dlib C++ Library - nativefont.h

    // Copyright (C) 2006 Keita Mochizuki
    // License: Boost Software License   See LICENSE.txt for the full license.
    #ifndef DLIB_IGG_FONT_RENDERER_H_
    #define DLIB_IGG_FONT_RENDERER_H_
    #ifndef DLIB_NO_GUI_SUPPORT

    #include "../platform.h"

    #include "../gui_widgets/fonts.h"
    #include "../unicode.h"
    #include "../uintn.h"

    #include <map>
    #include <memory>

    #include <stdio.h>
    #include <string.h>
    #include <stdlib.h>
    #include <locale.h>

    #if defined(WIN32)
    #include <windows.h>
    #include <mbstring.h>
    #elif defined(DLIB_POSIX)
    #include <stdint.h>
    #include <stdio.h>
    #include <string.h>
    #include <X11/Xlib.h>
    #include <X11/Xutil.h>
    #include <X11/Xlocale.h>
    #endif

    namespace nativefont
    {
    // ----------------------------------------------------------------------------------------

        namespace font_renderer
        {
            typedef dlib::uint8 byte;

    #ifdef WIN32
            template <typename T> struct input2native_trait{
            };
            template <> struct input2native_trait<char>{
                typedef char type_t;
            };
            template <> struct input2native_trait<wchar_t>{
                typedef wchar_t type_t;
            };
            template <> struct input2native_trait<dlib::unichar>{
                typedef wchar_t type_t;
            };
    #endif
            // T : N : sizeof_source_type
            template <int N> struct size2inner_trait{
            };
            template <> struct size2inner_trait<1>{
                typedef char type_t;
            };
            template <> struct size2inner_trait<2>{
                typedef dlib::uint16 type_t;
            };
            template <> struct size2inner_trait<4>{
                typedef dlib::unichar type_t;
            };

    // ----------------------------------------------------------------------------------------

            template <int N> struct create_helper{ };
            template <> struct create_helper<1>{
                typedef char type_t;
                type_t *istr;
                int len;
                create_helper(char *str){
                    len = (int)strlen(str);
                    istr = str;
                }
                ~create_helper(){}
            };
            template <> struct create_helper<2>{
                typedef wchar_t type_t;
                type_t *istr;
                bool allocated;
                int len;
                create_helper(wchar_t *str){
                    allocated = false;
                    len = (int)wcslen(str);
                    istr = str;
                }
                create_helper(dlib::unichar *str){
                    allocated = true;
                    len = 0;
                    int unicount = 0;
                    dlib::unichar *p = str;
                    while(*p){
                        if (*p > 0xffff){
                            len += 2;
                        }else{
                            len++;
                        }
                        unicount++;
                        p++;
                    }
                    istr = new wchar_t[len+1];
                    for (int i = 0, wi = 0; i < unicount; ++i){
                        dlib::unichar high, low;
                        if (str[i] > 0xffff){
                            dlib::unichar_to_surrogate_pair(str[i], high, low);
                            istr[wi] = (wchar_t)high, istr[wi+1] = (wchar_t)low;
                            wi += 2;
                        }else{
                            istr[wi] = (wchar_t)str[i];
                            wi += 1;
                        }
                    }
                    istr[len] = L'\0';
                }

                ~create_helper(){
                    if (allocated) delete[] istr;
                }
            };
            template <> struct create_helper<4>{
                typedef wchar_t type_t;
                type_t *istr;
                int len;
                create_helper(dlib::unichar *str){
                    len = (int)wcslen((wchar_t *)str);
                    istr = (type_t *)str;
                }
                ~create_helper(){}
            };

    // ----------------------------------------------------------------------------------------

            class font_renderer{
            public:

                struct rgb_type{
                    byte r, g, b;
                    rgb_type() : r(0), g(0), b(0){};
                    rgb_type(byte r_, byte g_, byte b_) : r(r_), g(g_), b(b_){};
                };
            private:

                byte *image;
                int width, height;
                void destroy(){
                    width = height = 0;
                    delete image;
                    image = 0;
                }
                struct vals_internal{
                    int width, height;
    #ifdef WIN32
                    COLORREF rgb2RGB(rgb_type &rgb){
                        return RGB(rgb.r, rgb.g, rgb.b);
                    }
                    HBITMAP hBmp, hBmpOld;
                    HDC hDCBmp;
                    BYTE *pixelint;
                    HFONT hFont, hFontOld;
                    HBRUSH hBrush;
                    int pix_width_prev, pix_height_prev;
                    bool first;
                    int ascender, descender;
                    int height_prev;
                    char attribute_prev;

                    template <typename T> void create(T *str, int height_want, bool italic, bool bold, bool fixed, rgb_type &background, rgb_type &foreground){
                        struct inner{
                            inline static BOOL GetTextExtentPoint32(HDC hDC, LPCSTR str, int len, LPSIZE lpsize){
                                return ::GetTextExtentPoint32A(hDC, str, len, lpsize);
                            }
                            inline static BOOL GetTextExtentPoint32(HDC hDC, LPCWSTR str, int len, LPSIZE lpsize){
                                return ::GetTextExtentPoint32W(hDC, str, len, lpsize);
                            }
                            inline static BOOL TextOut(HDC hDC, int nxstart, int nystart, LPCSTR str, int cbstr){
                                return ::TextOutA(hDC, nxstart, nystart, str, cbstr);
                            }
                            inline static BOOL TextOut(HDC hDC, int nxstart, int nystart, LPCWSTR str, int cbstr){
                                return ::TextOutW(hDC, nxstart, nystart, str, cbstr);
                            }
                        };

                        create_helper<sizeof(typename input2native_trait<T>::type_t)> ch(str);

                        if (hDCBmp == NULL){
                            HWND hWnd = GetDesktopWindow();
                            HDC hDC = GetDC(hWnd);
                            hDCBmp = CreateCompatibleDC(hDC);
                            ReleaseDC(hWnd, hDC);
                        }
                        SetTextColor(hDCBmp, rgb2RGB(foreground));
                        SetBkColor(hDCBmp, rgb2RGB(background));

                        char attribute = (italic ? 1 : 0) | (bold ? 2 : 0) | (fixed ? 4 : 0);
                        if (!hFont || height_prev != height || attribute != attribute_prev){
                            attribute_prev = attribute;
                            height_prev = height_want;
                            if (hFont){
                                SelectObject(hDCBmp, hFontOld);
                                DeleteObject(hFont);
                            }
                            hFont = CreateFont(height_want, 0, 0, 0, bold ? FW_BOLD : FW_DONTCARE, italic ? TRUE : FALSE,
                                               FALSE, FALSE, DEFAULT_CHARSET, OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS, DEFAULT_QUALITY,
                                               fixed ? (FIXED_PITCH | FF_DONTCARE) : (VARIABLE_PITCH | FF_DONTCARE), NULL);
                            hFontOld = (HFONT)SelectObject(hDCBmp, hFont);
                        }

                        {
                            SIZE sz;
                            inner::GetTextExtentPoint32(hDCBmp, ch.istr, ch.len, &sz);
                            width = ((sz.cx + 3) / 4) * 4;
                            height = sz.cy;
                        }

                        if (pix_width_prev < width || pix_height_prev < height){
                            if (hBmp){
                                SelectObject(hDCBmp, hBmpOld);
                                DeleteObject(hBmp);
                            }
                            pix_width_prev = width * 2;
                            pix_height_prev = height * 2;
                            BITMAPINFO bi;
                            ZeroMemory(&bi, sizeof(bi));
                            bi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
                            bi.bmiHeader.biBitCount = 24;
                            bi.bmiHeader.biPlanes = 1;
                            bi.bmiHeader.biWidth = pix_width_prev;
                            bi.bmiHeader.biHeight = -pix_height_prev;
                            hBmp = CreateDIBSection(NULL, &bi, DIB_RGB_COLORS, (void **)&pixelint, NULL, 0);
                            hBmpOld = (HBITMAP)SelectObject(hDCBmp, hBmp);
                        }

                        {
                            HBRUSH hBrush = CreateSolidBrush(rgb2RGB(background));
                            RECT rc;
                            rc.left = rc.top = 0;
                            rc.right = pix_width_prev;
                            rc.bottom = pix_height_prev;
                            FillRect(hDCBmp, &rc, hBrush);
                        }

                        inner::TextOut(hDCBmp, 0, 0, ch.istr, ch.len);
                        TEXTMETRICW tm;
                        GetTextMetricsW(hDCBmp,&tm);
                        ascender = tm.tmAscent;
                        descender = tm.tmDescent;
                    }

                    template <typename T> vals_internal(T *str, int height_want, bool italic = false,
                        bool bold = false, bool fixed = false, rgb_type background = rgb_type(), rgb_type foreground = rgb_type()){
                        first = true;
                        hFont = NULL;
                        hDCBmp = 0;
                        hBmpOld = 0;
                        hBmp = 0;
                        hDCBmp = 0;
                        pixelint = 0;
                        pix_width_prev = pix_height_prev = 0;
                        height_prev = -1;
                        attribute_prev = 0;
                        create(str, height_want, italic, bold, fixed, background, foreground);
                        first = false;
                    }

                    inline int get_ascender(){
                        return ascender;
                    }

                    inline int get_descender(){
                        return descender;
                    }

                    inline void get_pixel(int x, int y, byte &r, byte &g, byte &b){
                        byte *p = pixelint + (y * pix_width_prev + x) * 3;
                        r = *(p+2), g = *(p+1), b = *p;
                    }

                    void destroy(){
                        SelectObject(hDCBmp, hBmpOld);
                        DeleteObject(hBmp);
                        SelectObject(hDCBmp, hFontOld);
                        DeleteObject(hFont);
                        DeleteDC(hDCBmp);
                        hFont = NULL;
                        hDCBmp = 0;
                        hBmpOld = 0;
                        hBmp = 0;
                        hDCBmp = 0;
                        pixelint = 0;
                    }
                    ~vals_internal(){
                        destroy();
                    }
    #elif defined(DLIB_POSIX)
                    XImage *ximg;
                    Display *d;
                    GC gc;
                    XFontSet fs;
                    Pixmap pix;
                    Colormap cmap;
                    int ascender, descender;
                    int pix_width_prev, pix_height_prev;
                    char fontset_prev[256];
                    unsigned long rgb2color(rgb_type col, Display *d, Colormap &cmap){
                        XColor xcol;
                        xcol.red = col.r * 257;
                        xcol.green = col.g * 257;
                        xcol.blue = col.b * 257;
                        XAllocColor(d, cmap, &xcol);
                        return xcol.pixel;
                    }
                    template <typename T> void create(T *str, int height_want, bool italic, bool bold, bool fixed, rgb_type background, rgb_type foreground){
                        struct inner{
                            inline static int XTextExtents (XFontSet fs, char *str, int len, XRectangle *ink, XRectangle *logical){
                                return XmbTextExtents(fs, str, len, ink, logical);
                            }
                            inline static int XTextExtents (XFontSet fs, wchar_t *str, int len, XRectangle *ink, XRectangle *logical){
                                return XwcTextExtents(fs, str, len, ink, logical);
                            }
                            inline static void XDrawString(Display *d, Window w, XFontSet fs, GC gc, int x, int y, char *str, int num_bytes){
                                XmbDrawString(d, w, fs, gc, x, y, str, num_bytes);
                            }
                            inline static void XDrawString(Display *d, Window w, XFontSet fs, GC gc, int x, int y, wchar_t *str, int num_bytes){
                                XwcDrawString(d, w, fs, gc, x, y, str, num_bytes);
                            }
                        };
                        create_helper<sizeof(T)> ch((typename size2inner_trait<sizeof(T)>::type_t *)str);
                        setlocale(LC_CTYPE, "");
                        if (d == NULL){
                            d = XOpenDisplay(NULL);
                            if (d == 0)
                            {
                                d = XOpenDisplay(":0.0");
                                if (d == 0)
                                {
                                    throw dlib::gui_error("Unable to connect to the X display.");
                                }
                            }

                            cmap = DefaultColormap(d, DefaultScreen(d));
                        }
                        char fontset[256] = {0};
                        {
                            int offset = snprintf(fontset, sizeof(fontset), "-*-*-%s-%c-normal--%d-*-*-*-%c",
                                                  bold ? "bold" : "medium", italic ? 'i' : 'r', height_want, fixed ? 'c' : 'p');
                            if (fixed){
                                snprintf(&fontset[offset], sizeof(fontset) - offset, ",-*-*-%s-%c-normal--%d-*-*-*-m",
                                         bold ? "bold" : "medium", italic ? 'i' : 'r', height_want);
                            }
                        }
                        bool equal_font;
                        if (strcmp(fontset, fontset_prev) == 0){
                            equal_font = true;
                        }else{
                            equal_font = false;
                            strcpy(fontset_prev, fontset);
                        }

                        char **mlist;
                        int mcount;
                        char *def_str;
                        if (!equal_font){
                            if (fs){
                                XFreeFontSet(d, fs);
                            }
                            fs = XCreateFontSet(d, fontset, &mlist, &mcount, &def_str);
                            if (fs == NULL)
                               throw dlib::gui_error("gui_error: XCreateFontSet() failure");

                            XFontSetExtents *extent;
                            extent = XExtentsOfFontSet(fs);
                            ascender = -extent->max_logical_extent.y;
                            descender = extent->max_logical_extent.height - ascender;
                            XFreeStringList(mlist);
                        }
                        XRectangle ink, logical;
                        inner::XTextExtents (fs, ch.istr, ch.len, &ink, &logical);
                        width = logical.width;
                        height = height_want;

                        if (pix == None || pix_width_prev < width || pix_height_prev < height){
                            if (pix != None){
                                XFreeGC(d, gc);
                                XFreePixmap(d, pix);
                            }
                            pix_width_prev = width * 2;
                            pix_height_prev = height * 2;
                            pix = XCreatePixmap(d, DefaultRootWindow(d), pix_width_prev, pix_height_prev, XDefaultDepth(d, DefaultScreen(d)));
                            gc = XCreateGC(d, pix, 0, NULL);
                        }

                        unsigned long backcolor = rgb2color(background, d, cmap);
                        XSetForeground(d, gc, backcolor);
                        XSetBackground(d, gc, backcolor);
                        XFillRectangle(d, pix, gc, 0, 0, width, height);
                        XSetForeground(d, gc, rgb2color(foreground, d, cmap));
                        inner::XDrawString(d, pix, fs, gc, 0, ascender, ch.istr, ch.len);

                        if (ximg) XDestroyImage(ximg);
                        ximg = XGetImage(d, pix, 0, 0, width, height, AllPlanes, ZPixmap );
                    }

                    template <typename T> vals_internal(T *str, int height_want, bool italic = false,
                        bool bold = false, bool fixed = false, rgb_type background = rgb_type(), rgb_type foreground = rgb_type()){
                        fontset_prev[0] = '\0';
                        ximg = NULL;
                        d = NULL;
                        pix = None;
                        fs = NULL;
                        ascender = descender = -1;
                        pix_width_prev = pix_height_prev = -1;
                        create(str, height_want, italic, bold, fixed, background, foreground);
                    }

                    inline int get_ascender(){
                        return ascender;
                    }

                    inline int get_descender(){
                        return descender;
                    }

                    std::map<unsigned long,rgb_type> col2rgb;
                    rgb_type color2rgb(unsigned long color, Display *d, Colormap &cmap){
                        if (col2rgb.count(color)){
                            return col2rgb[color];
                        }else{
                            XColor xcol;
                            xcol.pixel = color;
                            XQueryColor(d, cmap, &xcol);
                            rgb_type rgb_((byte)(xcol.red/257), (byte)(xcol.green/257), (byte)(xcol.blue/257));
                            col2rgb[color] = rgb_;
                            return rgb_;
                        }
                    }
                    inline void get_pixel(int x, int y, byte &r, byte &g, byte &b){
                        rgb_type c = color2rgb(XGetPixel(ximg,x,y), d, cmap);
                        r = c.r, g = c.g, b = c.b;
                    }

                    ~vals_internal(){
                        XDestroyImage(ximg);

                        XFreeGC(d, gc);
                        XFreeFontSet(d, fs);
                        XFreePixmap(d, pix);
                        XCloseDisplay(d);
                    }
    #endif
                };

                struct image_size_setter{
                    void operator()(int&, int&){
                    }
                };

                int ascender, descender;
                vals_internal *vi;
            public:
                font_renderer() : image(0), width(0), height(0){
                    ascender = descender = 0;
                    vi = NULL;
                }

                template<typename T> font_renderer(T *str, int height_want, bool italic = false, bool bold = false, bool fixed = false,         rgb_type background = rgb_type(0,0,0), rgb_type foreground = rgb_type(255,255,255)){
                    render(str, height_want, italic, bold, fixed, background, foreground);
                }

                template<typename T> void render(T *str, int height_want,
                                                 bool italic = false, bool bold = false, bool fixed = false,
                                                 rgb_type background = rgb_type(0,0,0), rgb_type foreground = rgb_type(255,255,255)){
                    if (vi == NULL){
                        vi = new vals_internal(str, height_want, italic, bold, fixed, background, foreground);
                    }else{
                        vi->create(str, height_want, italic, bold, fixed, background, foreground);
                    }
                    width = vi->width, height = vi->height;
                    image = new byte[width * height * 3];
                    ascender = vi->get_ascender();
                    descender = vi->get_descender();

                    int h = height, w = width;
                    for (int j = 0, i3 = 0; j < h; ++j){
                        for (int i = 0; i < w; ++i, i3 += 3){
                            vi->get_pixel(i, j, image[i3], image[i3+1], image[i3+2]);
                        }
                    }
                }

                ~font_renderer(){
                    if (vi) delete vi;
                    destroy();
                }
                int get_width(){
                    return width;
                }
                int get_height(){
                    return height;
                }
                inline int get_ascender(){
                    return ascender;
                }
                inline int get_descender(){
                    return descender;
                }

                const byte *get_image(){
                    return image;
                }
            };
        }

    // ----------------------------------------------------------------------------------------

        class native_font : public dlib::font
        {
            unsigned long ascender_;
            native_font(){
                setlocale(LC_CTYPE, "");
                ascender_ = 0;
                get_letter((int)('x'));
            }
            typedef std::map<int,dlib::letter *> letters_map_type;
            letters_map_type letters;
            font_renderer::font_renderer fl;
        public:

            virtual ~native_font()
            {
                // delete all the letter objects we have in our letters map
                letters_map_type::iterator i;
                for (i = letters.begin(); i != letters.end(); ++i)
                {
                    delete i->second;
                }
            }

            virtual bool has_character (
                dlib::unichar ch
            )const{
                return (*this)[ch].width() > 0;
            }

            static const std::shared_ptr<font>& get_font (
            )
            {
                static std::shared_ptr<font> f(new native_font);
                return f;
            }

            virtual const dlib::letter& operator[] (dlib::unichar ch) const{
                return (const_cast<native_font *>(this))->get_letter(ch);
            }

            dlib::letter& get_letter (
                dlib::unichar ch
            ){
                if (letters.count(ch)){
                    dlib::letter *l = letters.find(ch)->second;
                    return *l;
                }

                dlib::unichar c[2];
                c[0] = ch;
                c[1] = 0;

                fl.render(c, height(),false,false,true);
                if (ascender_ == 0){
                    ascender_ = fl.get_ascender();
                }
                std::vector<dlib::letter::point> v;
                const font_renderer::byte *bp = fl.get_image();
                for (int j = 0; j < fl.get_height(); ++j){
                    for (int i = 0; i < fl.get_width(); ++i, bp += 3){
                        if (*bp){
                            v.push_back(dlib::letter::point(i,j-ascender()+1));
                        }
                    }
                }
                dlib::letter *l = new dlib::letter(fl.get_width(), (unsigned long)v.size());

                letters.insert(std::make_pair(ch,l));
                for (int i = 0; i < (int)v.size(); ++i){
                    (*l)[i] = v.at(i);
                }
                return *l;
            }

            virtual unsigned long height (
            ) const { return 12; }

            virtual unsigned long ascender (
            ) const { return ascender_; }

            virtual unsigned long left_overflow (
            ) const { return 1; }

            virtual unsigned long right_overflow (
            ) const { return 2; }
        };

    // ----------------------------------------------------------------------------------------

    }

    #endif // DLIB_NO_GUI_SUPPORT
    #endif // DLIB_IGG_FONT_RENDERER_H_