/*********************************************************************NVMH3****
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$Revision: #1 $

Copyright NVIDIA Corporation 2008
TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, THIS SOFTWARE IS PROVIDED
*AS IS* AND NVIDIA AND ITS SUPPLIERS DISCLAIM ALL WARRANTIES, EITHER EXPRESS
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LOSS) ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF
NVIDIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

Read (or Create) a 3D noise texture



To learn more about shading, shaders, and to bounce ideas off other shader
    authors and users, visit the NVIDIA Shader Library Forums at:

    http://developer.nvidia.com/forums/

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


//
// Un-Comment the PROCEDURAL_TEXTURE macro to enable texture generation in
//      DirectX9 ONLY
// DirectX10 may not issue errors, but will generate no texture either
//
// #define PROCEDURAL_TEXTURE
//

#ifndef _H_NOISE3D
#define _H_NOISE3D

#ifdef PROCEDURAL_TEXTURE

#ifndef NOISE_SCALE
#define NOISE_SCALE 5
#endif /* NOISE_SCALE */

// predefine as 1 for "pure" noise
#ifndef NOISE3D_LIMIT
#define NOISE3D_LIMIT 256
#endif /* NOISE3D_LIMIT */

#ifndef NOISE_VOLUME_SIZE
#define NOISE_VOLUME_SIZE 32
#endif /* NOISE_VOLUME_SIZE */

// function used to fill the volume noise texture
float4 noise_3d(float3 Pos : POSITION) : COLOR
{
    float4 Noise = (float4)0;
    for (int i = 1; i < NOISE3D_LIMIT; i += i) {
        Noise.r += (noise(Pos * NOISE_SCALE * i)) / i;
        Noise.g += (noise((Pos + 1)* NOISE_SCALE * i)) / i;
        Noise.b += (noise((Pos + 2) * NOISE_SCALE * i)) / i;
        Noise.a += (noise((Pos + 3) * NOISE_SCALE * i)) / i;
    }
    return (Noise+0.5);
}

texture gProcNoise3DTex  <
    string TextureType = "VOLUME";
    string function = "noise_3d";
	string UIName = "3D Noise Texture";
    string UIWidget = "None";
    int width  = NOISE_VOLUME_SIZE,
	    height = NOISE_VOLUME_SIZE,
		depth  = NOISE_VOLUME_SIZE;
>;
#else /* ! PROCEDURAL_TEXTURE */
texture gNoise3DTex  <
    string UIName = "3D Noise Texture";
    string ResourceName = "noiseL8_32x32x32.dds";
>;
#endif /* ! PROCEDURAL_TEXTURE */

// samplers
sampler3D gNoiseSampler = sampler_state 
{
#ifdef PROCEDUAL_TEXTURE
	Texture = <gProcNoise3DTex>;
#else /* ! PROCEDURAL_TEXTURE */
	Texture = <gNoise3DTex>;
#endif /* ! PROCEDURAL_TEXTURE */
    AddressU  = Wrap;        
    AddressV  = Wrap;
    AddressW  = Wrap;
#if DIRECT3D_VERSION >= 0xa00
    Filter = MIN_MAG_MIP_LINEAR;
#else /* DIRECT3D_VERSION < 0xa00 */
    MinFilter = Linear;
    MipFilter = Linear;
    MagFilter = Linear;
#endif /* DIRECT3D_VERSION */
};

////////////////// UTILITY MACROS ///////////////

// assumes "NoiseSampler" is available
#define NOISE3D(p) tex3D(NoiseSampler,(p))
#define SNOISE3D(p) (NOISE3D(p)-0.5)

#endif /* _H_NOISE3D */

//////////////////////////////////////////////////// eof ///