Added a Python port of the OGL library, deprecated the C++ wrapped version.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@27447 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

wxPython/wx/lib/ogl/__init__.py

@@ -0,0 +1,14 @@
+"""
+The Object Graphics Library provides for simple drawing and manipulation
+of 2D objects.
+"""
+
+__all__ = ["basic", "diagram", "canvas", "lines", "bmpshape", "divided", "composit"]
+
+from basic import *
+from diagram import *
+from canvas import *
+from lines import *
+from bmpshape import *
+from divided import *
+from composit import *

wxPython/wx/lib/ogl/bmpshape.py

@@ -0,0 +1,66 @@
+# -*- coding: iso-8859-1 -*-
+#----------------------------------------------------------------------------
+# Name:         bmpshape.py
+# Purpose:      Bitmap shape
+#
+# Author:       Pierre Hj<48>lm (from C++ original by Julian Smart)
+#
+# Created:      20040508
+# RCS-ID:       
+# Copyright:    (c) 2004 Pierre Hj<48>lm - 1998 Julian Smart
+# Licence:      wxWindows license
+#----------------------------------------------------------------------------
+
+from __future__ import division
+
+from basic import RectangleShape
+
+
+class BitmapShape(RectangleShape):
+    """Draws a bitmap (non-resizable)."""
+    def __init__(self):
+        RectangleShape.__init__(self, 100, 50)
+        self._filename=""
+
+    def OnDraw(self, dc):
+        if not self._bitmap.Ok():
+            return
+
+        x = self._xpos-self._bitmap.GetWidth() / 2
+        y = self._ypos-self._bitmap.GetHeight() / 2
+        dc.DrawBitmap(self._bitmap, x, y, True)
+
+    def SetSize(self, w, h, recursive = True):
+        if self._bitmap.Ok():
+            w = self._bitmap.GetWidth()
+            h = self._bitmap.GetHeight()
+
+        self.SetAttachmentSize(w, h)
+
+        self._width = w
+        self._height = h
+
+        self.SetDefaultRegionSize()
+
+    def GetBitmap(self):
+        """Return a the bitmap associated with this shape."""
+        return self._bitmap
+    
+    def SetBitmap(self, bitmap):
+        """Set the bitmap associated with this shape.
+
+        You can delete the bitmap from the calling application, since
+        reference counting will take care of holding on to the internal bitmap
+        data.
+        """
+        self._bitmap = bitmap
+        if self._bitmap.Ok():
+            self.SetSize(self._bitmap.GetWidth(), self._bitmap.GetHeight())
+            
+    def SetFilename(self, f):
+        """Set the bitmap filename."""
+        self._filename = f
+
+    def GetFilename(self):
+        """Return the bitmap filename."""
+        return self._filename

wxPython/wx/lib/ogl/canvas.py

@@ -0,0 +1,360 @@
+# -*- coding: iso-8859-1 -*-
+#----------------------------------------------------------------------------
+# Name:         canvas.py
+# Purpose:      The canvas class
+#
+# Author:       Pierre Hj<48>lm (from C++ original by Julian Smart)
+#
+# Created:      20040508
+# RCS-ID:       
+# Copyright:    (c) 2004 Pierre Hj<48>lm - 1998 Julian Smart
+# Licence:      wxWindows license
+#----------------------------------------------------------------------------
+
+from __future__ import division
+
+import wx
+from lines import LineShape
+from composit import *
+
+NoDragging, StartDraggingLeft, ContinueDraggingLeft, StartDraggingRight, ContinueDraggingRight = 0, 1, 2, 3, 4
+
+KEY_SHIFT, KEY_CTRL = 1, 2
+
+
+
+# Helper function: True if 'contains' wholly contains 'contained'.
+def WhollyContains(contains, contained):
+    xp1, yp1 = contains.GetX(), contains.GetY()
+    xp2, yp2 = contained.GetX(), contained.GetY()
+    
+    w1, h1 = contains.GetBoundingBoxMax()
+    w2, h2 = contained.GetBoundingBoxMax()
+    
+    left1 = xp1-w1 / 2.0
+    top1 = yp1-h1 / 2.0
+    right1 = xp1 + w1 / 2.0
+    bottom1 = yp1 + h1 / 2.0
+    
+    left2 = xp2-w2 / 2.0
+    top2 = yp2-h2 / 2.0
+    right2 = xp2 + w2 / 2.0
+    bottom2 = yp2 + h2 / 2.0
+    
+    return ((left1 <= left2) and (top1 <= top2) and (right1 >= right2) and (bottom1 >= bottom2))
+    
+
+
+class ShapeCanvas(wx.ScrolledWindow):
+    def __init__(self, parent = None, id=-1, pos = wx.DefaultPosition, size = wx.DefaultSize, style = wx.BORDER, name="ShapeCanvas"):
+        wx.ScrolledWindow.__init__(self, parent, id, pos, size, style, name)
+
+        self._shapeDiagram = None
+        self._dragState = NoDragging
+        self._draggedShape = None
+        self._oldDragX = 0
+        self._oldDragY = 0
+        self._firstDragX = 0
+        self._firstDragY = 0
+        self._checkTolerance = True
+
+        wx.EVT_PAINT(self, self.OnPaint)
+        wx.EVT_MOUSE_EVENTS(self, self.OnMouseEvent)
+
+    def SetDiagram(self, diag):
+        self._shapeDiagram = diag
+
+    def GetDiagram(self):
+        return self._shapeDiagram
+    
+    def OnPaint(self, evt):
+        dc = wx.PaintDC(self)
+        self.PrepareDC(dc)
+        
+        dc.SetBackground(wx.Brush(self.GetBackgroundColour(), wx.SOLID))
+        dc.Clear()
+
+        if self.GetDiagram():
+            self.GetDiagram().Redraw(dc)
+
+    def OnMouseEvent(self, evt):
+        dc = wx.ClientDC(self)
+        self.PrepareDC(dc)
+        
+        x, y = evt.GetLogicalPosition(dc)
+
+        keys = 0
+        if evt.ShiftDown():
+            keys |= KEY_SHIFT
+        if evt.ControlDown():
+            keys |= KEY_CTRL
+
+        dragging = evt.Dragging()
+
+        # Check if we're within the tolerance for mouse movements.
+        # If we're very close to the position we started dragging
+        # from, this may not be an intentional drag at all.
+        if dragging:
+            dx = abs(dc.LogicalToDeviceX(x-self._firstDragX))
+            dy = abs(dc.LogicalToDeviceY(y-self._firstDragY))
+            if self._checkTolerance and (dx <= self.GetDiagram().GetMouseTolerance()) and (dy <= self.GetDiagram().GetMouseTolerance()):
+                return
+            # If we've ignored the tolerance once, then ALWAYS ignore
+            # tolerance in this drag, even if we come back within
+            # the tolerance range.
+            self._checkTolerance = False
+
+        # Dragging - note that the effect of dragging is left entirely up
+        # to the object, so no movement is done unless explicitly done by
+        # object.
+        if dragging and self._draggedShape and self._dragState == StartDraggingLeft:
+            self._dragState = ContinueDraggingLeft
+
+            # If the object isn't m_draggable, transfer message to canvas
+            if self._draggedShape.Draggable():
+                self._draggedShape.GetEventHandler().OnBeginDragLeft(x, y, keys, self._draggedAttachment)
+            else:
+                self._draggedShape = None
+                self.OnBeginDragLeft(x, y, keys)
+
+            self._oldDragX, self._oldDragY = x, y
+
+        elif dragging and self._draggedShape and self._dragState == ContinueDraggingLeft:
+            # Continue dragging
+            self._draggedShape.GetEventHandler().OnDragLeft(False, self._oldDragX, self._oldDragY, keys, self._draggedAttachment)
+            self._draggedShape.GetEventHandler().OnDragLeft(True, x, y, keys, self._draggedAttachment)
+            self._oldDragX, self._oldDragY = x, y
+
+        elif evt.LeftUp and self._draggedShape and self._dragState == ContinueDraggingLeft:
+            self._dragState = NoDragging
+            self._checkTolerance = True
+
+            self._draggedShape.GetEventHandler().OnDragLeft(False, self._oldDragX, self._oldDragY, keys, self._draggedAttachment)
+            self._draggedShape.GetEventHandler().OnEndDragLeft(x, y, keys, self._draggedAttachment)
+            self._draggedShape = None
+
+        elif dragging and self._draggedShape and self._dragState == StartDraggingRight:
+            self._dragState = ContinueDraggingRight
+            if self._draggedShape.Draggable:
+                self._draggedShape.GetEventHandler().OnBeginDragRight(x, y, keys, self._draggedAttachment)
+            else:
+                self._draggedShape = None
+                self.OnBeginDragRight(x, y, keys)
+            self._oldDragX, self._oldDragY = x, y
+
+        elif dragging and self._draggedShape and self._dragState == ContinueDraggingRight:
+            # Continue dragging
+            self._draggedShape.GetEventHandler().OnDragRight(False, self._oldDragX, self._oldDragY, keys, self._draggedAttachment)
+            self._draggedShape.GetEventHandler().OnDragRight(True, x, y, keys, self._draggedAttachment)
+            self._oldDragX, self._oldDragY = x, y
+
+        elif evt.RightUp() and self._draggedShape and self._dragState == ContinueDraggingRight:
+            self._dragState = NoDragging
+            self._checkTolerance = True
+
+            self._draggedShape.GetEventHandler().OnDragRight(False, self._oldDragX, self._oldDragY, keys, self._draggedAttachment)
+            self._draggedShape.GetEventHandler().OnEndDragRight(x, y, keys, self._draggedAttachment)
+            self._draggedShape = None
+
+        # All following events sent to canvas, not object
+        elif dragging and not self._draggedShape and self._dragState == StartDraggingLeft:
+            self._dragState = ContinueDraggingLeft
+            self.OnBeginDragLeft(x, y, keys)
+            self._oldDragX, self._oldDragY = x, y
+
+        elif dragging and not self._draggedShape and self._dragState == ContinueDraggingLeft:
+            # Continue dragging
+            self.OnDragLeft(False, self._oldDragX, self._oldDragY, keys)
+            self.OnDragLeft(True, x, y, keys)
+            self._oldDragX, self._oldDragY = x, y                
+
+        elif evt.LeftUp() and not self._draggedShape and self._dragState == ContinueDraggingLeft:
+            self._dragState = NoDragging
+            self._checkTolerance = True
+
+            self.OnDragLeft(False, self._oldDragX, self._oldDragY, keys)
+            self.OnEndDragLeft(x, y, keys)
+            self._draggedShape = None
+
+        elif dragging and not self._draggedShape and self._dragState == StartDraggingRight:
+            self._dragState = ContinueDraggingRight
+            self.OnBeginDragRight(x, y, keys)
+            self._oldDragX, self._oldDragY = x, y
+
+        elif dragging and not self._draggedShape and self._dragState == ContinueDraggingRight:
+            # Continue dragging
+            self.OnDragRight(False, self._oldDragX, self._oldDragY, keys)
+            self.OnDragRight(True, x, y, keys)
+            self._oldDragX, self._oldDragY = x, y
+
+        elif evt.RightUp() and not self._draggedShape and self._dragState == ContinueDraggingRight:
+            self._dragState = NoDragging
+            self._checkTolerance = True
+
+            self.OnDragRight(False, self._oldDragX, self._oldDragY, keys)
+            self.OnEndDragRight(x, y, keys)
+            self._draggedShape = None
+
+        # Non-dragging events
+        elif evt.IsButton():
+            self._checkTolerance = True
+
+            # Find the nearest object
+            attachment = 0
+
+            nearest_object, attachment = self.FindShape(x, y)
+            if nearest_object: # Object event
+                if evt.LeftDown():
+                    self._draggedShape = nearest_object
+                    self._draggedAttachment = attachment
+                    self._dragState = StartDraggingLeft
+                    self._firstDragX = x
+                    self._firstDragY = y
+
+                elif evt.LeftUp():
+                    # N.B. Only register a click if the same object was
+                    # identified for down *and* up.
+                    if nearest_object == self._draggedShape:
+                        nearest_object.GetEventHandler().OnLeftClick(x, y, keys, attachment)
+                    self._draggedShape = None
+                    self._dragState = NoDragging
+
+                elif evt.LeftDClick():
+                    nearest_object.GetEventHandler().OnLeftDoubleClick(x, y, keys, attachment)
+                    self._draggedShape = None
+                    self._dragState = NoDragging
+
+                elif evt.RightDown():
+                    self._draggedShape = nearest_object
+                    self._draggedAttachment = attachment
+                    self._dragState = StartDraggingRight
+                    self._firstDragX = x
+                    self._firstDragY = y
+
+                elif evt.RightUp():
+                    if nearest_object == self._draggedShape:
+                        nearest_object.GetEventHandler().OnRightClick(x, y, keys, attachment)
+                    self._draggedShape = None
+                    self._dragState = NoDragging
+
+            else: # Canvas event
+                if evt.LeftDown():
+                    self._draggedShape = None
+                    self._dragState = StartDraggingLeft
+                    self._firstDragX = x
+                    self._firstDragY = y
+
+                elif evt.LeftUp():
+                    self.OnLeftClick(x, y, keys)
+                    self._draggedShape = None
+                    self._dragState = NoDragging
+
+                elif evt.RightDown():
+                    self._draggedShape = None
+                    self._dragState = StartDraggingRight
+                    self._firstDragX = x
+                    self._firstDragY = y
+
+                elif evt.RightUp():
+                    self.OnRightClick(x, y, keys)
+                    self._draggedShape = None
+                    self._dragState = NoDragging
+
+    def FindShape(self, x, y, info = None, notObject = None):
+        nearest = 100000.0
+        nearest_attachment = 0
+        nearest_object = None
+
+        # Go backward through the object list, since we want:
+        # (a) to have the control points drawn LAST to overlay
+        #     the other objects
+        # (b) to find the control points FIRST if they exist
+
+        for object in self.GetDiagram().GetShapeList()[::-1]:
+            # First pass for lines, which might be inside a container, so we
+            # want lines to take priority over containers. This first loop
+            # could fail if we clickout side a line, so then we'll
+            # try other shapes.
+            if object.IsShown() and \
+               isinstance(object, LineShape) and \
+               object.HitTest(x, y) and \
+               ((info == None) or isinstance(object, info)) and \
+               (not notObject or not notObject.HasDescendant(object)):
+                temp_attachment, dist = object.HitTest(x, y)
+                # A line is trickier to spot than a normal object.
+                # For a line, since it's the diagonal of the box
+                # we use for the hit test, we may have several
+                # lines in the box and therefore we need to be able
+                # to specify the nearest point to the centre of the line
+                # as our hit criterion, to give the user some room for
+                # manouevre.
+                if dist<nearest:
+                    nearest = dist
+                    nearest_object = object
+                    nearest_attachment = temp_attachment
+
+        for object in self.GetDiagram().GetShapeList()[::-1]:
+            # On second pass, only ever consider non-composites or
+            # divisions. If children want to pass up control to
+            # the composite, that's up to them.
+            if (object.IsShown() and 
+                   (isinstance(object, DivisionShape) or 
+                    not isinstance(object, CompositeShape)) and 
+                    object.HitTest(x, y) and 
+                    (info == None or isinstance(object, info)) and 
+                    (not notObject or not notObject.HasDescendant(object))):
+                temp_attachment, dist = object.HitTest(x, y)
+                if not isinstance(object, LineShape):
+                    # If we've hit a container, and we have already
+                    # found a line in the first pass, then ignore
+                    # the container in case the line is in the container.
+                    # Check for division in case line straddles divisions
+                    # (i.e. is not wholly contained).
+                    if not nearest_object or not (isinstance(object, DivisionShape) or WhollyContains(object, nearest_object)):
+                        nearest_object = object
+                        nearest_attachment = temp_attachment
+                        break
+
+        return nearest_object, nearest_attachment
+
+    def AddShape(self, object, addAfter = None):
+        self.GetDiagram().AddShape(object, addAfter)
+
+    def InsertShape(self, object):
+        self.GetDiagram().InsertShape(object)
+
+    def RemoveShape(self, object):
+        self.GetDiagram().RemoveShape(object)
+
+    def GetQuickEditMode(self):
+        return self.GetDiagram().GetQuickEditMode()
+    
+    def Redraw(self, dc):
+        self.GetDiagram().Redraw(dc)
+
+    def Snap(self, x, y):
+        return self.GetDiagram().Snap(x, y)
+
+    def OnLeftClick(self, x, y, keys = 0):
+        pass
+
+    def OnRightClick(self, x, y, keys = 0):
+        pass
+
+    def OnDragLeft(self, draw, x, y, keys = 0):
+        pass
+
+    def OnBeginDragLeft(self, x, y, keys = 0):
+        pass
+
+    def OnEndDragLeft(self, x, y, keys = 0):
+        pass
+
+    def OnDragRight(self, draw, x, y, keys = 0):
+        pass
+
+    def OnBeginDragRight(self, x, y, keys = 0):
+        pass
+
+    def OnEndDragRight(self, x, y, keys = 0):
+        pass

wxPython/wx/lib/ogl/diagram.py

@@ -0,0 +1,160 @@
+# -*- coding: iso-8859-1 -*-
+#----------------------------------------------------------------------------
+# Name:         diagram.py
+# Purpose:      Diagram class
+#
+# Author:       Pierre Hj<48>lm (from C++ original by Julian Smart)
+#
+# Created:      20040508
+# RCS-ID:       
+# Copyright:    (c) 2004 Pierre Hj<48>lm - 1998 Julian Smart
+# Licence:      wxWindows license
+#----------------------------------------------------------------------------
+
+from __future__ import division
+
+import wx
+
+DEFAULT_MOUSE_TOLERANCE = 3
+
+
+
+class Diagram(object):
+    """Encapsulates an entire diagram, with methods for drawing. A diagram has
+    an associated ShapeCanvas.
+
+    Derived from:
+      Object
+    """
+    def __init__(self):
+        self._diagramCanvas = None
+        self._quickEditMode = False
+        self._snapToGrid = True
+        self._gridSpacing = 5.0
+        self._shapeList = []
+        self._mouseTolerance = DEFAULT_MOUSE_TOLERANCE
+
+    def Redraw(self, dc):
+        """Draw the shapes in the diagram on the specified device context."""
+        if self._shapeList:
+            if self.GetCanvas():
+                self.GetCanvas().SetCursor(wx.HOURGLASS_CURSOR)
+            for object in self._shapeList:
+                object.Draw(dc)
+            if self.GetCanvas():
+                self.GetCanvas().SetCursor(wx.STANDARD_CURSOR)
+
+    def Clear(self, dc):
+        """Clear the specified device context."""
+        dc.Clear()
+
+    def AddShape(self, object, addAfter = None):
+        """Adds a shape to the diagram. If addAfter is not None, the shape
+        will be added after addAfter.
+        """
+        if not object in self._shapeList:
+            if addAfter:
+                self._shapeList.insert(self._shapeList.index(addAfter) + 1, object)
+            else:
+                self._shapeList.append(object)
+
+            object.SetCanvas(self.GetCanvas())
+
+    def InsertShape(self, object):
+        """Insert a shape at the front of the shape list."""
+        self._shapeList.insert(0, object)
+
+    def RemoveShape(self, object):
+        """Remove the shape from the diagram (non-recursively) but do not
+        delete it.
+        """
+        if object in self._shapeList:
+            self._shapeList.remove(object)
+            
+    def RemoveAllShapes(self):
+        """Remove all shapes from the diagram but do not delete the shapes."""
+        self._shapeList = []
+
+    def DeleteAllShapes(self):
+        """Remove and delete all shapes in the diagram."""
+        for shape in self._shapeList[:]:
+            if not shape.GetParent():
+                self.RemoveShape(shape)
+                
+    def ShowAll(self, show):
+        """Call Show for each shape in the diagram."""
+        for shape in self._shapeList:
+            shape.Show()
+
+    def DrawOutLine(self, dc, x1, y1, x2, y2):
+        """Draw an outline rectangle on the current device context."""
+        dc.SetPen(wx.Pen(wx.Color(0, 0, 0), 1, wx.DOT))
+        dc.SetBrush(wx.TRANSPARENT_BRUSH)
+
+        dc.DrawLines([[x1, y1], [x2, y1], [x2, y2], [x1, y2], [x1, y1]])
+
+    def RecentreAll(self, dc):
+        """Make sure all text that should be centred, is centred."""
+        for shape in self._shapeList:
+            shape.Recentre(dc)
+
+    def SetCanvas(self, canvas):
+        """Set the canvas associated with this diagram."""
+        self._diagramCanvas = canvas
+
+    def GetCanvas(self):
+        """Return the shape canvas associated with this diagram."""
+        return self._diagramCanvas
+        
+    def FindShape(self, id):
+        """Return the shape for the given identifier."""
+        for shape in self._shapeList:
+            if shape.GetId() == id:
+                return shape
+        return None
+
+    def Snap(self, x, y):
+        """'Snaps' the coordinate to the nearest grid position, if
+        snap-to-grid is on."""
+        if self._snapToGrid:
+            return self._gridSpacing * int(x / self._gridSpacing + 0.5), self._gridSpacing * int(y / self._gridSpacing + 0.5)
+        return x, y
+
+    def GetGridSpacing(self):
+        """Return the grid spacing."""
+        return self._gridSpacing
+
+    def GetSnapToGrid(self):
+        """Return snap-to-grid mode."""
+        return self._snapToGrid
+
+    def SetQuickEditMode(self, mode):
+        """Set quick-edit-mode on of off.
+
+        In this mode, refreshes are minimized, but the diagram may need
+        manual refreshing occasionally.
+        """
+        self._quickEditMode = mode
+
+    def GetQuickEditMode(self):
+        """Return quick edit mode."""
+        return self._quickEditMode
+
+    def SetMouseTolerance(self, tolerance):
+        """Set the tolerance within which a mouse move is ignored.
+
+        The default is 3 pixels.
+        """
+        self._mouseTolerance = tolerance
+
+    def GetMouseTolerance(self):
+        """Return the tolerance within which a mouse move is ignored."""
+        return self._mouseTolerance
+
+    def GetShapeList(self):
+        """Return the internal shape list."""
+        return self._shapeList
+
+    def GetCount(self):
+        """Return the number of shapes in the diagram."""
+        return len(self._shapeList)

wxPython/wx/lib/ogl/divided.py

@@ -0,0 +1,404 @@
+# -*- coding: iso-8859-1 -*-
+#----------------------------------------------------------------------------
+# Name:         divided.py
+# Purpose:      DividedShape class
+#
+# Author:       Pierre Hj<48>lm (from C++ original by Julian Smart)
+#
+# Created:      20040508
+# RCS-ID:       
+# Copyright:    (c) 2004 Pierre Hj<48>lm - 1998 Julian Smart
+# Licence:      wxWindows license
+#----------------------------------------------------------------------------
+
+from __future__ import division
+
+import sys
+import wx
+
+from basic import ControlPoint, RectangleShape, Shape
+from oglmisc import *
+
+
+
+class DividedShapeControlPoint(ControlPoint):
+    def __init__(self, the_canvas, object, region, size, the_m_xoffset, the_m_yoffset, the_type):
+        ControlPoint.__init__(self, the_canvas, object, size, the_m_xoffset, the_m_yoffset, the_type)
+        self.regionId = region
+
+    # Implement resizing of divided object division
+    def OnDragLeft(self, draw, x, y, keys = 0, attachment = 0):
+        dc = wx.ClientDC(self.GetCanvas())
+        self.GetCanvas().PrepareDC(dc)
+
+        dc.SetLogicalFunction(OGLRBLF)
+        dottedPen = wx.Pen(wx.Colour(0, 0, 0), 1, wx.DOT)
+        dc.SetPen(dottedPen)
+        dc.SetBrush(wx.TRANSPARENT_BRUSH)
+
+        dividedObject = self._shape
+        x1 = dividedObject.GetX()-dividedObject.GetWidth() / 2
+        y1 = y
+        x2 = dividedObject.GetX() + dividedObject.GetWidth() / 2
+        y2 = y
+
+        dc.DrawLine(x1, y1, x2, y2)
+
+    def OnBeginDragLeft(self, x, y, keys = 0, attachment = 0):
+        dc = wx.ClientDC(self.GetCanvas())
+        self.GetCanvas().PrepareDC(dc)
+
+        dc.SetLogicalFunction(OGLRBLF)
+        dottedPen = wx.Pen(wx.Colour(0, 0, 0), 1, wx.DOT)
+        dc.SetPen(dottedPen)
+        dc.SetBrush(wx.TRANSPARENT_BRUSH)
+
+        dividedObject = self._shape
+        
+        x1 = dividedObject.GetX()-dividedObject.GetWidth() / 2
+        y1 = y
+        x2 = dividedObject.GetX() + dividedObject.GetWidth() / 2
+        y2 = y
+
+        dc.DrawLine(x1, y1, x2, y2)
+        self._canvas.CaptureMouse()
+
+    def OnEndDragLeft(self, x, y, keys = 0, attachment = 0):
+        dc = wx.ClientDC(self.GetCanvas())
+        self.GetCanvas().PrepareDC(dc)
+
+        dividedObject = self._shape
+        if not dividedObject.GetRegions()[self.regionId]:
+            return
+        
+        thisRegion = dividedObject.GetRegions()[self.regionId]
+        nextRegion = None
+
+        dc.SetLogicalFunction(wx.COPY)
+
+        if self._canvas.HasCapture():
+            self._canvas.ReleaseMouse()
+
+        # Find the old top and bottom of this region,
+        # and calculate the new proportion for this region
+        # if legal.
+        currentY = dividedObject.GetY()-dividedObject.GetHeight() / 2
+        maxY = dividedObject.GetY() + dividedObject.GetHeight() / 2
+
+        # Save values
+        theRegionTop = 0
+        nextRegionBottom = 0
+        
+        for i in range(len(dividedObject.GetRegions())):
+            region = dividedObject.GetRegions()[i]
+            proportion = region._regionProportionY
+            yy = currentY + dividedObject.GetHeight() * proportion
+            actualY = min(maxY, yy)
+
+            if region == thisRegion:
+                thisRegionTop = currentY
+                
+                if i + 1<len(dividedObject.GetRegions()):
+                    nextRegion = dividedObject.GetRegions()[i + 1]
+            if region == nextRegion:
+                nextRegionBottom = actualY
+
+            currentY = actualY
+
+        if not nextRegion:
+            return
+
+        # Check that we haven't gone above this region or below
+        # next region.
+        if y <= thisRegionTop or y >= nextRegionBottom:
+            return
+
+        dividedObject.EraseLinks(dc)
+
+        # Now calculate the new proportions of this region and the next region
+        thisProportion = (y-thisRegionTop) / dividedObject.GetHeight()
+        nextProportion = (nextRegionBottom-y) / dividedObject.GetHeight()
+
+        thisRegion.SetProportions(0, thisProportion)
+        nextRegion.SetProportions(0, nextProportion)
+        self._yoffset = y-dividedObject.GetY()
+
+        # Now reformat text
+        for i, region in enumerate(dividedObject.GetRegions()):
+            if region.GetText():
+                s = region.GetText()
+                dividedObject.FormatText(dc, s, i)
+
+        dividedObject.SetRegionSizes()
+        dividedObject.Draw(dc)
+        dividedObject.GetEventHandler().OnMoveLinks(dc)
+        
+
+
+class DividedShape(RectangleShape):
+    """A DividedShape is a rectangle with a number of vertical divisions.
+    Each division may have its text formatted with independent characteristics,
+    and the size of each division relative to the whole image may be specified.
+
+    Derived from:
+      RectangleShape
+    """
+    def __init__(self, w, h):
+        RectangleShape.__init__(self, w, h)
+        self.ClearRegions()
+
+    def OnDraw(self, dc):
+        RectangleShape.OnDraw(self, dc)
+
+    def OnDrawContents(self, dc):
+        if self.GetRegions():
+            defaultProportion = 1 / len(self.GetRegions())
+        else:
+            defaultProportion = 0
+        currentY = self._ypos-self._height / 2
+        maxY = self._ypos + self._height / 2
+
+        leftX = self._xpos-self._width / 2
+        rightX = self._xpos + self._width / 2
+
+        if self._pen:
+            dc.SetPen(self._pen)
+
+        dc.SetTextForeground(self._textColour)
+
+        # For efficiency, don't do this under X - doesn't make
+        # any visible difference for our purposes.
+        if sys.platform[:3]=="win":
+            dc.SetTextBackground(self._brush.GetColour())
+
+        if self.GetDisableLabel():
+            return
+
+        xMargin = 2
+        yMargin = 2
+
+        dc.SetBackgroundMode(wx.TRANSPARENT)
+
+        for region in self.GetRegions():
+            dc.SetFont(region.GetFont())
+            dc.SetTextForeground(region.GetActualColourObject())
+
+            if region._regionProportionY<0:
+                proportion = defaultProportion
+            else:
+                proportion = region._regionProportionY
+
+            y = currentY + self._height * proportion
+            actualY = min(maxY, y)
+
+            centreX = self._xpos
+            centreY = currentY + (actualY-currentY) / 2
+
+            DrawFormattedText(dc, region._formattedText, centreX, centreY, self._width-2 * xMargin, actualY-currentY-2 * yMargin, region._formatMode)
+
+            if y <= maxY and region != self.GetRegions()[-1]:
+                regionPen = region.GetActualPen()
+                if regionPen:
+                    dc.SetPen(regionPen)
+                    dc.DrawLine(leftX, y, rightX, y)
+
+            currentY = actualY
+
+    def SetSize(self, w, h, recursive = True):
+        self.SetAttachmentSize(w, h)
+        self._width = w
+        self._height = h
+        self.SetRegionSizes()
+
+    def SetRegionSizes(self):
+        """Set all region sizes according to proportions and this object
+        total size.
+        """
+        if not self.GetRegions():
+            return
+
+        if self.GetRegions():
+            defaultProportion = 1 / len(self.GetRegions())
+        else:
+            defaultProportion = 0
+        currentY = self._ypos-self._height / 2
+        maxY = self._ypos + self._height / 2
+        
+        for region in self.GetRegions():
+            if region._regionProportionY <= 0:
+                proportion = defaultProportion
+            else:
+                proportion = region._regionProportionY
+
+            sizeY = proportion * self._height
+            y = currentY + sizeY
+            actualY = min(maxY, y)
+
+            centreY = currentY + (actualY-currentY) / 2
+
+            region.SetSize(self._width, sizeY)
+            region.SetPosition(0, centreY-self._ypos)
+
+            currentY = actualY
+
+    # Attachment points correspond to regions in the divided box
+    def GetAttachmentPosition(self, attachment, nth = 0, no_arcs = 1, line = None):
+        totalNumberAttachments = len(self.GetRegions()) * 2 + 2
+        if self.GetAttachmentMode() == ATTACHMENT_MODE_NONE or attachment >= totalNumberAttachments:
+            return Shape.GetAttachmentPosition(self, attachment, nth, no_arcs)
+
+        n = len(self.GetRegions())
+        isEnd = line and line.IsEnd(self)
+
+        left = self._xpos-self._width / 2
+        right = self._xpos + self._width / 2
+        top = self._ypos-self._height / 2
+        bottom = self._ypos + self._height / 2
+
+        # Zero is top, n + 1 is bottom
+        if attachment == 0:
+            y = top
+            if self._spaceAttachments:
+                if line and line.GetAlignmentType(isEnd) == LINE_ALIGNMENT_TO_NEXT_HANDLE:
+                    # Align line according to the next handle along
+                    point = line.GetNextControlPoint(self)
+                    if point.x<left:
+                        x = left
+                    elif point.x>right:
+                        x = right
+                    else:
+                        x = point.x
+                else:
+                    x = left + (nth + 1) * self._width / (no_arcs + 1)
+            else:
+                x = self._xpos
+        elif attachment == n + 1:
+            y = bottom
+            if self._spaceAttachments:
+                if line and line.GetAlignmentType(isEnd) == LINE_ALIGNMENT_TO_NEXT_HANDLE:
+                    # Align line according to the next handle along
+                    point = line.GetNextControlPoint(self)
+                    if point.x<left:
+                        x = left
+                    elif point.x>right:
+                        x = right
+                    else:
+                        x = point.x
+                else:
+                    x = left + (nth + 1) * self._width / (no_arcs + 1)
+            else:
+                x = self._xpos
+        else: # Left or right
+            isLeft = not attachment<(n + 1)
+            if isLeft:
+                i = totalNumberAttachments-attachment-1
+            else:
+                i = attachment-1
+
+            region = self.GetRegions()[i]
+            if region:
+                if isLeft:
+                    x = left
+                else:
+                    x = right
+
+                # Calculate top and bottom of region
+                top = self._ypos + region._y-region._height / 2
+                bottom = self._ypos + region._y + region._height / 2
+
+                # Assuming we can trust the absolute size and
+                # position of these regions
+                if self._spaceAttachments:
+                    if line and line.GetAlignmentType(isEnd) == LINE_ALIGNMENT_TO_NEXT_HANDLE:
+                        # Align line according to the next handle along
+                        point = line.GetNextControlPoint(self)
+                        if point.y<bottom:
+                            y = bottom
+                        elif point.y>top:
+                            y = top
+                        else:
+                            y = point.y
+                    else:
+                        y = top + (nth + 1) * region._height / (no_arcs + 1)
+                else:
+                    y = self._ypos + region._y
+            else:
+                return False
+        return x, y
+
+    def GetNumberOfAttachments(self):
+        # There are two attachments for each region (left and right),
+        # plus one on the top and one on the bottom.
+        n = len(self.GetRegions()) * 2 + 2
+
+        maxN = n-1
+        for point in self._attachmentPoints:
+            if point._id>maxN:
+                maxN = point._id
+
+        return maxN + 1
+
+    def AttachmentIsValid(self, attachment):
+        totalNumberAttachments = len(self.GetRegions()) * 2 + 2
+        if attachment >= totalNumberAttachments:
+            return Shape.AttachmentIsValid(self, attachment)
+        else:
+            return attachment >= 0
+
+    def MakeControlPoints(self):
+        RectangleShape.MakeControlPoints(self)
+        self.MakeMandatoryControlPoints()
+
+    def MakeMandatoryControlPoints(self):
+        currentY = self.GetY()-self._height / 2
+        maxY = self.GetY() + self._height / 2
+
+        for i, region in enumerate(self.GetRegions()):
+            proportion = region._regionProportionY
+
+            y = currentY + self._height * proportion
+            actualY = min(maxY, y)
+
+            if region != self.GetRegions()[-1]:
+                controlPoint = DividedShapeControlPoint(self._canvas, self, i, CONTROL_POINT_SIZE, 0, actualY-self.GetY(), 0)
+                self._canvas.AddShape(controlPoint)
+                self._controlPoints.append(controlPoint)
+
+            currentY = actualY
+
+    def ResetControlPoints(self):
+        # May only have the region handles, (n - 1) of them
+        if len(self._controlPoints)>len(self.GetRegions())-1:
+            RectangleShape.ResetControlPoints(self)
+
+        self.ResetMandatoryControlPoints()
+
+    def ResetMandatoryControlPoints(self):
+        currentY = self.GetY()-self._height / 2
+        maxY = self.GetY() + self._height / 2
+
+        i = 0
+        for controlPoint in self._controlPoints:
+            if isinstance(controlPoint, DividedShapeControlPoint):
+                region = self.GetRegions()[i]
+                proportion = region._regionProportionY
+
+                y = currentY + self._height * proportion
+                actualY = min(maxY, y)
+
+                controlPoint._xoffset = 0
+                controlPoint._yoffset = actualY-self.GetY()
+
+                currentY = actualY
+
+                i += 1
+                
+    def EditRegions(self):
+        """Edit the region colours and styles. Not implemented."""
+        print "EditRegions() is unimplemented"
+        
+    def OnRightClick(self, x, y, keys = 0, attachment = 0):
+        if keys & KEY_CTRL:
+            self.EditRegions()
+        else:
+            RectangleShape.OnRightClick(self, x, y, keys, attachment)

wxPython/wx/lib/ogl/oglmisc.py

@@ -0,0 +1,416 @@
+# -*- coding: iso-8859-1 -*-
+#----------------------------------------------------------------------------
+# Name:         oglmisc.py
+# Purpose:      Miscellaneous OGL support functions
+#
+# Author:       Pierre Hj<48>lm (from C++ original by Julian Smart)
+#
+# Created:      20040508
+# RCS-ID:       
+# Copyright:    (c) 2004 Pierre Hj<48>lm - 1998 Julian Smart
+# Licence:      wxWindows license
+#----------------------------------------------------------------------------
+
+from __future__ import division
+from math import *
+
+import wx
+
+# Control point types
+# Rectangle and most other shapes
+CONTROL_POINT_VERTICAL = 1
+CONTROL_POINT_HORIZONTAL = 2
+CONTROL_POINT_DIAGONAL = 3
+
+# Line
+CONTROL_POINT_ENDPOINT_TO = 4
+CONTROL_POINT_ENDPOINT_FROM = 5
+CONTROL_POINT_LINE = 6
+
+# Types of formatting: can be combined in a bit list
+FORMAT_NONE = 0             # Left justification
+FORMAT_CENTRE_HORIZ = 1     # Centre horizontally
+FORMAT_CENTRE_VERT = 2      # Centre vertically
+FORMAT_SIZE_TO_CONTENTS = 4 # Resize shape to contents
+
+# Attachment modes
+ATTACHMENT_MODE_NONE, ATTACHMENT_MODE_EDGE, ATTACHMENT_MODE_BRANCHING = 0, 1, 2
+
+# Shadow mode
+SHADOW_NONE, SHADOW_LEFT, SHADOW_RIGHT = 0, 1, 2
+
+OP_CLICK_LEFT, OP_CLICK_RIGHT, OP_DRAG_LEFT, OP_DRAG_RIGHT = 1, 2, 4, 8
+OP_ALL = OP_CLICK_LEFT | OP_CLICK_RIGHT | OP_DRAG_LEFT | OP_DRAG_RIGHT
+
+# Sub-modes for branching attachment mode
+BRANCHING_ATTACHMENT_NORMAL = 1
+BRANCHING_ATTACHMENT_BLOB = 2
+
+# logical function to use when drawing rubberband boxes, etc.
+OGLRBLF = wx.INVERT
+
+CONTROL_POINT_SIZE = 6
+
+# Types of arrowhead
+# (i) Built-in
+ARROW_HOLLOW_CIRCLE   = 1
+ARROW_FILLED_CIRCLE   = 2
+ARROW_ARROW           = 3
+ARROW_SINGLE_OBLIQUE  = 4
+ARROW_DOUBLE_OBLIQUE  = 5
+# (ii) Custom
+ARROW_METAFILE        = 20
+
+# Position of arrow on line
+ARROW_POSITION_START  = 0
+ARROW_POSITION_END    = 1
+ARROW_POSITION_MIDDLE = 2
+
+# Line alignment flags
+# Vertical by default
+LINE_ALIGNMENT_HORIZ              = 1
+LINE_ALIGNMENT_VERT               = 0
+LINE_ALIGNMENT_TO_NEXT_HANDLE     = 2
+LINE_ALIGNMENT_NONE               = 0
+
+
+
+# Format a string to a list of strings that fit in the given box.
+# Interpret %n and 10 or 13 as a new line.
+def FormatText(dc, text, width, height, formatMode):
+    i = 0
+    word=""
+    word_list = []
+    end_word = False
+    new_line = False
+    while i<len(text):
+        if text[i]=="%":
+            i += 1
+            if i == len(text):
+                word+="%"
+            else:
+                if text[i]=="n":
+                    new_line = True
+                    end_word = True
+                    i += 1
+                else:
+                    word+="%"+text[i]
+                    i += 1
+        elif text[i] in ["\012","\015"]:
+            new_line = True
+            end_word = True
+            i += 1
+        elif text[i]==" ":
+            end_word = True
+            i += 1
+        else:
+            word += text[i]
+            i += 1
+
+        if i == len(text):
+            end_word = True
+
+        if end_word:
+            word_list.append(word)
+            word=""
+            end_word = False
+        if new_line:
+            word_list.append(None)
+            new_line = False
+
+    # Now, make a list of strings which can fit in the box
+    string_list = []
+    buffer=""
+    for s in word_list:
+        oldBuffer = buffer
+        if s is None:
+            # FORCE NEW LINE
+            if len(buffer)>0:
+                string_list.append(buffer)
+            buffer=""
+        else:
+            if len(buffer):
+                buffer+=" "
+            buffer += s
+            x, y = dc.GetTextExtent(buffer)
+
+            # Don't fit within the bounding box if we're fitting
+            # shape to contents
+            if (x>width) and not (formatMode & FORMAT_SIZE_TO_CONTENTS):
+                # Deal with first word being wider than box
+                if len(oldBuffer):
+                    string_list.append(oldBuffer)
+                buffer = s
+    if len(buffer):
+        string_list.append(buffer)
+
+    return string_list
+
+
+
+def GetCentredTextExtent(dc, text_list, xpos = 0, ypos = 0, width = 0, height = 0):
+    if not text_list:
+        return 0, 0
+
+    max_width = 0
+    for line in text_list:
+        current_width, char_height = dc.GetTextExtent(line)
+        if current_width>max_width:
+            max_width = current_width
+
+    return max_width, len(text_list) * char_height
+
+
+
+def CentreText(dc, text_list, xpos, ypos, width, height, formatMode):
+    if not text_list:
+        return
+
+    # First, get maximum dimensions of box enclosing text
+    char_height = 0
+    max_width = 0
+    current_width = 0
+
+    # Store text extents for speed
+    widths = []
+    for line in text_list:
+        current_width, char_height = dc.GetTextExtent(line.GetText())
+        widths.append(current_width)
+        if current_width>max_width:
+            max_width = current_width
+
+    max_height = len(text_list) * char_height
+
+    if formatMode & FORMAT_CENTRE_VERT:
+        if max_height<height:
+            yoffset = ypos - height / 2 + (height - max_height) / 2
+        else:
+            yoffset = ypos - height / 2
+        yOffset = ypos
+    else:
+        yoffset = 0.0
+        yOffset = 0.0
+
+    if formatMode & FORMAT_CENTRE_HORIZ:
+        xoffset = xpos - width / 2
+        xOffset = xpos
+    else:
+        xoffset = 0.0
+        xOffset = 0.0
+
+    for i, line in enumerate(text_list):
+        if formatMode & FORMAT_CENTRE_HORIZ and widths[i]<width:
+            x = (width - widths[i]) / 2 + xoffset
+        else:
+            x = xoffset
+        y = i * char_height + yoffset
+
+        line.SetX(x - xOffset)
+        line.SetY(y - yOffset)
+        
+
+
+def DrawFormattedText(dc, text_list, xpos, ypos, width, height, formatMode):
+    if formatMode & FORMAT_CENTRE_HORIZ:
+        xoffset = xpos
+    else:
+        xoffset = xpos - width / 2
+
+    if formatMode & FORMAT_CENTRE_VERT:
+        yoffset = ypos
+    else:
+        yoffset = ypos - height / 2
+
+    # +1 to allow for rounding errors
+    dc.SetClippingRegion(xpos - width / 2, ypos - height / 2, width + 1, height + 1)
+
+    for line in text_list:
+        dc.DrawText(line.GetText(), xoffset + line.GetX(), yoffset + line.GetY())
+
+    dc.DestroyClippingRegion()
+
+
+
+def RoughlyEqual(val1, val2, tol = 0.00001):
+    return val1<(val2 + tol) and val1>(val2 - tol) and \
+           val2<(val1 + tol) and val2>(val1 - tol)
+
+
+
+def FindEndForBox(width, height, x1, y1, x2, y2):
+    xvec = [x1 - width / 2, x1 - width / 2, x1 + width / 2, x1 + width / 2, x1 - width / 2]
+    yvec = [y1 - height / 2, y1 + height / 2, y1 + height / 2, y1 - height / 2, y1 - height / 2]
+
+    return FindEndForPolyline(xvec, yvec, x2, y2, x1, y1)
+
+
+
+def CheckLineIntersection(x1, y1, x2, y2, x3, y3, x4, y4):
+    denominator_term = (y4 - y3) * (x2 - x1) - (y2 - y1) * (x4 - x3)
+    numerator_term = (x3 - x1) * (y4 - y3) + (x4 - x3) * (y1 - y3)
+
+    length_ratio = 1.0
+    k_line = 1.0
+
+    # Check for parallel lines
+    if denominator_term<0.005 and denominator_term>-0.005:
+        line_constant=-1.0
+    else:
+        line_constant = float(numerator_term) / denominator_term
+
+    # Check for intersection
+    if line_constant<1.0 and line_constant>0.0:
+        # Now must check that other line hits
+        if (y4 - y3)<0.005 and (y4 - y3)>-0.005:
+            k_line = (x1 - x3 + line_constant * (x2 - x1)) / (x4 - x3)
+        else:
+            k_line = (y1 - y3 + line_constant * (y2 - y1)) / (y4 - y3)
+        if k_line >= 0 and k_line<1:
+            length_ratio = line_constant
+        else:
+            k_line = 1
+
+    return length_ratio, k_line
+
+
+
+def FindEndForPolyline(xvec, yvec, x1, y1, x2, y2):
+    lastx = xvec[0]
+    lasty = yvec[0]
+
+    min_ratio = 1.0
+
+    for i in range(1, len(xvec)):
+        line_ratio, other_ratio = CheckLineIntersection(x1, y1, x2, y2, lastx, lasty, xvec[i], yvec[i])
+        lastx = xvec[i]
+        lasty = yvec[i]
+
+        if line_ratio<min_ratio:
+            min_ratio = line_ratio
+
+    # Do last (implicit) line if last and first doubles are not identical
+    if not (xvec[0] == lastx and yvec[0] == lasty):
+        line_ratio, other_ratio = CheckLineIntersection(x1, y1, x2, y2, lastx, lasty, xvec[0], yvec[0])
+        if line_ratio<min_ratio:
+            min_ratio = line_ratio
+
+    return x1 + (x2 - x1) * min_ratio, y1 + (y2 - y1) * min_ratio
+
+
+
+def PolylineHitTest(xvec, yvec, x1, y1, x2, y2):
+    isAHit = False
+    lastx = xvec[0]
+    lasty = yvec[0]
+
+    min_ratio = 1.0
+
+    for i in range(1, len(xvec)):
+        line_ratio, other_ratio = CheckLineIntersection(x1, y1, x2, y2, lastx, lasty, xvec[i], yvec[i])
+        if line_ratio != 1.0:
+            isAHit = True
+        lastx = xvec[i]
+        lasty = yvec[i]
+
+        if line_ratio<min_ratio:
+            min_ratio = line_ratio
+
+    # Do last (implicit) line if last and first doubles are not identical
+    if not (xvec[0] == lastx and yvec[0] == lasty):
+        line_ratio, other_ratio = CheckLineIntersection(x1, y1, x2, y2, lastx, lasty, xvec[0], yvec[0])
+        if line_ratio != 1.0:
+            isAHit = True
+
+    return isAHit
+
+
+
+def GraphicsStraightenLine(point1, point2):
+    dx = point2[0] - point1[0]
+    dy = point2[1] - point1[1]
+
+    if dx == 0:
+        return
+    elif abs(dy / dx)>1:
+        point2[0] = point1[0]
+    else:
+        point2[1] = point1[0]
+
+
+
+def GetPointOnLine(x1, y1, x2, y2, length):
+    l = sqrt((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1))
+    if l<0.01:
+        l = 0.01
+
+    i_bar = (x2 - x1) / l
+    j_bar = (y2 - y1) / l
+
+    return -length * i_bar + x2,-length * j_bar + y2
+
+
+
+def GetArrowPoints(x1, y1, x2, y2, length, width):
+    l = sqrt((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1))
+
+    if l<0.01:
+        l = 0.01
+
+    i_bar = (x2 - x1) / l
+    j_bar = (y2 - y1) / l
+    
+    x3=-length * i_bar + x2
+    y3=-length * j_bar + y2
+
+    return x2, y2, width*-j_bar + x3, width * i_bar + y3,-width*-j_bar + x3,-width * i_bar + y3
+
+
+
+def DrawArcToEllipse(x1, y1, width1, height1, x2, y2, x3, y3):
+    a1 = width1 / 2
+    b1 = height1 / 2
+
+    # Check that x2 != x3
+    if abs(x2 - x3)<0.05:
+        x4 = x2
+        if y3>y2:
+            y4 = y1 - sqrt((b1 * b1 - (((x2 - x1) * (x2 - x1)) * (b1 * b1) / (a1 * a1))))
+        else:
+            y4 = y1 + sqrt((b1 * b1 - (((x2 - x1) * (x2 - x1)) * (b1 * b1) / (a1 * a1))))
+        return x4, y4
+
+    # Calculate the x and y coordinates of the point where arc intersects ellipse
+    A = (1 / (a1 * a1))
+    B = ((y3 - y2) * (y3 - y2)) / ((x3 - x2) * (x3 - x2) * b1 * b1)
+    C = (2 * (y3 - y2) * (y2 - y1)) / ((x3 - x2) * b1 * b1)
+    D = ((y2 - y1) * (y2 - y1)) / (b1 * b1)
+    E = (A + B)
+    F = (C - (2 * A * x1) - (2 * B * x2))
+    G = ((A * x1 * x1) + (B * x2 * x2) - (C * x2) + D - 1)
+    H = ((y3 - y2) / (x32 - x2))
+    K = ((F * F) - (4 * E * G))
+
+    if K >= 0:
+        # In this case the line intersects the ellipse, so calculate intersection
+        if x2 >= x1:
+            ellipse1_x = ((F*-1) + sqrt(K)) / (2 * E)
+            ellipse1_y = ((H * (ellipse1_x - x2)) + y2)
+        else:
+            ellipse1_x = (((F*-1) - sqrt(K)) / (2 * E))
+            ellipse1_y = ((H * (ellipse1_x - x2)) + y2)
+    else:
+        # in this case, arc does not intersect ellipse, so just draw arc
+        ellipse1_x = x3
+        ellipse1_y = y3
+
+    return ellipse1_x, ellipse1_y
+
+
+
+def FindEndForCircle(radius, x1, y1, x2, y2):
+    H = sqrt((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1))
+
+    if H == 0:
+        return x1, y1
+    else:
+        return radius * (x2 - x1) / H + x1, radius * (y2 - y1) / H + y1