vtkTextRenderer.h

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// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// SPDX-License-Identifier: BSD-3-Clause
 
#ifndef vtkTextRenderer_h
#define vtkTextRenderer_h
 
#include "vtkObject.h"
#include "vtkRenderingCoreModule.h" // For export macro
#include "vtkTuple.h"               // For metrics struct
#include "vtkVector.h"              // For metrics struct
 
VTK_ABI_NAMESPACE_BEGIN
class vtkImageData;
class vtkPath;
class vtkStdString;
class vtkTextProperty;
VTK_ABI_NAMESPACE_END
 
namespace vtksys
{
class RegularExpression;
}
 
VTK_ABI_NAMESPACE_BEGIN
 
class VTKRENDERINGCORE_EXPORT vtkTextRendererCleanup
{
public:
  vtkTextRendererCleanup();
  ~vtkTextRendererCleanup();
 
private:
  vtkTextRendererCleanup(const vtkTextRendererCleanup& other) = delete;
  vtkTextRendererCleanup& operator=(const vtkTextRendererCleanup& rhs) = delete;
};
 
class VTKRENDERINGCORE_EXPORT vtkTextRenderer : public vtkObject
{
public:
  struct Metrics
  {
    Metrics()
      : BoundingBox(0)
      , TopLeft(0)
      , TopRight(0)
      , BottomLeft(0)
      , BottomRight(0)
      , Ascent(0)
      , Descent(0)
    {
    }
 
    vtkTuple<int, 4> BoundingBox;
 
 
    vtkVector2i TopLeft;
    vtkVector2i TopRight;
    vtkVector2i BottomLeft;
    vtkVector2i BottomRight;
 
    vtkVector2i Ascent;
    vtkVector2i Descent;
  };
 
  vtkTypeMacro(vtkTextRenderer, vtkObject);
  void PrintSelf(ostream& os, vtkIndent indent) override;
 
  static vtkTextRenderer* New();
 
  static vtkTextRenderer* GetInstance();
 
  enum Backend
  {
    Default = -1,
    Detect = 0,
    FreeType,
    MathText,
 
    UserBackend = 16
  };
 
 
  vtkSetMacro(DefaultBackend, int);
  vtkGetMacro(DefaultBackend, int);
 
 
  virtual int DetectBackend(const vtkStdString& str);
 
  virtual bool FreeTypeIsSupported() { return false; }
  virtual bool MathTextIsSupported() { return false; }
 
 
  bool GetBoundingBox(
    vtkTextProperty* tprop, const vtkStdString& str, int bbox[4], int dpi, int backend = Default)
  {
    return this->GetBoundingBoxInternal(tprop, str, bbox, dpi, backend);
  }
 
 
  bool GetMetrics(vtkTextProperty* tprop, const vtkStdString& str, Metrics& metrics, int dpi,
    int backend = Default)
  {
    return this->GetMetricsInternal(tprop, str, metrics, dpi, backend);
  }
 
 
  bool RenderString(vtkTextProperty* tprop, const vtkStdString& str, vtkImageData* data,
    int textDims[2], int dpi, int backend = Default)
  {
    return this->RenderStringInternal(tprop, str, data, textDims, dpi, backend);
  }
 
 
  int GetConstrainedFontSize(const vtkStdString& str, vtkTextProperty* tprop, int targetWidth,
    int targetHeight, int dpi, int backend = Default)
  {
    return this->GetConstrainedFontSizeInternal(
      str, tprop, targetWidth, targetHeight, dpi, backend);
  }
 
 
  bool StringToPath(
    vtkTextProperty* tprop, const vtkStdString& str, vtkPath* path, int dpi, int backend = Default)
  {
    return this->StringToPathInternal(tprop, str, path, dpi, backend);
  }
 
  void SetScaleToPowerOfTwo(bool scale) { this->SetScaleToPowerOfTwoInternal(scale); }
 
  friend class vtkTextRendererCleanup;
 
protected:
  vtkTextRenderer();
  ~vtkTextRenderer() override;
 
 
  virtual bool GetBoundingBoxInternal(
    vtkTextProperty* tprop, const vtkStdString& str, int bbox[4], int dpi, int backend) = 0;
  virtual bool GetMetricsInternal(
    vtkTextProperty* tprop, const vtkStdString& str, Metrics& metrics, int dpi, int backend) = 0;
  virtual bool RenderStringInternal(vtkTextProperty* tprop, const vtkStdString& str,
    vtkImageData* data, int textDims[2], int dpi, int backend) = 0;
  virtual int GetConstrainedFontSizeInternal(const vtkStdString& str, vtkTextProperty* tprop,
    int targetWidth, int targetHeight, int dpi, int backend) = 0;
  virtual bool StringToPathInternal(
    vtkTextProperty* tprop, const vtkStdString& str, vtkPath* path, int dpi, int backend) = 0;
  virtual void SetScaleToPowerOfTwoInternal(bool scale) = 0;
 
  static void SetInstance(vtkTextRenderer* instance);
 
 
  static vtkTextRenderer* Instance;
  static vtkTextRendererCleanup Cleanup;
 
  vtksys::RegularExpression* MathTextRegExp;
  vtksys::RegularExpression* MathTextRegExp2;
  vtksys::RegularExpression* MathTextRegExpColumn;
 
 
  virtual void CleanUpFreeTypeEscapes(vtkStdString& str);
 
  int DefaultBackend;
 
private:
  vtkTextRenderer(const vtkTextRenderer&) = delete;
  void operator=(const vtkTextRenderer&) = delete;
};
 
VTK_ABI_NAMESPACE_END
#endif // vtkTextRenderer_h