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#include "glbuffers.h"

#include <QtGui/qmatrix4x4.h>

//============================================================================//

//                                  GLTexture                                 //

//============================================================================//

GLTexture::GLTexture() : m_texture(0), m_failed(false)

{

    glGenTextures(1, &m_texture);

}

GLTexture::~GLTexture()

{

    glDeleteTextures(1, &m_texture);

}

//============================================================================//

//                                 GLTexture2D                                //

//============================================================================//

GLTexture2D::GLTexture2D(int width, int height)

{

    glBindTexture(GL_TEXTURE_2D, m_texture);

    glTexImage2D(GL_TEXTURE_2D, 0, 4, width, height, 0,

        GL_BGRA, GL_UNSIGNED_BYTE, 0);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

    //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);

    //glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE);

    glBindTexture(GL_TEXTURE_2D, 0);

}

GLTexture2D::GLTexture2D(const QString& fileName, int width, int height)

{

    // TODO: Add error handling.

    QImage image(fileName);

    if (image.isNull()) {

        m_failed = true;

        return;

    }

    image = image.convertToFormat(QImage::Format_ARGB32);

    //qDebug() << "Image size:" << image.width() << "x" << image.height();

    if (width <= 0)

        width = image.width();

    if (height <= 0)

        height = image.height();

    if (width != image.width() || height != image.height())

        image = image.scaled(width, height, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);

    glBindTexture(GL_TEXTURE_2D, m_texture);

    // Works on x86, so probably works on all little-endian systems.

    // Does it work on big-endian systems?

    glTexImage2D(GL_TEXTURE_2D, 0, 4, image.width(), image.height(), 0,

        GL_BGRA, GL_UNSIGNED_BYTE, image.bits());

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

    //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);

    //glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE);

    glBindTexture(GL_TEXTURE_2D, 0);

}

void GLTexture2D::load(int width, int height, QRgb *data)

{

    glBindTexture(GL_TEXTURE_2D, m_texture);

    glTexImage2D(GL_TEXTURE_2D, 0, 4, width, height, 0,

        GL_BGRA, GL_UNSIGNED_BYTE, data);

    glBindTexture(GL_TEXTURE_2D, 0);

}

void GLTexture2D::bind()

{

    glBindTexture(GL_TEXTURE_2D, m_texture);

    glEnable(GL_TEXTURE_2D);

}

void GLTexture2D::unbind()

{

    glBindTexture(GL_TEXTURE_2D, 0);

    glDisable(GL_TEXTURE_2D);

}

//============================================================================//

//                                 GLTexture3D                                //

//============================================================================//

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

{

    GLBUFFERS_ASSERT_OPENGL("GLTexture3D::GLTexture3D", glTexImage3D, return)

    glBindTexture(GL_TEXTURE_3D, m_texture);

    glTexImage3D(GL_TEXTURE_3D, 0, 4, width, height, depth, 0,

        GL_BGRA, GL_UNSIGNED_BYTE, 0);

    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_REPEAT);

    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_REPEAT);

    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_REPEAT);

    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

    //glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);

    //glTexParameteri(GL_TEXTURE_3D, GL_GENERATE_MIPMAP, GL_TRUE);

    glBindTexture(GL_TEXTURE_3D, 0);

}

void GLTexture3D::load(int width, int height, int depth, QRgb *data)

{

    GLBUFFERS_ASSERT_OPENGL("GLTexture3D::load", glTexImage3D, return)

    glBindTexture(GL_TEXTURE_3D, m_texture);

    glTexImage3D(GL_TEXTURE_3D, 0, 4, width, height, depth, 0,

        GL_BGRA, GL_UNSIGNED_BYTE, data);

    glBindTexture(GL_TEXTURE_3D, 0);

}

void GLTexture3D::bind()

{

    glBindTexture(GL_TEXTURE_3D, m_texture);

    glEnable(GL_TEXTURE_3D);

}

void GLTexture3D::unbind()

{

    glBindTexture(GL_TEXTURE_3D, 0);

    glDisable(GL_TEXTURE_3D);

}

//============================================================================//

//                                GLTextureCube                               //

//============================================================================//

GLTextureCube::GLTextureCube(int size)

{

    glBindTexture(GL_TEXTURE_CUBE_MAP, m_texture);

    for (int i = 0; i < 6; ++i)

        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, 4, size, size, 0,

            GL_BGRA, GL_UNSIGNED_BYTE, 0);

    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);

    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);

    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

    //glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);

    //glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_GENERATE_MIPMAP, GL_TRUE);

    glBindTexture(GL_TEXTURE_CUBE_MAP, 0);

}

GLTextureCube::GLTextureCube(const QStringList& fileNames, int size)

{

    // TODO: Add error handling.

    glBindTexture(GL_TEXTURE_CUBE_MAP, m_texture);

    int index = 0;

    foreach (QString file, fileNames) {

        QImage image(file);

        if (image.isNull()) {

            m_failed = true;

            break;

        }

        image = image.convertToFormat(QImage::Format_ARGB32);

        //qDebug() << "Image size:" << image.width() << "x" << image.height();

        if (size <= 0)

            size = image.width();

        if (size != image.width() || size != image.height())

            image = image.scaled(size, size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);

        // Works on x86, so probably works on all little-endian systems.

        // Does it work on big-endian systems?

        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + index, 0, 4, image.width(), image.height(), 0,

            GL_BGRA, GL_UNSIGNED_BYTE, image.bits());

        if (++index == 6)

            break;

    }

    // Clear remaining faces.

    while (index < 6) {

        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + index, 0, 4, size, size, 0,

            GL_BGRA, GL_UNSIGNED_BYTE, 0);

        ++index;

    }

    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);

    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);

    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

    //glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);

    //glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_GENERATE_MIPMAP, GL_TRUE);

    glBindTexture(GL_TEXTURE_CUBE_MAP, 0);

}

void GLTextureCube::load(int size, int face, QRgb *data)

{

    glBindTexture(GL_TEXTURE_CUBE_MAP, m_texture);

        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, 0, 4, size, size, 0,

            GL_BGRA, GL_UNSIGNED_BYTE, data);

    glBindTexture(GL_TEXTURE_CUBE_MAP, 0);

}

void GLTextureCube::bind()

{

    glBindTexture(GL_TEXTURE_CUBE_MAP, m_texture);

    glEnable(GL_TEXTURE_CUBE_MAP);

}

void GLTextureCube::unbind()

{

    glBindTexture(GL_TEXTURE_CUBE_MAP, 0);

    glDisable(GL_TEXTURE_CUBE_MAP);

}

//============================================================================//

//                            GLFrameBufferObject                             //

//============================================================================//

GLFrameBufferObject::GLFrameBufferObject(int width, int height)

    : m_fbo(0)

    , m_depthBuffer(0)

    , m_width(width)

    , m_height(height)

    , m_failed(false)

{

    GLBUFFERS_ASSERT_OPENGL("GLFrameBufferObject::GLFrameBufferObject",

        glGenFramebuffersEXT && glGenRenderbuffersEXT && glBindRenderbufferEXT && glRenderbufferStorageEXT, return)

    // TODO: share depth buffers of same size

    glGenFramebuffersEXT(1, &m_fbo);

    //glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_fbo);

    glGenRenderbuffersEXT(1, &m_depthBuffer);

    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, m_depthBuffer);

    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT, m_width, m_height);

    //glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_RENDERBUFFER_EXT, m_depthBuffer);

    //glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);

}

GLFrameBufferObject::~GLFrameBufferObject()

{

    GLBUFFERS_ASSERT_OPENGL("GLFrameBufferObject::~GLFrameBufferObject",

        glDeleteFramebuffersEXT && glDeleteRenderbuffersEXT, return)

    glDeleteFramebuffersEXT(1, &m_fbo);

    glDeleteRenderbuffersEXT(1, &m_depthBuffer);

}

void GLFrameBufferObject::setAsRenderTarget(bool state)

{

    GLBUFFERS_ASSERT_OPENGL("GLFrameBufferObject::setAsRenderTarget", glBindFramebufferEXT, return)

    if (state) {

        glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_fbo);

        glPushAttrib(GL_VIEWPORT_BIT);

        glViewport(0, 0, m_width, m_height);

    } else {

        glPopAttrib();

        glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);

    }

}

bool GLFrameBufferObject::isComplete()

{

    GLBUFFERS_ASSERT_OPENGL("GLFrameBufferObject::isComplete", glCheckFramebufferStatusEXT, return false)

    return GL_FRAMEBUFFER_COMPLETE_EXT == glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);

}

//============================================================================//

//                             GLRenderTargetCube                             //

//============================================================================//

GLRenderTargetCube::GLRenderTargetCube(int size)

    : GLTextureCube(size)

    , m_fbo(size, size)

{

}

void GLRenderTargetCube::begin(int face)

{

    GLBUFFERS_ASSERT_OPENGL("GLRenderTargetCube::begin",

        glFramebufferTexture2DEXT && glFramebufferRenderbufferEXT, return)

    m_fbo.setAsRenderTarget(true);

    glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,

        GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, m_texture, 0);

    glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_RENDERBUFFER_EXT, m_fbo.m_depthBuffer);

}

void GLRenderTargetCube::end()

{

    m_fbo.setAsRenderTarget(false);

}

void GLRenderTargetCube::getViewMatrix(QMatrix4x4& mat, int face)

{

    if (face < 0 || face >= 6) {

        qWarning("GLRenderTargetCube::getViewMatrix: 'face' must be in the range [0, 6). (face == %d)", face);

        return;

    }

    static int perm[6][3] = {

        {2, 1, 0},

        {2, 1, 0},

        {0, 2, 1},

        {0, 2, 1},

        {0, 1, 2},

        {0, 1, 2},

    };

    static float signs[6][3] = {

        {-1.0f, -1.0f, -1.0f},

        {+1.0f, -1.0f, +1.0f},

        {+1.0f, +1.0f, -1.0f},

        {+1.0f, -1.0f, +1.0f},

        {+1.0f, -1.0f, -1.0f},

        {-1.0f, -1.0f, +1.0f},

    };

    mat.fill(0.0f);

    for (int i = 0; i < 3; ++i)

        mat(i, perm[face][i]) = signs[face][i];

    mat(3, 3) = 1.0f;

}

void GLRenderTargetCube::getProjectionMatrix(QMatrix4x4& mat, float nearZ, float farZ)

{

    static const QMatrix4x4 reference(

            1.0f, 0.0f, 0.0f, 0.0f,

            0.0f, 1.0f, 0.0f, 0.0f,

            0.0f, 0.0f, 0.0f, 0.0f,

            0.0f, 0.0f, -1.0f, 0.0f);

    mat = reference;

    mat(2, 2) = (nearZ+farZ)/(nearZ-farZ);

    mat(2, 3) = 2.0f*nearZ*farZ/(nearZ-farZ);

}