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1 | // Copyright (c) 2017-2019 OPEN CASCADE SAS |
2 | // |
3 | // This file is part of Open CASCADE Technology software library. |
4 | // |
5 | // This library is free software; you can redistribute it and/or modify it under |
6 | // the terms of the GNU Lesser General Public License version 2.1 as published |
7 | // by the Free Software Foundation, with special exception defined in the file |
8 | // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT |
9 | // distribution for complete text of the license and disclaimer of any warranty. |
10 | // |
11 | // Alternatively, this file may be used under the terms of Open CASCADE |
12 | // commercial license or contractual agreement. |
13 | |
14 | #ifndef _OpenGl_TextureFormat_HeaderFile |
15 | #define _OpenGl_TextureFormat_HeaderFile |
16 | |
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17 | #include <Image_CompressedFormat.hxx> |
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18 | #include <Image_Format.hxx> |
19 | #include <OpenGl_GlCore13.hxx> |
20 | #include <Standard_Handle.hxx> |
21 | |
22 | class OpenGl_Context; |
23 | |
24 | //! Stores parameters of OpenGL texture format. |
25 | class OpenGl_TextureFormat |
26 | { |
27 | public: |
28 | |
29 | //! Returns texture format for specified type and number of channels. |
30 | //! @tparam theCompType component type |
31 | //! @tparam theNbComps number of components |
32 | template<class theCompType, int theNbComps> |
33 | static OpenGl_TextureFormat Create(); |
34 | |
35 | //! Find texture format suitable to specified image format. |
36 | //! @param theCtx [in] OpenGL context defining supported texture formats |
37 | //! @param theFormat [in] image format |
38 | //! @param theIsColorMap [in] flag indicating color nature of image (to select sRGB texture) |
39 | //! @return found format or invalid format |
40 | Standard_EXPORT static OpenGl_TextureFormat FindFormat (const Handle(OpenGl_Context)& theCtx, |
41 | Image_Format theFormat, |
42 | bool theIsColorMap); |
43 | |
44 | //! Find texture format suitable to specified internal (sized) texture format. |
45 | //! @param theCtx [in] OpenGL context defining supported texture formats |
46 | //! @param theSizedFormat [in] sized (internal) texture format (example: GL_RGBA8) |
47 | //! @return found format or invalid format |
48 | Standard_EXPORT static OpenGl_TextureFormat FindSizedFormat (const Handle(OpenGl_Context)& theCtx, |
49 | GLint theSizedFormat); |
50 | |
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51 | //! Find texture format suitable to specified compressed texture format. |
52 | //! @param theCtx [in] OpenGL context defining supported texture formats |
53 | //! @param theFormat [in] compressed texture format |
54 | //! @return found format or invalid format |
55 | Standard_EXPORT static OpenGl_TextureFormat FindCompressedFormat (const Handle(OpenGl_Context)& theCtx, |
56 | Image_CompressedFormat theFormat, |
57 | bool theIsColorMap); |
58 | |
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59 | public: |
60 | |
61 | //! Empty constructor (invalid texture format). |
62 | OpenGl_TextureFormat() : myInternalFormat (0), myPixelFormat (0), myDataType (0), myNbComponents (0) {} |
63 | |
64 | //! Return TRUE if format is defined. |
65 | bool IsValid() const |
66 | { |
67 | return myInternalFormat != 0 |
68 | && myPixelFormat != 0 |
69 | && myDataType != 0; |
70 | } |
71 | |
72 | //! Returns OpenGL internal format of the pixel data (example: GL_R32F). |
73 | GLint InternalFormat() const { return myInternalFormat; } |
74 | |
75 | //! Sets texture internal format. |
76 | void SetInternalFormat (GLint theInternal) { myInternalFormat = theInternal; } |
77 | |
78 | //! Returns OpenGL format of the pixel data (example: GL_RED). |
79 | GLenum PixelFormat() const { return myPixelFormat; } |
80 | |
81 | //! Sets OpenGL format of the pixel data. |
82 | void SetPixelFormat (GLenum theFormat) { myPixelFormat = theFormat; } |
83 | |
84 | //! Returns OpenGL data type of the pixel data (example: GL_FLOAT). |
85 | GLint DataType() const { return myDataType; } |
86 | |
87 | //! Sets OpenGL data type of the pixel data. |
88 | void SetDataType (GLint theType) { myDataType = theType; } |
89 | |
90 | //! Returns number of components (channels). Here for debugging purposes. |
91 | GLint NbComponents() const { return myNbComponents; } |
92 | |
93 | //! Sets number of components (channels). |
94 | void SetNbComponents (GLint theNbComponents) { myNbComponents = theNbComponents; } |
95 | |
96 | //! Return TRUE if internal texture format is sRGB(A). |
97 | bool IsSRGB() const |
98 | { |
99 | return myInternalFormat == GL_SRGB8 |
100 | || myInternalFormat == GL_SRGB8_ALPHA8; |
101 | } |
102 | |
103 | public: |
104 | |
105 | //! Returns OpenGL internal format of the pixel data (example: GL_R32F). |
106 | GLint Internal() const { return myInternalFormat; } |
107 | |
108 | //! Returns OpenGL format of the pixel data (example: GL_RED). |
109 | GLenum Format() const { return myPixelFormat; } |
110 | |
111 | private: |
112 | |
113 | GLint myInternalFormat; //!< OpenGL internal format of the pixel data |
114 | GLenum myPixelFormat; //!< OpenGL pixel format |
115 | GLint myDataType; //!< OpenGL data type of input pixel data |
116 | GLint myNbComponents; //!< number of channels for each pixel (from 1 to 4) |
117 | |
118 | }; |
119 | |
120 | //! Selects preferable texture format for specified parameters. |
121 | template<class T> struct OpenGl_TextureFormatSelector |
122 | { |
123 | // Not implemented |
124 | }; |
125 | |
126 | //! Specialization for unsigned byte. |
127 | template<> struct OpenGl_TextureFormatSelector<GLubyte> |
128 | { |
129 | static GLint DataType() { return GL_UNSIGNED_BYTE; } |
130 | static GLint Internal (GLuint theChannels) |
131 | { |
132 | switch (theChannels) |
133 | { |
134 | case 1: return GL_R8; |
135 | case 2: return GL_RG8; |
136 | case 3: return GL_RGB8; |
137 | case 4: return GL_RGBA8; |
138 | default: return GL_NONE; |
139 | } |
140 | } |
141 | }; |
142 | |
143 | //! Specialization for unsigned short. |
144 | template<> struct OpenGl_TextureFormatSelector<GLushort> |
145 | { |
146 | static GLint DataType() { return GL_UNSIGNED_SHORT; } |
147 | static GLint Internal (GLuint theChannels) |
148 | { |
149 | switch (theChannels) |
150 | { |
151 | case 1: return GL_R16; |
152 | case 2: return GL_RG16; |
153 | case 3: return GL_RGB16; |
154 | case 4: return GL_RGBA16; |
155 | default: return GL_NONE; |
156 | } |
157 | } |
158 | }; |
159 | |
160 | //! Specialization for float. |
161 | template<> struct OpenGl_TextureFormatSelector<GLfloat> |
162 | { |
163 | static GLint DataType() { return GL_FLOAT; } |
164 | static GLint Internal (GLuint theChannels) |
165 | { |
166 | switch (theChannels) |
167 | { |
168 | case 1: return GL_R32F; |
169 | case 2: return GL_RG32F; |
170 | case 3: return GL_RGB32F; |
171 | case 4: return GL_RGBA32F; |
172 | default: return GL_NONE; |
173 | } |
174 | } |
175 | }; |
176 | |
177 | //! Specialization for unsigned int. |
178 | template<> struct OpenGl_TextureFormatSelector<GLuint> |
179 | { |
180 | static GLint DataType() { return GL_UNSIGNED_INT; } |
181 | static GLint Internal (GLuint theChannels) |
182 | { |
183 | switch (theChannels) |
184 | { |
185 | case 1: return GL_RED; |
186 | case 2: return GL_RG; |
187 | case 3: return GL_RGB; |
188 | case 4: return GL_RGBA; |
189 | default: return GL_NONE; |
190 | } |
191 | } |
192 | }; |
193 | |
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194 | //! Specialization for signed byte. |
195 | template<> struct OpenGl_TextureFormatSelector<GLbyte> |
196 | { |
197 | static GLint DataType() { return GL_BYTE; } |
198 | static GLint Internal (GLuint theChannels) |
199 | { |
200 | switch (theChannels) |
201 | { |
202 | case 1: return GL_R8_SNORM; |
203 | case 2: return GL_RG8_SNORM; |
204 | case 3: return GL_RGB8_SNORM; |
205 | case 4: return GL_RGBA8_SNORM; |
206 | default: return GL_NONE; |
207 | } |
208 | } |
209 | }; |
210 | |
211 | //! Specialization for signed short. |
212 | template<> struct OpenGl_TextureFormatSelector<GLshort> |
213 | { |
214 | static GLint DataType() { return GL_SHORT; } |
215 | static GLint Internal (GLuint theChannels) |
216 | { |
217 | switch (theChannels) |
218 | { |
219 | case 1: return GL_R16_SNORM; |
220 | case 2: return GL_RG16_SNORM; |
221 | case 3: return GL_RGB16_SNORM; |
222 | case 4: return GL_RGBA16_SNORM; |
223 | default: return GL_NONE; |
224 | } |
225 | } |
226 | }; |
227 | |
228 | //! Specialization for signed int. |
229 | template<> struct OpenGl_TextureFormatSelector<GLint> |
230 | { |
231 | static GLint DataType() { return GL_INT; } |
232 | static GLint Internal (GLuint theChannels) |
233 | { |
234 | switch (theChannels) |
235 | { |
236 | case 1: return GL_RED_SNORM; |
237 | case 2: return GL_RG_SNORM; |
238 | case 3: return GL_RGB_SNORM; |
239 | case 4: return GL_RGBA_SNORM; |
240 | default: return GL_NONE; |
241 | } |
242 | } |
243 | }; |
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244 | |
245 | // ======================================================================= |
246 | // function : Create |
247 | // purpose : |
248 | // ======================================================================= |
249 | template<class theCompType, int theNbComps> |
250 | inline OpenGl_TextureFormat OpenGl_TextureFormat::Create() |
251 | { |
252 | OpenGl_TextureFormat aFormat; |
253 | aFormat.SetNbComponents (theNbComps); |
254 | aFormat.SetInternalFormat (OpenGl_TextureFormatSelector<theCompType>::Internal (theNbComps)); |
255 | aFormat.SetDataType (OpenGl_TextureFormatSelector<theCompType>::DataType()); |
256 | GLenum aPixelFormat = GL_NONE; |
257 | switch (theNbComps) |
258 | { |
259 | case 1: aPixelFormat = GL_RED; break; |
260 | case 2: aPixelFormat = GL_RG; break; |
261 | case 3: aPixelFormat = GL_RGB; break; |
262 | case 4: aPixelFormat = GL_RGBA; break; |
263 | } |
264 | aFormat.SetPixelFormat (aPixelFormat); |
265 | return aFormat; |
266 | } |
267 | |
268 | #endif // _OpenGl_TextureFormat_HeaderFile |