source/builders/font.cpp

   1 #include <msp/core/maputils.h>
   2 #include <msp/datafile/collection.h>
   3 #include "bindable.h"
   4 #include "gl.h"
   5 #include "font.h"
   6 #include "primitivebuilder.h"
   7 #include "texture2d.h"
   8
   9 using namespace std;
  10
  11 namespace Msp {
  12 namespace GL {
  13
  14 Font::Font():
  15         native_size(1),
  16         ascent(1),
  17         descent(0),
  18         cap_height(1),
  19         x_height(0.5)
  20 { }
  21
  22 // Avoid synthesizing ~RefPtr in files including font.h
  23 Font::~Font()
  24 { }
  25
  26 void Font::set_texture(const Texture2D &t)
  27 {
  28         texture = &t;
  29         texture.keep();
  30 }
  31
  32 const Texture2D &Font::get_texture() const
  33 {
  34         if(!texture)
  35                 throw logic_error("No texture");
  36         return *texture;
  37 }
  38
  39 void Font::add_glyph(const Glyph &g)
  40 {
  41         insert_unique(glyphs, g.code, g);
  42 }
  43
  44 void Font::set_kerning(unsigned l, unsigned r, float d)
  45 {
  46         kerning[CodePair(l, r)] = d;
  47 }
  48
  49 float Font::get_string_width(const string &str, StringCodec::Decoder &dec) const
  50 {
  51         float x = 0;
  52
  53         unsigned prev = 0;
  54         for(string::const_iterator i=str.begin(); i!=str.end();)
  55         {
  56                 unsigned c = dec.decode_char(str, i);
  57                 if(prev)
  58                         x += get_glyph_advance(prev, c);
  59                 prev = c;
  60         }
  61         x += get_glyph_advance(prev);
  62
  63         return x;
  64 }
  65
  66 void Font::build_string(const string &str, StringCodec::Decoder &dec, PrimitiveBuilder &bld) const
  67 {
  68         VertexBuilder::PushMatrix push_mtx(bld);
  69
  70         unsigned prev = 0;
  71         unsigned next = 0;
  72         for(string::const_iterator i=str.begin(); (next || i!=str.end());)
  73         {
  74                 unsigned c = (next ? next : dec.decode_char(str, i));
  75                 next = (i!=str.end() ? dec.decode_char(str, i) : 0);
  76
  77                 if(unsigned lig = get_ligature(c, next))
  78                 {
  79                         c = lig;
  80                         next = 0;
  81                 }
  82
  83                 GlyphMap::const_iterator j = glyphs.find(c);
  84                 if(j==glyphs.end())
  85                         continue;
  86
  87                 if(prev)
  88                         bld.transform(Matrix::translation(get_glyph_advance(prev, c), 0, 0));
  89
  90                 create_glyph_quad(j->second, bld);
  91                 prev = c;
  92         }
  93 }
  94
  95 void Font::create_glyph_quad(const Glyph &glyph, PrimitiveBuilder &bld) const
  96 {
  97         bld.begin(TRIANGLE_STRIP);
  98         bld.texcoord(glyph.x1, glyph.y2);
  99         bld.vertex(glyph.off_x, glyph.off_y+glyph.h);
 100         bld.texcoord(glyph.x1, glyph.y1);
 101         bld.vertex(glyph.off_x, glyph.off_y);
 102         bld.texcoord(glyph.x2, glyph.y2);
 103         bld.vertex(glyph.off_x+glyph.w, glyph.off_y+glyph.h);
 104         bld.texcoord(glyph.x2, glyph.y1);
 105         bld.vertex(glyph.off_x+glyph.w, glyph.off_y);
 106         bld.end();
 107 }
 108
 109 float Font::get_glyph_advance(unsigned code, unsigned next) const
 110 {
 111         GlyphMap::const_iterator i = glyphs.find(code);
 112         if(i==glyphs.end())
 113                 return 0;
 114
 115         float advance = i->second.advance;
 116
 117         if(next)
 118         {
 119                 KerningMap::const_iterator j = kerning.find(CodePair(code, next));
 120                 if(j!=kerning.end())
 121                         advance += j->second;
 122         }
 123
 124         return advance;
 125 }
 126
 127 unsigned Font::get_ligature(unsigned code, unsigned next) const
 128 {
 129         LigatureMap::const_iterator i = ligatures.find(CodePair(code, next));
 130         return (i!=ligatures.end() ? i->second : 0);
 131 }
 132
 133
 134 Font::Glyph::Glyph():
 135         code(0),
 136         x1(0),
 137         y1(0),
 138         x2(1),
 139         y2(1),
 140         w(1),
 141         h(1),
 142         off_x(0),
 143         off_y(0),
 144         advance(1)
 145 { }
 146
 147
 148 Font::Loader::Loader(Font &f):
 149         DataFile::CollectionObjectLoader<Font>(f, 0)
 150 {
 151         init();
 152 }
 153
 154 Font::Loader::Loader(Font &f, Collection &c):
 155         DataFile::CollectionObjectLoader<Font>(f, &c)
 156 {
 157         init();
 158 }
 159
 160 void Font::Loader::init()
 161 {
 162         add("native_size", &Font::native_size);
 163         add("ascent",      &Font::ascent);
 164         add("cap_height",  &Font::cap_height);
 165         add("descent",     &Font::descent);
 166         add("texture",     &Loader::texture);
 167         add("texture",     &Loader::texture_ref);
 168         add("glyph",       &Loader::glyph);
 169         add("kerning",     &Loader::kerning);
 170         add("ligature",    &Loader::ligature);
 171         add("x_height",    &Font::x_height);
 172 }
 173
 174 void Font::Loader::glyph(unsigned c)
 175 {
 176         Glyph gl;
 177         gl.code = c;
 178         load_sub(gl);
 179         obj.glyphs.insert(GlyphMap::value_type(c, gl));
 180 }
 181
 182 void Font::Loader::kerning(unsigned l, unsigned r, float d)
 183 {
 184         obj.kerning[CodePair(l, r)] = d;
 185 }
 186
 187 void Font::Loader::ligature(unsigned l, unsigned r, unsigned g)
 188 {
 189         obj.ligatures[CodePair(l, r)] = g;
 190 }
 191
 192 void Font::Loader::texture()
 193 {
 194         RefPtr<Texture2D> tex = new Texture2D;
 195         load_sub(*tex);
 196         obj.texture = tex;
 197 }
 198
 199 void Font::Loader::texture_ref(const string &name)
 200 {
 201         obj.texture = &get_collection().get<Texture2D>(name);
 202         obj.texture.keep();
 203 }
 204
 205
 206 Font::Glyph::Loader::Loader(Glyph &g):
 207         DataFile::ObjectLoader<Glyph>(g)
 208 {
 209         add("texcoords", &Loader::texcoords);
 210         add("size",      &Glyph::w,     &Glyph::h);
 211         add("offset",    &Glyph::off_x, &Glyph::off_y);
 212         add("advance",   &Glyph::advance);
 213 }
 214
 215 void Font::Glyph::Loader::texcoords(float x1_, float y1_, float x2_, float y2_)
 216 {
 217         obj.x1 = x1_;
 218         obj.y1 = y1_;
 219         obj.x2 = x2_;
 220         obj.y2 = y2_;
 221 }
 222
 223 } // namespace GL
 224 } // namespace Msp