/* Copyright (C) 1993, 2000 artofcode LLC.  All rights reserved.
  
  This program is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published by the
  Free Software Foundation; either version 2 of the License, or (at your
  option) any later version.

  This program is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License along
  with this program; if not, write to the Free Software Foundation, Inc.,
  59 Temple Place, Suite 330, Boston, MA, 02111-1307.

*/

/*$Id: gdevxxf.c,v 1.5.6.1.2.1 2003/01/17 00:49:02 giles Exp $ */
/* External font (xfont) implementation for X11. */
#include "math_.h"
#include "memory_.h"
#include "x_.h"
#include "gx.h"
#include "gxdevice.h"
#include "gdevx.h"
#include "gsstruct.h"
#include "gsutil.h"
#include "gserrors.h"
#include "gxxfont.h"

/* Define the smallest point size that we trust X to render reasonably well. */
#define min_X_font_size 6
/* Define the largest point size where X will do a better job than we can. */
#define max_X_font_size 35

extern gx_device_X gs_x11_device;

extern const byte gs_map_std_to_iso[256];
extern const byte gs_map_iso_to_std[256];

/* Declare the xfont procedures */
private xfont_proc_lookup_font(x_lookup_font);
private xfont_proc_char_xglyph(x_char_xglyph);
private xfont_proc_char_metrics(x_char_metrics);
private xfont_proc_render_char(x_render_char);
private xfont_proc_release(x_release);
private const gx_xfont_procs x_xfont_procs =
{
    x_lookup_font,
    x_char_xglyph,
    x_char_metrics,
    x_render_char,
    x_release
};

/* Return the xfont procedure record. */
const gx_xfont_procs *
gdev_x_get_xfont_procs(gx_device * dev)
{
    return &x_xfont_procs;
}

/* Define a X11 xfont. */
typedef struct x_xfont_s x_xfont;
struct x_xfont_s {
    gx_xfont_common common;
    gx_device_X *xdev;
    XFontStruct *font;
    int encoding_index;
    int My;
    int angle;
};

gs_private_st_dev_ptrs1(st_x_xfont, x_xfont, "x_xfont",
			x_xfont_enum_ptrs, x_xfont_reloc_ptrs, xdev);

/* ---------------- Utilities ---------------- */

/* Search one set of font maps for a font with a given name. */
private x11fontmap *
find_fontmap(x11fontmap *fmps, const byte *fname, uint len)
{
    x11fontmap *fmp = fmps;

    while (fmp) {
	if (len == strlen(fmp->ps_name) &&
	    strncmp(fmp->ps_name, (const char *)fname, len) == 0)
	    break;
	fmp = fmp->next;
    }
    return fmp;
}

/* Find an X font with a given name, encoding, and size. */
private char *
find_x_font(gx_device_X *xdev, char x11template[256], x11fontmap *fmp,
	    const char *encoding_name, x11fontlist *fls, int xheight,
	    bool *scalable_font)
{
    int i;
    char *x11fontname = 0;
    int len1 = strlen(fmp->x11_name) + 1;

    if (fls->count == -1) {
	sprintf(x11template, "%s-*-*-*-*-*-*-%s", fmp->x11_name,
		encoding_name);
	fls->names = XListFonts(xdev->dpy, x11template, 32, &fls->count);
    }
    *scalable_font = false;
    for (i = 0; i < fls->count; i++) {
	const char *szp = fls->names[i] + len1;
	int size = 0;

	while (*szp >= '0' && *szp <= '9')
	    size = size * 10 + *szp++ - '0';
	if (size == 0) {
	    *scalable_font = true;
	    continue;
	}
	if (size == xheight)
	    return fls->names[i];
    }
    if (*scalable_font && xdev->useScalableFonts) {
	sprintf(x11template, "%s-%d-0-0-0-*-0-%s", fmp->x11_name,
		xheight, encoding_name);
	x11fontname = x11template;
    }
    return x11fontname;
}

/* ---------------- xfont procedures ---------------- */

/* Look up a font. */
private gx_xfont *
x_lookup_font(gx_device * dev, const byte * fname, uint len,
	    int encoding_index, const gs_uid * puid, const gs_matrix * pmat,
	      gs_memory_t * mem)
{
    gx_device_X *xdev = (gx_device_X *) dev;
    x_xfont *xxf;
    char x11template[256];
    char *x11fontname = NULL;
    XFontStruct *x11font;
    x11fontmap *fmp;
    double height;
    int xwidth, xheight, angle;
    Boolean My;
    bool scalable_font;

    if (!xdev->useXFonts)
	return NULL;

    if (pmat->xy == 0 && pmat->yx == 0) {
	xwidth = fabs(pmat->xx * 1000) + 0.5;
	xheight = fabs(pmat->yy * 1000) + 0.5;
	height = fabs(pmat->yy * 1000);
	angle = (pmat->xx > 0 ? 0 : 180);
	My = (pmat->xx > 0 && pmat->yy > 0) || (pmat->xx < 0 && pmat->yy < 0);
    } else if (pmat->xx == 0 && pmat->yy == 0) {
	xwidth = fabs(pmat->xy * 1000) + 0.5;
	xheight = fabs(pmat->yx * 1000) + 0.5;
	height = fabs(pmat->yx * 1000);
	angle = (pmat->yx < 0 ? 90 : 270);
	My = (pmat->yx > 0 && pmat->xy < 0) || (pmat->yx < 0 && pmat->xy > 0);
    } else {
	return NULL;
    }

    /* Don't do very small fonts, where font metrics are way off */
    /* due to rounding and the server does a very bad job of scaling, */
    /* or very large fonts, where we can do just as good a job and */
    /* the server may lock up the entire window system while rasterizing */
    /* the whole font. */
    if (xwidth < min_X_font_size || xwidth > max_X_font_size ||
	xheight < min_X_font_size || xheight > max_X_font_size
	)
	return NULL;

    if (!xdev->useFontExtensions && (My || angle != 0))
	return NULL;

    switch (encoding_index) {
    case 0:
	fmp = find_fontmap(xdev->regular_fonts, fname, len);
	if (fmp == NULL)
	    return NULL;
	x11fontname =
	    find_x_font(xdev, x11template, fmp, "Adobe-fontspecific",
			&fmp->std, xheight, &scalable_font);
	if (!x11fontname) {
	    x11fontname =
		find_x_font(xdev, x11template, fmp, "ISO8859-1",
			    &fmp->iso, xheight, &scalable_font);
	    encoding_index = 1;
	}
	break;
    case 1:
	fmp = find_fontmap(xdev->regular_fonts, fname, len);
	if (fmp == NULL)
	    return NULL;
	x11fontname =
	    find_x_font(xdev, x11template, fmp, "ISO8859-1",
			&fmp->iso, xheight, &scalable_font);
	if (!x11fontname) {
	    x11fontname =
		find_x_font(xdev, x11template, fmp, "Adobe-fontspecific",
			    &fmp->std, xheight, &scalable_font);
	    encoding_index = 0;
	}
	break;
    case 2:
	fmp = xdev->symbol_fonts;
	goto sym;
    case 3:
	fmp = xdev->dingbat_fonts;
sym:	fmp = find_fontmap(fmp, fname, len);
	if (fmp == NULL)
	    return NULL;
	x11fontname =
	    find_x_font(xdev, x11template, fmp, "Adobe-fontspecific",
			&fmp->std, xheight, &scalable_font);
    default:
	return NULL;
    }
    if (!x11fontname)
	return NULL;

    if (xwidth != xheight || angle != 0 || My) {
	if (!xdev->useScalableFonts || !scalable_font)
	    return NULL;
	sprintf(x11template, "%s%s+%d-%d+%d-0-0-0-*-0-%s",
		fmp->x11_name, (My ? "+My" : ""),
		angle * 64, xheight, xwidth,
		(encoding_index == 1 ? "ISO8859-1" : "Adobe-fontspecific"));
	x11fontname = x11template;
    }
    x11font = XLoadQueryFont(xdev->dpy, x11fontname);
    if (x11font == NULL)
	return NULL;
    /* Don't bother with 16-bit or 2 byte fonts yet */
    if (x11font->min_byte1 || x11font->max_byte1) {
	XFreeFont(xdev->dpy, x11font);
	return NULL;
    }
    xxf = gs_alloc_struct(mem, x_xfont, &st_x_xfont, "x_lookup_font");
    if (xxf == NULL)
	return NULL;
    xxf->common.procs = &x_xfont_procs;
    xxf->xdev = xdev;
    xxf->font = x11font;
    xxf->encoding_index = encoding_index;
    xxf->My = (My ? -1 : 1);
    xxf->angle = angle;
    if (xdev->logXFonts) {
	dprintf3("Using %s\n  for %s at %g pixels.\n", x11fontname,
		 fmp->ps_name, height);
	dflush();
    }
    return (gx_xfont *) xxf;
}

/* Convert a character name or index to an xglyph code. */
private gx_xglyph
x_char_xglyph(gx_xfont * xf, gs_char chr, int encoding_index,
	      gs_glyph glyph, gs_proc_glyph_name_t glyph_name_proc)
{
    const x_xfont *xxf = (x_xfont *) xf;

    if (chr == gs_no_char)
	return gx_no_xglyph;	/* can't look up names yet */
    if (encoding_index != xxf->encoding_index) {
	if (encoding_index == 0 && xxf->encoding_index == 1)
	    chr = gs_map_std_to_iso[chr];
	else if (encoding_index == 1 && xxf->encoding_index == 0)
	    chr = gs_map_iso_to_std[chr];
	else
	    return gx_no_xglyph;
	if (chr == 0)
	    return gx_no_xglyph;
    }
    if (chr < xxf->font->min_char_or_byte2 ||
	chr > xxf->font->max_char_or_byte2)
	return gx_no_xglyph;
    if (xxf->font->per_char) {
	int i = chr - xxf->font->min_char_or_byte2;
	const XCharStruct *xc = &xxf->font->per_char[i];

	if ((xc->lbearing == 0) && (xc->rbearing == 0) &&
	    (xc->ascent == 0) && (xc->descent == 0))
	    return gx_no_xglyph;
    }
    return (gx_xglyph) chr;
}

/* Get the metrics for a character. */
private int
x_char_metrics(gx_xfont * xf, gx_xglyph xg, int wmode,
	       gs_point * pwidth, gs_int_rect * pbbox)
{
    const x_xfont *xxf = (const x_xfont *) xf;
    int width;

    if (wmode != 0)
	return gs_error_undefined;
    if (xxf->font->per_char == NULL) {
	width = xxf->font->max_bounds.width;
	pbbox->p.x = xxf->font->max_bounds.lbearing;
	pbbox->q.x = xxf->font->max_bounds.rbearing;
	pbbox->p.y = -xxf->font->max_bounds.ascent;
	pbbox->q.y = xxf->font->max_bounds.descent;
    } else {
	int i = xg - xxf->font->min_char_or_byte2;
	const XCharStruct *xc = &xxf->font->per_char[i];

	width = xc->width;
	pbbox->p.x = xc->lbearing;
	pbbox->q.x = xc->rbearing;
	pbbox->p.y = -xc->ascent;
	pbbox->q.y = xc->descent;
    }
    switch (xxf->angle) {
    case 0:
	pwidth->x = width, pwidth->y = 0; break;
    case 90:
	pwidth->x = 0, pwidth->y = -xxf->My * width; break;
    case 180:
	pwidth->x = -width, pwidth->y = 0; break;
    case 270:
	pwidth->x = 0, pwidth->y = xxf->My * width; break;
    }
    return 0;
}

/* Render a character. */
private int
x_render_char(gx_xfont * xf, gx_xglyph xg, gx_device * dev,
	      int xo, int yo, gx_color_index color, int required)
{
    x_xfont *xxf = (x_xfont *) xf;
    char chr = (char)xg;
    gs_point wxy;
    gs_int_rect bbox;
    int x, y, w, h;
    int code;

    if (dev->dname == gs_x11_device.dname && !((gx_device_X *)dev)->is_buffered) {
	gx_device_X *xdev = (gx_device_X *)dev;

	code = (*xf->common.procs->char_metrics) (xf, xg, 0, &wxy, &bbox);
	if (code < 0)
	    return code;
	/* Buffer text for more efficient X interaction. */
	if (xdev->text.item_count == MAX_TEXT_ITEMS ||
	    xdev->text.char_count == MAX_TEXT_CHARS ||
	    (IN_TEXT(xdev) &&
	     (yo != xdev->text.origin.y || color != xdev->fore_color ||
	      xxf->font->fid != xdev->fid))
	    ) {
	    DRAW_TEXT(xdev);
	    xdev->text.item_count = xdev->text.char_count = 0;
	}
	if (xdev->text.item_count == 0) {
	    X_SET_FILL_STYLE(xdev, FillSolid);
	    X_SET_FORE_COLOR(xdev, color);
	    X_SET_FUNCTION(xdev, GXcopy);
	    xdev->text.origin.x = xdev->text.x = xo;
	    xdev->text.origin.y = yo;
	    xdev->text.items[0].font = xdev->fid = xxf->font->fid;
	}
	/*
	 * The following is wrong for rotated text, but it doesn't matter,
	 * because the next call of x_render_char will have a different Y.
	 */
	{
	    int index = xdev->text.item_count;
	    XTextItem *item = &xdev->text.items[index];
	    char *pchar = &xdev->text.chars[xdev->text.char_count++];
	    int delta = xo - xdev->text.x;

	    *pchar = chr;
	    if (index > 0 && delta == 0) {
		/* Continue the same item. */
		item[-1].nchars++;
	    } else {
		/* Start a new item. */
		item->chars = pchar;
		item->nchars = 1;
		item->delta = delta;
		if (index > 0)
		    item->font = None;
		xdev->text.item_count++;
	    }
	    xdev->text.x = xo + wxy.x;
	}
	if (xdev->bpixmap != (Pixmap) 0) {
	    x = xo + bbox.p.x;
	    y = yo + bbox.p.y;
	    w = bbox.q.x - bbox.p.x;
	    h = bbox.q.y - bbox.p.y;
	    fit_fill(dev, x, y, w, h);
	    x_update_add(xdev, x, y, w, h);
	}
	return 0;
    } else if (!required)
	return -1;		/* too hard */
    else {
	/* Display on an intermediate bitmap, then copy the bits. */
	gx_device_X *xdev = xxf->xdev;
	int wbm, raster;
	int i;
	XImage *xim;
	Pixmap xpm;
	GC fgc;
	byte *bits;

	dev_proc_copy_mono((*copy_mono)) = dev_proc(dev, copy_mono);

	code = (*xf->common.procs->char_metrics) (xf, xg, 0, &wxy, &bbox);
	if (code < 0)
	    return code;
	w = bbox.q.x - bbox.p.x;
	h = bbox.q.y - bbox.p.y;
	wbm = ROUND_UP(w, align_bitmap_mod * 8);
	raster = wbm >> 3;
	bits = (byte *) gs_malloc(h, raster, "x_render_char");
	if (bits == 0)
	    return gs_error_limitcheck;
	xpm = XCreatePixmap(xdev->dpy, xdev->win, w, h, 1);
	fgc = XCreateGC(xdev->dpy, xpm, None, NULL);
	XSetForeground(xdev->dpy, fgc, 0);
	XFillRectangle(xdev->dpy, xpm, fgc, 0, 0, w, h);
	XSetForeground(xdev->dpy, fgc, 1);
	XSetFont(xdev->dpy, fgc, xxf->font->fid);
	XDrawString(xdev->dpy, xpm, fgc, -bbox.p.x, -bbox.p.y, &chr, 1);
	xim = XGetImage(xdev->dpy, xpm, 0, 0, w, h, 1, ZPixmap);
	i = 0;
	for (y = 0; y < h; y++) {
	    char b = 0;

	    for (x = 0; x < wbm; x++) {
		b = b << 1;
		if (x < w)
		    b += XGetPixel(xim, x, y);
		if ((x & 7) == 7)
		    bits[i++] = b;
	    }
	}
	code = (*copy_mono) (dev, bits, 0, raster, gx_no_bitmap_id,
			     xo + bbox.p.x, yo + bbox.p.y, w, h,
			     gx_no_color_index, color);
	gs_free((char *)bits, h, raster, "x_render_char");
	XFreePixmap(xdev->dpy, xpm);
	XFreeGC(xdev->dpy, fgc);
	XDestroyImage(xim);
	return (code < 0 ? code : 0);
    }
}

/* Release an xfont. */
private int
x_release(gx_xfont * xf, gs_memory_t * mem)
{
#if 0
    /* The device may not be open.  Cannot reliably free the font. */
    x_xfont *xxf = (x_xfont *) xf;

    XFreeFont(xxf->xdev->dpy, xxf->font);
#endif
    if (mem != NULL)
	gs_free_object(mem, xf, "x_release");
    return 0;
}