0025133: TKOpenGl - Crash on closing a view containing presentations with capping
[occt.git] / src / OpenGl / OpenGl_Font.hxx
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a174a3c5 1// Created on: 2013-01-29
2// Created by: Kirill GAVRILOV
d5f74e42 3// Copyright (c) 2013-2014 OPEN CASCADE SAS
a174a3c5 4//
973c2be1 5// This file is part of Open CASCADE Technology software library.
a174a3c5 6//
d5f74e42 7// This library is free software; you can redistribute it and/or modify it under
8// the terms of the GNU Lesser General Public License version 2.1 as published
973c2be1 9// by the Free Software Foundation, with special exception defined in the file
10// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
11// distribution for complete text of the license and disclaimer of any warranty.
a174a3c5 12//
973c2be1 13// Alternatively, this file may be used under the terms of Open CASCADE
14// commercial license or contractual agreement.
a174a3c5 15
16#ifndef _OpenGl_Font_H__
17#define _OpenGl_Font_H__
18
19#include <OpenGl_Texture.hxx>
20#include <OpenGl_Vec.hxx>
21
22#include <Font_FTFont.hxx>
23
24#include <NCollection_DataMap.hxx>
25#include <NCollection_Vector.hxx>
26#include <TCollection_AsciiString.hxx>
27
28//! Texture font.
29class OpenGl_Font : public OpenGl_Resource
30{
31
32public:
33
34 //! Simple structure stores tile rectangle.
35 struct Tile
36 {
37 Font_FTFont::Rect uv; //!< UV coordinates in texture
38 Font_FTFont::Rect px; //!< pixel displacement coordinates
39 GLuint texture; //!< GL texture ID
40 };
41
42 struct RectI
43 {
44 Standard_Integer Left;
45 Standard_Integer Right;
46 Standard_Integer Top;
47 Standard_Integer Bottom;
48 };
49
50public:
51
52 //! Main constructor.
53 Standard_EXPORT OpenGl_Font (const Handle(Font_FTFont)& theFont,
54 const TCollection_AsciiString& theKey = "");
55
56 //! Destroy object.
57 Standard_EXPORT virtual ~OpenGl_Font();
58
59 //! Destroy object - will release GPU memory if any
10b9c7df 60 Standard_EXPORT virtual void Release (OpenGl_Context* theCtx);
a174a3c5 61
62 //! @return key of shared resource
63 inline const TCollection_AsciiString& ResourceKey() const
64 {
65 return myKey;
66 }
67
68 //! @return FreeType font instance specified on construction.
69 inline const Handle(Font_FTFont)& FTFont() const
70 {
71 return myFont;
72 }
73
74 //! @return true if font was loaded successfully.
75 inline bool IsValid() const
76 {
77 return !myTextures.IsEmpty() && myTextures.First()->IsValid();
78 }
79
80 //! Notice that this method doesn't return initialization success state.
81 //! Use IsValid() instead.
82 //! @return true if initialization was already called.
83 inline bool WasInitialized() const
84 {
85 return !myTextures.IsEmpty();
86 }
87
88 //! Initialize GL resources.
89 //! FreeType font instance should be already initialized!
90 Standard_EXPORT bool Init (const Handle(OpenGl_Context)& theCtx);
91
92 //! Compute advance to the next character with kerning applied when applicable.
93 //! Assuming text rendered horizontally.
94 inline float AdvanceX (const Standard_Utf32Char theUChar,
95 const Standard_Utf32Char theUCharNext)
96 {
97 return myFont->AdvanceX (theUChar, theUCharNext);
98 }
99
100 //! @return vertical distance from the horizontal baseline to the highest character coordinate
101 inline float Ascender() const
102 {
103 return myAscender;
104 }
105
106 //! @return vertical distance from the horizontal baseline to the lowest character coordinate
107 inline float Descender() const
108 {
109 return myDescender;
110 }
111
112 //! @return default line spacing (the baseline-to-baseline distance)
113 inline float LineSpacing() const
114 {
115 return myLineSpacing;
116 }
117
118 //! Compute glyph rectangle at specified pen position (on baseline)
119 //! and render it to texture if not already.
120 //! @param theCtx active context
121 //! @param theUChar unicode symbol to render
122 //! @param theUCharNext next symbol to compute advance with kerning when available
123 //! @param theGlyph computed glyph position rectangle, texture ID and UV coordinates
124 //! @param thePen pen position on baseline to place new glyph
125 Standard_EXPORT void RenderGlyph (const Handle(OpenGl_Context)& theCtx,
126 const Standard_Utf32Char theUChar,
127 const Standard_Utf32Char theUCharNext,
128 Tile& theGlyph,
129 OpenGl_Vec2& thePen);
130
131protected:
132
133 //! Render new glyph to the texture.
134 bool renderGlyph (const Handle(OpenGl_Context)& theCtx,
135 const Standard_Utf32Char theChar);
136
137 //! Allocate new texture.
138 bool createTexture (const Handle(OpenGl_Context)& theCtx);
139
140protected:
141
142 TCollection_AsciiString myKey; //!< key of shared resource
143 Handle(Font_FTFont) myFont; //!< FreeType font instance
144 Standard_ShortReal myAscender; //!< ascender provided my FT font
145 Standard_ShortReal myDescender; //!< descender provided my FT font
146 Standard_ShortReal myLineSpacing; //!< line spacing provided my FT font
147 Standard_Integer myTileSizeX; //!< tile width
148 Standard_Integer myTileSizeY; //!< tile height
149 Standard_Integer myLastTileId; //!< id of last tile
150 RectI myLastTilePx;
151 Standard_Integer myTextureFormat; //!< texture format
152
153 NCollection_Vector<Handle(OpenGl_Texture)> myTextures; //!< array of textures
154 NCollection_Vector<Tile> myTiles; //!< array of loaded tiles
155
156 NCollection_DataMap<Standard_Utf32Char, Standard_Integer> myGlyphMap;
157
158public:
159
160 DEFINE_STANDARD_RTTI(OpenGl_Font) // Type definition
161
162};
163
164DEFINE_STANDARD_HANDLE(OpenGl_Font, OpenGl_Resource)
165
166#endif // _OpenGl_Font_H__