pdfium 矩阵

// Transform |page_object| by the given matrix.

//

//   page_object - handle to a page object.

//   a           - matrix value.

//   b           - matrix value.

//   c           - matrix value.

//   d           - matrix value.

//   e           - matrix value.

//   f           - matrix value.

//

// The matrix is composed as:

//   |a c e|

//   |b d f|

// and can be used to scale, rotate, shear and translate the |page_object|.

DLLEXPORT void STDCALL FPDFPageObj_Transform(FPDF_PAGEOBJECT page_object,

                                             double a,

                                             double b,

                                             double c,

                                             double d,

                                             double e,

                                             double f);

 

 

DLLEXPORT void STDCALL FPDFPageObj_Transform(FPDF_PAGEOBJECT page_object,

                                             double a,

                                             double b,

                                             double c,

                                             double d,

                                             double e,

                                             double f) {

  CPDF_PageObject* pPageObj = CPDFPageObjectFromFPDFPageObject(page_object);

  if (!pPageObj)

    return;

  CFX_Matrix matrix((float)a, (float)b, (float)c, (float)d, (float)e, (float)f);

  pPageObj->Transform(matrix);

}

 

class CPDF_PageObject : public CPDF_GraphicStates {
 public:
  enum Type {
    TEXT = 1,
    PATH,
    IMAGE,
    SHADING,
    FORM,
  };

  CPDF_PageObject();
  ~CPDF_PageObject() override;

  virtual Type GetType() const = 0;
  virtual void Transform(const CFX_Matrix& matrix) = 0;
  virtual bool IsText() const;
  virtual bool IsPath() const;
  virtual bool IsImage() const;
  virtual bool IsShading() const;
  virtual bool IsForm() const;
  virtual CPDF_TextObject* AsText();
  virtual const CPDF_TextObject* AsText() const;
  virtual CPDF_PathObject* AsPath();
  virtual const CPDF_PathObject* AsPath() const;
  virtual CPDF_ImageObject* AsImage();
  virtual const CPDF_ImageObject* AsImage() const;
  virtual CPDF_ShadingObject* AsShading();
  virtual const CPDF_ShadingObject* AsShading() const;
  virtual CPDF_FormObject* AsForm();
  virtual const CPDF_FormObject* AsForm() const;

  void SetDirty(bool value) { m_bDirty = value; }
  bool IsDirty() const { return m_bDirty; }
  void TransformClipPath(CFX_Matrix& matrix);
  void TransformGeneralState(CFX_Matrix& matrix);

  CFX_FloatRect GetRect() const {
    return CFX_FloatRect(m_Left, m_Bottom, m_Right, m_Top);
  }
  FX_RECT GetBBox(const CFX_Matrix* pMatrix) const;

  float m_Left;
  float m_Right;
  float m_Top;
  float m_Bottom;
  CPDF_ContentMark m_ContentMark;

 protected:
  void CopyData(const CPDF_PageObject* pSrcObject);

 private:
  CPDF_PageObject(const CPDF_PageObject& src) = delete;
  void operator=(const CPDF_PageObject& src) = delete;

  bool m_bDirty;
};