VSTGUI  4.10
Graphical User Interface Framework not only for VST plugins
 All Classes Namespaces Functions Variables Typedefs Enumerations Enumerator Friends Groups Pages
COffscreenContext Class Reference

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

+ Inheritance diagram for COffscreenContext:

Public Member Functions

CBitmapgetBitmap () const
 
 COffscreenContext (const PlatformGraphicsDeviceContextPtr device, const CRect &surfaceRect, const PlatformBitmapPtr &platformBitmap)
 
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 CDrawContext
void beginDraw ()
 
void endDraw ()
 
const CRectgetSurfaceRect () const
 
 CDrawContext (const PlatformGraphicsDeviceContextPtr device, const CRect &surfaceRect, double scaleFactor)
 
 ~CDrawContext () noexceptoverride
 
const
PlatformGraphicsDeviceContextPtr
getPlatformDeviceContext () const
 
void setBitmapInterpolationQuality (BitmapInterpolationQuality quality)
 set the current bitmap interpolation quality
 
BitmapInterpolationQuality getBitmapInterpolationQuality () const
 get the current bitmap interpolation quality
 
void setLineStyle (const CLineStyle &style)
 set the current line style
 
const CLineStylegetLineStyle () const
 get the current line style
 
void setLineWidth (CCoord width)
 set the current line width
 
CCoord getLineWidth () const
 get the current line width
 
void setDrawMode (CDrawMode mode)
 set the current draw mode, see CDrawMode
 
CDrawMode getDrawMode () const
 get the current draw mode, see CDrawMode
 
void setClipRect (const CRect &clip)
 set the current clip
 
CRectgetClipRect (CRect &clip) const
 get the current clip
 
void resetClipRect ()
 reset the clip to the default state
 
void setFillColor (const CColor &color)
 set current fill color
 
CColor getFillColor () const
 get current fill color
 
void setFrameColor (const CColor &color)
 set current stroke color
 
CColor getFrameColor () const
 get current stroke color
 
void setFontColor (const CColor &color)
 set current font color
 
CColor getFontColor () const
 get current font color
 
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
 
void setGlobalAlpha (float newAlpha)
 sets the global alpha value[0..1]
 
float getGlobalAlpha () const
 get current global alpha value
 
void saveGlobalState ()
 
void restoreGlobalState ()
 
const CGraphicsTransformgetCurrentTransform () const
 
const CRectgetAbsoluteClipRect () const
 
double getScaleFactor () const
 returns the backend scale factor.
 
CCoord getHairlineSize () const
 returns the current line size which corresponds to one pixel on screen.
 
void drawLine (const CPoint &start, const CPoint &end)
 
void drawLine (const LinePair &line)
 draw a line
 
void drawLines (const LineList &lines)
 draw multiple lines at once
 
void drawPolygon (const PointList &polygonPointList, const CDrawStyle drawStyle=kDrawStroked)
 draw a polygon
 
void drawRect (const CRect &rect, const CDrawStyle drawStyle=kDrawStroked)
 draw a rect
 
void drawArc (const CRect &rect, const float startAngle1, const float endAngle2, const CDrawStyle drawStyle=kDrawStroked)
 draw an arc, angles are in degree
 
void drawEllipse (const CRect &rect, const CDrawStyle drawStyle=kDrawStroked)
 draw an ellipse
 
void drawPoint (const CPoint &point, const CColor &color)
 draw a point
 
void drawBitmap (CBitmap *bitmap, const CRect &dest, const CPoint &offset=CPoint(0, 0), float alpha=1.f)
 don't call directly, please use CBitmap::draw instead
 
void drawBitmapNinePartTiled (CBitmap *bitmap, const CRect &dest, const CNinePartTiledDescription &desc, float alpha=1.f)
 
void fillRectWithBitmap (CBitmap *bitmap, const CRect &srcRect, const CRect &dstRect, float alpha)
 
void clearRect (const CRect &rect)
 clears the rect (makes r = 0, g = 0, b = 0, a = 0)
 
CGraphicsPathcreateGraphicsPath ()
 create a graphics path object, you need to forget it after usage
 
CGraphicsPathcreateTextPath (const CFontRef font, UTF8StringPtr text)
 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
 
void drawGraphicsPath (CGraphicsPath *path, PathDrawMode mode=kPathFilled, CGraphicsTransform *transformation=nullptr)
 
void fillLinearGradient (CGraphicsPath *path, const CGradient &gradient, const CPoint &startPoint, const CPoint &endPoint, bool evenOdd=false, CGraphicsTransform *transformation=nullptr)
 
void fillRadialGradient (CGraphicsPath *path, const CGradient &gradient, const CPoint &center, CCoord radius, const CPoint &originOffset=CPoint(0, 0), bool evenOdd=false, CGraphicsTransform *transformation=nullptr)
 
- Public Member Functions inherited from ReferenceCounted< T >
 ReferenceCounted ()=default
 
virtual ~ReferenceCounted () noexcept=default
 
 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
 

Static Public Member Functions

static SharedPointer
< COffscreenContext
create (const CPoint &size, double scaleFactor=1.)
 
static SharedPointer
< COffscreenContext
create (CFrame *frame, CCoord width, CCoord height, double scaleFactor=1.)
 

Protected Member Functions

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

Protected Attributes

SharedPointer< CBitmapbitmap
 

Additional Inherited Members

- Public Types inherited from CDrawContext
using LinePair = VSTGUI::LinePair
 
using LineList = VSTGUI::LineList
 
using PointList = VSTGUI::PointList
 
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)
{
// ...
}

Constructor & Destructor Documentation

COffscreenContext ( const PlatformGraphicsDeviceContextPtr  device,
const CRect surfaceRect,
const PlatformBitmapPtr platformBitmap 
)
COffscreenContext ( CBitmap bitmap)
explicitprotected
COffscreenContext ( const CRect surfaceRect)
explicitprotected

Member Function Documentation

void copyFrom ( CDrawContext pContext,
CRect  destRect,
CPoint  srcOffset = CPoint (0, 0) 
)

copy from offscreen to pContext

SharedPointer< COffscreenContext > create ( const CPoint size,
double  scaleFactor = 1. 
)
static
SharedPointer< COffscreenContext > create ( CFrame frame,
CCoord  width,
CCoord  height,
double  scaleFactor = 1. 
)
static
CBitmap* getBitmap ( ) const
inline
CCoord getHeight ( ) const
CCoord getWidth ( ) const

Member Data Documentation

SharedPointer<CBitmap> bitmap
protected

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