text: /***************************************************************************
   * Copyright 1998-2018 by authors (see AUTHORS.txt)                        *
   *                                                                         *
   *   This file is part of LuxCoreRender.                                   *
   *                                                                         *
   * Licensed under the Apache License, Version 2.0 (the "License");         *
   * you may not use this file except in compliance with the License.        *
   * You may obtain a copy of the License at                                 *
   *                                                                         *
   *     http://www.apache.org/licenses/LICENSE-2.0                          *
   *                                                                         *
   * Unless required by applicable law or agreed to in writing, software     *
   * distributed under the License is distributed on an "AS IS" BASIS,       *
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.*
   * See the License for the specific language governing permissions and     *
   * limitations under the License.                                          *
   ***************************************************************************/
  
  #ifndef _SLG_SUBTRACTTEX_H
  #define	_SLG_SUBTRACTTEX_H
  
  #include "slg/textures/texture.h"
  
  namespace slg {
  
  //------------------------------------------------------------------------------
  // Subtract texture
  //------------------------------------------------------------------------------
  
  class SubtractTexture : public Texture {
  public:
  	SubtractTexture(const Texture *t1, const Texture *t2) : tex1(t1), tex2(t2) { }
  	virtual ~SubtractTexture() { }
  	
  	virtual TextureType GetType() const { return SUBTRACT_TEX; }
  	virtual float GetFloatValue(const HitPoint &hitPoint) const;
  	virtual luxrays::Spectrum GetSpectrumValue(const HitPoint &hitPoint) const;
  	virtual float Y() const {
  		return tex1->Y() - tex2->Y();
  	}
  	virtual float Filter() const {
  		return tex1->Filter() - tex2->Filter();
  	}
  	
  	virtual luxrays::Normal Bump(const HitPoint &hitPoint, const float sampleDistance) const;
  
  	virtual void AddReferencedTextures(boost::unordered_set<const Texture *> &referencedTexs) const {
  		Texture::AddReferencedTextures(referencedTexs);
  		
  		tex1->AddReferencedTextures(referencedTexs);
  		tex2->AddReferencedTextures(referencedTexs);
  	}
  	virtual void AddReferencedImageMaps(boost::unordered_set<const ImageMap *> &referencedImgMaps) const {
  		tex1->AddReferencedImageMaps(referencedImgMaps);
  		tex2->AddReferencedImageMaps(referencedImgMaps);
  	}
  	
  	virtual void UpdateTextureReferences(const Texture *oldTex, const Texture *newTex) {
  		if (tex1 == oldTex)
  			tex1 = newTex;
  		if (tex2 == oldTex)
  			tex2 = newTex;
  	}
  	
  	const Texture *GetTexture1() const { return tex1; }
  	const Texture *GetTexture2() const { return tex2; }
  	
  	virtual luxrays::Properties ToProperties(const ImageMapCache &imgMapCache, const bool useRealFileName) const;
  	
  private:
  	const Texture *tex1;
  	const Texture *tex2;
  };
  
  }
  
  #endif	/* _SLG_SUBTRACTTEX_H */
  