#include <stdio.h>
#include <X11/Xos.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>

#define WIDTH	320
#define HEIGHT	240

#define RSIZE	4
#define GSIZE	4
#define BSIZE	4

Display *dpy;
int scr;
Window win;
GC gc;
XColor defs[RSIZE][GSIZE][BSIZE];
XImage *image;

XImage *init_ximage(int w,int h) {
    int format, bitmap_pad, depth;
    XImage *image;
    depth = DefaultDepth(dpy,scr);
    if (depth == 1) {
	format = XYPixmap; bitmap_pad = 32;
    } else if (depth == 8){
	format = ZPixmap; bitmap_pad = 8;
    } else if (depth == 16){
	format = ZPixmap; bitmap_pad = 16;
    } else if (depth==24) {
	format = ZPixmap; bitmap_pad = 32;
    } else {
	fprintf(stderr,"unsupported depth %d\n",depth);
	exit(-1);
    }
    image = XCreateImage(dpy,DefaultVisual(dpy,scr),depth,format,0,0,
			 w,h,bitmap_pad,0);
    if (image == 0) {
	fprintf(stderr,"XImage structure allocation failure\n");
	exit(-1);
    }
    if ((image->data =(char *) malloc(image->bytes_per_line * h)) == NULL) {
	fprintf(stderr,"image memory allocation failure\n");
	exit(-1);
    }
    return(image);
}

void init_cmap() {
    Colormap cmap;
    int i,j,k;

    cmap=DefaultColormap(dpy,scr);
    for (i=0; i<RSIZE; ++i) {
	for (j=0; j<GSIZE; ++j) {
	    for (k=0; k<BSIZE; ++k) {
		defs[i][j][k].red=(255 * i / (RSIZE-1)) << 8;
		defs[i][j][k].green=(255 * j / (GSIZE-1))<< 8;
		defs[i][j][k].blue=(255 * k / (BSIZE-1)) << 8;
		defs[i][j][k].flags=DoRed|DoGreen|DoBlue;
		if (!XAllocColor(dpy,cmap,&defs[i][j][k])) {
		    fprintf(stderr,"XAllocColor failed\n");
		    exit(-1);
		}
	    }
	}
    }
}

int init_xwin(int width, int height) {
    XGCValues gcv;
    XSetWindowAttributes xswa;
  
    if ((dpy = XOpenDisplay(NULL)) == NULL) {
	fprintf(stderr, "cant open display\n");
	exit(1);
    }
    scr = DefaultScreen(dpy);
    xswa.background_pixel = BlackPixel(dpy,scr);
    xswa.border_pixel = BlackPixel(dpy,scr);
    xswa.event_mask = ExposureMask | ButtonPressMask;
    win=XCreateWindow(dpy,RootWindow(dpy,scr),0,0,width,height,1,
		      CopyFromParent,CopyFromParent,CopyFromParent,
		      (CWBackPixel|CWBorderPixel|CWEventMask),&xswa);
    init_cmap();
    gcv.foreground = WhitePixel(dpy,scr);
    gcv.background = BlackPixel(dpy,scr);
    gcv.line_width = 1;
    gc = XCreateGC(dpy,win,(GCForeground|GCBackground|GCLineWidth),&gcv);
    XMapWindow(dpy,win);
}

#define N_DITH	4
int bayer[N_DITH][N_DITH] = {
    {  0,  8,  2, 10 },
    { 12,  4, 14,  6 },
    {  3, 11,  1,  9 },
    { 15,  7, 13,  5 }
};

int dither(int d,int csize,int x,int y) {
    int n,e,span;
    span = 255 / csize;
    n = d / span;
    if (n == csize) return(n);
    e = d - n * span;
    if (e * N_DITH * N_DITH
	> bayer[x%N_DITH][y%N_DITH] * span) return(n+1);
    else return(n);
}

void set_rgb(XImage *image,int x0,int y0,unsigned char *data,int w,int h) {
    int x,y;
    unsigned int r,g,b;
    unsigned long red,green,blue;
    unsigned char *s=data;

    for (y=y0; y<y0+h; ++y) {
	for (x=x0; x<x0+w; ++x) {
	    red = *s++; green = *s++; blue = *s++;
	    r = dither(red,RSIZE-1,x,y);
	    g = dither(green,GSIZE-1,x,y);
	    b = dither(blue,BSIZE-1,x,y);
	    XPutPixel(image,x,y,defs[r][g][b].pixel);
	}
    }
}

unsigned char *load_rgb(char *fname,int w,int h) {
    FILE *fp;
    unsigned char *data,*s;
    int i;
    if ((data=(unsigned char *)malloc(w*h*3)) == NULL) {
	fprintf(stderr,"can not malloc %d\n",w*h*3); exit(-1);
    }
    if ((fp=fopen(fname,"r")) == NULL) {
	fprintf(stderr,"can not open %s\n",fname); exit(-1);
    }
    for (i=0,s=data; i<w*h*3; ++i) {
	*s++ = (unsigned char) getc(fp);
    }
    fclose(fp);
    return(data);
}

int main(int argc, char **argv) {
    int ac=argc;
    char **av=argv;
    char *fname="sample.rgb";
    int width=WIDTH, height=HEIGHT;
    unsigned char *data;

    while (--ac) {
	++av;
	if (!strcmp(*av,"-f")) {
	    if (! --ac) goto Usage;
	    fname = *++av;
	} else if (!strcmp(*av,"-w")) {
	    if (! --ac) goto Usage;
	    width = atoi(*++av);
	} else if (!strcmp(*av,"-h")) {
	    if (! --ac) goto Usage;
	    height = atoi(*++av);
	} else {
	Usage:
	    fprintf(stderr,"usage: %s -w width -h height -f filename\n",argv[0]);
	    exit(-1);
	}
    }
    data = load_rgb(fname,width,height);
    init_xwin(width,height);
    image = init_ximage(width,height);
    set_rgb(image,0,0,data,width,height);
    for (;;) {
	XEvent ev;
	XNextEvent(dpy,&ev);
	switch (ev.type) {
	  case Expose:
	    XPutImage(dpy,win,gc,image,0,0,0,0,width,height);
	    break;
	  case ButtonPress:
	    exit(0);
	    break;
	  default:
	    break;
	}
    }
}

PROMPT$ <I>gcc -I/usr/X11R6/include x14.c -o x14 -L/usr/X11R6/lib -lX11 -lsocket -lnsl</I> <IMG SRC="/local-icons/enter.gif">
                ←Solaris2.Xの豺
侑詫來髭苳紫窿 ㍗齟臼匐釿跿粤 堪㍼ ㌣齟臼匐蛯 ㈹惘右踉晒髭苳浜嘔箪跫竅讚蜒闔鶩緕鬯芍罌
                ←Linuxなどの豺
侑詫來髭苳侍唄 ㊥ 隰鱧皃踉晒髭苳浜嘔箪跫竅讚蜒闔鶩緕鬯芍罌

*** x14.c	Mon May 22 19:57:26 2006
--- x14a.c	Mon May 22 19:57:50 2006
***************
*** 15,21 ****
  Window win;
  GC gc;
  XColor defs[RSIZE][GSIZE][BSIZE];
! XImage *image;
  
  XImage *init_ximage(int w,int h) {
      int format, bitmap_pad, depth;
--- 15,21 ----
  Window win;
  GC gc;
  XColor defs[RSIZE][GSIZE][BSIZE];
! XImage *image, *image2;
  
  XImage *init_ximage(int w,int h) {
      int format, bitmap_pad, depth;
***************
*** 146,160 ****
  int main(int argc, char **argv) {
      int ac=argc;
      char **av=argv;
!     char *fname="sample.rgb";
      int width=WIDTH, height=HEIGHT;
!     unsigned char *data;
  
      while (--ac) {
  	++av;
  	if (!strcmp(*av,"-f")) {
  	    if (! --ac) goto Usage;
  	    fname = *++av;
  	} else if (!strcmp(*av,"-w")) {
  	    if (! --ac) goto Usage;
  	    width = atoi(*++av);
--- 146,163 ----
  int main(int argc, char **argv) {
      int ac=argc;
      char **av=argv;
!     char *fname="sample.rgb", *fname2="face1.rgb";
      int width=WIDTH, height=HEIGHT;
!     unsigned char *data,*data2;
  
      while (--ac) {
  	++av;
  	if (!strcmp(*av,"-f")) {
  	    if (! --ac) goto Usage;
  	    fname = *++av;
+ 	} else if (!strcmp(*av,"-f2")) {
+ 	    if (! --ac) goto Usage;
+ 	    fname2 = *++av;
  	} else if (!strcmp(*av,"-w")) {
  	    if (! --ac) goto Usage;
  	    width = atoi(*++av);
***************
*** 163,182 ****
  	    height = atoi(*++av);
  	} else {
  	Usage:
! 	    fprintf(stderr,"usage: %s -w width -h height -f filename\n",argv[0]);
  	    exit(-1);
  	}
      }
      data = load_rgb(fname,width,height);
      init_xwin(width,height);
      image = init_ximage(width,height);
      set_rgb(image,0,0,data,width,height);
      for (;;) {
  	XEvent ev;
  	XNextEvent(dpy,&ev);
  	switch (ev.type) {
  	  case Expose:
  	    XPutImage(dpy,win,gc,image,0,0,0,0,width,height);
  	    break;
  	  case ButtonPress:
  	    exit(0);
--- 166,189 ----
  	    height = atoi(*++av);
  	} else {
  	Usage:
! 	    fprintf(stderr,"usage: %s -w width -h height -f filename -f2 filename\n",argv[0]);
  	    exit(-1);
  	}
      }
      data = load_rgb(fname,width,height);
+     data2 = load_rgb(fname2,16,16);
      init_xwin(width,height);
      image = init_ximage(width,height);
+     image2 = init_ximage(16,16);
      set_rgb(image,0,0,data,width,height);
+     set_rgb(image2,0,0,data2,16,16);
      for (;;) {
  	XEvent ev;
  	XNextEvent(dpy,&ev);
  	switch (ev.type) {
  	  case Expose:
  	    XPutImage(dpy,win,gc,image,0,0,0,0,width,height);
+ 	    XPutImage(dpy,win,gc,image2,0,0,64,128,16,16);
  	    break;
  	  case ButtonPress:
  	    exit(0);

PROMPT$ <I>x14b  -f tmp.rgb  -f2 face1.rgb</I> <IMG SRC="/local-icons/enter.gif">
320x240の大きさの画像 tmp.rgb の紊髻蔚ぢの大きさの画像 face1.rgb が動く