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C-/C++-Quelltext

class Texture
{

    private:

        Texture (const GLuint nTextureID) : m_nTextureID (nTextureID) { }


    public:

        ~Texture () { glDeleteTextures (1, &m_nTextureID); }


    public:

        static Texture* loadFromBMP (const std::string& sFile);

        GLuint getID () const
        {
            return m_nTextureID;
        }

        void setActive () const
        {
            glBindTexture (GL_TEXTURE_2D, m_nTextureID);
        }


    private:

        const GLuint m_nTextureID;

};

C-/C++-Quelltext

Texture* Texture::loadFromBMP (const std::string& sFile)
{
    std::ifstream fIn (sFile.c_str (), std::ios::in | std::ios::binary);
    if (fIn.good ())
    {
        try
        {
            // read header

            unsigned short nFormat;
            fIn.read (reinterpret_cast <char*> (&nFormat), 2);
            if (nFormat != 19778)
            {
                std::cerr << "(EE) Failed to read: " << sFile << std::endl;
                std::cerr << "(EE)   Not a Windows Bitmap." << std::endl;
                std::cerr << std::endl;
                fIn.close ();
                return NULL;
            }

            fIn.seekg (18);
            signed int nWidth, nHeight;
            fIn.read (reinterpret_cast <char*> (&nWidth), 4);
            fIn.read (reinterpret_cast <char*> (&nHeight), 4);

            // compute body size

            const unsigned int nBodySize = 3 * nWidth * nHeight;

            // read planes

            unsigned short nPlanes;
            fIn.read (reinterpret_cast <char*> (&nPlanes), 2);

            // read bits per pixel

            unsigned short nBPP;
            fIn.read (reinterpret_cast <char*> (&nBPP), 2);

            // ensure format is supported

            if (nPlanes != 1 || nBPP != 24)
            {
                std::cerr << "(EE) Failed to read: " << sFile << std::endl;
                std::cerr << "(EE)   Unsupported format: " << nBPP << " bpp, " << nPlanes << " plane(s)" << std::endl;
                std::cerr << "(EE)   Only bitmaps with 24 color depth and 1 plane are supported." << std::endl;
                std::cerr << std::endl;
                fIn.close ();
                return NULL;
            }

            // seek past the rest of the header

            fIn.seekg (54);

            // read body data

            char* const pcData = new char [nBodySize];
            fIn.read (pcData, nBodySize);

            // we are done reading the file

            fIn.close ();

            // reverse byte order (convert 'BGR' to 'RGB')

            for (unsigned int j = 0; j < nBodySize ; j += 3)
            {
                pcData [j] ^= pcData [j + 2];
                pcData [j + 2] ^= pcData [j];
            }

            // now we need to create the texture

            GLuint nTextureID;
            glGenTextures (1, &nTextureID);
            glBindTexture (GL_TEXTURE_2D, nTextureID);
            glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
            glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

            // 2D texture, level of detail 0 (normal), 3 components (red, green, blue), x size, y size,

            // border 0 (normal), rgb color data, unsigned byte data, and finally the data itself

            glTexImage2D (GL_TEXTURE_2D, 0, 3, nWidth, nHeight, 0, GL_RGB, GL_UNSIGNED_BYTE, pcData);
            delete [] pcData;

            // finish

            return new Texture (nTextureID);
        }
        catch (...)
        {
            fIn.close ();
            std::cerr << "(EE) Failed to read: " << sFile << std::endl;
            std::cerr << "(EE)   Unknown error." << std::endl;
            std::cerr << std::endl;
            return NULL;
        }
    }
    else
    {
        fIn.close ();
        std::cerr << "(EE) Failed to read: " << sFile << std::endl;
        std::cerr << "(EE)   Either file not found or not allowed to open for reading." << std::endl;
        std::cerr << std::endl;
        return NULL;
    }
}

C-/C++-Quelltext

static Texture* s_aTextures []; // Member einer Klasse C


// [...]


Texture* C::s_aTextures [] = { NULL, NULL, NULL, NULL, NULL, NULL };

// [...]


s_aTextures [0] = Texture::loadFromBMP ("test1.bmp");
s_aTextures [1] = Texture::loadFromBMP ("test2.bmp");
s_aTextures [2] = Texture::loadFromBMP ("test3.bmp");
s_aTextures [3] = Texture::loadFromBMP ("test4.bmp");
s_aTextures [4] = Texture::loadFromBMP ("test5.bmp");
s_aTextures [5] = Texture::loadFromBMP ("test6.bmp");

C-/C++-Quelltext

s_aTextures [2] -> setActive ();