a174a3c5 |
1 | // Created on: 2013-01-29 |
2 | // Created by: Kirill GAVRILOV |
3 | // Copyright (c) 2013 OPEN CASCADE SAS |
4 | // |
5 | // The content of this file is subject to the Open CASCADE Technology Public |
6 | // License Version 6.5 (the "License"). You may not use the content of this file |
7 | // except in compliance with the License. Please obtain a copy of the License |
8 | // at http://www.opencascade.org and read it completely before using this file. |
9 | // |
10 | // The Initial Developer of the Original Code is Open CASCADE S.A.S., having its |
11 | // main offices at: 1, place des Freres Montgolfier, 78280 Guyancourt, France. |
12 | // |
13 | // The Original Code and all software distributed under the License is |
14 | // distributed on an "AS IS" basis, without warranty of any kind, and the |
15 | // Initial Developer hereby disclaims all such warranties, including without |
16 | // limitation, any warranties of merchantability, fitness for a particular |
17 | // purpose or non-infringement. Please see the License for the specific terms |
18 | // and conditions governing the rights and limitations under the License. |
19 | |
20 | #ifndef _OpenGl_Font_H__ |
21 | #define _OpenGl_Font_H__ |
22 | |
23 | #include <OpenGl_Texture.hxx> |
24 | #include <OpenGl_Vec.hxx> |
25 | |
26 | #include <Font_FTFont.hxx> |
27 | |
28 | #include <NCollection_DataMap.hxx> |
29 | #include <NCollection_Vector.hxx> |
30 | #include <TCollection_AsciiString.hxx> |
31 | |
32 | //! Texture font. |
33 | class OpenGl_Font : public OpenGl_Resource |
34 | { |
35 | |
36 | public: |
37 | |
38 | //! Simple structure stores tile rectangle. |
39 | struct Tile |
40 | { |
41 | Font_FTFont::Rect uv; //!< UV coordinates in texture |
42 | Font_FTFont::Rect px; //!< pixel displacement coordinates |
43 | GLuint texture; //!< GL texture ID |
44 | }; |
45 | |
46 | struct RectI |
47 | { |
48 | Standard_Integer Left; |
49 | Standard_Integer Right; |
50 | Standard_Integer Top; |
51 | Standard_Integer Bottom; |
52 | }; |
53 | |
54 | public: |
55 | |
56 | //! Main constructor. |
57 | Standard_EXPORT OpenGl_Font (const Handle(Font_FTFont)& theFont, |
58 | const TCollection_AsciiString& theKey = ""); |
59 | |
60 | //! Destroy object. |
61 | Standard_EXPORT virtual ~OpenGl_Font(); |
62 | |
63 | //! Destroy object - will release GPU memory if any |
64 | Standard_EXPORT virtual void Release (const OpenGl_Context* theCtx); |
65 | |
66 | //! @return key of shared resource |
67 | inline const TCollection_AsciiString& ResourceKey() const |
68 | { |
69 | return myKey; |
70 | } |
71 | |
72 | //! @return FreeType font instance specified on construction. |
73 | inline const Handle(Font_FTFont)& FTFont() const |
74 | { |
75 | return myFont; |
76 | } |
77 | |
78 | //! @return true if font was loaded successfully. |
79 | inline bool IsValid() const |
80 | { |
81 | return !myTextures.IsEmpty() && myTextures.First()->IsValid(); |
82 | } |
83 | |
84 | //! Notice that this method doesn't return initialization success state. |
85 | //! Use IsValid() instead. |
86 | //! @return true if initialization was already called. |
87 | inline bool WasInitialized() const |
88 | { |
89 | return !myTextures.IsEmpty(); |
90 | } |
91 | |
92 | //! Initialize GL resources. |
93 | //! FreeType font instance should be already initialized! |
94 | Standard_EXPORT bool Init (const Handle(OpenGl_Context)& theCtx); |
95 | |
96 | //! Compute advance to the next character with kerning applied when applicable. |
97 | //! Assuming text rendered horizontally. |
98 | inline float AdvanceX (const Standard_Utf32Char theUChar, |
99 | const Standard_Utf32Char theUCharNext) |
100 | { |
101 | return myFont->AdvanceX (theUChar, theUCharNext); |
102 | } |
103 | |
104 | //! @return vertical distance from the horizontal baseline to the highest character coordinate |
105 | inline float Ascender() const |
106 | { |
107 | return myAscender; |
108 | } |
109 | |
110 | //! @return vertical distance from the horizontal baseline to the lowest character coordinate |
111 | inline float Descender() const |
112 | { |
113 | return myDescender; |
114 | } |
115 | |
116 | //! @return default line spacing (the baseline-to-baseline distance) |
117 | inline float LineSpacing() const |
118 | { |
119 | return myLineSpacing; |
120 | } |
121 | |
122 | //! Compute glyph rectangle at specified pen position (on baseline) |
123 | //! and render it to texture if not already. |
124 | //! @param theCtx active context |
125 | //! @param theUChar unicode symbol to render |
126 | //! @param theUCharNext next symbol to compute advance with kerning when available |
127 | //! @param theGlyph computed glyph position rectangle, texture ID and UV coordinates |
128 | //! @param thePen pen position on baseline to place new glyph |
129 | Standard_EXPORT void RenderGlyph (const Handle(OpenGl_Context)& theCtx, |
130 | const Standard_Utf32Char theUChar, |
131 | const Standard_Utf32Char theUCharNext, |
132 | Tile& theGlyph, |
133 | OpenGl_Vec2& thePen); |
134 | |
135 | protected: |
136 | |
137 | //! Render new glyph to the texture. |
138 | bool renderGlyph (const Handle(OpenGl_Context)& theCtx, |
139 | const Standard_Utf32Char theChar); |
140 | |
141 | //! Allocate new texture. |
142 | bool createTexture (const Handle(OpenGl_Context)& theCtx); |
143 | |
144 | protected: |
145 | |
146 | TCollection_AsciiString myKey; //!< key of shared resource |
147 | Handle(Font_FTFont) myFont; //!< FreeType font instance |
148 | Standard_ShortReal myAscender; //!< ascender provided my FT font |
149 | Standard_ShortReal myDescender; //!< descender provided my FT font |
150 | Standard_ShortReal myLineSpacing; //!< line spacing provided my FT font |
151 | Standard_Integer myTileSizeX; //!< tile width |
152 | Standard_Integer myTileSizeY; //!< tile height |
153 | Standard_Integer myLastTileId; //!< id of last tile |
154 | RectI myLastTilePx; |
155 | Standard_Integer myTextureFormat; //!< texture format |
156 | |
157 | NCollection_Vector<Handle(OpenGl_Texture)> myTextures; //!< array of textures |
158 | NCollection_Vector<Tile> myTiles; //!< array of loaded tiles |
159 | |
160 | NCollection_DataMap<Standard_Utf32Char, Standard_Integer> myGlyphMap; |
161 | |
162 | public: |
163 | |
164 | DEFINE_STANDARD_RTTI(OpenGl_Font) // Type definition |
165 | |
166 | }; |
167 | |
168 | DEFINE_STANDARD_HANDLE(OpenGl_Font, OpenGl_Resource) |
169 | |
170 | #endif // _OpenGl_Font_H__ |