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** This file contains pre-release code and may not be distributed.

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** contained in the Technology Preview License Agreement accompanying

** this package.

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** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

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****************************************************************************/

#ifndef GLBUFFERS_H

#define GLBUFFERS_H

//#include <GL/glew.h>

#include "glextensions.h"

#include <QtGui>

#include <QtOpenGL>

#define BUFFER_OFFSET(i) ((char*)0 + (i))

#define SIZE_OF_MEMBER(cls, member) sizeof(static_cast<cls *>(0)->member)

#define GLBUFFERS_ASSERT_OPENGL(prefix, assertion, returnStatement)                         \

if (m_failed || !(assertion)) {                                                             \

    if (!m_failed) qCritical(prefix ": The necessary OpenGL functions are not available."); \

    m_failed = true;                                                                        \

    returnStatement;                                                                        \

}

QT_BEGIN_NAMESPACE

class QMatrix4x4;

QT_END_NAMESPACE

class GLTexture

{

public:

    GLTexture();

    virtual ~GLTexture();

    virtual void bind() = 0;

    virtual void unbind() = 0;

    virtual bool failed() const {return m_failed;}

protected:

    GLuint m_texture;

    bool m_failed;

};

class GLFrameBufferObject

{

public:

    friend class GLRenderTargetCube;

    // friend class GLRenderTarget2D;

    GLFrameBufferObject(int width, int height);

    virtual ~GLFrameBufferObject();

    bool isComplete();

    virtual bool failed() const {return m_failed;}

protected:

    void setAsRenderTarget(bool state = true);

    GLuint m_fbo;

    GLuint m_depthBuffer;

    int m_width, m_height;

    bool m_failed;

};

class GLTexture2D : public GLTexture

{

public:

    GLTexture2D(int width, int height);

    GLTexture2D(const QString& fileName, int width = 0, int height = 0);

    void load(int width, int height, QRgb *data);

    virtual void bind();

    virtual void unbind();

};

class GLTexture3D : public GLTexture

{

public:

    GLTexture3D(int width, int height, int depth);

    // TODO: Implement function below

    //GLTexture3D(const QString& fileName, int width = 0, int height = 0);

    void load(int width, int height, int depth, QRgb *data);

    virtual void bind();

    virtual void unbind();

};

class GLTextureCube : public GLTexture

{

public:

    GLTextureCube(int size);

    GLTextureCube(const QStringList& fileNames, int size = 0);

    void load(int size, int face, QRgb *data);

    virtual void bind();

    virtual void unbind();

};

// TODO: Define and implement class below

//class GLRenderTarget2D : public GLTexture2D

class GLRenderTargetCube : public GLTextureCube

{

public:

    GLRenderTargetCube(int size);

    // begin rendering to one of the cube's faces. 0 <= face < 6

    void begin(int face);

    // end rendering

    void end();

    virtual bool failed() {return m_failed || m_fbo.failed();}

    static void getViewMatrix(QMatrix4x4& mat, int face);

    static void getProjectionMatrix(QMatrix4x4& mat, float nearZ, float farZ);

private:

    GLFrameBufferObject m_fbo;

};

struct VertexDescription

{

    enum

    {

        Null = 0, // Terminates a VertexDescription array

        Position,

        TexCoord,

        Normal,

        Color,

    };

    int field; // Position, TexCoord, Normal, Color

    int type; // GL_FLOAT, GL_UNSIGNED_BYTE

    int count; // number of elements

    int offset; // field's offset into vertex struct

    int index; // 0 (unused at the moment)

};

// Implementation of interleaved buffers.

// 'T' is a struct which must include a null-terminated static array

// 'VertexDescription* description'.

// Example:

/*

struct Vertex

{

    GLfloat position[3];

    GLfloat texCoord[2];

    GLfloat normal[3];

    GLbyte color[4];

    static VertexDescription description[];

};

VertexDescription Vertex::description[] = {

    {VertexDescription::Position, GL_FLOAT, SIZE_OF_MEMBER(Vertex, position) / sizeof(GLfloat), offsetof(Vertex, position), 0},

    {VertexDescription::TexCoord, GL_FLOAT, SIZE_OF_MEMBER(Vertex, texCoord) / sizeof(GLfloat), offsetof(Vertex, texCoord), 0},

    {VertexDescription::Normal, GL_FLOAT, SIZE_OF_MEMBER(Vertex, normal) / sizeof(GLfloat), offsetof(Vertex, normal), 0},

    {VertexDescription::Color, GL_BYTE, SIZE_OF_MEMBER(Vertex, color) / sizeof(GLbyte), offsetof(Vertex, color), 0},

    {VertexDescription::Null, 0, 0, 0, 0},

};

*/

template<class T>

class GLVertexBuffer

{

public:

    GLVertexBuffer(int length, const T *data = 0, int mode = GL_STATIC_DRAW)

        : m_length(0)

        , m_mode(mode)

        , m_buffer(0)

        , m_failed(false)

    {

        GLBUFFERS_ASSERT_OPENGL("GLVertexBuffer::GLVertexBuffer", glGenBuffers && glBindBuffer && glBufferData, return)

		glGenBuffers(1, &m_buffer);

		glBindBuffer(GL_ARRAY_BUFFER, m_buffer);

		glBufferData(GL_ARRAY_BUFFER, (m_length = length) * sizeof(T), data, mode);

    }

    ~GLVertexBuffer()

    {

        GLBUFFERS_ASSERT_OPENGL("GLVertexBuffer::~GLVertexBuffer", glDeleteBuffers, return)

        glDeleteBuffers(1, &m_buffer);

    }

    void bind()

    {

        GLBUFFERS_ASSERT_OPENGL("GLVertexBuffer::bind", glBindBuffer, return)

        glBindBuffer(GL_ARRAY_BUFFER, m_buffer);

        for (VertexDescription *desc = T::description; desc->field != VertexDescription::Null; ++desc) {

            switch (desc->field) {

            case VertexDescription::Position:

                glVertexPointer(desc->count, desc->type, sizeof(T), BUFFER_OFFSET(desc->offset));

                glEnableClientState(GL_VERTEX_ARRAY);

                break;

            case VertexDescription::TexCoord:

                glTexCoordPointer(desc->count, desc->type, sizeof(T), BUFFER_OFFSET(desc->offset));

                glEnableClientState(GL_TEXTURE_COORD_ARRAY);

                break;

            case VertexDescription::Normal:

                glNormalPointer(desc->type, sizeof(T), BUFFER_OFFSET(desc->offset));

                glEnableClientState(GL_NORMAL_ARRAY);

                break;

            case VertexDescription::Color:

                glColorPointer(desc->count, desc->type, sizeof(T), BUFFER_OFFSET(desc->offset));

                glEnableClientState(GL_COLOR_ARRAY);

                break;

            default:

                break;

            }

        }

    }

    void unbind()

    {

        GLBUFFERS_ASSERT_OPENGL("GLVertexBuffer::unbind", glBindBuffer, return)

        glBindBuffer(GL_ARRAY_BUFFER, 0);

        for (VertexDescription *desc = T::description; desc->field != VertexDescription::Null; ++desc) {

            switch (desc->field) {

            case VertexDescription::Position:

                glDisableClientState(GL_VERTEX_ARRAY);

                break;

            case VertexDescription::TexCoord:

                glDisableClientState(GL_TEXTURE_COORD_ARRAY);

                break;

            case VertexDescription::Normal:

                glDisableClientState(GL_NORMAL_ARRAY);

                break;

            case VertexDescription::Color:

                glDisableClientState(GL_COLOR_ARRAY);

                break;

            default:

                break;

            }

        }

    }

    int length() const {return m_length;}

    T *lock()

    {

        GLBUFFERS_ASSERT_OPENGL("GLVertexBuffer::lock", glBindBuffer && glMapBuffer, return 0)

        glBindBuffer(GL_ARRAY_BUFFER, m_buffer);

        //glBufferData(GL_ARRAY_BUFFER, m_length, NULL, m_mode);

        GLvoid* buffer = glMapBuffer(GL_ARRAY_BUFFER, GL_READ_WRITE);

        m_failed = (buffer == 0);

        return reinterpret_cast<T *>(buffer);

    }

    void unlock()

    {

        GLBUFFERS_ASSERT_OPENGL("GLVertexBuffer::unlock", glBindBuffer && glUnmapBuffer, return)

        glBindBuffer(GL_ARRAY_BUFFER, m_buffer);

        glUnmapBuffer(GL_ARRAY_BUFFER);

    }

    bool failed()

    {

        return m_failed;

    }

private:

    int m_length, m_mode;

    GLuint m_buffer;

    bool m_failed;

};

template<class T>

class GLIndexBuffer

{

public:

    GLIndexBuffer(int length, const T *data = 0, int mode = GL_STATIC_DRAW)

        : m_length(0)

        , m_mode(mode)

        , m_buffer(0)

        , m_failed(false)

    {

        GLBUFFERS_ASSERT_OPENGL("GLIndexBuffer::GLIndexBuffer", glGenBuffers && glBindBuffer && glBufferData, return)

        glGenBuffers(1, &m_buffer);

        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_buffer);

        glBufferData(GL_ELEMENT_ARRAY_BUFFER, (m_length = length) * sizeof(T), data, mode);

    }

    ~GLIndexBuffer()

    {

        GLBUFFERS_ASSERT_OPENGL("GLIndexBuffer::~GLIndexBuffer", glDeleteBuffers, return)

        glDeleteBuffers(1, &m_buffer);

    }

    void bind()

    {

        GLBUFFERS_ASSERT_OPENGL("GLIndexBuffer::bind", glBindBuffer, return)

        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_buffer);

    }

    void unbind()

    {

        GLBUFFERS_ASSERT_OPENGL("GLIndexBuffer::unbind", glBindBuffer, return)

        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

    }

    int length() const {return m_length;}

    T *lock()

    {

        GLBUFFERS_ASSERT_OPENGL("GLIndexBuffer::lock", glBindBuffer && glMapBuffer, return 0)

        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_buffer);

        GLvoid* buffer = glMapBuffer(GL_ELEMENT_ARRAY_BUFFER, GL_READ_WRITE);

        m_failed = (buffer == 0);

        return reinterpret_cast<T *>(buffer);

    }

    void unlock()

    {

        GLBUFFERS_ASSERT_OPENGL("GLIndexBuffer::unlock", glBindBuffer && glUnmapBuffer, return)

        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_buffer);

        glUnmapBuffer(GL_ELEMENT_ARRAY_BUFFER);

    }

    bool failed()

    {

        return m_failed;

    }

private:

    int m_length, m_mode;

    GLuint m_buffer;

    bool m_failed;

};

#endif