw.dpy);

        /* Timing */
        dt = timestamp() - started;
        if (dt < DTIME)
            sleep_for(DTIME - dt);
    }

    nk_xfont_del(xw.dpy, xw.font);
    nk_xlib_shutdown();
    XUnmapWindow(xw.dpy, xw.win);
    XFreeColormap(xw.dpy, xw.cmap);
    XDestroyWindow(xw.dpy, xw.win);
    XCloseDisplay(xw.dpy);
    return 0;
}