VCF::GraphicsContext Class Reference

A GraphicsContext provides the lowest level graphics interface to the native systems 2D drawing operations. More...

#include <vcf/GraphicsKit/GraphicsContext.h>

Inheritance diagram for VCF::GraphicsContext:


Public Types
typedef std::vector< GraphicsState * >	GraphicsStateCollection
typedef GraphicsStateCollection::iterator	GraphicsStateIterator
typedef GraphicsStateCollection::const_iterator	GraphicsStateConstIterator
enum	DrawingOperation { doStroke, doFill, doText, doImage }
	represents what kind of high level drawing operation we are performing. More...
enum	GraphicsDrawingState { gsNone = 0, gsAddingGraphicsOps, gsExecutingGraphicsOps }
enum	TextDrawingOptions { tdoNone = 0, tdoWordWrap = 1, tdoLeftAlign = 2, tdoCenterHorzAlign = 4, tdoRightAlign = 8, tdoBottomAlign = 16, tdoCenterVertAlign = 32, tdoTopAlign = 64 }
	text drawing options More...
enum	EdgeType { etNoSides = 0x000, etLeftSide = 0x001, etRightSide = 0x002, etTopSide = 0x004, etBottomSide = 0x008, etAllSides = 0x00F, etRecessed = 0x010, etEtched = 0x020, etRaised = 0x030, etSunken = 0x040 }
enum	ThemeTextType { ttMenuItemFont = 0, ttSelectedMenuItemFont, ttSystemFont, ttSystemSmallFont, ttControlFont, ttMessageFont, ttToolTipFont }
enum	CompositingMode { cmNone = 0xFF, cmClear = 0, cmSource, cmDestination, cmSrcOver, cmDestOver, cmSrcIn, cmDestIn, cmSrcOut, cmDestOut, cmSrcATop, cmDestATop, cmXOR, cmPlus, cmMinus, cmMultiply, cmScreen, cmOverlay, cmDarken, cmLighten, cmColorDodge, cmColorBurn, cmHardLight, cmSoftLight, cmExclusion, cmDifference, cmContrast, cmCustom }
	These are the set of standard compositing or "blend" modes that the GraphicsContext supports. More...
enum	LineCapStyle { lcsButtCap = 0, lcsRoundCap, lcsSquareCap }
	The set of enum values define the standard line cap style. More...
enum	LineJoinStyle { ljsMiterJoin = 0, ljsRoundJoin, ljsBevelJoin }
	The set of enum values for defining the line join style. More...
enum	RenderAreaAlphaState { rasDefault = 0, rasNonDefaultAlphaVals, rasDirty }
	Describes the state of the alpha channel. More...
Public Member Functions
	GraphicsContext ()
	GraphicsContext (const uint32 &width, const uint32 &height)
	Creates a new blank graphics context of the specified width and height.
	GraphicsContext (OSHandleID contextID)
	Create a new context based on a context ID.
virtual	~GraphicsContext ()
void	init ()
	This is going to be removed from the bext release.
ContextPeer *	getPeer ()
bool	isAntiAliasingOn ()
void	setAntiAliasingOn (bool antiAliasingOn)
void	setCurrentFont (Font *font)
	sets the current font A copy of the Font is made when this is set
void	setCurrentFont (const Font *font)
	sets the current font A copy of the Font is made when this is set
Font *	getCurrentFont ()
	returns the current Font
void	setCurrentFill (Fill *fill)
	sets the current fill
void	setCurrentStroke (Stroke *stroke)
	sets the current stroke
void	setClippingRect (Rect *rect)
void	setClippingPath (Path *clippingPath)
Rect	getClippingRect ()
Path *	getClippingPath ()
Rect	getViewableBounds ()
void	setViewableBounds (const Rect &bounds)
void	setRenderArea (Rect bounds)
	This method sets the image bounds for the drawing area image.
void	deleteRenderArea ()
	This deletes the drawing area, and frees any resources associated with it.
void	flushRenderArea ()
	Draws the drawing area image on to the graphics context.
void	cacheRenderAreaAlpha ()
void	resetRenderAreaAlpha ()
bool	hasRenderArea ()
void	renderAreaAlphaOverwritten ()
void	setRenderAreaAlphaSize (bool usingNonDefaultAlpha)
Image *	getRenderArea ()
agg::rendering_buffer *	getRenderingBuffer ()
void	setRenderingBuffer (agg::rendering_buffer *buffer)
agg::scanline_u8 &	internal_getRenderAreaScanline ()
int	saveState ()
	saves the state of a Graphics context after the paint operations are done.
void	restoreState (int state)
	Restores the state of a Graphics context after the paint operations are done.
LineCapStyle	getLineCapStyle ()
	Returns the current line cap style.
void	setLineCapStyle (LineCapStyle val)
	Sets the line cap style.
LineJoinStyle	getLineJoinStyle ()
void	setLineJoinStyle (LineJoinStyle val)
double	getMiterLimit ()
	Returns the current miter limit.
void	setMiterLimit (double val)
	Sets the current miter limit.
void	setCompositingMode (CompositingMode compositeMode)
	Sets the current compositing mode.
CompositingMode	getCompositingMode ()
	Returns the current composite mode.
void	setColor (Color *color)
	Sets the current color of the graphics context to use for filling or stroking paths.
void	setColor (const Color *color)
	Sets the current color of the graphics context to use for filling or stroking paths.
Color *	getColor ()
Image *	getAlphaMask ()
void	setAlphaMask (Image *alphaMask)
void	setOrigin (const double &x, const double &y)
	Sets the context's origin for drawing.
void	setOrigin (const Point &pt)
Point	getOrigin ()
void	setRotation (const double &theta)
	sets the current rotation value of the transformation matrix.
void	setTranslation (const double transX, const double &transY)
	Set the x and y translation values for the transformation matrix.
void	setShear (const double &shearX, const double &shearY)
	Sets the x and y shear values, in degrees, for the transformation matrix.
void	setScale (const double &scaleX, const double &scaleY)
	Sets the x and y scale values for the transformation matrix.
void	concatRotation (const double &theta)
void	concatTranslation (const double transX, const double &transY)
void	concatShear (const double &shearX, const double &shearY)
void	concatScale (const double &scaleX, const double &scaleY)
bool	isDefaultTransform ()
	This test to see if the current rotation translation, scale, and shear values are all at their default values.
void	makeDefaultTransform ()
	This (re)sets the current values for rotation, shear, scale, and translation to their default values.
double	getRotation ()
double	getTranslationX ()
double	getTranslationY ()
double	getShearX ()
double	getShearY ()
double	getScaleX ()
double	getScaleY ()
bool	isXORModeOn ()
void	setXORModeOn (const bool &XORModeOn)
void	setAlpha (const double &alpha)
double	getAlpha ()
void	copyContext (const Rect &sourceRect, const Rect &destRect, GraphicsContext *context)
void	fillPath ()
void	strokePath ()
void	draw (Path *path)
	draws a path.
void	drawImage (const double &x, const double &y, Image *image, const bool &renderImmediately=true)
	draws an image at the x,y, coordinates
void	drawImage (const Point &pt, Image *image, const bool &renderImmediately=true)
void	bitBlit (const double &x, const double &y, Image *image)
	"Blits" the image to the underlying graphics context.
void	bitBlit (const Point &pt, Image *image)
void	bitBlit (const double &x, const double &y, Rect imageBounds, Image image)
void	bitBlit (const Point &pt, Rect imageBounds, Image image)
void	drawImageWithState (const double &x, const double &y, Image *image, const bool &enabled, const bool &renderImmediately=true)
	draws an image at the x,y, coordinates, with state
void	drawImageWithState (const Point &pt, Image *image, const bool &enabled, const bool &renderImmediately=true)
void	drawImageWithinBounds (Rect bounds, Image image, const bool &renderImmediately=true)
	draws a portion of the image.
void	drawPartialImage (const double &x, const double &y, Rect imageBounds, Image image, const bool &renderImmediately=true)
	draws a partial image at the x,y, coordinates specified
void	drawPartialImage (const Point &pt, Rect imageBounds, Image image, const bool &renderImmediately=true)
void	renderImages (bool freeImages=true)
void	setCurrentTransform (const Matrix2D &transform)
Matrix2D *	getCurrentTransform ()
void	setStrokeWidth (const double &width)
	End of high level gaphics functions.
double	getStrokeWidth ()
void	textAt (const double &x, const double &y, const String &text)
void	textAt (const Point &pt, const String &text)
void	textAt (const double &x, const double &y, const String &text, const int32 drawOptions)
void	textAt (const Point &pt, const String &text, const int32 drawOptions)
void	textWithStateAt (const double &x, const double &y, const String &text, const bool &enabled)
void	textWithStateAt (const Point &pt, const String &text, const bool &enabled)
void	textBoundedBy (Rect *bounds, const String &text, const bool &wordWrap=true)
	draws text within the bounds specified.
void	textBoundedBy (Rect *bounds, const String &text, const int32 drawOptions)
double	getTextWidth (const String &text)
double	getTextHeight (const String &text)
void	rectangle (const double &x1, const double &y1, const double &x2, const double &y2)
void	rectangle (const Rect &rc)
void	rectangle (const Point &pt1, const Point &pt2)
void	rectangle (Rect *r)
void	lineTo (const double &x, const double &y)
void	lineTo (const Point &pt)
void	moveTo (const double &x, const double &y)
void	moveTo (const Point &pt)
void	closePath (const double &x, const double &y)
void	closePath (const Point &pt)
void	roundRect (const double &x1, const double &y1, const double &x2, const double &y2, const double &xc, const double &yc)
void	roundRect (const Rect &rc, const Point &ptc)
void	roundRect (const Point &pt1, const Point &pt2, const Point &ptc)
void	roundRect (Rect r, Point p)
void	circle (const double &x, const double &y, const double &radius)
void	circle (const Point &pt, const double &radius)
void	ellipse (const double &x1, const double &y1, const double &x2, const double &y2)
void	ellipse (const Point &pt1, const Point &pt2)
void	arc (const double &centerX, const double &centerY, const double &radiusWidth, const double &radiusHeight, const double &startAngle, const double &endAngle)
void	arc (const Point &centerPt, const Size &radius, const double &startAngle, const double &endAngle)
void	pie (const double &x1, const double &y1, const double &x2, const double &y2, const double &x3, const double &y3, const double &x4, const double &y4)
void	pie (const Point &pt1, const Point &pt2, const Point &pt3, const Point &pt4)
void	chord (const double &x1, const double &y1, const double &x2, const double &y2, const double &x3, const double &y3, const double &x4, const double &y4)
void	chord (const Point &pt1, const Point &pt2, const Point &pt3, const Point &pt4)
void	polyline (const std::vector< Point > &pts)
void	curve (const double &x1, const double &y1, const double &x2, const double &y2, const double &x3, const double &y3, const double &x4, const double &y4)
void	curve (const Point &pt1, const Point &pt2, const Point &pt3, const Point &pt4)
void	drawThemeSelectionRect (Rect *rect, DrawUIState &state)
	The following functions are related to theme compliant drawing.
void	drawThemeFocusRect (Rect *rect, DrawUIState &state)
void	drawThemeButtonRect (Rect rect, ButtonState &state, Rect captionRect=NULL)
void	drawThemeButtonFocusRect (Rect *rect)
void	drawThemeCheckboxRect (Rect *rect, ButtonState &state)
void	drawThemeRadioButtonRect (Rect *rect, ButtonState &state)
void	drawThemeComboboxRect (Rect *rect, ButtonState &state)
void	drawThemeScrollButtonRect (Rect *rect, ScrollBarState &state)
void	drawThemeDisclosureButton (Rect *rect, DisclosureButtonState &state)
	Draws a button that is used to open up more details, for example the button that opens up a tree node to reveal it's children, that is compliant with the native windowing systems default look and feel.
void	drawThemeTab (Rect *rect, TabState &state)
	Draws a tab, the part of the TabbedPages control that acts like a little button to activate a page, that is compliant with the native windowing systems default look and feel.
void	drawThemeTabPage (Rect *rect, DrawUIState &state)
	Draws a tab page - the page on which other controls for the page are parented to, that is compliant with the native windowing systems default look and feel.
void	drawThemeTabContent (Rect *rect, DrawUIState &state)
void	drawThemeTabs (Rect *rect, DrawUIState &paneState, TabState &selectedTabState, TabState &otherTabs, const std::vector< String > &tabNames, int selectedTabIndex)
void	drawThemeTickMarks (Rect *rect, SliderState &state)
	Draws tick marks, like that used for a slider control, that is compliant with the native windowing systems default look and feel.
void	drawThemeSlider (Rect *rect, SliderState &state)
	Draws a slider control, like that used for a slider control, that is compliant with the native windowing systems default look and feel.
void	drawThemeProgress (Rect *rect, ProgressState &state)
	Draws a progress bar control, that is compliant with the native windowing systems default look and feel.
void	drawThemeImage (Rect rect, Image image, DrawUIState &state)
void	drawThemeHeader (Rect *rect, ButtonState &state)
	Draws a header control that is compliant with the native windowing systems default look and feel.
void	drawThemeEdge (Rect *rect, DrawUIState &state, const int32 &edgeSides, const int32 &edgeStyle)
	draws edges, useful for separators, that is compliant with the native windowing systems default look and feel.
void	drawThemeSizeGripper (Rect *rect, DrawUIState &state)
	Draws a size gripper for resizing a control/window that is compliant with the native windowing systems default look and feel.
void	drawThemeBackground (Rect *rect, BackgroundState &state)
	Draws a them compliant background.
void	drawThemeMenuItem (Rect *rect, MenuState &state)
	Draws the background appropriate for a menu item that is compliant with the native windowing systems default look and feel.
void	drawThemeMenuItemText (Rect *rect, MenuState &state)
	Draws the menu items text such that it's compliant with the native windowing platform look and feel.
void	drawThemeText (Rect *rect, TextState &state)
Protected Member Functions
void	buildArc (double centerX, double centerY, double radiusWidth, double radiusHeight, double startAngle, double endAngle, std::vector< Point > &pts, const Matrix2D &transform)
void	buildRoundRect (double x1, double y1, double x2, double y2, double cornerArcWidth, double cornerArcHeight, std::vector< Point > &pts, const Matrix2D &transform)
void	buildEllipse (double x1, double y1, double x2, double y2, std::vector< Point > &pts, const Matrix2D &transform)
void	checkPathOperations ()
void	execPathOperations ()
void	renderImage (agg::rendering_buffer &destBuffer, Rect &destRect, ImageOperation &imgOp)
Rect	getRenderDestRect ()
Rect	getTransformedImageRect (ImageOperation &imgOp)
Point	getTransformedImagePoint (ImageOperation &imgOp)
Protected Attributes
ContextPeer *	contextPeer_
GraphicsDrawingState	currentDrawingState_
std::vector< PointOperation >	pathOperations_
std::vector< ImageOperation >	imageOperations_
Rect	viewableBounds_
RenderArea *	renderArea_
GraphicsStateCollection	stateCollection_
	the collection of all the saved Graphics states.
int	graphicsStateIndex_
	the index of the current state in the collection of all the saved Graphics states.
GraphicsState *	currentGraphicsState_
	the current Graphics state that has been saved.
Classes
struct	ImageOperation
struct	PointOperation

Detailed Description

A GraphicsContext provides the lowest level graphics interface to the native systems 2D drawing operations.

Based loosely on PostScript, a Context takes a series of of drawing operations, or commands (lineTo, moveTo, etc), and then executes them by either filling or strokeing the path(s) that result from the commands. Thus calling ellipse() will not draw anything till the strokePath() or fillPath() methods have been called. All path commands should add their information to a stack of some sort that is then looped through and executed using the appropriate native graphics calls. At each path command a test should be made as to whether the buffer should be cleared. The buffer should be cleared only after the stroke of fill methods have been called. For example:

    ellipse(23,23,45,67) //added to buffer
    moveTo(89,100) //add to buffer
    lineTo(300,40) //add to buffer
    strokePath()
    fillPath()
    rectangle(200,300,400,400)//buffer cleared, then add to buffer

Version:: 1.0

Author:: Jim Crafton

Member Typedef Documentation

typedef std::vector<GraphicsState*> VCF::GraphicsContext::GraphicsStateCollection

typedef GraphicsStateCollection::const_iterator VCF::GraphicsContext::GraphicsStateConstIterator

typedef GraphicsStateCollection::iterator VCF::GraphicsContext::GraphicsStateIterator

Member Enumeration Documentation

enum VCF::GraphicsContext::CompositingMode

These are the set of standard compositing or "blend" modes that the GraphicsContext supports.
The last mode, cmCustom, is for future use, and will allow some custom compositing function to be used. The blend/compositing modes below are the same as used in AGG and in the PDF specification. [todo] We should have some little pictures of what each blend mode looks like... [/todo]
Enumerator:

cmNone

cmClear

cmSource

cmDestination

cmSrcOver

cmDestOver

cmSrcIn

cmDestIn

cmSrcOut

cmDestOut

cmSrcATop

cmDestATop

cmXOR

cmPlus

cmMinus

cmMultiply

cmScreen

cmOverlay

cmDarken

cmLighten

cmColorDodge

cmColorBurn

cmHardLight

cmSoftLight

cmExclusion

cmDifference

cmContrast

cmCustom

enum VCF::GraphicsContext::DrawingOperation

represents what kind of high level drawing operation we are performing.
We can stroke a path, fill a path, draw an image, or draw text. This is used by the ConextPeer's prepareForDrawing() so it know's how best to prepare the low level graphics resources. For example strokePath() would call the ConextPeer's prepareForDrawing() and pass in GraphicsContext::doStroke, indicating that any upcoming calls to moveTo, lineTo, rectangle, etc will be drawn using the attributes of the GraphicsContext's stroke.
Enumerator:

doStroke

doFill

doText

doImage

enum VCF::GraphicsContext::EdgeType

Enumerator:

etNoSides

etLeftSide

etRightSide

etTopSide

etBottomSide

etAllSides

etRecessed

etEtched

etRaised

etSunken

enum VCF::GraphicsContext::GraphicsDrawingState

Enumerator:

gsNone

gsAddingGraphicsOps

gsExecutingGraphicsOps

enum VCF::GraphicsContext::LineCapStyle

The set of enum values define the standard line cap style.
These are the same line cap styles that the PDF spec and Win32 uses.
Enumerator:

lcsButtCap

lcsRoundCap

lcsSquareCap

enum VCF::GraphicsContext::LineJoinStyle

The set of enum values for defining the line join style.
These values are the same as those found in the PDF spec and Win32.
Enumerator:

ljsMiterJoin

ljsRoundJoin

ljsBevelJoin

enum VCF::GraphicsContext::RenderAreaAlphaState

Describes the state of the alpha channel.
The state is used to check whether or not the render area's alpha values have been accidentally overwritten by native GDI calls. If they have, we can then reset them back to 255, which is the default value.
The default state is rasDefault, which means that all the render area's alpha values are at 0xFF (255).
When the graphics context's drawing routine's are called they may, depending on the platform, overwrite the render area's alpha values. If this happens then the state must be set to rasDirty, indicating that the graphics context needs to reset the alpha values back to the original state before any drawing gets done that depends on accurate alpha values being present in the render area's buffer.
If the alpha values of the render area have been modified by the programmer and need to be retained, then the default state should be changed from rasDefault to rasNonDefaultAlphaVals.
Enumerator:

rasDefault

rasNonDefaultAlphaVals

rasDirty

enum VCF::GraphicsContext::TextDrawingOptions

text drawing options

Enumerator:

tdoNone

tdoWordWrap

tdoLeftAlign

tdoCenterHorzAlign

tdoRightAlign

tdoBottomAlign

tdoCenterVertAlign

tdoTopAlign

enum VCF::GraphicsContext::ThemeTextType

Enumerator:

ttMenuItemFont

ttSelectedMenuItemFont

ttSystemFont

ttSystemSmallFont

ttControlFont

ttMessageFont

ttToolTipFont

Constructor & Destructor Documentation

VCF::GraphicsContext::GraphicsContext ( )

VCF::GraphicsContext::GraphicsContext ( const uint32 & width,

const uint32 & height

)

Creates a new blank graphics context of the specified width and height.

VCF::GraphicsContext::GraphicsContext ( OSHandleID contextID )

Create a new context based on a context ID.
See ContextPeer getContextID() Doing this should caryy over any of the current settings of the context that the contextID represents.

virtual VCF::GraphicsContext::~GraphicsContext ( ) [virtual]

Member Function Documentation

void VCF::GraphicsContext::arc ( const Point & centerPt,

const Size & radius,

const double & startAngle,

const double & endAngle

) [inline]

void VCF::GraphicsContext::arc ( const double & centerX,

const double & centerY,

const double & radiusWidth,

const double & radiusHeight,

const double & startAngle,

const double & endAngle

)

VCF::GraphicsContext Class Reference

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Classes

Detailed Description

Member Typedef Documentation

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation