Drawing context abstraction. More...

#include <drawer2d.h>

Inheritance diagram for a2dDrawer2D:

Collaboration diagram for a2dDrawer2D:

Public Member Functions
	a2dDrawer2D (int width=0, int height=0)
	constructor More...

	a2dDrawer2D (const wxSize &size)
	constructor More...

	a2dDrawer2D (const a2dDrawer2D &other)
	copy constructor

virtual	~a2dDrawer2D ()
	destructor

void	SetDisplay (wxWindow *window)
	the display

void	SetPrimitiveThreshold (wxUint16 pixels, bool asrect=true)
	set at what size to stop drawing

wxUint16	GetPrimitiveThreshold () const
	get drawing threshold More...

bool	GetThresholdDrawRectangle () const
	underneath the threshold draw a rectangle instead of the real object.

void	SetPolygonFillThreshold (wxUint16 pixels)
	set threshold at which polygon is drawn filled or only outline

wxUint16	GetPolygonFillThreshold () const
	get threshold at which polygon is drawn filled or only outline

virtual wxDC *	GetRenderDC () const
	get the DC that is used for rendering

virtual wxDC *	GetDeviceDC () const
	get the DC that is used for rendering

void	SetDisplayAberration (double aber)
	Set the display aberration of curved shapes. More...

double	GetDisplayAberration () const
	Returns the display aberration of curved shapes. More...

virtual wxBitmap	GetBuffer () const =0
	Return the buffer as a bitmap.

virtual void	SetBufferSize (int w, int h)=0
	Change the buffer size. More...

virtual void	CopyIntoBuffer (const wxBitmap &bitm)

void	BlitBuffer ()
	blit whole buffer to device

void	BlitBuffer (int x, int y, int width, int height, int xbuf=0, int ybuf=0)
	blit given rect contents within buffer to device

virtual void	BlitBuffer (wxRect rect, const wxPoint &bufferpos=wxPoint(0, 0))=0
	blit given rect contents within buffer to device

virtual void	BlitBuffer (wxDC *dc, wxRect rect, const wxPoint &bufferpos=wxPoint(0, 0))=0
	used for blitting to a wxDC.

virtual void	ShiftBuffer (int dxy, bool yshift)
	quick scroll over small distance

virtual wxBitmap	GetSubBitmap (wxRect sub_rect) const =0
	A way to get parts form the buffer that is drawn into. More...

bool	GetYaxis () const
	get y axis orientation

virtual void	SetYaxis (bool up)
	set if the Yaxis goes up or down

void	SetMappingDeviceRect (int mapx, int mapy, int mapWidth, int mapHeight, bool remap=false)
	to change the default mapping (to the complete buffer). More...

virtual void	SetMappingWidthHeight (double vx1, double vy1, double width, double height)
	Give the virtual size to be displayed, the mapping matrix will be calculated. More...

void	SetMappingWidthHeight (const a2dBoundingBox &box)
	Give the virtual size to be displayed, the mapping matrix will be calculated. More...

void	SetMappingUpp (double vx1, double vy1, double xpp, double ypp)
	Give the virtual size to be displayed, the mapping matrix will be calculated. More...

double	GetUppX () const
	return xpp Number of user units per pixel in x

double	GetUppY () const
	return ypp Number of user units per pixel in y

void	SetMinX (double x)
	Set Minimal X of the visible part in world coordinates.

void	SetMinY (double y)
	Set Minimal Y of the visible part in world coordinates.

void	SetUppX (double x)
	set world units per pixel in X

void	SetUppY (double y)
	set world units per pixel in Y

bool	GetVirtualAreaSet () const
	if the virtual area has been set already return true else false. More...

void	StartRefreshDisplayDisable ()
	when called a mapping change will result not result in a refresh of the m_display. More...

void	EndRefreshDisplayDisable ()
	see StartRefreshDisplayDisable()

bool	GetRefreshDisplayDisable () const
	see StartRefreshDisplayDisable()

int	GetWidth () const
	get buffer/device width

int	GetHeight () const
	get buffer/device height

int	GetMapWidth () const
	get mapping to device width

int	GetMapHeight () const
	get mapping to device height

int	GetMapX () const
	X mapping position in device coordinates.

int	GetMapY () const
	Y mapping position in device coordinates.

double	GetVisibleMinX () const
	get Minimal X of the visible part in world coordinates

double	GetVisibleMinY () const
	get Minimal X of the visible part in world coordinates

virtual double	GetVisibleMaxX () const
	get Maximum X of the visible part in world coordinates

virtual double	GetVisibleMaxY () const
	get Maximum Y of the visible part in world coordinates

virtual double	GetVisibleWidth () const
	get Width of visible part in world coordinates

virtual double	GetVisibleHeight () const
	get Height of visible part in world coordinates

a2dBoundingBox	GetVisibleBbox () const
	get visible area as a boundingbox in world coordinates

wxRect	ToDevice (const a2dBoundingBox &bbox)
	convert the bounding box in world coordinates to device coordinates and return that rectangle.

a2dBoundingBox	ToWorld (const wxRect &rect)
	convert the rect in device coordinates to a bounding box in world coordinates and return that boundingbox.

double	DeviceToWorldX (double x) const
	convert x from device to world coordinates

double	DeviceToWorldY (double y) const
	convert y from device to world coordinates

double	DeviceToWorldXRel (double x) const
	convert x relative from device to world coordinates More...

double	DeviceToWorldYRel (double y) const
	convert y relative from device to world coordinates More...

int	WorldToDeviceX (double x) const
	convert x from world to device coordinates

int	WorldToDeviceY (double y) const
	convert y from world to device coordinates

int	WorldToDeviceXRel (double x) const
	convert x relative from world to device coordinates More...

int	WorldToDeviceYRel (double y) const
	convert y relative from world to device coordinates More...

double	WorldToDeviceXRelNoRnd (double x) const
	convert x relative from world to device coordinates (result not rounded to integer) More...

double	WorldToDeviceYRelNoRnd (double y) const
	convert y relative from world to device coordinates (result not rounded to integer) More...

const a2dAffineMatrix &	GetMappingMatrix ()
	get the world-to-device (aka mapping) matrix

void	SetMappingMatrix (const a2dAffineMatrix &mapping)

virtual void	SetTransform (const a2dAffineMatrix &userToWorld)
	set user-to-world transform matrix. More...

const a2dAffineMatrix &	GetTransform () const
	get the user-to-world transform matrix. More...

const a2dAffineMatrix &	GetUserToDeviceTransform () const
	get matrix which transforms directly from user coordinates to device

virtual void	PushTransform ()
	Save the current user-to-world transform on the affine stack.

virtual void	PushIdentityTransform ()
	push no transform, to draw directly in device coordinates

virtual void	PushTransform (const a2dAffineMatrix &affine)
	Save the current transform on the affine stack and then multiply it by the given affine. More...

virtual void	PopTransform (void)
	Recall the previously saved user-to-world transform off the matrix stack.

void	SetSplineAberration (double aber)
	Set the detail level for spline drawing. More...

virtual void	ResetStyle ()
	set a pre-defined style reseting cashed values. More...

void	SetDrawerStroke (const a2dStroke &stroke)
	Used to set the current stroke. More...

a2dStroke	GetDrawerStroke () const
	get the current stroke

void	SetDrawerFill (const a2dFill &fill)
	Used to set the current fill. More...

a2dFill	GetDrawerFill () const
	get the current fill

void	SetFont (const a2dFont &font)
	set font to use for drawing text

a2dFont	GetFont () const
	get font used for drawing text

void	SetNormalizedFont (bool forceNormalizedFont)
	Use a fixed device height for drawing text.

bool	GetNormalizedFont ()
	Get setting for a fixed device height for drawing text.

void	SetSmallTextThreshold (wxUint16 pixels)

wxUint16	GetSmallTextThreshold () const
	See SetSmallTextThreshold.

virtual void	DrawVpath (const a2dVpath *path)
	Draw vector path in world coordinates.

virtual void	DrawPolyPolygon (a2dListOfa2dVertexList polylist, wxPolygonFillMode fillStyle=wxODDEVEN_RULE)
	draw a list of polygons ( contour clockwise becomes hole )

virtual void	DrawPolygon (a2dVertexArray *points, bool spline=false, wxPolygonFillMode fillStyle=wxODDEVEN_RULE)
	Draw polygon in world coordinates using pointarray.

virtual void	DrawPolygon (const a2dVertexList *list, bool spline=false, wxPolygonFillMode fillStyle=wxODDEVEN_RULE)
	Draw polygon in world coordinates using pointlist.

virtual void	DrawLines (a2dVertexArray *points, bool spline=false)
	Draw polyline in world coordinates using pointarray.

virtual void	DrawLines (const a2dVertexList *list, bool spline=false)
	Draw polyline in world coordinates using pointlist.

virtual void	DrawLine (double x1, double y1, double x2, double y2)
	Draw line in world coordinates.

virtual void	DrawArc (double x1, double y1, double x2, double y2, double xc, double yc, bool chord)
	Draw Arc in world coordinates.

virtual void	DrawEllipticArc (double xc, double yc, double width, double height, double sa, double ea, bool chord)
	Draw Elliptic Arc in world coordinates.

virtual void	DrawRoundedRectangle (double x, double y, double width, double height, double radius, bool pixelsize=false)
	Draw RoundedRectangle in world coordinates.

virtual void	DrawCenterRoundedRectangle (double xc, double yc, double width, double height, double radius, bool pixelsize=false)
	Draw CenterRoundedRectangle in world coordinates. More...

virtual void	DrawCircle (double x, double y, double radius)
	Draw Circle in world coordinates. More...

virtual void	DrawEllipse (double x, double y, double width, double height)
	Draw Ellipse in world coordinates. More...

virtual void	DrawImage (const wxImage &image, double x, double y, double width, double height, wxUint8 Opacity=255)=0
	Draw wxImage in world coordinates. More...

virtual void	DrawImage (const a2dImageRGBA &image, double x, double y, double width, double height, wxUint8 Opacity=255)=0

void	DrawImage (const wxImage &image, double x=0, double y=0, wxUint8 Opacity=255)
	Draw wxImage in world coordinates. More...

virtual void	DrawPoint (double xc, double yc)=0
	draw a single point

void	SetRealScale (bool realScale)
	If true use real scale else different scale by x and y.

virtual void	DrawText (const wxString &text, double x, double y, int alignment=wxMINX\|wxMINY, bool Background=true)
	Draw text in user coordinates. More...

virtual void	DeviceDrawAnnotation (const wxString &text, wxCoord x, wxCoord y, const wxFont &font)
	text drawn in device coordinates

void	SetDrawStyle (a2dDrawStyle drawstyle)
	set drawstyle to use for drawing, More...

a2dDrawStyle	GetDrawStyle () const
	get drawstyle used for drawing.

void	SetPrintMode (bool onOff)
	to modify drawing feature when used as context for printing

void	OverRuleFixedStyle ()
	id style is FIXED, saves current style and sets style to a2dFILLED

void	ResetFixedStyle ()
	only way to reset style after SetDrawStyle( a2dFIXED*** );

void	ReStoreFixedStyle ()
	when fixed drawing style is set, it can be overruled. More...

void	SetDisableDrawing (bool disableDrawing)
	when set, all drawing functions return immediately. More...

bool	GetDisableDrawing ()
	see SetDisableDrawing()

virtual void	SetClippingRegion (a2dVertexList *points, bool spline=false, wxPolygonFillMode fillStyle=wxODDEVEN_RULE)=0
	set clipping region from polygon to which everything drawn will be clipped.

virtual void	ExtendClippingRegion (a2dVertexList *points, bool spline=false, wxPolygonFillMode fillStyle=wxODDEVEN_RULE, a2dBooleanClip clipoperation=a2dCLIP_AND)=0
	extend clipping region with a polygon to which everything drawn will be clipped.

virtual void	ExtendAndPushClippingRegion (a2dVertexList *points, bool spline=false, wxPolygonFillMode fillStyle=wxODDEVEN_RULE, a2dBooleanClip clipoperation=a2dCLIP_AND)=0
	push on stack the current clipping region and extend clipping region More...

virtual void	PopClippingRegion ()=0
	pop a previously pushed clipping region

virtual void	SetClippingRegionDev (wxCoord minx, wxCoord miny, wxCoord maxx, wxCoord maxy)=0
	set clipping region using x y values in device coordinates

virtual void	SetClippingRegion (double minx, double miny, double maxx, double maxy)=0
	set clipping region using x y values in world coordinates

virtual void	DestroyClippingRegion ()=0
	set clipping region off

void	GetClippingBox (double &x, double &y, double &w, double &h) const
	what is the current clipping region in world coordinates

a2dBoundingBox &	GetClippingBox ()
	what is the current clipping region in world coordinates

void	GetClippingMinMax (double &xmin, double &ymin, double &xmax, double &ymax) const
	what is the current clipping region in world coordinates

wxRect &	GetClippingBoxDev ()
	what is the current clipping region in device coordinates

void	GetClippingBoxDev (int &x, int &y, int &w, int &h) const
	what is the current clipping region in device coordinates

void	Init ()
	Initialize a drawer.

virtual void	BeginDraw ()=0
	start to draw on this context (used to initialize a specific drawer)

virtual void	EndDraw ()=0
	end drawing on this context (used to reset a specific drawer)

void	SetOpacityFactor (wxUint8 OpacityFactor)
	when enabling m_useOpacityFactor, this is how transparent More...

wxUint8	GetOpacityFactor ()
	see SetOpacityFactor()

virtual bool	HasAlpha ()
	does a derived drawer have alpha support or not

void	DrawCharStrokeCb (wxChar c)
	Wrapper for DrawCharStroke. More...

void	DrawCharFreetypeCb (wxChar c)
	Wrapper for DrawCharFreetype. More...

void	DrawCharDcCb (wxChar c)
	Wrapper for DrawCharDc. More...

Static Public Attributes
static const a2dSignal	sig_changedZoom = wxNewId()

Protected Member Functions
virtual void	SetActiveStroke (const a2dStroke &stroke)
	sync with actual API graphical context More...

virtual void	SetActiveFill (const a2dFill &fill)
	sync with actual API graphical context More...

virtual void	DoSetDrawStyle (a2dDrawStyle drawstyle)=0

virtual void	DoSetActiveStroke ()=0
	per drawer implementation

virtual void	DoSetActiveFill ()=0
	per drawer implementation

virtual void	DoSetActiveFont (const a2dFont &font)

wxPen	ConvertActiveToPen ()
	get active stroke as wxPen

wxBrush	ConvertActiveToBrush ()
	get active fill as wxBrush

bool	IsStrokeOnly ()
	wxART2D_USE_GRAPHICS_CONTEXT More...

bool	IsStroked ()

int	ToDeviceLines (a2dVertexArray *points, a2dBoundingBox &devbbox, bool &smallPoly, bool replaceByRectangle=false)
	convert vertex array containing line and arc segments in user coordinates to device coordinate lines.

int	ToDeviceLines (const a2dVertexList *list, a2dBoundingBox &devbbox, bool &smallPoly, bool replaceByRectangle=false)
	convert vertex list containing line and arc segments in user coordinates to device coordinate lines.

void	SetMappingUpp (double x, double y, double wx, double wy, double vx1, double vy1, double xpp, double ypp)
	Given the rectangle in world coordinate to be displayed, update the mappingmatrix. More...

unsigned int	ConvertSplinedPolygon2 (unsigned int n)
	converts internal device points array to spline. Returns new number of points.

unsigned int	ConvertSplinedPolyline2 (unsigned int n)
	converts internal device points array to spline. Returns new number of points.

bool	Clipping (double &x1, double &y1, double &x2, double &y2)
	clip lines

int	GetClipCode (double x, double y)
	clip code of a point

void	FillPolygon (int n, wxRealPoint points[])
	Used for filling with Gradient fill style.

bool	MoveUp (int n, wxRealPoint points[], double horline, int &index, int direction)
	Used for filling with Gradient fill style.

void	DetectCriticalPoints (int n, wxRealPoint points[])
	Used for filling with Gradient fill style.

void	DrawTextGeneric (const wxString &text, double x, double y, void(a2dDrawer2D::*drawchar)(wxChar))

virtual void	DrawCharUnknown (wxChar c)
	Draw a cross instead of a character.

virtual void	DrawTextUnknown (const wxString &text, double x, double y, bool words=false)
	Draw a cross, indicating an unsupported font type for this drawer. More...

virtual void	DrawCharStroke (wxChar c)
	Draw a stroke character. More...

virtual void	DrawTextStroke (const wxString &text, double x, double y)
	Draw text in user coordinates, based on a stroke font. More...

virtual void	DrawCharFreetype (wxChar c)
	Draw a freetype character. More...

virtual void	DrawTextFreetype (const wxString &text, double x, double y)
	Draw text in world coordinates, based on a freetype font .

virtual void	DrawCharDc (wxChar c)
	Draw a dc character. More...

virtual void	DrawTextDc (const wxString &text, double x, double y)
	Draw text in user coordinates, based on a dc font .

wxPoint *	_convertToIntPointCache (int n, wxRealPoint *pts)
	Convert double points to integer coords in the point cache and return pointer.

virtual void	DeviceDrawPolygon (unsigned int n, bool spline, wxPolygonFillMode fillStyle)
	draw an internal polygon in device coordinates

virtual void	DeviceDrawLines (unsigned int n, bool spline)
	draw an internal polyline in device coordinates

virtual void	DeviceDrawLine (double x1, double y1, double x2, double y2)
	draw in pixels

virtual void	DeviceDrawHorizontalLine (int x1, int y1, int x2, bool use_stroke_color)
	Draw a pixel-width, unstroked horizontal line in device (pixel) coordinates. More...

virtual void	DeviceDrawVerticalLine (int x1, int y1, int y2, bool use_stroke_color)
	Draw a pixel-width, unstroked vertical line in device (pixel) coordinates. More...

virtual void	DeviceDrawPixel (int x1, int y1, unsigned char r, unsigned char g, unsigned char b, unsigned char a=255)
	draw a single, unstroked pixel in device coordinates with the given color

Protected Attributes
bool	m_frozen
	buffer updating activity possible or not

bool	m_mouseevents
	enable/ disable mouse events handling by canvas

a2dStroke	m_currentstroke
	used while rendering

a2dFill	m_currentfill
	used while rendering

a2dStroke	m_activestroke
	used while rendering

a2dFill	m_activefill
	used while rendering

a2dFont	m_currentfont
	current font set

a2dDrawStyle	m_drawstyle
	drawstyle (like invert mode)

a2dStroke	m_fixStrokeRestore
	used to restore an overruled fix style

a2dFill	m_fixFillRestore
	used to restore an overruled fix style

a2dDrawStyle	m_fixDrawstyle
	used to restore an overruled fix style

bool	m_yaxis
	up or down

double	m_virt_minX
	virtual coordinates box its miminum X

double	m_virt_minY
	virtual coordinates box its miminum Y

double	m_xpp
	user units per pixel in x

double	m_ypp
	user units per pixel in y

bool	m_fixedStyledOverRuled
	keep track of this

bool	m_forceNormalizedFont
	up or down

wxUint16	m_smallTextThreshold

bool	m_pendingSig_changedZoom
	When display refresh is on hold, this triggers a delayed zoom signal, when released.

a2dVertexList	m_tempPoints
	used internally in some methods to avoid constructor, new, ...

wxUint8	m_StrokeOpacityCol1
	active stroke alpha

wxUint8	m_StrokeOpacityCol2
	active stroke alpha

wxUint8	m_FillOpacityCol1
	active fill alpha

wxUint8	m_FillOpacityCol2
	active fill alpha

unsigned char	m_colour1redStroke
	active stroke colours

unsigned char	m_colour1greenStroke
	active stroke colours

unsigned char	m_colour1blueStroke
	active stroke colours

unsigned char	m_colour1redFill
	active fill colours

unsigned char	m_colour1greenFill
	active fill colours

unsigned char	m_colour1blueFill
	active fill colours

unsigned char	m_colour2redFill
	active fill colours

unsigned char	m_colour2greenFill
	active fill colours

unsigned char	m_colour2blueFill
	active fill colours

a2dAffineMatrix	m_worldtodevice
	world to device coordinate mapping

a2dAffineMatrix	m_usertoworld
	pointer to current user-to-world transform matrix

a2dAffineMatrix	m_usertodevice
	pointer to current user-to-device transform matrix ( so includes mapping matrix )

bool	m_virtualarea_set
	is the virtual area set already (used during startup)

int	m_refreshDisplay
	see SetRefreshDisplay()

int	m_width
	device size width

int	m_height
	device size height

int	m_mapX
	X mapping position in device coordinates.

int	m_mapY
	Y mapping position in device coordinates.

int	m_mapWidth
	width for mapping in device coordinates

int	m_mapHeight
	height for mapping in device coordinates

a2dCriticalPointList	m_CRlist
	critical point list for polygon

a2dAETList	m_AETlist
	scanline list of intersections with polygon

std::vector< wxPoint >	m_cpointsInt
	cached array for containing transformed device coordinates (integer)

std::vector< wxRealPoint >	m_cpointsDouble
	cached array for containing transformed device coordinates (double)

double	m_splineaberration
	accuracy of spline

a2dClipRegionList	m_clipregionlist
	pushed clipping regions

double	m_displayaberration
	accuracy of arc segment calculation etc. in device coordinates

wxUint16	m_drawingthreshold
	object smaller than this value will not be rendered

wxUint16	m_polygonFillThreshold
	polygon smaller than this value will be rendered non filled.

bool	m_asrectangle
	underneath the threshold draw rectangles if true else nothing

a2dBoundingBox	m_clipboxworld
	current clipping area in world coordinates

wxRect	m_clipboxdev
	current clipping area in device coordinates

int	m_beginDraw_endDraw
	counter for BeginDraw EndDraw calls

wxWindow *	m_display
	view its window.

bool	m_disableDrawing
	all drawing is disabled when this is true

wxUint8	m_OpacityFactor
	opacity will be the one set, derived by this

std::vector< a2dAffineMatrix >	m_affineStack
	Affine transform stack. More...

bool	m_realScale
	If true use real scale else different scale by x and y.

bool	m_printingMode
	can be used to modify drawing features when used as context for printing

Detailed Description

Drawing context abstraction.

a2dDrawer2D presents a unified abstract view of underlying system-dependent drawing contexts. It provides a simple low-level interface for drawing rectangles and other basic primitives, and it also handles the mapping and transformations from world coordinates to device coordinates.

The current a2dFill and a2dStroke need to be set, those classes are always reference counted, and a2dDrawer2D will increment and decrement them when setting and releasing them. This means that if the reference count reaches zero it will actually be deleted.

Mapping from device to Logical/World coordinates needs to be set for a drawer. The Yaxis orientation can also be set via the SetYaxis() method.

About Transformations

There are three different coordinate systems used by a2dDrawer2D, and two transformations that map between them. These are referred to in a2d as

User coordinates
World coordinates
Device coordinates

User coordinates are the coordinates you give to drawing functions like DrawCircle(). User coordinates are transformed to World coordinates by the transformation returned from GetTransform(). The idea behind user coordinates is that one can draw in a relative coordinate system, which can be at a position, angle and scale relative to the world coordinates. The drawing context will correctly transform the relative coordinates, to world and device. This way of drawing especialy becomes important when working with canvas objects. Inside such object one can use drawing functions relative to the origin of that object, and one does not have to take into account how and where this object is placed in the world coordinate system. World coordinates are transformed to Device coordinates using the transformation returned by GetMappingMatrix(). One can draw in device coordinates without transformations by calling PushIdentityTransform(). PopTransform() will restore the previous transformation. As an example one can draw the vertexes in a plot as a circle in device coordinates (with a fixed radius in pixels that is), while the curve itself is draw in normal user coordinates.

Given an input point (x,y), the final location on the output device (e.g. screen) in device units (e.g. pixels) for any of the Draw*() methods is given by

(devx,devy) = GetMappingMatrix() * GetTransform() * (x,y)

The compound of the world-to-device mapping and user-to-world transform is also kept up-to-date. It can be obtained by calling GetUserToDeviceTransform(). So we can also say

(devx,devy) = GetUserToDeviceTransform() * (x,y)

We can also depict this relationship as

            User coordinates
           /                \
  [ GetTransform() ]         |
          |                  |
    World coordinates     [ GetUserToDeviceTransform() ]
          |                  |
[ GetMappingMatrix() ]       |
           \                /
          Device coordiantes

The Mapping Matrix

The mapping matrix returned by GetMappingMatrix() contains only translation and axis-aligned scaling. So an input of an axis-aligned rectangle is always transformed to another axis-aligned rectangle. This lets you have an unlimited virtual canvas (aka "world") and map different portions of it to the drawing surface. Additionally, some objects like fonts are aware of the orientation of the Y axis defined by the mapping, and will draw right-side up, even if the Y axis is mirrored in the mapping.

The mapping matrix can be manipulated using the following methods:

The User to World Transform Matrix

The user-to-world transform matrix returned by GetTransform() is a 2x3 affine matrix that can contain translation, rotation, and scaling (including shearing and mirroring).

The relative transform can be manipulated with these methods:

double buffering

A derived drawing context can be buffered or not. But this class is prepared as a buffered drawing context, so it assumes in certain member fucntions that one is drawing to a buffer. A drawing context which does not use a buffer needs to implement those pur virtual members and give assert.

See Also: a2dDcDrawer, a2dMemDcDrawer, a2dAggDrawer

Definition at line 177 of file drawer2d.h.

Constructor & Destructor Documentation

a2dDrawer2D::a2dDrawer2D	(	int	width = `0`,
		int	height = `0`
	)

constructor

Remarks: Do not forget to call SetDocument() if used standalone (in a a2dDocumentCommandProcessor setting this is taken care of).

Definition at line 77 of file drawer2d.cpp.

a2dDrawer2D::a2dDrawer2D ( const wxSize & size )

constructor

Remarks: Do not forget to call SetDocument() if used standalone (in a a2dDocumentCommandProcessor setting this is taken care of)

Definition at line 65 of file drawer2d.cpp.

Member Function Documentation

void a2dDrawer2D::DeviceDrawHorizontalLine	(	int	x1,
		int	y1,
		int	x2,
		bool	use_stroke_color
	)

protectedvirtual

Draw a pixel-width, unstroked horizontal line in device (pixel) coordinates.

This method is useful for implementing low level fill routines.

Parameters

x1	x start of line
x2	x end of line
y1	y of line
use_stroke_color	If true, then use the current stroke color If false, then use the current fill color.

Reimplemented in a2dDcDrawer.

Definition at line 3090 of file drawer2d.cpp.

void a2dDrawer2D::DeviceDrawVerticalLine	(	int	x1,
		int	y1,
		int	y2,
		bool	use_stroke_color
	)

protectedvirtual

Draw a pixel-width, unstroked vertical line in device (pixel) coordinates.

This method is useful for implementing low level fill routines.

Parameters

x1	x of line
y1	y start of line
y2	y end of line
use_stroke_color	If true, then use the current stroke color If false, then use the current fill color.

Reimplemented in a2dDcDrawer.

Definition at line 3095 of file drawer2d.cpp.

double a2dDrawer2D::DeviceToWorldXRel ( double x ) const

inline

convert x relative from device to world coordinates

Use this to convert a length of a line for instance

Definition at line 444 of file drawer2d.h.

double a2dDrawer2D::DeviceToWorldYRel ( double y ) const

inline

convert y relative from device to world coordinates

Use this to convert a length of a line for instance

Definition at line 449 of file drawer2d.h.

void a2dDrawer2D::DrawCenterRoundedRectangle	(	double	xc,
		double	yc,
		double	width,
		double	height,
		double	radius,
		bool	pixelsize = `false`
	)

virtual

Draw CenterRoundedRectangle in world coordinates.

Draws a rounded rectangle centered at the point (xc,yc) in world coordinates.

Reimplemented in a2dBlindDrawer2D.

Definition at line 2040 of file drawer2d.cpp.

virtual void a2dDrawer2D::DrawCharDc ( wxChar c )

inlineprotectedvirtual

Draw a dc character.

This is an internal function, used by DrawTextDc This function assumes that the affine matrix has been set up by the calling function in such a way, that the (0,0) coordinate will match with the lowerleft bbox corner of the character. Also mirroring should be performed by the calling function.

Reimplemented in a2dAggDrawerBase, and a2dDcDrawer.

Definition at line 981 of file drawer2d.h.

void a2dDrawer2D::DrawCharDcCb ( wxChar c )

inline

Wrapper for DrawCharDc.

See Also: DrawCharStrokeCb

Definition at line 804 of file drawer2d.h.

virtual void a2dDrawer2D::DrawCharFreetype ( wxChar c )

inlineprotectedvirtual

Draw a freetype character.

This is an internal function, used by DrawTextFreetype This function assumes that the affine matrix has been set up by the calling function in such a way, that the (0,0) coordinate will match with the lowerleft bbox corner of the character. Also mirroring should be performed by the calling function.

Reimplemented in a2dAggDrawerBase, a2dMemDcDrawer, and a2dDcDrawer.

Definition at line 966 of file drawer2d.h.

void a2dDrawer2D::DrawCharFreetypeCb ( wxChar c )

inline

Wrapper for DrawCharFreetype.

See Also: DrawCharStrokeCb

Definition at line 800 of file drawer2d.h.

void a2dDrawer2D::DrawCharStroke ( wxChar c )

protectedvirtual

Draw a stroke character.

This is an internal function, used by DrawTextStroke. This function assumes that the affine matrix has been set up by the calling function in such a way, that the (0,0) coordinate will match with the lowerleft bbox corner of the character. Also mirroring should be performed by the calling function.

Reimplemented in a2dAggDrawerBase.

Definition at line 2270 of file drawer2d.cpp.

void a2dDrawer2D::DrawCharStrokeCb ( wxChar c )

inline

Wrapper for DrawCharStroke.

ISO C++ seems(?) to forbid directly calling the address of virtual member functions. Calling &a2dDrawer2D::DrawCharStroke refers to the actual function in a2dDrawer2D and does not refer to the virtual function. Calling &(this->DrawCharStroke) should refer to the virtual function and is accepted by some compilers (MSVC, gcc <3.3), but according to gcc 3.4 this is not allowed by ISO C++. Therefore the virtual function is called through this intermediate function

Definition at line 796 of file drawer2d.h.

void a2dDrawer2D::DrawCircle	(	double	x,
		double	y,
		double	radius
	)

virtual

Draw Circle in world coordinates.

Remarks: circle gets rotates and scaled etc. in x and y when required.

Reimplemented in a2dBlindDrawer2D, a2dAggDrawerBase, and a2dDcDrawer.

Definition at line 2116 of file drawer2d.cpp.

void a2dDrawer2D::DrawEllipse	(	double	x,
		double	y,
		double	width,
		double	height
	)

virtual

Draw Ellipse in world coordinates.

Remarks: ellipse gets rotates and scaled etc. in x and y when required.

Reimplemented in a2dBlindDrawer2D, a2dAggDrawerBase, and a2dDcDrawer.

Definition at line 2121 of file drawer2d.cpp.

virtual void a2dDrawer2D::DrawImage	(	const wxImage &	image,
		double	x,
		double	y,
		double	width,
		double	height,
		wxUint8	Opacity = `255`
	)

pure virtual

Draw wxImage in world coordinates.

Draw the wxImage to the screen in such a manner that the image is mapped into the rectangle defined by points (x-width/2,y-width/2) and (x+width/2,y+height/2) in world coordinates, with the center of the image at (x,y).

Parameters

image	image to draw
x	world x position of center of image
y	world y position of center of image
width	width in world coordinates to map width of image to
height	height in world coordinates to map height of image to

Implemented in a2dBlindDrawer2D, a2dAggDrawerRgba, a2dAggDrawer, a2dMemDcDrawer, and a2dDcDrawer.

void a2dDrawer2D::DrawImage	(	const wxImage &	image,
		double	x = `0`,
		double	y = `0`,
		wxUint8	Opacity = `255`
	)

inline

Draw wxImage in world coordinates.

Equivalent to calling DrawImage(image, x,y, image.GetWidth(),image.GetHeight())

Parameters

image	image to draw
x	world x position of center of image
y	world y position of center of image

Definition at line 649 of file drawer2d.h.

void a2dDrawer2D::DrawText	(	const wxString &	text,
		double	x,
		double	y,
		int	alignment = `wxMINX \| wxMINY`,
		bool	Background = `true`
	)

virtual

Draw text in user coordinates.

Draws text at the given position in user coordinates.

Adding rotation etc. to the user transform matrix makes it possible to draw rotated text.

Parameters

text	The text which should be drawn.
x,y	The position to draw at.
alignment	Use this to align the text (eg. wxMINX \| wxMINY). See also a2dFontAlignment.
Background	with or without background rectangle

See Also: SetFont()

Definition at line 2329 of file drawer2d.cpp.

void a2dDrawer2D::DrawTextGeneric	(	const wxString &	text,
		double	x,
		double	y,
		void(a2dDrawer2D::*)(wxChar)	drawchar
	)

protected

This function will draw each character separately using the function drawchar. It will also advance and kern the characters, by adjusting the affine matrices. The character will also be checked against the clipbox. This function assumes (0,0) is the lowerleft bbox corner. This function will not draw the background fill.

Parameters

text	The text to be drawn.
x	x-Position of the text.
y	y-Position of the text.
drawchar	A function which will draw a given character.

Definition at line 2291 of file drawer2d.cpp.

void a2dDrawer2D::DrawTextStroke	(	const wxString &	text,
		double	x,
		double	y
	)

protectedvirtual

Draw text in user coordinates, based on a stroke font.

todo what about the style (pixel or not of stroke font )

Definition at line 2245 of file drawer2d.cpp.

void a2dDrawer2D::DrawTextUnknown	(	const wxString &	text,
		double	x,
		double	y,
		bool	words = `false`
	)

protectedvirtual

Draw a cross, indicating an unsupported font type for this drawer.

Draws text at the given position in user coordinates. Adding rotation etc. to that matrix makes it possible to draw rotated text.

Parameters

text	draw unknown text
x	x position
y	y position
words	If false, draw a boxed cross for the whole line. If true, draw a piece of line for each word.

Definition at line 2198 of file drawer2d.cpp.

virtual void a2dDrawer2D::ExtendAndPushClippingRegion	(	a2dVertexList *	points,
		bool	spline = `false`,
		wxPolygonFillMode	fillStyle = `wxODDEVEN_RULE`,
		a2dBooleanClip	clipoperation = `a2dCLIP_AND`
	)

pure virtual

push on stack the current clipping region and extend clipping region

The clipping region will be extended with a polygon to which everything drawn will be clipped.

Implemented in a2dBlindDrawer2D, a2dAggDrawerBase, and a2dDcDrawer.

double a2dDrawer2D::GetDisplayAberration ( ) const

inline

Returns the display aberration of curved shapes.

, The drawing of curved shapes will not deviate more than this from the ideal curve.

Definition at line 244 of file drawer2d.h.

wxUint16 a2dDrawer2D::GetPrimitiveThreshold ( ) const

inline

get drawing threshold

See Also: SetDrawingThreshold

Definition at line 214 of file drawer2d.h.

virtual wxBitmap a2dDrawer2D::GetSubBitmap ( wxRect sub_rect ) const

pure virtual

A way to get parts form the buffer that is drawn into.

Used for freetype text at the moment since it mixes with the colors already there.

Implemented in a2dBlindDrawer2D, a2dAggDrawerRgba, a2dAggDrawer, a2dMemDcDrawer, and a2dDcDrawer.

const a2dAffineMatrix& a2dDrawer2D::GetTransform ( ) const

inline

get the user-to-world transform matrix.

The user-to-world matrix transforms all drawing primitives from user coordinates to world coordinates.

Definition at line 500 of file drawer2d.h.

bool a2dDrawer2D::GetVirtualAreaSet ( ) const

inline

if the virtual area has been set already return true else false.

Use this during initialization of an application.

Definition at line 374 of file drawer2d.h.

bool a2dDrawer2D::IsStroked ( )

inlineprotected

return true if the the drawstyle in combination with the active stroke, does not require stroking

Definition at line 860 of file drawer2d.h.

bool a2dDrawer2D::IsStrokeOnly ( )

inlineprotected

wxART2D_USE_GRAPHICS_CONTEXT

return true if the drawstyle in combination with the active stroke and fill, does not require filling

Definition at line 847 of file drawer2d.h.

void a2dDrawer2D::PushTransform ( const a2dAffineMatrix & affine )

virtual

Save the current transform on the affine stack and then multiply it by the given affine.

This is a convenience function that is equivalent to calling

PushTransform(); Transform(affine);

Definition at line 459 of file drawer2d.cpp.

void a2dDrawer2D::ResetStyle ( )

virtual

set a pre-defined style reseting cashed values.

setting a style ( stroke fill ) for a a2dDrawer2D, takes into account the style that is currently set for it. If the style being set is equal to the current style, internal nothing is done for the underlying device. Of course this only works if everyone obeys the rules. Routines not using a2dDrawer2D as an entry to device, may fool this trick. Therefore to be sure to start with a proper a2dDrawer2D, first call this function. It will make the a2dDrawer2D style the actual style used on the device.

Reimplemented in a2dBlindDrawer2D, a2dAggDrawerBase, and a2dDcDrawer.

Definition at line 545 of file drawer2d.cpp.

void a2dDrawer2D::ReStoreFixedStyle ( )

when fixed drawing style is set, it can be overruled.

The last fixed style stroke and fill are restored.

Definition at line 711 of file drawer2d.cpp.

void a2dDrawer2D::SetActiveFill ( const a2dFill & fill )

protectedvirtual

sync with actual API graphical context

The fill is set to the API that is doing the actual drawing. Depending on the API the m_drawStyle should be taken into account, if it does not already yield for any stroke set by SetDrawStyle()

Definition at line 633 of file drawer2d.cpp.

void a2dDrawer2D::SetActiveStroke ( const a2dStroke & stroke )

protectedvirtual

sync with actual API graphical context

The stroke is set to the API that is doing the actual drawing. Depending on the API the m_drawStyle should be taken into account, if it does not already yield for any stroke set by SetDrawStyle()

Definition at line 581 of file drawer2d.cpp.

virtual void a2dDrawer2D::SetBufferSize	(	int	w,
		int	h
	)

pure virtual

Change the buffer size.

Remarks: SetMappingDeviceRect() is NOT reset.

Implemented in a2dBlindDrawer2D, a2dAggDrawerRgba, a2dAggDrawer, a2dMemDcDrawer, and a2dDcDrawer.

void a2dDrawer2D::SetDisableDrawing ( bool disableDrawing )

inline

when set, all drawing functions return immediately.

This can be used to render only nested parts of documents. The parent part are drawn from their a2dCanvasObjects, but in reality nothing will be drawn until drawing is enabled for the deeper nested objects.

Definition at line 716 of file drawer2d.h.

void a2dDrawer2D::SetDisplayAberration ( double aber )

inline

Set the display aberration of curved shapes.

The drawing of curved shapes will not deviate more than this from the ideal curve.

Remarks: the smaller the number the longer the drawing takes.

Parameters

aber	maximum deviation in device coordinates

Definition at line 238 of file drawer2d.h.

void a2dDrawer2D::SetDrawerFill ( const a2dFill & fill )

Used to set the current fill.

The a2dFill objects are reference counted, so passing a fill pointer allocated with 'new' to this function will not result in a leak.

Definition at line 621 of file drawer2d.cpp.

void a2dDrawer2D::SetDrawerStroke ( const a2dStroke & stroke )

Used to set the current stroke.

The a2dStroke objects are reference counted, so passing a stroke pointer allocated with 'new' to this function will not result in a leak.

Definition at line 565 of file drawer2d.cpp.

void a2dDrawer2D::SetDrawStyle ( a2dDrawStyle drawstyle )

set drawstyle to use for drawing,

The draw style is used for drawing in a certain fashion.

The current fill, stroke are not changed while setting a diffrent drawstyle. Therefore first set the required fill and stroke. Setting a2dFIX_STYLE or a2dFIX_STYLE_INVERT can only be reset using ResetFixedStyle(). Still it can be temprarely overruled with OverRuleFixedStyle() to be restored with ReStoreFixedStyle().

New settings for fill, stroke may or may not have effect in how is drawn, but do change the current fill are stroke, independent of the drawing style. This depends if it makes sense to have a different style when the drawstyle is in action. When drawstyle is set, the last set fill, stroke are made active when needed.

Parameters

drawstyle one of the draw styles

Definition at line 557 of file drawer2d.cpp.

void a2dDrawer2D::SetMappingDeviceRect	(	int	mapx,
		int	mapy,
		int	mapWidth,
		int	mapHeight,
		bool	remap = `false`
	)

to change the default mapping (to the complete buffer).

By default the mapping from world coordinates to device coordinates is based on the size of the double buffer. For application where the a2dDrawer2D is used as a double buffered device context within a a2dCanvas window, it is better to oversize the buffer of the a2dDrawer2D. This prevents continuously reallocating/redrawing of the buffer after even the smallest resize. To still keep the mapping to what is visible on the window client window, one can independently from the buffer size set the mapping rectangle. Even a rectangle bigger then the buffer rectangle is possible, but of course the a2dDrawer2D will never draw outside the buffer eventually.

Parameters

remap if true change mapping to

Definition at line 216 of file drawer2d.cpp.

void a2dDrawer2D::SetMappingMatrix ( const a2dAffineMatrix & mapping )

set world to device matrix ( better use SetMappingWidthHeight() etc. ) Side ffect m_usertodevice is modified to m_worldtodevice * m_usertoworld

Definition at line 396 of file drawer2d.cpp.

void a2dDrawer2D::SetMappingUpp	(	double	vx1,
		double	vy1,
		double	xpp,
		double	ypp
	)

Give the virtual size to be displayed, the mapping matrix will be calculated.

To display all of a drawing, set this here to the boundingbox of the root object of the canvas.

So vx1 and vx2 to the minimum x and y of the boundingbox. Calculate xpp and ypp in such a manner that it will show the whole drawing.

The buffer size or SetMappingDeviceRect() is used when setting the mapping with this function.

Remarks: when a user-to-world matrix SetTransform() is set, the m_usertodevice is recalculated to take the new mapping matrix and the already set user-to-world matrix into account.

Parameters

vx1,:	minimum x coordinate of display area
vy1,:	minimum y coordinate of display area
xpp,:	Number of user units per pixel in x
ypp,:	Number of user units per pixel in y

Definition at line 250 of file drawer2d.cpp.

void a2dDrawer2D::SetMappingUpp	(	double	x,
		double	y,
		double	wx,
		double	wy,
		double	vx1,
		double	vy1,
		double	xpp,
		double	ypp
	)

protected

Given the rectangle in world coordinate to be displayed, update the mappingmatrix.

To display all of a drawing, set this to the bounding box of the root object of the canvas.

So vx1 and vx2 to the minimum x and y of the bounding box. Calculate xpp and ypp in such a manner that it will show the whole drawing.

The buffer size or SetMappingDeviceRect() are not used when setting the mapping with this function. In fact all other mapping functions in a2dDrawer2D use this function to set the mapping for the a2dDrawer2D in the end.

Remarks: when a relative world matrix SetTransform() is set, the m_usertodevice is recalculated to take the new mapping matrix and the already set user matrix into account.

Parameters

x,:	map to device x (non zero if canvas window is smaller than drawer)
y,:	map to device y (non zero if canvas window is smaller than drawer)
wx,:	map to device of this size in x, normally same as width of buffer bitmap
wy,:	map to device of this size in y, normally same as height of buffer bitmap
vx1,:	minimum x coordinate of display area
vy1,:	minimum y coordinate of display area
xpp,:	Number of world units per pixel in x
ypp,:	Number of world units per pixel in y

transformation from world to device coordinates

Definition at line 257 of file drawer2d.cpp.

void a2dDrawer2D::SetMappingWidthHeight	(	double	vx1,
		double	vy1,
		double	width,
		double	height
	)

virtual

Give the virtual size to be displayed, the mapping matrix will be calculated.

The current buffer size is used to calculate how to at least display all of the area given.

See Also: SetMappingDeviceRect to map to a different device/buffer rectangle.

Remarks: do not use during start up since window/buffer size is not well defined in that case resulting in; bad settings for the mapping.

Parameters

vx1,:	minimum x coordinate of display area
vy1,:	minimum y coordinate of display area
width,:	width of displayed area in world coordinates
height,:	height of displayed area in world coordinates

Definition at line 333 of file drawer2d.cpp.

void a2dDrawer2D::SetMappingWidthHeight ( const a2dBoundingBox & box )

Give the virtual size to be displayed, the mapping matrix will be calculated.

The current buffer size is used to calculate how to at least display all of the area given.

Remarks: do not use during start up since window/buffer size is not well defined in that case resulting in; bad settings for the mapping.

See Also: SetMappingDeviceRect to map to a different device/buffer rectangle.

Parameters

box	a boundingbox to set mapping

Definition at line 358 of file drawer2d.cpp.

void a2dDrawer2D::SetOpacityFactor ( wxUint8 OpacityFactor )

when enabling m_useOpacityFactor, this is how transparent

Parameters

OpacityFactor Real opacity is set opacity * m_OpacityFactor/255

Definition at line 550 of file drawer2d.cpp.

void a2dDrawer2D::SetSmallTextThreshold ( wxUint16 pixels )

inline

set device text size at which textdrawing will switch to device specific text drawing. Small text will only be drawn correctly, when fitting text to pixels. For bigger text it is no problem, so at a certain size one switches to device specific drawing of text. only works if m_forceNormalizedFont = false;

Definition at line 576 of file drawer2d.h.

void a2dDrawer2D::SetSplineAberration ( double aber )

Set the detail level for spline drawing.

Parameters

aber	Accuracy in world coordinates

Definition at line 195 of file drawer2d.cpp.

void a2dDrawer2D::SetTransform ( const a2dAffineMatrix & userToWorld )

virtual

set user-to-world transform matrix.

Sets the current user-to-world transform matrix at the top of the transform stack. The user-to-world matrix transforms all drawing primitives from user coordinates to world coordinates.

Parameters

userToWorld The matrix for transforming from user to world.

Definition at line 446 of file drawer2d.cpp.

void a2dDrawer2D::StartRefreshDisplayDisable ( )

inline

when called a mapping change will result not result in a refresh of the m_display.

m_refreshDisplay is incremented, and EndRefreshDisplayDisable() does decrement it. When m_refreshDisplay > 0 no refresh is done when changing mapping.

Used to prevent looping and unneeded refresh when changing mapping several times within a function.

Definition at line 383 of file drawer2d.h.

int a2dDrawer2D::WorldToDeviceXRel ( double x ) const

inline

convert x relative from world to device coordinates

Use this to convert a length of a line for instance

Definition at line 460 of file drawer2d.h.

double a2dDrawer2D::WorldToDeviceXRelNoRnd ( double x ) const

inline

convert x relative from world to device coordinates (result not rounded to integer)

Use this to convert a length of a line for instance

Definition at line 470 of file drawer2d.h.

int a2dDrawer2D::WorldToDeviceYRel ( double y ) const

inline

convert y relative from world to device coordinates

Use this to convert a length of a line for instance

Definition at line 465 of file drawer2d.h.

double a2dDrawer2D::WorldToDeviceYRelNoRnd ( double y ) const

inline

convert y relative from world to device coordinates (result not rounded to integer)

Use this to convert a length of a line for instance

Definition at line 475 of file drawer2d.h.

Member Data Documentation

std::vector<a2dAffineMatrix> a2dDrawer2D::m_affineStack

protected

Affine transform stack.

The stack actually is a double stack, for both m_relativetransform and m_usertodevice This prevents some additional affine matrix multiplications. The stack is implemented as a 'fixed' array, preventing (slow) dynamic memory allocation.

Definition at line 1218 of file drawer2d.h.

const a2dSignal a2dDrawer2D::sig_changedZoom = wxNewId()

static

id for changed zoom sent from a2dDrawer2D to a2dEventDistributer when zoom has changed.

Definition at line 1232 of file drawer2d.h.

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

Public Member Functions

Static Public Attributes

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation