326 lines
10 KiB
C++
326 lines
10 KiB
C++
/*=========================================================================
|
|
|
|
Program: Visualization Toolkit
|
|
Module: vtkTextRenderer.h
|
|
|
|
Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
|
|
All rights reserved.
|
|
See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
|
|
|
|
This software is distributed WITHOUT ANY WARRANTY; without even
|
|
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
|
|
PURPOSE. See the above copyright notice for more information.
|
|
|
|
=========================================================================*/
|
|
|
|
/**
|
|
* @class vtkTextRenderer
|
|
* @brief Interface for generating images and path data from
|
|
* string data, using multiple backends.
|
|
*
|
|
*
|
|
* vtkTextRenderer produces images, bounding boxes, and vtkPath
|
|
* objects that represent text. The advantage of using this class is to easily
|
|
* integrate mathematical expressions into renderings by automatically switching
|
|
* between FreeType and MathText backends. If the input string contains at least
|
|
* two "$" symbols separated by text, the MathText backend will be used.
|
|
* Alternatively, the presence of unescaped "|" symbols defines multicolumn lines,
|
|
* which are processed with the MathText backend.
|
|
*
|
|
* If the string does not meet these criteria, or if no MathText implementation is
|
|
* available, the faster FreeType rendering facilities are used. Literal $
|
|
* symbols can be used by escaping them with backslashes, "\$" (or "\\$" if the
|
|
* string is set programmatically).
|
|
*
|
|
* For example, "Acceleration ($\\frac{m}{s^2}$)" will use MathText, but
|
|
* "\\$500, \\$100" will use FreeType.
|
|
*
|
|
* By default, the backend is set to Detect, which determines the backend based
|
|
* on the contents of the string. This can be changed by setting the
|
|
* DefaultBackend ivar.
|
|
*
|
|
* Note that this class is abstract -- link to the vtkRenderingFreetype module
|
|
* to get the default implementation.
|
|
*/
|
|
|
|
#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
|
|
|
|
class vtkImageData;
|
|
class vtkPath;
|
|
class vtkStdString;
|
|
class vtkTextProperty;
|
|
|
|
namespace vtksys
|
|
{
|
|
class RegularExpression;
|
|
}
|
|
|
|
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
|
|
{
|
|
/**
|
|
* Construct a Metrics object with all members initialized to 0.
|
|
*/
|
|
Metrics()
|
|
: BoundingBox(0)
|
|
, TopLeft(0)
|
|
, TopRight(0)
|
|
, BottomLeft(0)
|
|
, BottomRight(0)
|
|
, Ascent(0)
|
|
, Descent(0)
|
|
{
|
|
}
|
|
|
|
/**
|
|
* The axis-aligned bounding box of the rendered text and background, in
|
|
* pixels. The origin of the bounding box is the anchor point of the data
|
|
* when considering justification. Layout is { xMin, xMax, yMin, yMax }.
|
|
*/
|
|
vtkTuple<int, 4> BoundingBox;
|
|
|
|
///@{
|
|
/**
|
|
* The corners of the rendered text (or background, if applicable), in pixels.
|
|
* Uses the same origin as BoundingBox.
|
|
*/
|
|
vtkVector2i TopLeft;
|
|
vtkVector2i TopRight;
|
|
vtkVector2i BottomLeft;
|
|
vtkVector2i BottomRight;
|
|
///@}
|
|
|
|
/**
|
|
* Vectors representing the rotated ascent and descent of the text. This is
|
|
* the distance above or below the baseline. Not all backends support this,
|
|
* and may leave these vectors set to 0.
|
|
* @{
|
|
*/
|
|
vtkVector2i Ascent;
|
|
vtkVector2i Descent;
|
|
/**@}*/
|
|
};
|
|
|
|
vtkTypeMacro(vtkTextRenderer, vtkObject);
|
|
void PrintSelf(ostream& os, vtkIndent indent) override;
|
|
|
|
/**
|
|
* This is a singleton pattern New. There will be only ONE reference
|
|
* to a vtkTextRenderer subclass object per process. Clients that
|
|
* call this method must use Delete() on the object so that reference
|
|
* counting will work. The single instance will be unreferenced when
|
|
* the program exits. You should just use the static GetInstance() method
|
|
* anyway to get the singleton. This method may return NULL if the object
|
|
* factory cannot find an override.
|
|
*/
|
|
static vtkTextRenderer* New();
|
|
|
|
/**
|
|
* Return the singleton instance with no reference counting. May return NULL
|
|
* if the object factory cannot find an override.
|
|
*/
|
|
static vtkTextRenderer* GetInstance();
|
|
|
|
/**
|
|
* Available backends. FreeType and MathText are provided in the default
|
|
* implementation of this interface. Enum values less than 16 are reserved.
|
|
* Custom overrides should define other backends starting at 16.
|
|
*/
|
|
enum Backend
|
|
{
|
|
Default = -1,
|
|
Detect = 0,
|
|
FreeType,
|
|
MathText,
|
|
|
|
UserBackend = 16
|
|
};
|
|
|
|
///@{
|
|
/**
|
|
* The backend to use when none is specified. Default: Detect
|
|
*/
|
|
vtkSetMacro(DefaultBackend, int);
|
|
vtkGetMacro(DefaultBackend, int);
|
|
///@}
|
|
|
|
///@{
|
|
/**
|
|
* Determine the appropriate back end needed to render the given string.
|
|
*/
|
|
virtual int DetectBackend(const vtkStdString& str);
|
|
///@}
|
|
|
|
/**
|
|
* Test for availability of various backends
|
|
*/
|
|
virtual bool FreeTypeIsSupported() { return false; }
|
|
virtual bool MathTextIsSupported() { return false; }
|
|
|
|
///@{
|
|
/**
|
|
* Given a text property and a string, get the bounding box {xmin, xmax,
|
|
* ymin, ymax} of the rendered string in pixels. The origin of the bounding
|
|
* box is the anchor point described by the horizontal and vertical
|
|
* justification text property variables.
|
|
* Return true on success, false otherwise.
|
|
*/
|
|
bool GetBoundingBox(
|
|
vtkTextProperty* tprop, const vtkStdString& str, int bbox[4], int dpi, int backend = Default)
|
|
{
|
|
return this->GetBoundingBoxInternal(tprop, str, bbox, dpi, backend);
|
|
}
|
|
///@}
|
|
|
|
///@{
|
|
/**
|
|
* Given a text property and a string, get some metrics for the rendered
|
|
* string.
|
|
* Return true on success, false otherwise.
|
|
*/
|
|
bool GetMetrics(vtkTextProperty* tprop, const vtkStdString& str, Metrics& metrics, int dpi,
|
|
int backend = Default)
|
|
{
|
|
return this->GetMetricsInternal(tprop, str, metrics, dpi, backend);
|
|
}
|
|
///@}
|
|
|
|
///@{
|
|
/**
|
|
* Given a text property and a string, this function initializes the
|
|
* vtkImageData *data and renders it in a vtkImageData.
|
|
* Return true on success, false otherwise. If using the overload that
|
|
* specifies "textDims", the array will be overwritten with the pixel width
|
|
* and height defining a tight bounding box around the text in the image,
|
|
* starting from the upper-right corner. This is used when rendering for a
|
|
* texture on graphics hardware that requires texture image dimensions to be
|
|
* a power of two; textDims can be used to determine the texture coordinates
|
|
* needed to cleanly fit the text on the target.
|
|
* The origin of the image's extents is aligned with the anchor point
|
|
* described by the text property's vertical and horizontal justification
|
|
* options.
|
|
*/
|
|
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);
|
|
}
|
|
///@}
|
|
|
|
///@{
|
|
/**
|
|
* This function returns the font size (in points) and sets the size in @a
|
|
* tprop that is required to fit the string in the target rectangle. The
|
|
* computed font size will be set in @a tprop as well. If an error occurs,
|
|
* this function will return -1.
|
|
*/
|
|
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);
|
|
}
|
|
///@}
|
|
|
|
///@{
|
|
/**
|
|
* Given a text property and a string, this function populates the vtkPath
|
|
* path with the outline of the rendered string. The origin of the path
|
|
* coordinates is aligned with the anchor point described by the text
|
|
* property's horizontal and vertical justification options.
|
|
* Return true on success, false otherwise.
|
|
*/
|
|
bool StringToPath(
|
|
vtkTextProperty* tprop, const vtkStdString& str, vtkPath* path, int dpi, int backend = Default)
|
|
{
|
|
return this->StringToPathInternal(tprop, str, path, dpi, backend);
|
|
}
|
|
///@}
|
|
|
|
/**
|
|
* Set to true if the graphics implementation requires texture image dimensions
|
|
* to be a power of two. Default is true, but this member will be set
|
|
* appropriately by vtkOpenGLRenderWindow::OpenGLInitContext when GL is
|
|
* inited.
|
|
*/
|
|
void SetScaleToPowerOfTwo(bool scale) { this->SetScaleToPowerOfTwoInternal(scale); }
|
|
|
|
friend class vtkTextRendererCleanup;
|
|
|
|
protected:
|
|
vtkTextRenderer();
|
|
~vtkTextRenderer() override;
|
|
|
|
///@{
|
|
/**
|
|
* Virtual methods for concrete implementations of the public methods.
|
|
*/
|
|
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;
|
|
///@}
|
|
|
|
/**
|
|
* Set the singleton instance. Call Delete() on the supplied
|
|
* instance after setting it to fix the reference count.
|
|
*/
|
|
static void SetInstance(vtkTextRenderer* instance);
|
|
|
|
///@{
|
|
/**
|
|
* The singleton instance and the singleton cleanup instance.
|
|
*/
|
|
static vtkTextRenderer* Instance;
|
|
static vtkTextRendererCleanup Cleanup;
|
|
///@}
|
|
|
|
vtksys::RegularExpression* MathTextRegExp;
|
|
vtksys::RegularExpression* MathTextRegExp2;
|
|
vtksys::RegularExpression* MathTextRegExpColumn;
|
|
|
|
///@{
|
|
/**
|
|
* Replace all instances of "\$" with "$".
|
|
*/
|
|
virtual void CleanUpFreeTypeEscapes(vtkStdString& str);
|
|
///@}
|
|
|
|
/**
|
|
* The backend to use when none is specified. Default: Detect
|
|
*/
|
|
int DefaultBackend;
|
|
|
|
private:
|
|
vtkTextRenderer(const vtkTextRenderer&) = delete;
|
|
void operator=(const vtkTextRenderer&) = delete;
|
|
};
|
|
|
|
#endif // vtkTextRenderer_h
|