plfreetype.h

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//    Header file for Support routines for freetype font engine
//
//    See plfreetype.c for more details
//
//  Copyright (C) 2004  Andrew Roach
//
//  This file is part of PLplot.
//
//  PLplot is free software; you can redistribute it and/or modify
//  it under the terms of the GNU Library General Public License as published
//  by the Free Software Foundation; either version 2 of the License, or
//  (at your option) any later version.
//
//  PLplot 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 Library General Public License for more details.
//
//  You should have received a copy of the GNU Library General Public License
//  along with PLplot; if not, write to the Free Software
//  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
//
//
//

#ifndef __PLFREETY_H__
#define __PLFREETY_H__

#ifdef PL_HAVE_FREETYPE

#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_GLYPH_H
#include FT_OUTLINE_H
#include FT_MODULE_H

#define FT_Data    _FT_Data_

#ifndef GetGValue
#define GetGValue( rgb )    ( (unsigned char) ( ( (unsigned short) ( rgb ) ) >> 8 ) )
#endif
#ifndef GetRValue
#define GetRValue( rgb )    ( (unsigned char) ( rgb ) )
#endif
#ifndef GetBValue
#define GetBValue( rgb )    ( (unsigned char) ( ( rgb ) >> 16 ) )
#endif
#ifndef RGB
#define RGB( r, g, b )      ( ( ( r ) |          \
                                ( ( g ) << 8 ) | \
                                ( b ) << 16 ) )
#endif

typedef void ( *plD_pixel_fp )( PLStream *, PLINT, PLINT );
typedef PLINT ( *plD_read_pixel_fp )( PLStream *, PLINT, PLINT );
typedef PLINT ( *plD_set_pixel_fp )( PLStream *, PLINT, PLINT, PLINT );

//--------------------------------------------------------------------------
// Define the FT_Data data structure.
//
// These are the "globalish" variables used by Freetype
// They are kept here so they are moderately thread safe, and stream specific
//--------------------------------------------------------------------------

typedef struct FT_Data
{
    short x;
    short y;

    char  *textbuf;             // temporary string buffer

//
//  If set to 1, scale won't do anything, but this is an "arbitrary" scale
//  factor for the transformation between virtual and real coordinates. This
//  is included to fix up the problem with the "hidden line removal bug" of
//  the 3D plots, which is fixed by providing a super-scaled image. This
//  should be a mirror, for example, of dev->scale in the PNG driver. If I
//  was thinking 12 months ahead, I would have put that scale factor in
//  "pls", not "dev", but at this late stage, we can just live with it
//  now...
//
    PLFLT scale;

    //
    // If different scales are used for x and y, set the next variables instead
    // of scale.
    //
    PLFLT         scalex;
    PLFLT         scaley;

    unsigned char greek;

//
//  Set "invert_y" to 1 if the y coordinates need to be inverted for
//  plotting. Most bitmaps will need this.
//
    unsigned char invert_y;

//
//  ymax should be equal to, what it says - the maximum y coordinate of the
//  bitmap. This is used in the process of calculating the inversion of the
//  bitmap when invert_y is set to 1. If invert_y isn't set, this setting is
//  ignored.
//
    short             ymax;


    plD_pixel_fp      pixel;            // pointer to a function which draws a single pixel
    plD_set_pixel_fp  set_pixel;        // pointer to a function which draws a single pixel directly
    plD_read_pixel_fp read_pixel;       // pointer to a function which reads the RGB value of a pixel and returns it


    int want_smooth_text;               // flag to request text smoothing (won't
                                        // necessarily get it though
    int smooth_text;                    // Flag to indicate type of anti-aliasing used, if freetype text is active


//
//  List of font names and paths corresponding to the "predefined" fonts of
//  plplot. 1024 chars is presumably generous for each one's length, but at
//  least we probably won't get in trouble this way.
//

    // 30 = five families * 3 styles * 2 weights = N_TrueTypeLookup
    char font_name[30][1024];

//
//  This is a mirror of pls->fci and is basically used for detecting when
//  fonts have been changed .
//

    PLUNICODE fci;
    PLFLT     chrht;                    // Mirror of pls's copy so we can detect when the font SIZE has been changed
    PLFLT     xdpi, ydpi;               // Mirror of pls's copy, so that we can detect, if resolution was changed

    FT_Matrix matrix;                   // used for rotating etc... the font.
    FT_Vector pos;                      // used for calculating offsets of text boxes/sizes


//
//  The next few variables hold the original size of CMAP0, the number of
//  extra slots added for anti-aliasing, and the "width" of the table used
//  for anti-aliasing.
//

    PLINT ncol0_org;            // Original number of colours in CMAP0
    PLINT ncol0_xtra;           // number of extra colours defined in CMAP0 for anti-aliasing
    PLINT ncol0_width;          // Number of greyscale levels for each of the original colours
    PLINT last_icol0;           // Last colour in cmap0, which should be one of the originals


//
//  The rest of the variables should be considered very much PRIVATE, and
//  more to the point, subject to change.
//
//  Don't rely on them existing in future versions of plplot's freetype
//  support. If/when the Freetype cache manager is added to plplot, most, if
//  not all, of these variables will move elsewhere.
//

    FT_Library   library;               // pointer to freetype library
    FT_Face      face;                  // pointer to a font face
    FT_GlyphSlot slot;                  // pointer to a glyph slot
    FT_Glyph     image;                 // bitmap or outline image of font

    short        colour;                // deprecated ?? must check code

    PLINT        shade, col_idx;        // Used for antialiasing

//
//  If a driver is 24Bit, and supports reading pixel values as well as writing,
//  we can use a more advanced antialiasing algorithm, which blends the text
//  with the background. Set to 1 if you have this.
//
    unsigned char BLENDED_ANTIALIASING;
} FT_Data;


#endif

#endif // __PLFREETY_H__