ASPiK SDK
VSTGUI::COffscreenContext Class Reference

A draw context using a bitmap as it's back buffer. More...

#include <coffscreencontext.h>

Inheritance diagram for VSTGUI::COffscreenContext:
VSTGUI::CDrawContext VSTGUI::ReferenceCounted< T > VSTGUI::IReference VSTGUI::Cairo::Context

Public Member Functions

CBitmapgetBitmap () const
 
COffscreenContext Methods
void copyFrom (CDrawContext *pContext, CRect destRect, CPoint srcOffset=CPoint(0, 0))
 copy from offscreen to pContext
 
CCoord getWidth () const
 
CCoord getHeight () const
 
- Public Member Functions inherited from VSTGUI::CDrawContext
virtual void beginDraw ()
 
virtual void endDraw ()
 
virtual void setLineStyle (const CLineStyle &style)
 set the current line style
 
const CLineStylegetLineStyle () const
 get the current line style
 
virtual void setLineWidth (CCoord width)
 set the current line width
 
CCoord getLineWidth () const
 get the current line width
 
virtual void setDrawMode (CDrawMode mode)
 set the current draw mode, see CDrawMode
 
CDrawMode getDrawMode () const
 get the current draw mode, see CDrawMode
 
virtual void setClipRect (const CRect &clip)
 set the current clip
 
CRectgetClipRect (CRect &clip) const
 get the current clip
 
virtual void resetClipRect ()
 reset the clip to the default state
 
virtual void setFillColor (const CColor &color)
 set current fill color
 
CColor getFillColor () const
 get current fill color
 
virtual void setFrameColor (const CColor &color)
 set current stroke color
 
CColor getFrameColor () const
 get current stroke color
 
virtual void setFontColor (const CColor &color)
 set current font color
 
CColor getFontColor () const
 get current font color
 
virtual void setFont (const CFontRef font, const CCoord &size=0, const int32_t &style=-1)
 set current font
 
const CFontRef getFont () const
 get current font
 
CCoord getStringWidth (UTF8StringPtr pStr)
 get the width of an UTF-8 encoded string
 
void drawString (UTF8StringPtr string, const CRect &_rect, const CHoriTxtAlign hAlign=kCenterText, bool antialias=true)
 draw an UTF-8 encoded string
 
void drawString (UTF8StringPtr string, const CPoint &_point, bool antialias=true)
 draw an UTF-8 encoded string
 
CCoord getStringWidth (IPlatformString *pStr)
 get the width of a platform string
 
void drawString (IPlatformString *string, const CRect &_rect, const CHoriTxtAlign hAlign=kCenterText, bool antialias=true)
 draw a platform string
 
void drawString (IPlatformString *string, const CPoint &_point, bool antialias=true)
 draw a platform string
 
virtual void setGlobalAlpha (float newAlpha)
 sets the global alpha value[0..1]
 
float getGlobalAlpha () const
 get current global alpha value
 
virtual void saveGlobalState ()
 
virtual void restoreGlobalState ()
 
const CGraphicsTransformgetCurrentTransform () const
 
const CRectgetAbsoluteClipRect () const
 
virtual double getScaleFactor () const
 
CCoord getHairlineSize () const
 
void drawLine (const CPoint &start, const CPoint &end)
 
virtual void drawLine (const LinePair &line)=0
 draw a line
 
virtual void drawLines (const LineList &lines)=0
 draw multiple lines at once
 
virtual void drawPolygon (const PointList &polygonPointList, const CDrawStyle drawStyle=kDrawStroked)=0
 draw a polygon
 
virtual void drawRect (const CRect &rect, const CDrawStyle drawStyle=kDrawStroked)=0
 draw a rect
 
virtual void drawArc (const CRect &rect, const float startAngle1, const float endAngle2, const CDrawStyle drawStyle=kDrawStroked)=0
 draw an arc, angles are in degree
 
virtual void drawEllipse (const CRect &rect, const CDrawStyle drawStyle=kDrawStroked)=0
 draw an ellipse
 
virtual void drawPoint (const CPoint &point, const CColor &color)=0
 draw a point
 
virtual void drawBitmap (CBitmap *bitmap, const CRect &dest, const CPoint &offset=CPoint(0, 0), float alpha=1.f)=0
 don't call directly, please use CBitmap::draw instead
 
virtual void drawBitmapNinePartTiled (CBitmap *bitmap, const CRect &dest, const CNinePartTiledDescription &desc, float alpha=1.f)
 
virtual void fillRectWithBitmap (CBitmap *bitmap, const CRect &srcRect, const CRect &dstRect, float alpha)
 
virtual void clearRect (const CRect &rect)=0
 clears the rect (makes r = 0, g = 0, b = 0, a = 0)
 
virtual CGraphicsPathcreateGraphicsPath ()=0
 create a graphics path object, you need to forget it after usage
 
virtual CGraphicsPathcreateTextPath (const CFontRef font, UTF8StringPtr text)=0
 create a graphics path from a text
 
CGraphicsPathcreateRoundRectGraphicsPath (const CRect &size, CCoord radius)
 create a rect with round corners as graphics path, you need to forget it after usage
 
virtual void drawGraphicsPath (CGraphicsPath *path, PathDrawMode mode=kPathFilled, CGraphicsTransform *transformation=nullptr)=0
 
virtual void fillLinearGradient (CGraphicsPath *path, const CGradient &gradient, const CPoint &startPoint, const CPoint &endPoint, bool evenOdd=false, CGraphicsTransform *transformation=nullptr)=0
 
virtual void fillRadialGradient (CGraphicsPath *path, const CGradient &gradient, const CPoint &center, CCoord radius, const CPoint &originOffset=CPoint(0, 0), bool evenOdd=false, CGraphicsTransform *transformation=nullptr)=0
 
- Public Member Functions inherited from VSTGUI::ReferenceCounted< T >
 ReferenceCounted (const ReferenceCounted &)
 
ReferenceCountedoperator= (const ReferenceCounted &)
 
void forget () override
 decrease refcount and delete object if refcount == 0
 
void remember () override
 increase refcount
 
virtual int32_t getNbReference () const
 get refcount
 
virtual void beforeDelete ()
 

Static Public Member Functions

static SharedPointer< COffscreenContextcreate (CFrame *frame, CCoord width, CCoord height, double scaleFactor=1.)
 

Protected Member Functions

 COffscreenContext (CBitmap *bitmap)
 
 COffscreenContext (const CRect &surfaceRect)
 
- Protected Member Functions inherited from VSTGUI::CDrawContext
 CDrawContext (const CRect &surfaceRect)
 
virtual void init ()
 
void pushTransform (const CGraphicsTransform &transformation)
 
void popTransform ()
 
const UTF8StringgetDrawString (UTF8StringPtr string)
 
void clearDrawString ()
 

Protected Attributes

SharedPointer< CBitmapbitmap
 
- Protected Attributes inherited from VSTGUI::CDrawContext
UTF8StringdrawStringHelper
 
CRect surfaceRect
 
CDrawContextState currentState
 

Additional Inherited Members

- Public Types inherited from VSTGUI::CDrawContext
using LinePair = std::pair< CPoint, CPoint >
 
using LineList = std::vector< LinePair >
 
using PointList = std::vector< CPoint >
 
enum  PathDrawMode { kPathFilled, kPathFilledEvenOdd, kPathStroked }
 

Detailed Description

A draw context using a bitmap as it's back buffer.

There are two usage scenarios :

Drawing into a bitmap and then push the contents into another draw context

if (auto offscreen = COffscreenContext::create (frame, 100, 100))
{
offscreen->beginDraw ();
// ...
// draw into offscreen
// ...
offscreen->endDraw ();
offscreen->copyFrom (otherContext, destRect);
}

Drawing static content into a bitmap and reuse the bitmap for drawing

if (cachedBitmap == 0)
{
if (auto offscreen = COffscreenContext::create (frame, 100, 100))
{
offscreen->beginDraw ();
// ...
// draw into offscreen
// ...
offscreen->endDraw ();
cachedBitmap = offscreen->getBitmap ();
if (cachedBitmap)
cachedBitmap->remember ();
}
}
if (cachedBitmap)
{
// ...
}

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