#if !defined(AFX_IWSTRINGEFFECT_H__863ADE82_7789_4E54_BE7D_B8F0740FD81B__INCLUDED_)
#define AFX_IWSTRINGEFFECT_H__863ADE82_7789_4E54_BE7D_B8F0740FD81B__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#include <wchar.h>

class IWStringEffect
{
public:
  ///function returns extra size that effect needs
  /**
  @param curSize size of string that enters to the effect
  @return count of extra characters needs to effects;
  */
  virtual unsigned long GetEffectExtraSize(unsigned long curSize) {return 0;}

  ///function renders begin of string. 
  /** Function returns number of characters rendered, and must be <= then size returned by GetEffectExtraSize()
  @param renderPtr pointer to render buffer
  @param curSize size of string that enters to the effect
  @return number of characters rendered. Entered string will be rendered behind.
  */
  virtual unsigned long PreRenderString(wchar_t *renderPtr,unsigned long curSize) {return 0;}

  ///function renders effect. 
  /** 
  @param renderPtr pointer to begin of render buffer.
  @param rendered number of characters rendered by previous effect. Value doesn't point to the end
  of buffer, function must add result of PreRenderString */
  virtual void RenderString(wchar_t *renderPtr, unsigned long rendered)=0;
};

#endif