
// $Id: rotated.c,v 1.2 2002/03/05 21:28:24 we7u Exp $
//
// Note that this version has been changed since xvertext 5.0 in order
// to get rid of compiler warnings and such.  The original 5.0 notice
// is below.  --we7u


/* ********************************************************************** */

/* xvertext 5.0, Copyright (c) 1993 Alan Richardson (mppa3@uk.ac.sussex.syma)
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose and without fee is hereby granted, provided
 * that the above copyright notice appear in all copies and that both the
 * copyright notice and this permission notice appear in supporting
 * documentation.  All work developed as a consequence of the use of
 * this program should duly acknowledge such use. No representations are
 * made about the suitability of this software for any purpose.  It is
 * provided "as is" without express or implied warranty.
 */

/* ********************************************************************** */


/* BETTER: xvertext now does rotation at any angle!!
 *
 * BEWARE: function arguments have CHANGED since version 2.0!!
 */

/* ********************************************************************** */


#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xatom.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include "rotated.h"


/* ---------------------------------------------------------------------- */


/* Make sure cache size is set */

#ifndef CACHE_SIZE_LIMIT
#define CACHE_SIZE_LIMIT 0
#endif /*CACHE_SIZE_LIMIT */
    
/* Make sure a cache method is specified */

#ifndef CACHE_XIMAGES
#ifndef CACHE_BITMAPS
#define CACHE_BITMAPS
#endif /*CACHE_BITMAPS*/
#endif /*CACHE_XIMAGES*/


/* ---------------------------------------------------------------------- */


/* Debugging macros */

#ifdef DEBUG
static int debug=1;
#else
static int debug=0;
#endif /*DEBUG*/

#define DEBUG_PRINT1(a) if (debug) printf (a)
#define DEBUG_PRINT2(a, b) if (debug) printf (a, b)
#define DEBUG_PRINT3(a, b, c) if (debug) printf (a, b, c)
#define DEBUG_PRINT4(a, b, c, d) if (debug) printf (a, b, c, d)
#define DEBUG_PRINT5(a, b, c, d, e) if (debug) printf (a, b, c, d, e)


/* ---------------------------------------------------------------------- */


#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif


/* ---------------------------------------------------------------------- */


/* A structure holding everything needed for a rotated string */

typedef struct rotated_text_item_template {
    Pixmap bitmap;
    XImage *ximage;
    
    char *text;
    char *font_name;
    Font fid;
    float angle;
    int align;
    float magnify;
    
    int cols_in;
    int rows_in;
    int cols_out;
    int rows_out;
    
    int nl;
    int max_width;
    float *corners_x;
    float *corners_y;
    
    long int size;
    int cached;

    struct rotated_text_item_template *next;
} RotatedTextItem;

RotatedTextItem *first_text_item=NULL;


/* ---------------------------------------------------------------------- */


/* A structure holding current magnification and bounding box padding */

static struct style_template {
    float magnify;
    int bbx_pad;
} style={
    1.,
    0
    };


/* ---------------------------------------------------------------------- */


static char            *my_strdup();
static char            *my_strtok();

float                   XRotVersion();
void                    XRotSetMagnification();
void                    XRotSetBoundingBoxPad();
int                     XRotDrawString();
int                     XRotDrawImageString();
int                     XRotDrawAlignedString();
int                     XRotDrawAlignedImageString();
XPoint                 *XRotTextExtents();

static XImage          *MakeXImage();
static int              XRotPaintAlignedString();
static int              XRotDrawHorizontalString();
static RotatedTextItem *XRotRetrieveFromCache();
static RotatedTextItem *XRotCreateTextItem();
static void             XRotAddToLinkedList();
static void             XRotFreeTextItem();
static XImage          *XRotMagnifyImage();


/* ---------------------------------------------------------------------- */


/**************************************************************************/
/* Routine to mimic `strdup()' (some machines don't have it)              */
/**************************************************************************/

static char *my_strdup(str)
    char *str;
{
    char *s;
    
    if(str==NULL)
        return NULL;
    
    s=(char *)malloc((unsigned)(strlen(str)+1));
    if(s!=NULL) 
        strcpy(s, str);
    
    return s;
}


/* ---------------------------------------------------------------------- */


/**************************************************************************/
/* Routine to replace `strtok' : this one returns a zero length string if */
/* it encounters two consecutive delimiters                               */
/**************************************************************************/

static char *my_strtok(str1, str2)
    char *str1, *str2;
{
    char *ret;
    int i, j, stop;
    static int start, len;
    static char *stext;
    
    if(str2==NULL)
        return NULL;
    
    /* initialise if str1 not NULL */
    if(str1!=NULL) {
        start=0;
        stext=str1;
        len=strlen(str1);
    }
    
    /* run out of tokens ? */
    if(start>=len)
        return NULL;
    
    /* loop through characters */
    for(i=start; i<len; i++) {
        /* loop through delimiters */
        stop=0;
        for(j=0; j < (int)strlen(str2); j++)
            if(stext[i]==str2[j])
                stop=1;
        
        if(stop)
            break;
    }
    
    stext[i]='\0';
    
    ret=stext+start;
    
    start=i+1;
    
    return ret;
}


/* ---------------------------------------------------------------------- */


/**************************************************************************/
/* Return version/copyright information                                   */
/**************************************************************************/

float XRotVersion(str, n)
    char *str;
    int n;
{
    if(str!=NULL)
        strncpy(str, XV_COPYRIGHT, n);
    return XV_VERSION;
}


/* ---------------------------------------------------------------------- */


/**************************************************************************/
/* Set the font magnification factor for all subsequent operations        */
/**************************************************************************/

void XRotSetMagnification(m)
    float m;
{
    if(m>0.)
        style.magnify=m;
}


/* ---------------------------------------------------------------------- */


/**************************************************************************/
/* Set the padding used when calculating bounding boxes                   */
/**************************************************************************/

void XRotSetBoundingBoxPad(p)
    int p;
{
    if(p>=0)
        style.bbx_pad=p;
}


/* ---------------------------------------------------------------------- */


/**************************************************************************/
/*  Create an XImage structure and allocate memory for it                 */
/**************************************************************************/

static XImage *MakeXImage(dpy, w, h)
    Display *dpy;
    int w, h;
{
    XImage *I;
    char *data;
    
    /* reserve memory for image */
    data=(char *)calloc((unsigned)(((w-1)/8+1)*h), 1);
    if(data==NULL)
        return NULL;
    
    /* create the XImage */
    I=XCreateImage(dpy, DefaultVisual(dpy, DefaultScreen(dpy)), 1, XYBitmap,
                   0, data, w, h, 8, 0);
    if(I==NULL)
        return NULL;
    
    I->byte_order=I->bitmap_bit_order=MSBFirst;
    return I;
}


/* ---------------------------------------------------------------------- */


/**************************************************************************/
/*  A front end to XRotPaintAlignedString:                                */
/*      -no alignment, no background                                      */
/**************************************************************************/

int XRotDrawString(dpy, font, angle, drawable, gc, x, y, str)
    Display *dpy;
    XFontStruct *font;
    float angle;
    Drawable drawable;
    GC gc;
    int x, y;
    char *str;
{
    return (XRotPaintAlignedString(dpy, font, angle, drawable, gc,
                                   x, y, str, NONE, 0));
}


/* ---------------------------------------------------------------------- */


/**************************************************************************/
/*  A front end to XRotPaintAlignedString:                                */
/*      -no alignment, paints background                                  */
/**************************************************************************/

int XRotDrawImageString(dpy, font, angle, drawable, gc, x, y, str)
    Display *dpy;
    XFontStruct *font;
    float angle;
    Drawable drawable;
    GC gc;
    int x, y;
    char *str;
{
    return(XRotPaintAlignedString(dpy, font, angle, drawable, gc,
                                  x, y, str, NONE, 1));
}


/* ---------------------------------------------------------------------- */


/**************************************************************************/
/*  A front end to XRotPaintAlignedString:                                */
/*      -does alignment, no background                                    */
/**************************************************************************/

int XRotDrawAlignedString(dpy, font, angle, drawable, gc, x, y, text, align)
    Display *dpy;
    XFontStruct *font;
    float angle;
    Drawable drawable;
    GC gc;
    int x, y;
    char *text;
    int align;
{
    return(XRotPaintAlignedString(dpy, font, angle, drawable, gc,
                                  x, y, text, align, 0));
}


/* ---------------------------------------------------------------------- */


/**************************************************************************/
/*  A front end to XRotPaintAlignedString:                                */
/*      -does alignment, paints background                                */
/**************************************************************************/

int XRotDrawAlignedImageString(dpy, font, angle, drawable, gc, x, y, text,
                               align)
    Display *dpy;
    XFontStruct *font;
    float angle;
    Drawable drawable;
    GC gc;
    int x, y;
    char *text;
    int align;
{
    return(XRotPaintAlignedString(dpy, font, angle, drawable, gc,
                                  x, y, text, align, 1));
}


/* ---------------------------------------------------------------------- */


/**************************************************************************/
/*  Aligns and paints a rotated string                                    */
/**************************************************************************/

static int XRotPaintAlignedString(dpy, font, angle, drawable, gc, x, y, text,
                                  align, bg)
    Display *dpy;
    XFontStruct *font;
    float angle;
    Drawable drawable;
    GC gc;
    int x, y;
    char *text;
    int align;
    int bg;
{
    int i;
    GC my_gc;
    int xp, yp;
    float hot_x, hot_y;
    float hot_xp, hot_yp;
    float sin_angle, cos_angle;
    RotatedTextItem *item;
    Pixmap bitmap_to_paint;
    
    /* return early for NULL/empty strings */
    if(text==NULL)
        return 0;
    
    if(strlen(text)==0)
        return 0;

    /* manipulate angle to 0<=angle<360 degrees */
    while(angle<0)
        angle+=360;
    
    while(angle>=360)
        angle-=360;
    
    angle*=M_PI/180;
    
    /* horizontal text made easy */
    if(angle==0. && style.magnify==1.) 
        return(XRotDrawHorizontalString(dpy, font, drawable, gc, x, y,
                                        text, align, bg));
    
    /* get a rotated bitmap */
    item=XRotRetrieveFromCache(dpy, font, angle, text, align);
    if(item==NULL)
        return(0);
    
    /* this gc has similar properties to the user's gc */
    my_gc=XCreateGC(dpy, drawable, 0, 0);
    XCopyGC(dpy, gc, GCForeground|GCBackground|GCFunction|GCPlaneMask,
            my_gc);

    /* alignment : which point (hot_x, hot_y) relative to bitmap centre
       coincides with user's specified point? */
    
    /* y position */
    if(align==TLEFT || align==TCENTRE || align==TRIGHT)
        hot_y=(float)item->rows_in/2*style.magnify;
    else if(align==MLEFT || align==MCENTRE || align==MRIGHT)
        hot_y=0;
    else if(align==BLEFT || align==BCENTRE || align==BRIGHT)
        hot_y=-(float)item->rows_in/2*style.magnify;
    else
        hot_y=-((float)item->rows_in/2-(float)font->descent)*style.magnify;
    
    /* x position */
    if(align==TLEFT || align==MLEFT || align==BLEFT || align==NONE)
        hot_x=-(float)item->max_width/2*style.magnify;
    else if(align==TCENTRE || align==MCENTRE || align==BCENTRE)
        hot_x=0;
    else
        hot_x=(float)item->max_width/2*style.magnify;
    
    /* pre-calculate sin and cos */
    sin_angle=sin(angle);
    cos_angle=cos(angle);
    
    /* rotate hot_x and hot_y around bitmap centre */
    hot_xp= hot_x*cos_angle - hot_y*sin_angle;
    hot_yp= hot_x*sin_angle + hot_y*cos_angle;
    
    /* text background will be drawn using XFillPolygon */
    if(bg) {
        GC depth_one_gc;
        XPoint *xpoints;
        Pixmap empty_stipple;
        
        /* reserve space for XPoints */
        xpoints=(XPoint *)malloc((unsigned)(4*item->nl*sizeof(XPoint)));
        if(!xpoints)
            return 1;
        
        /* rotate corner positions */
        for(i=0; i<4*item->nl; i++) {
            xpoints[i].x=(float)x + ( (item->corners_x[i]-hot_x)*cos_angle + 
                                      (item->corners_y[i]+hot_y)*sin_angle);
            xpoints[i].y=(float)y + (-(item->corners_x[i]-hot_x)*sin_angle + 
                                      (item->corners_y[i]+hot_y)*cos_angle);
        }
        
        /* we want to swap foreground and background colors here;
           XGetGCValues() is only available in R4+ */
        
        empty_stipple=XCreatePixmap(dpy, drawable, 1, 1, 1);
        
        depth_one_gc=XCreateGC(dpy, empty_stipple, 0, 0);
        XSetForeground(dpy, depth_one_gc, 0);
        XFillRectangle(dpy, empty_stipple, depth_one_gc, 0, 0, 2, 2);

        XSetStipple(dpy, my_gc, empty_stipple);
        XSetFillStyle(dpy, my_gc, FillOpaqueStippled);
        
        XFillPolygon(dpy, drawable, my_gc, xpoints, 4*item->nl, Nonconvex,
                     CoordModeOrigin);
        
        /* free our resources */
        free((char *)xpoints);
        XFreeGC(dpy, depth_one_gc);
        XFreePixmap(dpy, empty_stipple);
    }
    
    /* where should top left corner of bitmap go ? */
    xp=(float)x-((float)item->cols_out/2 +hot_xp);
    yp=(float)y-((float)item->rows_out/2 -hot_yp);
    
    /* by default we draw the rotated bitmap, solid */
    bitmap_to_paint=item->bitmap;

    /* handle user stippling */
#ifndef X11R3
    {
        GC depth_one_gc;
        XGCValues values;
        Pixmap new_bitmap, inverse;
        
        /* try and get some GC properties */
        if(XGetGCValues(dpy, gc, 
                        GCStipple|GCFillStyle|GCForeground|GCBackground|
                        GCTileStipXOrigin|GCTileStipYOrigin,
                        &values)) {

            /* only do this if stippling requested */
            if((values.fill_style==FillStippled ||
                values.fill_style==FillOpaqueStippled) && !bg) {

                /* opaque stipple: draw rotated text in background colour */
                if(values.fill_style==FillOpaqueStippled) {
                    XSetForeground(dpy, my_gc, values.background);
                    XSetFillStyle(dpy, my_gc, FillStippled);
                    XSetStipple(dpy, my_gc, item->bitmap);
                    XSetTSOrigin(dpy, my_gc, xp, yp);
                    XFillRectangle(dpy, drawable, my_gc, xp, yp,
                                   item->cols_out, item->rows_out);
                    XSetForeground(dpy, my_gc, values.foreground);
                }

                /* this will merge the rotated text and the user's stipple */
                new_bitmap=XCreatePixmap(dpy, drawable,
                                         item->cols_out, item->rows_out, 1);

                /* create a GC */
                depth_one_gc=XCreateGC(dpy, new_bitmap, 0, 0);
                XSetForeground(dpy, depth_one_gc, 1);
                XSetBackground(dpy, depth_one_gc, 0);

                /* set the relative stipple origin */
                XSetTSOrigin(dpy, depth_one_gc, 
                             values.ts_x_origin-xp, values.ts_y_origin-yp);

                /* fill the whole bitmap with the user's stipple */
                XSetStipple(dpy, depth_one_gc, values.stipple);
                XSetFillStyle(dpy, depth_one_gc, FillOpaqueStippled);
                XFillRectangle(dpy, new_bitmap, depth_one_gc,
                               0, 0, item->cols_out, item->rows_out);

                /* set stipple origin back to normal */
                XSetTSOrigin(dpy, depth_one_gc, 0, 0);

                /* this will contain an inverse copy of the rotated text */
                inverse=XCreatePixmap(dpy, drawable,
                                      item->cols_out, item->rows_out, 1);

                /* invert text */
                XSetFillStyle(dpy, depth_one_gc, FillSolid);
                XSetFunction(dpy, depth_one_gc, GXcopyInverted);
                XCopyArea(dpy, item->bitmap, inverse, depth_one_gc,
                          0, 0, item->cols_out, item->rows_out, 0, 0);

                /* now delete user's stipple everywhere EXCEPT on text */
                XSetForeground(dpy, depth_one_gc, 0);
                XSetBackground(dpy, depth_one_gc, 1);
                XSetStipple(dpy, depth_one_gc, inverse);
                XSetFillStyle(dpy, depth_one_gc, FillStippled);
                XSetFunction(dpy, depth_one_gc, GXcopy);
                XFillRectangle(dpy, new_bitmap, depth_one_gc,
                               0, 0, item->cols_out, item->rows_out);

                /* free resources */
                XFreePixmap(dpy, inverse);
                XFreeGC(dpy, depth_one_gc);

                /* this is the new bitmap */
                bitmap_to_paint=new_bitmap;
            }
        }
    }
#endif /*X11R3*/

    /* paint text using stipple technique */
    XSetFillStyle(dpy, my_gc, FillStippled);
    XSetStipple(dpy, my_gc, bitmap_to_paint);
    XSetTSOrigin(dpy, my_gc, xp, yp);
    XFillRectangle(dpy, drawable, my_gc, xp, yp, 
                   item->cols_out, item->rows_out);
    
    /* free our resources */
    XFreeGC(dpy, my_gc);

    /* stippled bitmap no longer needed */
    if(bitmap_to_paint!=item->bitmap)
        XFreePixmap(dpy, bitmap_to_paint);

#ifdef CACHE_XIMAGES
    XFreePixmap(dpy, item->bitmap);
#endif /*CACHE_XIMAGES*/

    /* if item isn't cached, destroy it completely */
    if(!item->cached) 
        XRotFreeTextItem(dpy,item);

    /* we got to the end OK! */
    return 0;
}


/* ---------------------------------------------------------------------- */


/**************************************************************************/
/*  Draw a horizontal string in a quick fashion                           */
/**************************************************************************/

static int XRotDrawHorizontalString(dpy, font, drawable, gc, x, y, text, 
                             align, bg)
    Display *dpy;
    XFontStruct *font;
    Drawable drawable;
    GC gc;
    int x, y;
    char *text;
    int align;
    int bg;
{
    GC my_gc;
    int nl=1, i;
    int height;
    int xp, yp;
    char *str1, *str2, *str3;
    char *str2_a="\0", *str2_b="\n\0";
    int dir, asc, desc;
    XCharStruct overall;

    DEBUG_PRINT1("**\nHorizontal text.\n");

    /* this gc has similar properties to the user's gc (including stipple) */
    my_gc=XCreateGC(dpy, drawable, 0, 0);
    XCopyGC(dpy, gc,
            GCForeground|GCBackground|GCFunction|GCStipple|GCFillStyle|
            GCTileStipXOrigin|GCTileStipYOrigin|GCPlaneMask, my_gc);
    XSetFont(dpy, my_gc, font->fid);
        
    /* count number of sections in string */
    if(align!=NONE)
        for(i=0; i < (int)(strlen(text)-1); i++)
            if(text[i]=='\n')
                nl++;
    
    /* ignore newline characters if not doing alignment */
    if(align==NONE)
        str2=str2_a;
    else
        str2=str2_b;
    
    /* overall font height */
    height=font->ascent+font->descent;
    
    /* y position */
    if(align==TLEFT || align==TCENTRE || align==TRIGHT)
        yp=y+font->ascent;
    else if(align==MLEFT || align==MCENTRE || align==MRIGHT)
        yp=y-nl*height/2+font->ascent;
    else if(align==BLEFT || align==BCENTRE || align==BRIGHT)
        yp=y-nl*height+font->ascent;
    else
        yp=y;
    
    str1=my_strdup(text);
    if(str1==NULL)
        return 1;
    
    str3=my_strtok(str1, str2);
    
    /* loop through each section in the string */
    do {
        XTextExtents(font, str3, strlen(str3), &dir, &asc, &desc,
                     &overall);

        /* where to draw section in x ? */
        if(align==TLEFT || align==MLEFT || align==BLEFT || align==NONE)
            xp=x;
        else if(align==TCENTRE || align==MCENTRE || align==BCENTRE)
            xp=x-overall.rbearing/2;
        else
            xp=x-overall.rbearing;
        
        /* draw string onto bitmap */
        if(!bg)
            XDrawString(dpy, drawable, my_gc, xp, yp, str3, strlen(str3));
        else
            XDrawImageString(dpy, drawable, my_gc, xp, yp, str3, strlen(str3));
        
        /* move to next line */
        yp+=height;
        
        str3=my_strtok((char *)NULL, str2);
    }
    while(str3!=NULL);
    
    free(str1);
    XFreeGC(dpy, my_gc);

    return 0;
}


/* ---------------------------------------------------------------------- */


/**************************************************************************/
/*   Query cache for a match with this font/text/angle/alignment          */
/*       request, otherwise arrange for its creation                      */
/**************************************************************************/

static RotatedTextItem *XRotRetrieveFromCache(dpy, font, angle, text, align)
    Display *dpy;
    XFontStruct *font;
    float angle;
    char *text;
    int align;
{
    Font fid;
    char *font_name=NULL;
    unsigned long name_value;
    RotatedTextItem *item=NULL;
    RotatedTextItem *i1=first_text_item;
    
    /* get font name, if it exists */
    if(XGetFontProperty(font, XA_FONT, &name_value)) {
        DEBUG_PRINT1("got font name OK\n");
        font_name=XGetAtomName(dpy, name_value);
        fid=0;
    }
#ifdef CACHE_FID
    /* otherwise rely (unreliably?) on font ID */
    else {
        DEBUG_PRINT1("can't get fontname, caching FID\n");
        font_name=NULL;
        fid=font->fid;
    }
#else
    /* not allowed to cache font ID's */
    else {
        DEBUG_PRINT1("can't get fontname, can't cache\n");
        font_name=NULL;
        fid=0;
    }
#endif /*CACHE_FID*/
    
    /* look for a match in cache */

    /* matching formula:
       identical text;
       identical fontname (if defined, font ID's if not);
       angles close enough (<0.00001 here, could be smaller);
       HORIZONTAL alignment matches, OR it's a one line string;
       magnifications the same */

    while(i1 && !item) {
        /* match everything EXCEPT fontname/ID */
        if(strcmp(text, i1->text)==0 &&
           fabs(angle-i1->angle)<0.00001 &&
           style.magnify==i1->magnify &&
           (i1->nl==1 ||
            ((align==0)?9:(align-1))%3==
              ((i1->align==0)?9:(i1->align-1))%3)) {

            /* now match fontname/ID */
            if(font_name!=NULL && i1->font_name!=NULL) {
                if(strcmp(font_name, i1->font_name)==0) {
                    item=i1;
                    DEBUG_PRINT1("Matched against font names\n");
                }
                else
                    i1=i1->next;
            }
#ifdef CACHE_FID
            else if(font_name==NULL && i1->font_name==NULL) {
                if(fid==i1->fid) {
                    item=i1;
                    DEBUG_PRINT1("Matched against FID's\n");
                }
                else
                    i1=i1->next;
            }
#endif /*CACHE_FID*/
            else
                i1=i1->next;
        }
        else
            i1=i1->next;
    }
    
    if(item)
        DEBUG_PRINT1("**\nFound target in cache.\n");
    if(!item)
        DEBUG_PRINT1("**\nNo match in cache.\n");

    /* no match */
    if(!item) {
        /* create new item */
        item=XRotCreateTextItem(dpy, font, angle, text, align);
        if(!item)
            return NULL;

        /* record what it shows */
        item->text=my_strdup(text);

        /* fontname or ID */
        if(font_name!=NULL) {
            item->font_name=my_strdup(font_name);
            item->fid=0;
        }
        else {
            item->font_name=NULL;
            item->fid=fid;
        }

        item->angle=angle;
        item->align=align;
        item->magnify=style.magnify;

        /* cache it */
        XRotAddToLinkedList(dpy, item);
    }

    if(font_name)
        XFree(font_name);

    /* if XImage is cached, need to recreate the bitmap */

#ifdef CACHE_XIMAGES
    {
        GC depth_one_gc;

        /* create bitmap to hold rotated text */
        item->bitmap=XCreatePixmap(dpy, DefaultRootWindow(dpy),
                                   item->cols_out, item->rows_out, 1);
        
        /* depth one gc */
        depth_one_gc=XCreateGC(dpy, item->bitmap, NULL, 0);
        XSetBackground(dpy, depth_one_gc, 0);
        XSetForeground(dpy, depth_one_gc, 1);

        /* make the text bitmap from XImage */
        XPutImage(dpy, item->bitmap, depth_one_gc, item->ximage, 0, 0, 0, 0,
                  item->cols_out, item->rows_out);

        XFreeGC(dpy, depth_one_gc);
    }
#endif /*CACHE_XIMAGES*/
    
    return item;
}


/* ---------------------------------------------------------------------- */


/**************************************************************************/
/*  Create a rotated text item                                            */
/**************************************************************************/

static RotatedTextItem *XRotCreateTextItem(dpy, font, angle, text, align)
    Display *dpy;
    XFontStruct *font;
    float angle;
    char *text;
    int align;
{
    RotatedTextItem *item=NULL;
    Pixmap canvas;
    GC font_gc;
    XImage *I_in;
    register int i, j;
    char *str1, *str2, *str3;
    char *str2_a="\0", *str2_b="\n\0";
    int height;
    int byte_w_in, byte_w_out;
    int xp, yp;
    float sin_angle, cos_angle;
    int it, jt;
    float di, dj;
    int ic=0;
    float xl, xr, xinc;
    int byte_out;
    int dir, asc, desc;
    XCharStruct overall;
    int old_cols_in=0, old_rows_in=0;
    
    /* allocate memory */
    item=(RotatedTextItem *)malloc((unsigned)sizeof(RotatedTextItem));
    if(!item)
        return NULL;
        
    /* count number of sections in string */
    item->nl=1;
    if(align!=NONE)
        for(i=0; i < (int)(strlen(text)-1); i++)
            if(text[i]=='\n')
                item->nl++;
    
    /* ignore newline characters if not doing alignment */
    if(align==NONE)
        str2=str2_a;
    else
        str2=str2_b;
    
    /* find width of longest section */
    str1=my_strdup(text);
    if(str1==NULL)
        return NULL;
    
    str3=my_strtok(str1, str2);

    XTextExtents(font, str3, strlen(str3), &dir, &asc, &desc,
                 &overall);
    
    item->max_width=overall.rbearing;
    
    /* loop through each section */
    do {
        str3=my_strtok((char *)NULL, str2);

        if(str3!=NULL) {
            XTextExtents(font, str3, strlen(str3), &dir, &asc, &desc,
                         &overall);

            if(overall.rbearing>item->max_width)
                item->max_width=overall.rbearing;
        }
    }
    while(str3!=NULL);
    
    free(str1);
    
    /* overall font height */
    height=font->ascent+font->descent;
    
    /* dimensions horizontal text will have */
    item->cols_in=item->max_width;
    item->rows_in=item->nl*height;
    
    /* bitmap for drawing on */
    canvas=XCreatePixmap(dpy, DefaultRootWindow(dpy),
                         item->cols_in, item->rows_in, 1);
    
    /* create a GC for the bitmap */
    font_gc=XCreateGC(dpy, canvas, 0, 0);
    XSetBackground(dpy, font_gc, 0);
    XSetFont(dpy, font_gc, font->fid);
    
    /* make sure the bitmap is blank */
    XSetForeground(dpy, font_gc, 0);
    XFillRectangle(dpy, canvas, font_gc, 0, 0, 
                   item->cols_in+1, item->rows_in+1);
    XSetForeground(dpy, font_gc, 1);
    
    /* pre-calculate sin and cos */
    sin_angle=sin(angle);
    cos_angle=cos(angle);
    
    /* text background will be drawn using XFillPolygon */
    item->corners_x=
        (float *)malloc((unsigned)(4*item->nl*sizeof(float)));
    if(!item->corners_x)
        return NULL;
    
    item->corners_y=
        (float *)malloc((unsigned)(4*item->nl*sizeof(float)));
    if(!item->corners_y)
        return NULL;
    
    /* draw text horizontally */
    
    /* start at top of bitmap */
    yp=font->ascent;
    
    str1=my_strdup(text);
    if(str1==NULL)
        return NULL;
    
    str3=my_strtok(str1, str2);
    
    /* loop through each section in the string */
    do {
        XTextExtents(font, str3, strlen(str3), &dir, &asc, &desc,
                &overall);

        /* where to draw section in x ? */
        if(align==TLEFT || align==MLEFT || align==BLEFT || align==NONE)
            xp=0;
        else if(align==TCENTRE || align==MCENTRE || align==BCENTRE)
            xp=(item->max_width-overall.rbearing)/2;
        else
            xp=item->max_width-overall.rbearing;

        /* draw string onto bitmap */
        XDrawString(dpy, canvas, font_gc, xp, yp, str3, strlen(str3));
        
        /* keep a note of corner positions of this string */
        item->corners_x[ic]=((float)xp-(float)item->cols_in/2)*style.magnify;
        item->corners_y[ic]=((float)(yp-font->ascent)-(float)item->rows_in/2)
            *style.magnify;
        item->corners_x[ic+1]=item->corners_x[ic];
        item->corners_y[ic+1]=item->corners_y[ic]+(float)height*style.magnify;
        item->corners_x[item->nl*4-1-ic]=item->corners_x[ic]+
            (float)overall.rbearing*style.magnify;
        item->corners_y[item->nl*4-1-ic]=item->corners_y[ic];
        item->corners_x[item->nl*4-2-ic]=
            item->corners_x[item->nl*4-1-ic];
        item->corners_y[item->nl*4-2-ic]=item->corners_y[ic+1];
        
        ic+=2;
        
        /* move to next line */
        yp+=height;
        
        str3=my_strtok((char *)NULL, str2);
    }
    while(str3!=NULL);
    
    free(str1);
    
    /* create image to hold horizontal text */
    I_in=MakeXImage(dpy, item->cols_in, item->rows_in);
    if(I_in==NULL)
        return NULL;
    
    /* extract horizontal text */
    XGetSubImage(dpy, canvas, 0, 0, item->cols_in, item->rows_in,
                 1, XYPixmap, I_in, 0, 0);
    I_in->format=XYBitmap;
    
    /* magnify horizontal text */
    if(style.magnify!=1.) {
        I_in=XRotMagnifyImage(dpy, I_in);

        old_cols_in=item->cols_in;
        old_rows_in=item->rows_in;
        item->cols_in=(float)item->cols_in*style.magnify;
        item->rows_in=(float)item->rows_in*style.magnify;
    }

    /* how big will rotated text be ? */
    item->cols_out=fabs((float)item->rows_in*sin_angle) +
        fabs((float)item->cols_in*cos_angle) +0.99999 +2;

    item->rows_out=fabs((float)item->rows_in*cos_angle) +
        fabs((float)item->cols_in*sin_angle) +0.99999 +2;

    if(item->cols_out%2==0)
        item->cols_out++;
    
    if(item->rows_out%2==0)
        item->rows_out++;
    
    /* create image to hold rotated text */
    item->ximage=MakeXImage(dpy, item->cols_out, item->rows_out);
    if(item->ximage==NULL)
        return NULL;
    
    byte_w_in=(item->cols_in-1)/8+1;
    byte_w_out=(item->cols_out-1)/8+1;
    
    /* we try to make this bit as fast as possible - which is why it looks
       a bit over-the-top */
    
    /* vertical distance from centre */
    dj=0.5-(float)item->rows_out/2;

    /* where abouts does text actually lie in rotated image? */
    if(angle==0 || angle==M_PI/2 || 
       angle==M_PI || angle==3*M_PI/2) {
        xl=0;
        xr=(float)item->cols_out;
        xinc=0;
    }
    else if(angle<M_PI) {
        xl=(float)item->cols_out/2+
            (dj-(float)item->rows_in/(2*cos_angle))/
                tan(angle)-2;
        xr=(float)item->cols_out/2+
            (dj+(float)item->rows_in/(2*cos_angle))/
                tan(angle)+2;
        xinc=1./tan(angle);
    }
    else {
        xl=(float)item->cols_out/2+
            (dj+(float)item->rows_in/(2*cos_angle))/
                tan(angle)-2;
        xr=(float)item->cols_out/2+
            (dj-(float)item->rows_in/(2*cos_angle))/
                tan(angle)+2;
        
        xinc=1./tan(angle);
    }

    /* loop through all relevent bits in rotated image */
    for(j=0; j<item->rows_out; j++) {
        
        /* no point re-calculating these every pass */
        di=(float)((xl<0)?0:(int)xl)+0.5-(float)item->cols_out/2;
        byte_out=(item->rows_out-j-1)*byte_w_out;
        
        /* loop through meaningful columns */
        for(i=((xl<0)?0:(int)xl); 
            i<((xr>=item->cols_out)?item->cols_out:(int)xr); i++) {
            
            /* rotate coordinates */
            it=(float)item->cols_in/2 + ( di*cos_angle + dj*sin_angle);
            jt=(float)item->rows_in/2 - (-di*sin_angle + dj*cos_angle);
            
            /* set pixel if required */
            if(it>=0 && it<item->cols_in && jt>=0 && jt<item->rows_in)
                if((I_in->data[jt*byte_w_in+it/8] & 128>>(it%8))>0)
                    item->ximage->data[byte_out+i/8]|=128>>i%8;
            
            di+=1;
        }
        dj+=1;
        xl+=xinc;
        xr+=xinc;
    }
    XDestroyImage(I_in);
    
    if(style.magnify!=1.) {
        item->cols_in=old_cols_in;
        item->rows_in=old_rows_in;
    }


#ifdef CACHE_BITMAPS

    /* create a bitmap to hold rotated text */
    item->bitmap=XCreatePixmap(dpy, DefaultRootWindow(dpy),
                               item->cols_out, item->rows_out, 1);
    
    /* make the text bitmap from XImage */
    XPutImage(dpy, item->bitmap, font_gc, item->ximage, 0, 0, 0, 0,
              item->cols_out, item->rows_out);

    XDestroyImage(item->ximage);

#endif /*CACHE_BITMAPS*/

    XFreeGC(dpy, font_gc);
    XFreePixmap(dpy, canvas);

    return item;
}


/* ---------------------------------------------------------------------- */


/**************************************************************************/
/*  Adds a text item to the end of the cache, removing as many items      */
/*      from the front as required to keep cache size below limit         */
/**************************************************************************/

static void XRotAddToLinkedList(dpy, item)
    Display *dpy;
    RotatedTextItem *item;
{
    
    static long int current_size=0;
    static RotatedTextItem *last=NULL;
    RotatedTextItem *i1=first_text_item, *i2=NULL;

#ifdef CACHE_BITMAPS

    /* I don't know how much memory a pixmap takes in the server -
           probably this + a bit more we can't account for */

    item->size=((item->cols_out-1)/8+1)*item->rows_out;

#else

    /* this is pretty much the size of a RotatedTextItem */

    item->size=((item->cols_out-1)/8+1)*item->rows_out +
        sizeof(XImage) + strlen(item->text) + 
            item->nl*8*sizeof(float) + sizeof(RotatedTextItem);

    if(item->font_name!=NULL)
        item->size+=strlen(item->font_name);
    else
        item->size+=sizeof(Font);

#endif /*CACHE_BITMAPS */

#ifdef DEBUG
    /* count number of items in cache, for debugging */
    {
        int i=0;

        while(i1) {
            i++;
            i1=i1->next;
        }
        DEBUG_PRINT2("Cache has %d items.\n", i);
        i1=first_text_item;
    }
#endif

    DEBUG_PRINT4("current cache size=%ld, new item=%ld, limit=%ld\n",
                 current_size, item->size, (long)(CACHE_SIZE_LIMIT*1024));

    /* if this item is bigger than whole cache, forget it */
    if(item->size>CACHE_SIZE_LIMIT*1024) {
        DEBUG_PRINT1("Too big to cache\n\n");
        item->cached=0;
        return;
    }

    /* remove elements from cache as needed */
    while(i1 && current_size+item->size>CACHE_SIZE_LIMIT*1024) {

        DEBUG_PRINT2("Removed %d bytes\n", (int)i1->size);

        if(i1->font_name!=NULL)
            DEBUG_PRINT5("  (`%s'\n   %s\n   angle=%f align=%d)\n",
                         i1->text, i1->font_name, i1->angle, i1->align);

#ifdef CACHE_FID
        if(i1->font_name==NULL)
            DEBUG_PRINT5("  (`%s'\n  FID=%ld\n   angle=%f align=%d)\n",
                         i1->text, i1->fid, i1->angle, i1->align);
#endif /*CACHE_FID*/

        current_size-=i1->size;

        i2=i1->next;

        /* free resources used by the unlucky item */
        XRotFreeTextItem(dpy, i1);

        /* remove it from linked list */
        first_text_item=i2;
        i1=i2;
    }

    /* add new item to end of linked list */
    if(first_text_item==NULL) {
        item->next=NULL;
        first_text_item=item;
        last=item;
    }
    else {
        item->next=NULL;
        last->next=item;
        last=item;
    }

    /* new cache size */
    current_size+=item->size;

    item->cached=1;

    DEBUG_PRINT1("Added item to cache.\n");
}


/* ---------------------------------------------------------------------- */


/**************************************************************************/
/*  Free the resources used by a text item                                */
/**************************************************************************/

static void XRotFreeTextItem(dpy, item)
    Display *dpy;
    RotatedTextItem *item;
{
    free(item->text);

    if(item->font_name!=NULL)
        free(item->font_name);

    free((char *)item->corners_x);
    free((char *)item->corners_y);

#ifdef CACHE_BITMAPS
    XFreePixmap(dpy, item->bitmap);
#else
    XDestroyImage(item->ximage);
#endif /* CACHE_BITMAPS */

    free((char *)item);
}


/* ---------------------------------------------------------------------- */


/**************************************************************************/
/* Magnify an XImage using bilinear interpolation                         */
/**************************************************************************/

static XImage *XRotMagnifyImage(dpy, ximage)
    Display *dpy;
    XImage *ximage;
{
    int i, j;
    float x, y;
    float u,t;
    XImage *I_out;
    int cols_in, rows_in;
    int cols_out, rows_out;
    register int i2, j2;
    float z1, z2, z3, z4;
    int byte_width_in, byte_width_out;
    float mag_inv;

    /* size of input image */
    cols_in=ximage->width;
    rows_in=ximage->height;

    /* size of final image */
    cols_out=(float)cols_in*style.magnify;
    rows_out=(float)rows_in*style.magnify;

    /* this will hold final image */
    I_out=MakeXImage(dpy, cols_out, rows_out);
    if(I_out==NULL)
        return NULL;

    /* width in bytes of input, output images */
    byte_width_in=(cols_in-1)/8+1;
    byte_width_out=(cols_out-1)/8+1;

    /* for speed */
    mag_inv=1./style.magnify;

    y=0.;

    /* loop over magnified image */
    for(j2=0; j2<rows_out; j2++) {
        x=0;
        j=y;

        for(i2=0; i2<cols_out; i2++) {
            i=x;

            /* bilinear interpolation - where are we on bitmap ? */
            /* right edge */
            if(i==cols_in-1 && j!=rows_in-1) {
                t=0;
                u=y-(float)j;

                z1=(ximage->data[j*byte_width_in+i/8] & 128>>(i%8))>0;
                z2=z1;
                z3=(ximage->data[(j+1)*byte_width_in+i/8] & 128>>(i%8))>0;
                z4=z3;
            }
            /* top edge */
            else if(i!=cols_in-1 && j==rows_in-1) {
                t=x-(float)i;
                u=0;

                z1=(ximage->data[j*byte_width_in+i/8] & 128>>(i%8))>0;
                z2=(ximage->data[j*byte_width_in+(i+1)/8] & 128>>((i+1)%8))>0;
                z3=z2;
                z4=z1;
            }
            /* top right corner */
            else if(i==cols_in-1 && j==rows_in-1) {
                u=0;
                t=0;

                z1=(ximage->data[j*byte_width_in+i/8] & 128>>(i%8))>0;
                z2=z1;
                z3=z1;
                z4=z1;
            }
            /* somewhere `safe' */
            else {
                t=x-(float)i;
                u=y-(float)j;

                z1=(ximage->data[j*byte_width_in+i/8] & 128>>(i%8))>0;
                z2=(ximage->data[j*byte_width_in+(i+1)/8] & 128>>((i+1)%8))>0;
                z3=(ximage->data[(j+1)*byte_width_in+(i+1)/8] &
                    128>>((i+1)%8))>0;
                z4=(ximage->data[(j+1)*byte_width_in+i/8] & 128>>(i%8))>0;
            }

            /* if interpolated value is greater than 0.5, set bit */
            if(((1-t)*(1-u)*z1 + t*(1-u)*z2 + t*u*z3 + (1-t)*u*z4)>0.5)
                I_out->data[j2*byte_width_out+i2/8]|=128>>i2%8;

            x+=mag_inv;
        }
        y+=mag_inv;
    }
    
    /* destroy original */
    XDestroyImage(ximage);

    /* return big image */
    return I_out;
}



/* ---------------------------------------------------------------------- */


/**************************************************************************/
/* Calculate the bounding box some text will have when painted            */
/**************************************************************************/

XPoint *XRotTextExtents(dpy, font, angle, x, y, text, align)
    Display *dpy;
    XFontStruct *font;
    float angle;
    int x, y;
    char *text;
    int align;
{
    register int i;
    char *str1, *str2, *str3;
    char *str2_a="\0", *str2_b="\n\0";
    int height;
    float sin_angle, cos_angle;
    int nl, max_width;
    int cols_in, rows_in;
    float hot_x, hot_y;
    XPoint *xp_in, *xp_out;
    int dir, asc, desc;
    XCharStruct overall;
   
    /* manipulate angle to 0<=angle<360 degrees */
    while(angle<0)
        angle+=360;
    
    while(angle>360)
        angle-=360;

    angle*=M_PI/180;

    /* count number of sections in string */
    nl=1;
    if(align!=NONE) {
            for (i=0; i < (int)(strlen(text)-1); i++) {
                if(text[i]=='\n') {
                        nl++;
            }
        }
    }
    
    /* ignore newline characters if not doing alignment */
    if(align==NONE)
            str2=str2_a;
    else
            str2=str2_b;

    /* find width of longest section */
    str1=my_strdup(text);
    if(str1==NULL)
            return NULL;

    str3=my_strtok(str1, str2);

    XTextExtents(font, str3, strlen(str3), &dir, &asc, &desc, &overall);

    max_width=overall.rbearing;
    
    /* loop through each section */
    do {
            str3=my_strtok((char *)NULL, str2);

            if(str3!=NULL) {
                XTextExtents(font, str3, strlen(str3), &dir, &asc, &desc, &overall);

            if(overall.rbearing>max_width)
                    max_width=overall.rbearing;
            }
    }
    while(str3!=NULL);
 
    free(str1);
    
    /* overall font height */
    height=font->ascent+font->descent;
    
    /* dimensions horizontal text will have */
    cols_in=max_width;
    rows_in=nl*height;
    
    /* pre-calculate sin and cos */
    sin_angle=sin(angle);
    cos_angle=cos(angle);
    
    /* y position */
    if(align==TLEFT || align==TCENTRE || align==TRIGHT)
        hot_y=(float)rows_in/2*style.magnify;
    else if(align==MLEFT || align==MCENTRE || align==MRIGHT)
            hot_y=0;
    else if(align==BLEFT || align==BCENTRE || align==BRIGHT)
            hot_y=-(float)rows_in/2*style.magnify;
    else
            hot_y=-((float)rows_in/2-(float)font->descent)*style.magnify;
    
    /* x position */
    if(align==TLEFT || align==MLEFT || align==BLEFT || align==NONE)
            hot_x=-(float)max_width/2*style.magnify;
    else if(align==TCENTRE || align==MCENTRE || align==BCENTRE)
            hot_x=0;
    else
        hot_x=(float)max_width/2*style.magnify;
   
    /* reserve space for XPoints */
    xp_in=(XPoint *)malloc((unsigned)(5*sizeof(XPoint)));
    if(!xp_in)
        return NULL;

    xp_out=(XPoint *)malloc((unsigned)(5*sizeof(XPoint)));
    if(!xp_out)
        return NULL;

    /* bounding box when horizontal, relative to bitmap centre */
    xp_in[0].x=-(float)cols_in*style.magnify/2-style.bbx_pad;
    xp_in[0].y= (float)rows_in*style.magnify/2+style.bbx_pad;
    xp_in[1].x= (float)cols_in*style.magnify/2+style.bbx_pad;
    xp_in[1].y= (float)rows_in*style.magnify/2+style.bbx_pad;
    xp_in[2].x= (float)cols_in*style.magnify/2+style.bbx_pad;
    xp_in[2].y=-(float)rows_in*style.magnify/2-style.bbx_pad;
    xp_in[3].x=-(float)cols_in*style.magnify/2-style.bbx_pad;
    xp_in[3].y=-(float)rows_in*style.magnify/2-style.bbx_pad;
    xp_in[4].x=xp_in[0].x;
    xp_in[4].y=xp_in[0].y;
        
    /* rotate and translate bounding box */
    for(i=0; i<5; i++) {
            xp_out[i].x=(float)x + ( ((float)xp_in[i].x-hot_x)*cos_angle +
                                 ((float)xp_in[i].y+hot_y)*sin_angle);
            xp_out[i].y=(float)y + (-((float)xp_in[i].x-hot_x)*sin_angle +
                                 ((float)xp_in[i].y+hot_y)*cos_angle);
    }

    free((char *)xp_in);

    return xp_out;
}


