bWidgets::bwPaintEngine Class Reference

Main interface to implement any drawing of geometry or text. More...

#include <bwPaintEngine.h>

Public Member Functions
virtual	~bwPaintEngine ()=default
virtual void	setupViewport (const bwRectanglePixel &rect, const class bwColor &clear_color)=0
virtual void	enableMask (const bwRectanglePixel &rect)=0
virtual void	drawPolygon (const class bwPainter &painter, const class bwPolygon &polygon)=0
virtual void	drawText (const class bwPainter &painter, const std::string &text, const bwRectanglePixel &rect, const TextAlignment alignment)=0
virtual void	drawIcon (const class bwPainter &painter, const class bwIconInterface &icon_interface, const bwRectanglePixel &rect)=0

Detailed Description

Main interface to implement any drawing of geometry or text.

bwPaintEngine mainly gives us two benefits:

• Abstracting away any drawing to the application, out of bWidgets.
• Support multiple drawing backends (e.g. OpenGL and Vulcan).

Having support for multiple drawing backends is not only useful for supporting multiple graphics libraries (as in OpenGL, DirectX, Vulcan, etc.), but also to draw on different mediums. E.g. for drawing into textures or exporting as HTML & CSS code.

Creating a paint-engine is done by subclassing this class and implementing the abstract functions.

Note

Even though the name may suggest this is the equivalent to Qt's QPaintEngine, this is more of a combination of both, QPaintEngine and QPaintDevice.

Constructor & Destructor Documentation

~bwPaintEngine()

virtual bWidgets::bwPaintEngine::~bwPaintEngine ( )

virtualdefault

Member Function Documentation

drawIcon()

virtual void bWidgets::bwPaintEngine::drawIcon ( const class bwPainter &  painter, const class bwIconInterface &  icon_interface, const bwRectanglePixel &  rect  )

pure virtual

Draw the icon referenced by icon_interface.

Parameters

painter	Provides all aditional information needed for drawing (e.g. color for theme controlled monochrome icons etc.).
rect	The bounding-box to draw the icon into.

drawPolygon()

virtual void bWidgets::bwPaintEngine::drawPolygon ( const class bwPainter &  painter, const class bwPolygon &  polygon  )

pure virtual

The main polygon draw function which is used to draw all geometry of widgets.

Parameters

painter

Provides all aditional information needed for drawing (color, draw-style, etc.).

drawText()

virtual void bWidgets::bwPaintEngine::drawText ( const class bwPainter &  painter, const std::string &  text, const bwRectanglePixel &  rect, const TextAlignment  alignment  )

pure virtual

The main text draw function which is used to draw all text of widgets.

Parameters

painter	Provides all aditional information needed for drawing (color, draw-style, etc.).
rect	The bounding-box to draw the text into.

enableMask()

virtual void bWidgets::bwPaintEngine::enableMask ( const bwRectanglePixel &  rect )

pure virtual

setupViewport()

virtual void bWidgets::bwPaintEngine::setupViewport ( const bwRectanglePixel &  rect, const class bwColor &  clear_color  )

pure virtual

Setup function for application to prepare viewport (prepare matrices, clear background, etc.) for drawing.

Note

bWidgets doesn't call this itself, this is just a utility for the application to use.

Parameters

rect	The rectangle defining the viewport location and size.
clear_color	Color to be used for buffer clearing.

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The documentation for this class was generated from the following file:

• bwidgets/bwPaintEngine.h