varying vec3 Normal;
uniform mat4 mWorldViewProj;
uniform mat4 mInvWorld;
uniform mat4 mTransWorld;
uniform vec3 mLightPos;
uniform vec4 mLightColor;

void main(void)
{
    gl_FrontColor = gl_Color;
    Normal = gl_NormalMatrix * gl_Normal;
    gl_TexCoord[0] = gl_MultiTexCoord0;
    gl_Position = ftransform();
 
}

uniform vec3 mLightPos;
uniform vec4 mLightColor;
uniform sample    r2D Texture0;
 
varying vec3 Normal;

vec4 CelShading ( vec4 color )
{
    float Intensity = dot( mLightPos , normalize(Normal) );
    float factor = 0.8;
    if ( Intensity < 0.5 ) factor = 0.2;
        color *= vec4 ( factor, factor, factor, 1.0 );
 
    return color;
}

void main (void)
{
    vec4 color = texture2D( Texture0 , vec2( gl_TexCoord[0] ) );
 
    color = CelShading ( color );
 
    gl_FragColor = color;
}

namespace irr
{
namespace video
{


class CShaderPerso : public irr::video::IShaderConstantSetCallBack
{
      
private :
        IrrlichtDevice* m_device;

public:

    CShaderPerso( IrrlichtDevice* device )
    {
        m_device = device;
    }
    
    virtual void OnSetConstants(irr::video::IMaterialRendererServices* services, irr::s32 userData)
    {
        video::IVideoDriver* driver = services->getVideoDriver();

        core::matrix4 invWorld = driver->getTransform(video::ETS_WORLD);
        invWorld.makeInverse();
        services->setVertexShaderConstant("mInvWorld", invWorld.pointer(), 16);

        core::matrix4 worldViewProj;
        worldViewProj = driver->getTransform(video::ETS_PROJECTION);
        worldViewProj *= driver->getTransform(video::ETS_VIEW);
        worldViewProj *= driver->getTransform(video::ETS_WORLD);
        services->setVertexShaderConstant("mWorldViewProj", worldViewProj.pointer(), 16);

        core::vector3df pos = irr::core::vector3df(100,50,30);
        services->setVertexShaderConstant ( "mLightPos" , reinterpret_cast<f32*>( &pos ) , 3 );

        video::SColorf col(0.0f,1.0f,1.0f,0.0f);
        services->setVertexShaderConstant("mLightColor", reinterpret_cast<f32*>(&col), 4);

        core::matrix4 world = driver->getTransform(video::ETS_WORLD);
        world = world.getTransposed();
        services->setVertexShaderConstant("mTransWorld", world.pointer(), 16);

    }

};

}
}