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#include "qglcube.h"
#include "qglbuilder.h"
#include "qvector3darray.h"

QT_BEGIN_NAMESPACE

/*!
    \class QGLCube
    \brief The QGLCube class represents the geometry of simple six-sided cube in 3D space.
    \since 4.8
    \ingroup qt3d
    \ingroup qt3d::geometry

    The following example adds a cube of 2 units on a side to a
    geometry builder, and draws it at (10, 25, 0) in a QGLPainter:

    \code
    QGLBuilder list;
    list.newSection(QGL::Faceted);
    list << QGLCube(2);
    painter->translate(10, 25, 0);
    list.draw(painter);
    \endcode

    QGLCube will create a default set of texture coordinates that shows
    the same texture of all six faces.
*/

/*!
    \fn QGLCube::QGLCube(qreal size)

    Constructs the geometry for a regular cube of \a size
    units on a side.
*/

/*!
    \fn qreal QGLCube::size() const

    Returns the size of this cube.

    \sa setSize()
*/

/*!
    \fn void QGLCube::setSize(qreal size)

    Sets the \a size of this cube.

    \sa size()
*/

static const int vertexDataLen = 6 * 4 * 3;

static const float vertexData[vertexDataLen] = {
    // +X
    0.5f, 0.5f, -0.5f,
    0.5f, 0.5f, 0.5f,
    0.5f, -0.5f, 0.5f,
    0.5f, -0.5f, -0.5f,
    // -X
    -0.5f, -0.5f, -0.5f,
    -0.5f, -0.5f, 0.5f,
    -0.5f, 0.5f, 0.5f,
    -0.5f, 0.5f, -0.5f,

    // +Y
    -0.5f, 0.5f, -0.5f,
    -0.5f, 0.5f, 0.5f,
    0.5f, 0.5f, 0.5f,
    0.5f, 0.5f, -0.5f,
    // -Y
    0.5f, -0.5f, -0.5f,
    0.5f, -0.5f, 0.5f,
    -0.5f, -0.5f, 0.5f,
    -0.5f, -0.5f, -0.5f,

    // +Z
    0.5f, -0.5f, 0.5f,
    0.5f, 0.5f, 0.5f,
    -0.5f, 0.5f, 0.5f,
    -0.5f, -0.5f, 0.5f,
    // -Z
    0.5f, 0.5f, -0.5f,
    0.5f, -0.5f, -0.5f,
    -0.5f, -0.5f, -0.5f,
    -0.5f, 0.5f, -0.5f
};

static const int texCoordDataLen = 6 * 4 * 2;

static const float texCoordData[texCoordDataLen] = {
    // +X
    1.0f, 1.0f,
    0.0f, 1.0f,
    0.0f, 0.0f,
    1.0f, 0.0f,
    // -X
    0.0f, 0.0f,
    1.0f, 0.0f,
    1.0f, 1.0f,
    0.0f, 1.0f,

    // +Y
    0.0f, 1.0f,
    0.0f, 0.0f,
    1.0f, 0.0f,
    1.0f, 1.0f,
    // -Y
    1.0f, 0.0f,
    1.0f, 1.0f,
    0.0f, 1.0f,
    0.0f, 0.0f,

    // +Z
    1.0f, 0.0f,
    1.0f, 1.0f,
    0.0f, 1.0f,
    0.0f, 0.0f,
    // -Z
    0.0f, 1.0f,
    0.0f, 0.0f,
    1.0f, 0.0f,
    1.0f, 1.0f,
};

/*!
    \relates QGLCube

    Builds the geometry for \a cube within the specified
    geometry \a builder.

    This operator specifies the positions, and 2D texture
    co-ordinates for all of the vertices that make up the cube.
    Normals will be calculated by the \a builder, depending on its
    current section's smoothing setting.
*/
QGLBuilder& operator<<(QGLBuilder& builder, const QGLCube& cube)
{
    QGeometryData op;

    QVector3DArray vrts = QVector3DArray::fromRawData(
            reinterpret_cast<const QVector3D *>(vertexData), vertexDataLen / 3);
    if (cube.size() != 1.0f)
        vrts.scale(cube.size());

    op.appendVertexArray(vrts);

    QVector2DArray texx = QVector2DArray::fromRawData(
            reinterpret_cast<const QVector2D *>(texCoordData), texCoordDataLen / 2);

    op.appendTexCoordArray(texx);

    builder.addQuads(op);
    return builder;
}

QT_END_NAMESPACE