GLTexImage.h

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//      File:           GLTexImage.h
//      Author:         Changchang Wu
//      Description : interface for the GLTexImage class.
//              GLTexImage:             naive texture class. 
//                                              sevral different quad drawing functions are provied
//              GLTexPacked:    packed version (four value packed as four channels of a pixel)
//              GLTexInput:             GLTexImage + some input information
//
//      Copyright (c) 2007 University of North Carolina at Chapel Hill
//      All Rights Reserved
//
//      Permission to use, copy, modify and distribute this software and its
//      documentation for educational, research and non-profit purposes, without
//      fee, and without a written agreement is hereby granted, provided that the
//      above copyright notice and the following paragraph appear in all copies.
//      
//      The University of North Carolina at Chapel Hill make no representations
//      about the suitability of this software for any purpose. It is provided
//      'as is' without express or implied warranty. 
//
//      Please send BUG REPORTS to ccwu@cs.unc.edu
//


#ifndef GL_TEX_IMAGE_H
#define GL_TEX_IMAGE_H

class GlobalUtil;
class GLTexImage :public GlobalUtil 
{       
protected:
        GLuint  _texID;
        int             _imgWidth;
        int             _imgHeight;
        int             _texWidth;
        int             _texHeight;
        int             _drawWidth;
        int             _drawHeight;
public:
        static void DetachFBO(int i);
        static void UnbindTex();
        static void UnbindMultiTex(int n);
        static void DrawQuad(float x1, float x2, float y1, float y2);

public:
        virtual void DrawQuadUS(int scale);
        virtual void DrawQuadDS(int scale);
        virtual void DrawImage();
        virtual void TexConvertRGB();
        virtual void ZeroHistoMargin();
        virtual void SetImageSize(int width, int height);
        virtual void InitTexture(int width, int height, int clamp_to_edge =1 );
        void InitTexture(int width, int height, int clamp_to_edge, GLuint format);
        virtual void FillMargin(int marginx, int marginy);
public:
        void DrawScaledQuad(float scale);
        int  CopyToPBO(GLuint pbo, int width, int height, GLenum format = GL_RGBA);
        void CopyFromPBO(GLuint pbo, int width, int height, GLenum format = GL_RGBA);
        void FitRealTexViewPort();
        void DrawQuadMT8();
        void DrawQuadMT4();
        void DrawQuadReduction();
        void DrawQuadReduction(int w, int h);
        void DrawMargin(int right, int bottom);
        void DrawQuad();
        void FitTexViewPort();
        void ZeroHistoMargin(int hw, int hh);
        int  CheckTexture();
public:
        void AttachToFBO(int i );
        void BindTex();
        operator GLuint (){return _texID;}      
        GLuint GetTexID(){return _texID;}
        int     GetImgPixelCount(){return _imgWidth*_imgHeight;}
        int GetTexPixelCount(){return _texWidth*_texHeight;}
        int     GetImgWidth(){return _imgWidth;}
        int GetImgHeight(){return _imgHeight;}
        int     GetTexWidth(){return _texWidth;}
        int GetTexHeight(){return _texHeight;}
        int     GetDrawWidth(){return _drawWidth;}
        int GetDrawHeight(){return _drawHeight;}
        //int   IsTexTight(){return _texWidth == _drawWidth && _texHeight == _drawHeight;}
        int     IsTexPacked(){return _drawWidth != _imgWidth;}
        GLTexImage();
        virtual ~GLTexImage();
        friend class SiftGPU;
};

//class for handle data input, to support all openGL-supported data format, 
//data are first uploaded to an openGL texture then converted, and optionally
//when the datatype is simple, we downsample/convert on cpu
class GLTexInput:public GLTexImage
{
public:
        int      _down_sampled;
        int      _rgb_converted;
    int      _data_modified;

        float *        _converted_data;
    const void*    _pixel_data;
public:
        static int  IsSimpleGlFormat(unsigned int gl_format, unsigned int gl_type)
        {
                //the formats there is a cpu code to conver rgb and downsample
                 return (gl_format ==GL_LUMINANCE ||gl_format == GL_LUMINANCE_ALPHA||
                                gl_format == GL_RGB||   gl_format == GL_RGBA||
                                gl_format == GL_BGR || gl_format == GL_BGRA) && 
                                (gl_type == GL_UNSIGNED_BYTE || gl_type == GL_FLOAT || gl_type == GL_UNSIGNED_SHORT); 
        }
//in vc6, template member function doesn't work
#if !defined(_MSC_VER) || _MSC_VER > 1200
        template <class Uint> 
        static int DownSamplePixelDataI(unsigned int gl_format, int width, int height, 
                int ds, const Uint * pin, Uint * pout);
        template <class Uint> 
        static int DownSamplePixelDataI2F(unsigned int gl_format, int width, int height, 
                int ds, const Uint * pin, float * pout, int skip  = 0);
#endif
        static int DownSamplePixelDataF(unsigned int gl_format, int width, int height, 
                int ds, const float * pin, float * pout, int skip = 0);
    static int TruncateWidthCU(int w) {return  w & 0xfffffffc; }
public:
        GLTexInput() : _down_sampled(0), _rgb_converted(0), _data_modified(0), 
                    _converted_data(0), _pixel_data(0){}
        int SetImageData(int width, int height, const void * data, 
                                        unsigned int gl_format, unsigned int gl_type);
        int LoadImageFile(char * imagepath, int & w, int &h);
    void VerifyTexture();
    virtual ~GLTexInput();
};

//GLTexPacked doesn't have any data
//so that we can use the GLTexImage* pointer to index a GLTexPacked Vector

class GLTexPacked:public GLTexImage
{
public:
        virtual void    DrawImage();
        virtual void    DrawQuadUS(int scale);
        virtual void    DrawQuadDS(int scale);
        virtual void    FillMargin(int marginx, int marginy);
        virtual void    InitTexture(int width, int height, int clamp_to_edge =1);
        virtual void    TexConvertRGB();
        virtual void    SetImageSize(int width, int height);
        virtual void    ZeroHistoMargin();
        //virtual void  GetHistWH(int& w, int& h){return w = (3 + sz)>>1;}
public:
        void    DrawMargin(int right, int bottom, int mx, int my);
        GLTexPacked():GLTexImage(){}
};


#endif // !defined(GL_TEX_IMAGE_H)