Texture.h

/*
 *  Copyright (C) 2005-2018 Team Kodi
 *  This file is part of Kodi - https://kodi.tv
 *
 *  SPDX-License-Identifier: GPL-2.0-or-later
 *  See LICENSES/README.md for more information.
 */

#pragma once

#include "guilib/TextureFormats.h"

#include <cstddef>
#include <memory>
#include <string>

class IImage;


#pragma pack(1)
struct COLOR {unsigned char b,g,r,x;};  // Windows GDI expects 4bytes per color
#pragma pack()

enum class TEXTURE_SCALING
{
  LINEAR,
  NEAREST,
};

class CTexture
{

public:
  CTexture(unsigned int width = 0, unsigned int height = 0, unsigned int format = XB_FMT_A8R8G8B8);
  virtual ~CTexture();

  static std::unique_ptr<CTexture> CreateTexture(unsigned int width = 0,
                                                 unsigned int height = 0,
                                                 unsigned int format = XB_FMT_A8R8G8B8);

  static std::unique_ptr<CTexture> LoadFromFile(const std::string& texturePath,
                                                unsigned int idealWidth = 0,
                                                unsigned int idealHeight = 0,
                                                bool requirePixels = false,
                                                const std::string& strMimeType = "");

  static std::unique_ptr<CTexture> LoadFromFileInMemory(unsigned char* buffer,
                                                        size_t bufferSize,
                                                        const std::string& mimeType,
                                                        unsigned int idealWidth = 0,
                                                        unsigned int idealHeight = 0);

  bool LoadFromMemory(unsigned int width, unsigned int height, unsigned int pitch, unsigned int format, bool hasAlpha, const unsigned char* pixels);
  bool LoadPaletted(unsigned int width, unsigned int height, unsigned int pitch, unsigned int format, const unsigned char *pixels, const COLOR *palette);

  bool HasAlpha() const;

  void SetMipmapping();
  bool IsMipmapped() const;
  void SetScalingMethod(TEXTURE_SCALING scalingMethod) { m_scalingMethod = scalingMethod; }
  TEXTURE_SCALING GetScalingMethod() const { return m_scalingMethod; }
  void SetCacheMemory(bool bCacheMemory) { m_bCacheMemory = bCacheMemory; }
  bool GetCacheMemory() const { return m_bCacheMemory; }

  virtual void CreateTextureObject() = 0;
  virtual void DestroyTextureObject() = 0;
  virtual void LoadToGPU() = 0;
  virtual void BindToUnit(unsigned int unit) = 0;

  unsigned char* GetPixels() const { return m_pixels; }
  unsigned int GetPitch() const { return GetPitch(m_textureWidth); }
  unsigned int GetRows() const { return GetRows(m_textureHeight); }
  unsigned int GetTextureWidth() const { return m_textureWidth; }
  unsigned int GetTextureHeight() const { return m_textureHeight; }
  unsigned int GetWidth() const { return m_imageWidth; }
  unsigned int GetHeight() const { return m_imageHeight; }
  unsigned int GetOriginalWidth() const { return m_originalWidth; }
  unsigned int GetOriginalHeight() const { return m_originalHeight; }

  int GetOrientation() const { return m_orientation; }
  void SetOrientation(int orientation) { m_orientation = orientation; }

  void Update(unsigned int width, unsigned int height, unsigned int pitch, unsigned int format, const unsigned char *pixels, bool loadToGPU);
  void Allocate(unsigned int width, unsigned int height, unsigned int format);
  void ClampToEdge();

  static unsigned int PadPow2(unsigned int x);
  static bool SwapBlueRed(unsigned char *pixels, unsigned int height, unsigned int pitch, unsigned int elements = 4, unsigned int offset=0);

private:
  // no copy constructor
  CTexture(const CTexture& copy) = delete;

protected:
  bool LoadFromFileInMem(unsigned char* buffer, size_t size, const std::string& mimeType,
                         unsigned int maxWidth, unsigned int maxHeight);
  bool LoadFromFileInternal(const std::string& texturePath, unsigned int maxWidth, unsigned int maxHeight, bool requirePixels, const std::string& strMimeType = "");
  bool LoadIImage(IImage* pImage, unsigned char* buffer, unsigned int bufSize, unsigned int width, unsigned int height);
  // helpers for computation of texture parameters for compressed textures
  unsigned int GetPitch(unsigned int width) const;
  unsigned int GetRows(unsigned int height) const;
  unsigned int GetBlockSize() const;

  unsigned int m_imageWidth;
  unsigned int m_imageHeight;
  unsigned int m_textureWidth;
  unsigned int m_textureHeight;
  unsigned int m_originalWidth;   
  unsigned int m_originalHeight;  

  unsigned char* m_pixels;
  bool m_loadedToGPU;
  unsigned int m_format;
  int m_orientation;
  bool m_hasAlpha =  true ;
  bool m_mipmapping =  false ;
  TEXTURE_SCALING m_scalingMethod = TEXTURE_SCALING::LINEAR;
  bool m_bCacheMemory = false;
};