/*
 * This file: image_f_io.c (part of the WSCRAWL program)
 *
 * This file contains the "Image File I/O" package for wscrawl (or anything
 * for that matter.)  The format used is the standard X-Window Dump form
 * that the MIT client "xwd" uses.  This File I/O was made possible by the
 * help and extensive source code of Mark Cook of Hewlett-Packard, who I
 * bothered endlessly to get this working.
 *
 * I tried to make this file of routines as self-contained and portable as
 * possible.  Please feel free to use this file as is, or with modifications,
 * for any and all applications.  -- Brian Wilson
 *
 * This file was last modified: 10/7/91 (initial port to wscrawl 2.0)
 */

#define TRUE		1
#define FALSE		0
#define BAD_CHOICE		-1
#define NO_DUPLICATE   		-1
#define UNALLOCATED    		-1

#include <X11/Xos.h>
#ifndef VMS
#include <X11/XWDFile.h>
#else
#include "XWDFILE.H"
#endif
#include <X11/Xlib.h>
#include <stdio.h>
#include <stdlib.h>

static int Image_Size(XImage * image, int format);
static int Get_Colors(XColor ** colors, Display * disp, Colormap the_colormap);
static void _swapshort(char *bp, unsigned n);
static void _swaplong(char *bp, unsigned n);
static int allocate_colors_and_assign_em(Display * disp, Window win_id, XImage ** image_ptr, XColor * cells);

/*
 * save_image_on_disk - this routine saves the region specified by the various
 *               parameters out to disk in the "defacto standard" (xwd) format.
 *               This has now been modified to take two window id's.  The
 *               first is to gather "window" information such as visual
 *               type, etc, and the second is where the image comes from.
 *               This is because in wscrawl 2.0, the image comes from a
 *               Pixmap, so pixmaps are VALID for the second win_id, but
 *               not for the first.  In the simple case of getting an
 *               image from a window, just pass the window id in twice.
 *
 *               "the_colormap" can be NULL if you wish to use the default
 *               colormap.  Most times this will be the case.
 */
int save_image_on_disk(Display * disp,
		        Window info_win_id,
		        Pixmap win_id,
		        int x,
		        int y,
		        int width,
		        int height,
		        char *name_of_file,
		        Colormap the_colormap)
{
    unsigned long swaptest = TRUE;
    XRectangle box2;
    XRectangle *box;
    FILE *out_file_ptr;
    XColor *colors;
    unsigned buffer_size;
    int win_name_size;
    int header_size;
    int format = ZPixmap;
    int ncolors, i;
    XWindowAttributes win_info;
    XImage *ImagePix;
    XWDFileHeader header;

    /*
     * convert to form this code understands (I got code from Mark Cook)
     */
    box = &box2;
    box->x = x;
    box->y = y;
    box->width = width;
    box->height = height;

    /*
     * Open the file in which the image is to be stored
     */
    if ((out_file_ptr = fopen(name_of_file, "w")) == NULL) {
	printf("ERROR: Could not open file %s.\n", name_of_file);
	return (0);
    } else {			/* Dump the image to the specified file */
	if (the_colormap == (Colormap) NULL) {
	    the_colormap =
		    XDefaultColormapOfScreen(XDefaultScreenOfDisplay(disp));
	}
	if (!XGetWindowAttributes(disp, info_win_id, &win_info)) {
	    printf("Can't get window attributes.\n");
	    return (0);
	}
	/*
	 * sizeof(char) is included for the null string terminator.
	 */
	win_name_size = strlen(name_of_file) + sizeof(char);

	ImagePix = XGetImage(disp, win_id, box->x, box->y, box->width,
			     box->height, AllPlanes, format);
	XFlush(disp);

	if (ImagePix == NULL) {
	    printf("GetImage failed.\n");
	    return (0);
	}
	buffer_size = Image_Size(ImagePix, format);	/* determines size of
							 * pixmap */

	/*
	 * Get the RGB values for the current color cells
	 */
	if ((ncolors = Get_Colors(&colors, disp, the_colormap)) == 0) {
	    printf("Cannot alloc memory for color structs.\n");
	    return (0);
	}
	XFlush(disp);

	header_size = sizeof(header) + win_name_size;	/* Calculates header
							 * size */

	/*
	 * Assemble the file header information
	 */
	header.header_size = (xwdval) header_size;
	header.file_version = (xwdval) XWD_FILE_VERSION;
	header.pixmap_format = (xwdval) format;
	header.pixmap_depth = (xwdval) ImagePix->depth;

	header.pixmap_width = (xwdval) ImagePix->width;
	header.pixmap_height = (xwdval) ImagePix->height;
	header.xoffset = (xwdval) ImagePix->xoffset;
	header.byte_order = (xwdval) ImagePix->byte_order;
	header.bitmap_unit = (xwdval) ImagePix->bitmap_unit;
	header.bitmap_bit_order = (xwdval) ImagePix->bitmap_bit_order;
	header.bitmap_pad = (xwdval) ImagePix->bitmap_pad;
	header.bits_per_pixel = (xwdval) ImagePix->bits_per_pixel;
	header.bytes_per_line = (xwdval) ImagePix->bytes_per_line;
	header.visual_class = (xwdval) win_info.visual->class;
	header.red_mask = (xwdval) win_info.visual->red_mask;
	header.green_mask = (xwdval) win_info.visual->green_mask;
	header.blue_mask = (xwdval) win_info.visual->blue_mask;
	header.bits_per_rgb = (xwdval) win_info.visual->bits_per_rgb;
	header.colormap_entries = (xwdval) win_info.visual->map_entries;
	header.ncolors = ncolors;
	header.window_width = (xwdval) ImagePix->width;
	header.window_height = (xwdval) ImagePix->height;
	header.window_x = (xwdval) 0;
	header.window_y = (xwdval) 0;
	header.window_bdrwidth = (xwdval) 0;

	if (*(char *) &swaptest) {
	    _swaplong((char *) &header, sizeof(header));
	    for (i = 0; i < ncolors; i++) {
		_swaplong((char *) &colors[i].pixel, sizeof(long));
		_swapshort((char *) &colors[i].red, 3 * sizeof(short));
	    }
	}
	/*
	 * Write out the file header information
	 */
	(void) fwrite((char *) &header, sizeof(header), 1, out_file_ptr);
	(void) fwrite(name_of_file, win_name_size, 1, out_file_ptr);

	/*
	 * Write out the color cell RGB values
	 */
	(void) fwrite((char *) colors, sizeof(XColor), ncolors, out_file_ptr);

	/*
	 * Write out the buffer
	 */
	(void) fwrite(ImagePix->data, (int) buffer_size, 1, out_file_ptr);

	if (ncolors > 0)
	    free(colors);	/* free the color buffer */

	fclose(out_file_ptr);
	XFlush(disp);
	XDestroyImage(ImagePix);
    }
}


/*
 * Image_Size - this routine takes an XImage and returns it's total byte count
 */
static int Image_Size(XImage * image, int format)
{
    if (format != ZPixmap)
	return (image->bytes_per_line * image->height * image->depth);
    else
	return (image->bytes_per_line * image->height);
}


/*
 * Get_Colors - takes a pointer to an XColor struct and returns the total
 *            number of cells in the current colormap, plus all of their
 *            RGB values.
 */
static int Get_Colors(XColor ** colors, Display * disp, Colormap the_colormap)
{
    int i, ncolors;

    ncolors = DisplayCells(disp, DefaultScreen(disp));

    if ((*colors = (XColor *) malloc(sizeof(XColor) * ncolors)) == NULL)
	return (FALSE);

    for (i = 0; i < ncolors; i++)
	(*colors)[i].pixel = i;

    XQueryColors(disp, the_colormap, *colors, ncolors);
    return (ncolors);
}


/*
 * _swapshort - this routine is stolen, and I don't know what it does
 */
static void _swapshort(char *bp, unsigned n)
{
    register char c;
    /* register char *ep = bp + n; */
    register char *ep;

    ep = bp + n;
    while (bp < ep) {
	c = *bp;
	*bp = *(bp + 1);
	bp++;
	*bp++ = c;
    }
}


/*
 * _swaplong - this routine is stolen, and I don't know what it does
 */
static void _swaplong(char *bp, unsigned n)
{
    register char c;
    /* register char *ep = bp + n; */
    register char *sp;
    register char *ep;

    ep = bp + n;
    while (bp < ep) {
	sp = bp + 3;
	c = *sp;
	*sp = *bp;
	*bp++ = c;
	sp = bp + 1;
	c = *sp;
	*sp = *bp;
	*bp++ = c;
	bp += 2;
    }
}


/*
 * read_image_from_disk - this routine reads the file indicated and allocates
 *               and loads up and then finally returns the XImage structure
 *               ready to blow out to the indicated display.  If at all
 *               possible, it attempts to return an image with the
 *               depth equalling the depth of the disp passed in.  Either
 *               way, it will return the depth it managed to get.
 */
XImage *read_image_from_disk(Display * disp,
			      Window win_id,
			      char *name_of_file,
			      int *width,
			      int *height,
			      int *depth)
{
    XImage *ImagePix;
    unsigned long swaptest = TRUE;
    unsigned buffer_size;
    char *buffer;
    char *win_name;
    int format;
    int i, name_size, ncolors;
    XColor *colors;
    FILE *in_file;
    XWDFileHeader header;

    if ((in_file = fopen(name_of_file, "r")) == NULL) {	/* open file for read */
	printf("ERROR: could not open file %s.\n", name_of_file);
	return (0);
    }
    if (fread((char *) &header, sizeof(header), 1, in_file) != 1) {	/* read header */
	printf("ERROR: unable to read imagefile header.\n");
	return (0);
    }
    if (*(char *) &swaptest)
	_swaplong((char *) &header, sizeof(header));

    /*
     * check to see if the dump file is in the proper format
     */
    if (header.file_version != XWD_FILE_VERSION) {
	printf("ERROR: Imagefile format version mismatch.\n");
	return (0);
    }
    if (header.header_size < sizeof(header)) {
	printf("ERROR: Imagefile header is too small.\n");
	return (0);
    }
    name_size = (header.header_size - sizeof(header));	/* space for window name */

    if ((win_name = malloc((unsigned) name_size * sizeof(char))) == NULL) {
	printf("ERROR: Can't malloc window name storage.\n");
	return (0);
    }
    /*
     * Read in window name
     */
    if (fread(win_name, sizeof(char), name_size, in_file) != name_size) {
	printf("ERROR: Unable to read window name from file.\n");
	return (0);
    }
    /*
     * Malloc the image data space and initialize it
     */
    if ((ImagePix = (XImage *) malloc(sizeof(XImage))) == NULL) {
	printf("ERROR: Can't malloc space for the image.\n");
	return (0);
    }
    ImagePix->width = (int) header.pixmap_width;
    ImagePix->height = (int) header.pixmap_height;
    ImagePix->xoffset = (int) header.xoffset;
    ImagePix->format = (int) header.pixmap_format;
    ImagePix->byte_order = (int) header.byte_order;
    ImagePix->bitmap_unit = (int) header.bitmap_unit;
    ImagePix->bitmap_bit_order = (int) header.bitmap_bit_order;
    ImagePix->bitmap_pad = (int) header.bitmap_pad;
    ImagePix->depth = (int) header.pixmap_depth;
    ImagePix->bits_per_pixel = (int) header.bits_per_pixel;
    ImagePix->bytes_per_line = (int) header.bytes_per_line;
    ImagePix->red_mask = header.red_mask;
    ImagePix->green_mask = header.green_mask;
    ImagePix->blue_mask = header.blue_mask;
    ImagePix->obdata = NULL;
    _XInitImageFuncPtrs(ImagePix);

    format = ImagePix->format;

    /*
     * malloc memory for the RGB values from the old colormap and read in the
     * values
     */
    if (ncolors = header.ncolors) {
	if ((colors = (XColor *) malloc(ncolors * sizeof(XColor))) == NULL) {
	    printf("ERROR: Can't malloc space for the image cmap.\n");
	    if (win_name)
		free(win_name);
	    if (ImagePix)
		XDestroyImage(ImagePix);
	    return (0);
	}
	if (fread((char *) colors, sizeof(XColor), ncolors, in_file) != ncolors) {
	    printf("ERROR: Unable to read cmap from imagefile.\n");
	    if (win_name)
		free(win_name);
	    if (ImagePix)
		XDestroyImage(ImagePix);
	    if (colors)
		free((char *) colors);
	    return (0);
	}
	if (*(char *) &swaptest) {
	    for (i = 0; i < ncolors; i++) {
		_swaplong((char *) &colors[i].pixel, sizeof(long));
		_swapshort((char *) &colors[i].red, 3 * sizeof(short));
	    }
	}
    }
    buffer_size = Image_Size(ImagePix, format);	/* malloc the pixel buffer */
    if ((buffer = malloc(buffer_size * sizeof(char))) == NULL) {
	printf("ERROR: Can't malloc the data buffer.\n");
	if (win_name)
	    free(win_name);
	if (ImagePix)
	    XDestroyImage(ImagePix);
	if (colors)
	    free((char *) colors);
	return (0);
    }
    ImagePix->data = buffer;

    /*
     * Read in the pixmap buffer
     */
    if (fread(buffer, sizeof(char), (int) buffer_size, in_file) != buffer_size) {
	printf("ERROR: Unable to read pixmap from imagefile.\n");
	if (win_name)
	    free(win_name);
	if (ImagePix)
	    XDestroyImage(ImagePix);
	if (colors)
	    free((char *) colors);
	if (buffer)
	    free((char *) buffer);
	return (0);
    }
    (void) fclose(in_file);	/* we are done with the infile */

    *depth = ImagePix->depth;	/* even if the rest fails, return the
				 * dimensions */
    *width = ImagePix->width;
    *height = ImagePix->height;

    if (win_name && (name_size > 0))
	free(win_name);

    if (allocate_colors_and_assign_em(disp, win_id, &ImagePix, colors)
	!= TRUE) {
	/*
	 * the above converts the pixels in the xwd file over to the current
	 * colormap, and also swaps the image to a new depth if the depth the
	 * image was stored on disk as disagrees with the depth of the window
	 * it is to be blasted into.  This block is if that fails.
	 */
	printf("ERROR: Can't convert xwd file to usuable format.\n");
	printf("       Probably because the display is a wimpy non-HP.\n");
	if (ImagePix)
	    XDestroyImage(ImagePix);
	if (colors)
	    free((char *) colors);
	return (0);
    } else if (colors)
	free((char *) colors);

    *depth = ImagePix->depth;	/* the depth may have changed */
    return (ImagePix);
}


/*
 * allocate_colors_and_assign_em - this function takes an XImage and it's
 *            colormap as it was at the time the image was created, and
 *            allocates cells in the system colormap matching those old colors
 *            and shuffles the pixels in the image to point to our new color
 *            cells instead of those old color cells.
 */
static int allocate_colors_and_assign_em(Display * disp, Window win_id, XImage ** image_ptr, XColor * cells)
{
    int width, height, i, j, num_cells_in_colormap;
    unsigned long *opv, *npv;	/* old and new pixel values */
    unsigned long tmp_pixel_value;
    XColor screen_in_out;
    XImage *diff_depth_im, *image;
    XWindowAttributes win_attr;
    int buffer_size;
    char *buffer;

    image = *image_ptr;		/* for my sanity */
    height = image->height;
    width = image->width;

    /*
     * determine the number of cells in the colormap by taking 2 to the power
     * of the number of bits of depth this display has.
     */
    for (i = 0, num_cells_in_colormap = 1; i < (*image_ptr)->depth; i++)
	num_cells_in_colormap *= 2;

    if (num_cells_in_colormap > 256) {
	printf("WARNING: This is a monster deep display image, dude.  This ");
	printf("image\n");
	printf("         will take %d mega-bytes of free memory to process.\n",
	   ((num_cells_in_colormap * sizeof(unsigned long)) / 1024) / 1024);
    }
    /*
     * set up temporary storage for the old and new pixel values
     */
    opv = (unsigned long *) malloc(num_cells_in_colormap * sizeof(unsigned long));
    npv = (unsigned long *) malloc(num_cells_in_colormap * sizeof(unsigned long));

    if (!opv || !npv) {
	printf("ERROR: unable to malloc the temporary pixel storage.\n");
	if (opv)
	    free((char *) opv);
	if (npv)
	    free((char *) npv);
	return (0);
    }
    /*
     * Each opv value is a flag indicating whether or not that pixel is
     * present in the image.  Each npv value is it's replacement value.
     */
    for (i = 0; i < num_cells_in_colormap; i++) {
	opv[i] = FALSE;
	npv[i] = UNALLOCATED;
    }

    for (i = 0; i < height; i++)/* examine each pxl in image; recrd all used
				 * values */
	for (j = 0; j < width; j++) {
	    tmp_pixel_value = XGetPixel(image, j, i);
	    if (tmp_pixel_value >= num_cells_in_colormap) {
		printf("ERROR: Bad pixel value at x=%d, y=%d, pixel=%ld\n",
		       j, i, tmp_pixel_value);
	    } else
		opv[tmp_pixel_value] = TRUE;
	}

    /*
     * For each TRUE opv allocate the colors
     */
    for (i = 0; i < num_cells_in_colormap; i++) {
	if (opv[i]) {
	    screen_in_out.red = cells[i].red;
	    screen_in_out.green = cells[i].green;
	    screen_in_out.blue = cells[i].blue;
	    screen_in_out.flags = DoRed | DoGreen | DoBlue;

	    if (XAllocColor(disp,
		    XDefaultColormapOfScreen(XDefaultScreenOfDisplay(disp)),
			    &screen_in_out) == 0) {
		printf("ERROR: out of colors on this display. ");
		printf("Cannot import image.\n");
		return (0);
	    } else
		npv[i] = screen_in_out.pixel;
	}
    }

    XGetWindowAttributes(disp, win_id, &win_attr);

    if (win_attr.depth == image->depth) {	/* cool, this is easy */
	for (i = 0; i < height; i++)
	    for (j = 0; j < width; j++)
		XPutPixel(image, j, i, npv[XGetPixel(image, j, i)]);
    } else {			/* oh darn it, this is tough */
	/*
	 * the concept here is to creat a new image that IS the correct depth
	 * and then do "PutPixel" into it, filling it with the correct color
	 * pixels.
	 */
	diff_depth_im = XCreateImage(disp, win_attr.visual, win_attr.depth,
				 image->format, image->xoffset, NULL, width,
				     height, image->bitmap_pad, 0);

	buffer_size = Image_Size(diff_depth_im,
				 diff_depth_im->format);	/* malloc pixel buffer */
	if ((buffer = malloc(buffer_size * sizeof(char))) == NULL) {
	    printf("ERROR: Can't malloc data buffer for differing depth.\n");
	    return (0);
	}
	diff_depth_im->data = buffer;

	for (i = 0; i < height; i++)
	    for (j = 0; j < width; j++)
		XPutPixel(diff_depth_im, j, i,
			  npv[XGetPixel(image, j, i)]);

	*image_ptr = diff_depth_im;
	XDestroyImage(image);	/* free up space of wrong depth image */
    }

    if (opv)
	free((char *) opv);
    if (npv)
	free((char *) npv);

    return (1);
}
