desgui.base.ftglyphrender source code

1 /+
2 The MIT License (MIT)
3 
4     Copyright (c) <2013> <Oleg Butko (deviator), Anton Akzhigitov (Akzwar)>
5 
6     Permission is hereby granted, free of charge, to any person obtaining a copy
7     of this software and associated documentation files (the "Software"), to deal
8     in the Software without restriction, including without limitation the rights
9     to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10     copies of the Software, and to permit persons to whom the Software is
11     furnished to do so, subject to the following conditions:
12 
13     The above copyright notice and this permission notice shall be included in
14     all copies or substantial portions of the Software.
15 
16     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17     IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19     AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20     LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22     THE SOFTWARE.
23 +/
24 
25 module desgui.base.ftglyphrender;
26 
27 public import desgui.core.textrender;
28 import desmath.linear.vector;
29 import desil;
30 
31 import derelict.freetype.ft;
32 import derelict.freetype.types;
33 
34 import desutil.logger;
35 mixin( PrivateLoggerMixin );
36 
37 class FTGlyphRenderException: Exception
38 {
39     @safe pure nothrow this( string msg, string file=__FILE__, size_t line=__LINE__ )
40     { super( msg, file, line ); }
41 }
42 
43 class FTGlyphRender : DiGlyphRender
44 {
45 private:
46     static lib_inited = false;
47     static FT_Library ft;
48 
49     static FTGlyphRender[string] openFTGR;
50 
51     FT_Face face;
52 
53     static this()
54     {
55         if( !lib_inited )
56         {
57             DerelictFT.load();
58             if( FT_Init_FreeType( &ft ) )
59                 throw new FTGlyphRenderException( "Couldn't init freetype library" );
60 
61             lib_inited = true;
62         }
63     }
64 
65     this( string fontname )
66     {
67         import std.file;
68         if( !fontname.exists )
69             throw new FTGlyphRenderException( "Couldn't open font '" ~ fontname ~ "': file not exist" );
70 
71         bool loaderror = false;
72         foreach( i; 0 .. 100 )
73         {
74             if( FT_New_Face( ft, fontname.dup.ptr, 0, &face ) ) loaderror = true;
75             else { loaderror = false; break; }
76             log_error( "font load attempt: %d", i );
77         }
78 
79         if( loaderror )
80             throw new FTGlyphRenderException( "Couldn't open font '" ~ fontname ~ "': loading error" );
81 
82         if( FT_Select_Charmap( face, FT_Encoding.FT_ENCODING_UNICODE ) )
83             throw new FTGlyphRenderException( "Couldn't select unicode encoding" );
84     }
85 
86     auto color = col4( 1,1,1,1 );
87 public:
88 
89     static DiGlyphRender get( string fontname )
90     {
91         if( fontname !in openFTGR )
92             openFTGR[fontname] = new FTGlyphRender( fontname );
93         return openFTGR[fontname];
94     }
95 
96     void setParams( in DiGlyphParam p )
97     {
98         FT_Set_Pixel_Sizes( face, 0, p.height );
99         color = p.color;
100     }
101 
102     @property ImageType imtype() const { return ImageType( ImCompType.UBYTE, 4 ); }
103 
104     DiGlyphInfo render( wchar ch )
105     {
106         if( FT_Load_Char( face, cast(size_t)ch, FT_LOAD_RENDER ) )
107             throw new FTGlyphRenderException( "Couldn't load char" );
108 
109         auto g = face.glyph;
110         ivec2 sz = ivec2( g.bitmap.width, g.bitmap.rows );
111 
112         alias vec!(4,ubyte,"rgba") bcol4;
113 
114         auto ret = DiGlyphInfo( ivec2( g.bitmap_left, -g.bitmap_top ), 
115                                 ivec2( cast(int)( g.advance.x >> 6 ), 
116                                        cast(int)( g.advance.y >> 6 ) ),
117                                 Image( imsize_t(sz), imtype ) );
118 
119         foreach( y; 0 .. sz.y )
120             foreach( x; 0 .. sz.x )
121                 ret.img.access!bcol4(x,y) = bcol4( col4( color.rgb, color.a * g.bitmap.buffer[y*sz.x+x] / 255.0 ) * 255 );
122 
123         return ret;
124     }
125 
126     ~this() 
127     { 
128         if( FT_Done_Face !is null )
129             FT_Done_Face( face ); 
130     }
131 
132     static ~this() 
133     { 
134         if( lib_inited && FT_Done_FreeType !is null ) 
135             FT_Done_FreeType( ft ); 
136     }
137 }