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

**

** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the demonstration applications of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:LGPL$

** No Commercial Usage

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

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

** Alternatively, this file may be used under the terms of the GNU Lesser

** 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

** ensure the GNU Lesser General Public License version 2.1 requirements

** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at qt-info@nokia.com.

**

**

**

**

**

**

**

**

** $QT_END_LICENSE$

**

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

varying vec3 position, normal;

varying vec4 specular, ambient, diffuse, lightDirection;

uniform sampler2D tex;

uniform sampler3D noise;

//const vec4 marbleColors[2] = {vec4(0.9, 0.9, 0.9, 1), vec4(0.6, 0.5, 0.5, 1)};

uniform vec4 marbleColors[2];

void main()

{

    float turbulence = 0.0;

    float scale = 1.0;

    for (int i = 0; i < 4; ++i) {

        turbulence += scale * (texture3D(noise, 0.125 * gl_TexCoord[1].xyz / scale).x - 0.5);

        scale *= 0.5;

    }

    vec3 N = normalize(normal);

    // assume directional light

    gl_MaterialParameters M = gl_FrontMaterial;

    float NdotL = dot(N, lightDirection.xyz);

    float RdotL = dot(reflect(normalize(position), N), lightDirection.xyz);

    vec4 unlitColor = mix(marbleColors[0], marbleColors[1], exp(-4.0 * abs(turbulence)));

    gl_FragColor = (ambient + diffuse * max(NdotL, 0.0)) * unlitColor +

                    M.specular * specular * pow(max(RdotL, 0.0), M.shininess);

}