// Copyright (c) 2017-2019 OPEN CASCADE SAS // // This file is part of Open CASCADE Technology software library. // // This library is free software; you can redistribute it and/or modify it under // the terms of the GNU Lesser General Public License version 2.1 as published // by the Free Software Foundation, with special exception defined in the file // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT // distribution for complete text of the license and disclaimer of any warranty. // // Alternatively, this file may be used under the terms of Open CASCADE // commercial license or contractual agreement. #ifndef _OpenGl_TextureFormat_HeaderFile #define _OpenGl_TextureFormat_HeaderFile #include #include #include #include #include class OpenGl_Context; //! Stores parameters of OpenGL texture format. class OpenGl_TextureFormat { public: //! Returns texture format for specified type and number of channels. //! @tparam theCompType component type //! @tparam theNbComps number of components template static OpenGl_TextureFormat Create(); //! Find texture format suitable to specified image format. //! @param theCtx [in] OpenGL context defining supported texture formats //! @param theFormat [in] image format //! @param theIsColorMap [in] flag indicating color nature of image (to select sRGB texture) //! @return found format or invalid format Standard_EXPORT static OpenGl_TextureFormat FindFormat (const Handle(OpenGl_Context)& theCtx, Image_Format theFormat, bool theIsColorMap); //! Find texture format suitable to specified internal (sized) texture format. //! @param theCtx [in] OpenGL context defining supported texture formats //! @param theSizedFormat [in] sized (internal) texture format (example: GL_RGBA8) //! @return found format or invalid format Standard_EXPORT static OpenGl_TextureFormat FindSizedFormat (const Handle(OpenGl_Context)& theCtx, GLint theSizedFormat); //! Find texture format suitable to specified compressed texture format. //! @param theCtx [in] OpenGL context defining supported texture formats //! @param theFormat [in] compressed texture format //! @return found format or invalid format Standard_EXPORT static OpenGl_TextureFormat FindCompressedFormat (const Handle(OpenGl_Context)& theCtx, Image_CompressedFormat theFormat, bool theIsColorMap); //! Format pixel format enumeration. Standard_EXPORT static TCollection_AsciiString FormatFormat (GLint theInternalFormat); //! Format data type enumeration. Standard_EXPORT static TCollection_AsciiString FormatDataType (GLint theDataType); public: //! Empty constructor (invalid texture format). OpenGl_TextureFormat() : myImageFormat (Image_Format_UNKNOWN), myInternalFormat (0), myPixelFormat (0), myDataType (0), myNbComponents (0) {} //! Return TRUE if format is defined. bool IsValid() const { return myInternalFormat != 0 && myPixelFormat != 0 && myDataType != 0; } //! Returns OpenGL internal format of the pixel data (example: GL_R32F). GLint InternalFormat() const { return myInternalFormat; } //! Sets texture internal format. void SetInternalFormat (GLint theInternal) { myInternalFormat = theInternal; } //! Returns OpenGL format of the pixel data (example: GL_RED). GLenum PixelFormat() const { return myPixelFormat; } //! Sets OpenGL format of the pixel data. void SetPixelFormat (GLenum theFormat) { myPixelFormat = theFormat; } //! Returns OpenGL data type of the pixel data (example: GL_FLOAT). GLint DataType() const { return myDataType; } //! Sets OpenGL data type of the pixel data. void SetDataType (GLint theType) { myDataType = theType; } //! Returns number of components (channels). Here for debugging purposes. GLint NbComponents() const { return myNbComponents; } //! Sets number of components (channels). void SetNbComponents (GLint theNbComponents) { myNbComponents = theNbComponents; } //! Return TRUE if internal texture format is sRGB(A). bool IsSRGB() const { return myInternalFormat == GL_SRGB8 || myInternalFormat == GL_SRGB8_ALPHA8; } //! Returns image format (best match or Image_Format_UNKNOWN if no suitable fit). Image_Format ImageFormat() const { return myImageFormat; } //! Sets image format. void SetImageFormat (Image_Format theFormat) { myImageFormat = theFormat; } public: //! Returns OpenGL internal format of the pixel data (example: GL_R32F). GLint Internal() const { return myInternalFormat; } //! Returns OpenGL format of the pixel data (example: GL_RED). GLenum Format() const { return myPixelFormat; } private: Image_Format myImageFormat; //!< image format GLint myInternalFormat; //!< OpenGL internal format of the pixel data GLenum myPixelFormat; //!< OpenGL pixel format GLint myDataType; //!< OpenGL data type of input pixel data GLint myNbComponents; //!< number of channels for each pixel (from 1 to 4) }; //! Selects preferable texture format for specified parameters. template struct OpenGl_TextureFormatSelector { // Not implemented }; //! Specialization for unsigned byte. template<> struct OpenGl_TextureFormatSelector { static GLint DataType() { return GL_UNSIGNED_BYTE; } static GLint Internal (GLuint theChannels) { switch (theChannels) { case 1: return GL_R8; case 2: return GL_RG8; case 3: return GL_RGB8; case 4: return GL_RGBA8; default: return GL_NONE; } } }; //! Specialization for unsigned short. template<> struct OpenGl_TextureFormatSelector { static GLint DataType() { return GL_UNSIGNED_SHORT; } static GLint Internal (GLuint theChannels) { switch (theChannels) { case 1: return GL_R16; case 2: return GL_RG16; case 3: return GL_RGB16; case 4: return GL_RGBA16; default: return GL_NONE; } } }; //! Specialization for float. template<> struct OpenGl_TextureFormatSelector { static GLint DataType() { return GL_FLOAT; } static GLint Internal (GLuint theChannels) { switch (theChannels) { case 1: return GL_R32F; case 2: return GL_RG32F; case 3: return GL_RGB32F; case 4: return GL_RGBA32F; default: return GL_NONE; } } }; //! Specialization for unsigned int. template<> struct OpenGl_TextureFormatSelector { static GLint DataType() { return GL_UNSIGNED_INT; } static GLint Internal (GLuint theChannels) { switch (theChannels) { case 1: return GL_RED; case 2: return GL_RG; case 3: return GL_RGB; case 4: return GL_RGBA; default: return GL_NONE; } } }; //! Specialization for signed byte. template<> struct OpenGl_TextureFormatSelector { static GLint DataType() { return GL_BYTE; } static GLint Internal (GLuint theChannels) { switch (theChannels) { case 1: return GL_R8_SNORM; case 2: return GL_RG8_SNORM; case 3: return GL_RGB8_SNORM; case 4: return GL_RGBA8_SNORM; default: return GL_NONE; } } }; //! Specialization for signed short. template<> struct OpenGl_TextureFormatSelector { static GLint DataType() { return GL_SHORT; } static GLint Internal (GLuint theChannels) { switch (theChannels) { case 1: return GL_R16_SNORM; case 2: return GL_RG16_SNORM; case 3: return GL_RGB16_SNORM; case 4: return GL_RGBA16_SNORM; default: return GL_NONE; } } }; //! Specialization for signed int. template<> struct OpenGl_TextureFormatSelector { static GLint DataType() { return GL_INT; } static GLint Internal (GLuint theChannels) { switch (theChannels) { case 1: return GL_RED_SNORM; case 2: return GL_RG_SNORM; case 3: return GL_RGB_SNORM; case 4: return GL_RGBA_SNORM; default: return GL_NONE; } } }; // ======================================================================= // function : Create // purpose : // ======================================================================= template inline OpenGl_TextureFormat OpenGl_TextureFormat::Create() { OpenGl_TextureFormat aFormat; aFormat.SetNbComponents (theNbComps); aFormat.SetInternalFormat (OpenGl_TextureFormatSelector::Internal (theNbComps)); aFormat.SetDataType (OpenGl_TextureFormatSelector::DataType()); GLenum aPixelFormat = GL_NONE; switch (theNbComps) { case 1: aPixelFormat = GL_RED; break; case 2: aPixelFormat = GL_RG; break; case 3: aPixelFormat = GL_RGB; break; case 4: aPixelFormat = GL_RGBA; break; } aFormat.SetPixelFormat (aPixelFormat); return aFormat; } #endif // _OpenGl_TextureFormat_HeaderFile