fxfont.h

/*
    Copyright (c) 2009 Andrew Caudwell (acaudwell@gmail.com)
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:
    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.
    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in the
       documentation and/or other materials provided with the distribution.
    3. The name of the author may not be used to endorse or promote products
       derived from this software without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
    OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
    IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
    NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
    THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    Portions of this code are derivived from FTGL (FTTextureFont.cpp)

    FTGL - OpenGL font library

    Copyright (c) 2001-2004 Henry Maddocks <ftgl@opengl.geek.nz>
    Copyright (c) 2008 Sam Hocevar <sam@zoy.org>

    Permission is hereby granted, free of charge, to any person obtaining
    a copy of this software and associated documentation files (the
    "Software"), to deal in the Software without restriction, including
    without limitation the rights to use, copy, modify, merge, publish,
    distribute, sublicense, and/or sell copies of the Software, and to
    permit persons to whom the Software is furnished to do so, subject to
    the following conditions:

    The above copyright notice and this permission notice shall be
    included in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
    IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
    TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
    SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#ifndef FX_FONT_H
#define FX_FONT_H

#include "display.h"
#include "vectors.h"
#include "logger.h"
#include "resource.h"
#include "texture.h"
#include "vbo.h"

#include <string>
#include <vector>
#include <map>

#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_GLYPH_H
#include "ftgl/FTUnicode.h"

class FXFontException : public ResourceException {
public:
    FXFontException(const std::string & font_file) : ResourceException(font_file) {}
};


class FXGlyph;
class FXGlyphSet;

class FXGlyphPage {
    GLubyte* texture_data;
    bool     needs_update;
    int      page_width;
    int      page_height;
public:
    TextureResource* texture;

    FXGlyphPage(int page_width, int page_height);
    ~FXGlyphPage();

    bool addGlyph(FXGlyph* glyph);

    void updateTexture();

    int cursor_x, cursor_y;
    int max_glyph_height;
};

class FXGlyph {
    unsigned int chr;

    vec2 dims;
    vec2 corner;
    vec2 advance;
    int  height;
public:
    vec2 vertex_positions[4];
    vec2 vertex_texcoords[4];

    FXGlyphPage* page;
    vec4 texcoords;
    FXGlyphSet* set;
    FT_Glyph       ftglyph;
    FT_BitmapGlyph glyph_bitmap;

    FXGlyph(FXGlyphSet* set, unsigned int chr);
    ~FXGlyph();

    const vec2& getAdvance() const { return advance; };
    const vec2& getCorner() const { return corner; };
    const vec2& getDimensions() const { return dims; };

    int getHeight() const { return height; };

    void setPage(FXGlyphPage* page, const vec4& texcoords);

    void drawToVBO(quadbuf& buffer, const vec2& offset, const vec4& colour) const;
    void draw(const vec2& pos) const;
};

class FXGlyphSet {
    FT_Library freetype;
    FT_Face ft_face;
    FT_Int32 ft_flags;
    std::string fontfile;
    int max_height;
    int size;
    int dpi;
    float tab_width;
    vec2 unit_scale;
    bool pre_caching;

    std::vector<FXGlyphPage*> pages;

    std::map<unsigned int, FXGlyph*> glyphs;

    void init();
    FXGlyph* getGlyph(unsigned int chr);
public:
    FXGlyphSet(FT_Library freetype, const std::string& fontfile, int size, int dpi, FT_Int32 ft_flags);
    ~FXGlyphSet();

    void precache(const std::string& chars);

    FT_Face getFTFace() const { return ft_face; }
    FT_Int32 getFlags() const { return ft_flags; }

    const std::string& getFontFile() const { return fontfile; }

    float getWidth(const std::string& text);

    float getAscender() const;
    float getDescender() const;

    float getMaxWidth()  const;
    float getMaxHeight() const;

    int getSize() const { return size; };

    void drawToVBO(vec2& cursor, const std::string& text, const vec4& colour);
    void draw(const std::string& text);

    void drawPages();
};

class FXFont {

    FXGlyphSet* glyphset;

    std::string fontfile;
    bool shadow;
    bool round;

    float shadow_strength;
    vec2 shadow_offset;
    vec4 shadow_colour;
    vec4 colour;

    bool align_right, align_top;

    void render(float x, float y, const std::string& text, const vec4& colour) const;
    void init();
public:
    FXFont();
    FXFont(FXGlyphSet* glyphset);

    bool initialized() const { return (glyphset!=0); }

    void print(float x, float y, const char *str, ...) const;
    void draw(float x, float y, const std::string& text) const;

    float getWidth(const std::string& text) const;
    float getHeight() const;

    float getAscender() const;
    float getDescender() const;

    void alignTop(bool top);
    void alignRight(bool right);

    void roundCoordinates(bool round);

    const std::string& getFontFile() const;

    float getMaxWidth() const;
    float getMaxHeight() const;

    int getFontSize() const;

    bool dropShadow() const { return shadow; };

    void dropShadow(bool shadow);
    void shadowStrength(float s);
    void shadowOffset(float x, float y);

    void setColour(const vec4& colour);
    void setAlpha(float alpha);

    void drawGlyphes();
};

typedef std::map<int,FXGlyphSet*> fontSizeMap;

class FXFontManager {

    std::string font_dir;

    std::map<std::string, fontSizeMap*> fonts;
    FT_Library library;
public:
    quadbuf font_vbo;

    FXFontManager();
    bool use_vbo;

    void setDir(std::string font_dir);
    void init();

    void unload();
    void reload();

    void destroy();
    void purge();

    void startBuffer();
    void commitBuffer();
    void drawBuffer();

    FXFont grab(std::string font_file, int size, int dpi = 72, FT_Int32 ft_flags = FT_LOAD_DEFAULT);
};

extern FXFontManager fontmanager;

#endif