Ejemplo n.º 1
0
        /// <summary>
        /// Helper routine to render two distinct stroke nodes
        /// </summary>
        private static void RenderTwoStrokeNodes(   StreamGeometryContext context,
                                                    StrokeNode strokeNodePrevious,
                                                    Rect strokeNodePreviousBounds,
                                                    StrokeNode strokeNodeCurrent,
                                                    Rect strokeNodeCurrentBounds,
                                                    List<Point> pointBuffer1,
                                                    List<Point> pointBuffer2,
                                                    List<Point> pointBuffer3
#if DEBUG_RENDERING_FEEDBACK
                                                   ,DrawingContext debugDC,
                                                   double feedbackSize,
                                                   bool showFeedback
#endif
                                                    )
        {
            Debug.Assert(pointBuffer1 != null);
            Debug.Assert(pointBuffer2 != null);
            Debug.Assert(pointBuffer3 != null);
            Debug.Assert(context != null);
            
            
            //see if we need to render a quad - if there is not at least a 70% overlap
            if (FuzzyContains(strokeNodePreviousBounds, strokeNodeCurrentBounds, 70d) != RectCompareResult.NoItersection)
            {
                //we're between 100% and 70% overlapped
                //just render two distinct figures with a connecting quad (if needed)
                strokeNodePrevious.GetContourPoints(pointBuffer1);
                AddFigureToStreamGeometryContext(context, pointBuffer1, strokeNodePrevious.IsEllipse/*isBezierFigure*/);

                Quad quad = strokeNodeCurrent.GetConnectingQuad();
                if (!quad.IsEmpty)
                {
                    pointBuffer3.Add(quad.A);
                    pointBuffer3.Add(quad.B);
                    pointBuffer3.Add(quad.C);
                    pointBuffer3.Add(quad.D);
                    AddFigureToStreamGeometryContext(context, pointBuffer3, false/*isBezierFigure*/);
                }

                strokeNodeCurrent.GetContourPoints(pointBuffer2);
                AddFigureToStreamGeometryContext(context, pointBuffer2, strokeNodeCurrent.IsEllipse/*isBezierFigure*/);
            }
            else
            {
                //we're less than 70% overlapped, it's safe to run our optimization
#if DEBUG_RENDERING_FEEDBACK
                strokeNodeCurrent.GetPointsAtStartOfSegment(pointBuffer1, pointBuffer2, debugDC, feedbackSize, showFeedback);
                strokeNodeCurrent.GetPointsAtEndOfSegment(pointBuffer1, pointBuffer2, debugDC, feedbackSize, showFeedback);
#else
                strokeNodeCurrent.GetPointsAtStartOfSegment(pointBuffer1, pointBuffer2);
                strokeNodeCurrent.GetPointsAtEndOfSegment(pointBuffer1, pointBuffer2);
#endif
                //render
                ReverseDCPointsRenderAndClear(context, pointBuffer1, pointBuffer2, pointBuffer3, strokeNodeCurrent.IsEllipse, false/*clear the point collections*/);
            }
        }
Ejemplo n.º 2
0
        internal static void CalcGeometryAndBounds(StrokeNodeIterator iterator,
                                                   DrawingAttributes drawingAttributes,
#if DEBUG_RENDERING_FEEDBACK
                                                   DrawingContext debugDC,
                                                   double feedbackSize,
                                                   bool showFeedback,
#endif
                                                   bool calculateBounds,
                                                   out Geometry geometry,
                                                   out Rect bounds)
        {

            Debug.Assert(iterator != null && drawingAttributes != null);

            //we can use our new algorithm for identity only.
            Matrix stylusTipTransform = drawingAttributes.StylusTipTransform;
            if (stylusTipTransform != Matrix.Identity && stylusTipTransform._type != MatrixTypes.TRANSFORM_IS_SCALING)
            {
                //second best optimization
                CalcGeometryAndBoundsWithTransform(iterator, drawingAttributes, stylusTipTransform._type, calculateBounds, out geometry, out bounds);
            }
            else
            {

                StreamGeometry streamGeometry = new StreamGeometry();
                streamGeometry.FillRule = FillRule.Nonzero;

                StreamGeometryContext context = streamGeometry.Open();
                geometry = streamGeometry;
                Rect empty = Rect.Empty;
                bounds = empty;
                try
                {
                    //
                    // We keep track of three StrokeNodes as we iterate across
                    // the Stroke. Since these are structs, the default ctor will
                    // be called and .IsValid will be false until we initialize them
                    //
                    StrokeNode emptyStrokeNode = new StrokeNode();
                    StrokeNode prevPrevStrokeNode = new StrokeNode();
                    StrokeNode prevStrokeNode = new StrokeNode();
                    StrokeNode strokeNode = new StrokeNode();

                    Rect prevPrevStrokeNodeBounds = empty;
                    Rect prevStrokeNodeBounds = empty;
                    Rect strokeNodeBounds = empty;

                    //percentIntersect is a function of drawingAttributes height / width
                    double percentIntersect = 95d;
                    double maxExtent = Math.Max(drawingAttributes.Height, drawingAttributes.Width);
                    percentIntersect += Math.Min(4.99999d, ((maxExtent / 20d) * 5d));

                    double prevAngle = double.MinValue;
                    bool isStartOfSegment = true;
                    bool isEllipse = drawingAttributes.StylusTip == StylusTip.Ellipse;
                    bool ignorePressure = drawingAttributes.IgnorePressure;
                    //
                    // Two List<Point>'s that get reused for adding figures
                    // to the streamgeometry.
                    //
                    List<Point> pathFigureABSide = new List<Point>();//don't prealloc.  It causes Gen2 collections to rise and doesn't help execution time
                    List<Point> pathFigureDCSide = new List<Point>();
                    List<Point> polyLinePoints =  new List<Point>(4);

                    int iteratorCount = iterator.Count;
                    for (int index = 0, previousIndex = -1; index < iteratorCount; )
                    {
                        if (!prevPrevStrokeNode.IsValid)
                        {
                            if (prevStrokeNode.IsValid)
                            {
                                //we're sliding our pointers forward
                                prevPrevStrokeNode = prevStrokeNode;
                                prevPrevStrokeNodeBounds = prevStrokeNodeBounds;
                                prevStrokeNode = emptyStrokeNode;
                            }
                            else
                            {
                                prevPrevStrokeNode = iterator[index++, previousIndex++];
                                prevPrevStrokeNodeBounds = prevPrevStrokeNode.GetBounds();
                                continue; //so we always check if index < iterator.Count
                            }
                        }

                        //we know prevPrevStrokeNode is valid
                        if (!prevStrokeNode.IsValid)
                        {
                            if (strokeNode.IsValid)
                            {
                                //we're sliding our pointers forward
                                prevStrokeNode = strokeNode;
                                prevStrokeNodeBounds = strokeNodeBounds;
                                strokeNode = emptyStrokeNode;
                            }
                            else
                            {
                                //get the next strokeNode, but don't automatically update previousIndex
                                prevStrokeNode = iterator[index++, previousIndex];
                                prevStrokeNodeBounds = prevStrokeNode.GetBounds();

                                RectCompareResult result = 
                                    FuzzyContains(  prevStrokeNodeBounds, 
                                                    prevPrevStrokeNodeBounds,
                                                    isStartOfSegment ? 99.99999d : percentIntersect);

                                if (result == RectCompareResult.Rect1ContainsRect2)
                                {
                                    // this node already contains the prevPrevStrokeNodeBounds (PP):
                                    //
                                    //  |------------|
                                    //  | |----|     |
                                    //  | | PP |  P  |                            
                                    //  | |----|     |
                                    //  |------------|
                                    //
                                    prevPrevStrokeNode = iterator[index - 1, prevPrevStrokeNode.Index - 1]; ;
                                    prevPrevStrokeNodeBounds = Rect.Union(prevStrokeNodeBounds, prevPrevStrokeNodeBounds);

                                    // at this point prevPrevStrokeNodeBounds already contains this node
                                    // we can just ignore this node
                                    prevStrokeNode = emptyStrokeNode;

                                    // update previousIndex to point to this node
                                    previousIndex = index - 1;

                                    // go back to our main loop
                                    continue;
                                }
                                else if (result == RectCompareResult.Rect2ContainsRect1)
                                {
                                    // this prevPrevStrokeNodeBounds (PP) already contains this node:
                                    //
                                    //  |------------|
                                    //  |      |----||
                                    //  |  PP  | P  ||                            
                                    //  |      |----||
                                    //  |------------|
                                    //

                                    //prevPrevStrokeNodeBounds already contains this node
                                    //we can just ignore this node
                                    prevStrokeNode = emptyStrokeNode;

                                    // go back to our main loop, but do not update previousIndex
                                    // because it should continue to point to previousPrevious
                                    continue;
                                }

                                Debug.Assert(!prevStrokeNode.GetConnectingQuad().IsEmpty, "prevStrokeNode.GetConnectingQuad() is Empty!");
                                
                                // if neither was true, we now have two of our three nodes required to 
                                // start our computation, we need to update previousIndex to point
                                // to our current, valid prevStrokeNode
                                previousIndex = index - 1;
                                continue; //so we always check if index < iterator.Count
                            }
                        }

                        //we know prevPrevStrokeNode and prevStrokeNode are both valid 
                        if (!strokeNode.IsValid)
                        {
                            strokeNode = iterator[index++, previousIndex];
                            strokeNodeBounds = strokeNode.GetBounds();

                            RectCompareResult result =
                                    FuzzyContains(  strokeNodeBounds,
                                                    prevStrokeNodeBounds,
                                                    isStartOfSegment ? 99.99999 : percentIntersect);

                            RectCompareResult result2 =
                                    FuzzyContains(  strokeNodeBounds,
                                                    prevPrevStrokeNodeBounds,
                                                    isStartOfSegment ? 99.99999 : percentIntersect);

                            if ( isStartOfSegment &&
                                 result == RectCompareResult.Rect1ContainsRect2 &&
                                 result2 == RectCompareResult.Rect1ContainsRect2)
                            {
                                if (pathFigureABSide.Count > 0)
                                {
                                    //we've started a stroke, we need to end it before resetting
                                    //prevPrev
#if DEBUG_RENDERING_FEEDBACK
                                    prevStrokeNode.GetPointsAtEndOfSegment(pathFigureABSide, pathFigureDCSide, debugDC, feedbackSize, showFeedback);
#else
                                    prevStrokeNode.GetPointsAtEndOfSegment(pathFigureABSide, pathFigureDCSide);
#endif
                                    //render
                                    ReverseDCPointsRenderAndClear(context, pathFigureABSide, pathFigureDCSide, polyLinePoints, isEllipse, true/*clear the point collections*/);
                                }
                                //we're resetting
                                //prevPrevStrokeNode.  We need to gen one
                                //without a connecting quad
                                prevPrevStrokeNode = iterator[index - 1, prevPrevStrokeNode.Index - 1];
                                prevPrevStrokeNodeBounds = prevPrevStrokeNode.GetBounds();
                                prevStrokeNode = emptyStrokeNode;
                                strokeNode = emptyStrokeNode;

                                // increment previousIndex to to point to this node
                                previousIndex = index - 1;
                                continue;

                            }
                            else if (result == RectCompareResult.Rect1ContainsRect2)
                            {
                                // this node (C) already contains the prevStrokeNodeBounds (P):
                                //
                                //          |------------|
                                //  |----|  | |----|     |
                                //  | PP |  | | P  |  C  |                            
                                //  |----|  | |----|     |
                                //          |------------|
                                //
                                //we have to generate a new stroke node that points
                                //to pp since the connecting quad from C to P could be empty
                                //if they have the same point
                                strokeNode = iterator[index - 1, prevStrokeNode.Index - 1];
                                if (!strokeNode.GetConnectingQuad().IsEmpty)
                                {
                                    //only update prevStrokeNode if we have a valid connecting quad
                                    prevStrokeNode = strokeNode;
                                    prevStrokeNodeBounds = Rect.Union(strokeNodeBounds, prevStrokeNodeBounds);

                                    // update previousIndex, since it should point to this node now
                                    previousIndex = index - 1;
                                }

                                // at this point we can just ignore this node
                                strokeNode = emptyStrokeNode;
                                //strokeNodeBounds = empty;

                                prevAngle = double.MinValue; //invalidate
                                
                                // go back to our main loop
                                continue;
                            }
                            else if (result == RectCompareResult.Rect2ContainsRect1)
                            {
                                // this prevStrokeNodeBounds (P) already contains this node (C):
                                //
                                //          |------------|
                                // |----|   |      |----||
                                // | PP |   |  P   | C  ||                            
                                // |----|   |      |----||
                                //          |------------|
                                //
                                //prevStrokeNodeBounds already contains this node
                                //we can just ignore this node
                                strokeNode = emptyStrokeNode;

                                // go back to our main loop, but do not update previousIndex
                                // because it should continue to point to previous
                                continue;
                            }

                            Debug.Assert(!strokeNode.GetConnectingQuad().IsEmpty, "strokeNode.GetConnectingQuad was empty, this is unexpected");

                            //
                            // NOTE: we do not check if C contains PP, or PP contains C because
                            // that indicates a change in direction, which we handle below
                            //
                            // if neither was true P and C are separate, 
                            // we now have all three nodes required to 
                            // start our computation, we need to update previousIndex to point
                            // to our current, valid prevStrokeNode
                            previousIndex = index - 1;
                        }


                        // see if we have an overlap between the first and third node
                        bool overlap = prevPrevStrokeNodeBounds.IntersectsWith(strokeNodeBounds);

                        // prevPrevStrokeNode, prevStrokeNode and strokeNode are all 
                        // valid nodes now.  Now we need to figure out what do add to our 
                        // PathFigure.  First calc bounds on the strokeNode we know we need to render
                        if (calculateBounds)
                        {
                            bounds.Union(prevStrokeNodeBounds);
                        }

                        // determine what points to add to pathFigureABSide and pathFigureDCSide
                        // from prevPrevStrokeNode
                        if (pathFigureABSide.Count == 0)
                        {
                            Debug.Assert(pathFigureDCSide.Count == 0);
                            if (calculateBounds)
                            {
                                bounds.Union(prevPrevStrokeNodeBounds);
                            }

                            if (isStartOfSegment && overlap)
                            {
                                //render a complete first stroke node or we can get artifacts
                                prevPrevStrokeNode.GetContourPoints(polyLinePoints);
                                AddFigureToStreamGeometryContext(context, polyLinePoints, prevPrevStrokeNode.IsEllipse/*isBezierFigure*/);
                                polyLinePoints.Clear();
                            }

                            // we're starting a new pathfigure
                            // we need to add parts of the prevPrevStrokeNode contour
                            // to pathFigureABSide and pathFigureDCSide
#if DEBUG_RENDERING_FEEDBACK
                            prevStrokeNode.GetPointsAtStartOfSegment(pathFigureABSide, pathFigureDCSide, debugDC, feedbackSize, showFeedback);
#else
                            prevStrokeNode.GetPointsAtStartOfSegment(pathFigureABSide, pathFigureDCSide);
#endif

                            //set our marker, we're no longer at the start of the stroke
                            isStartOfSegment = false;
                        }

                        

                        if (prevAngle == double.MinValue)
                        {
                            //prevAngle is no longer valid
                            prevAngle = GetAngleBetween(prevPrevStrokeNode.Position, prevStrokeNode.Position);
                        }
                        double delta = GetAngleDeltaFromLast(prevStrokeNode.Position, strokeNode.Position, ref prevAngle);
                        bool directionChangedOverAbsoluteThreshold = Math.Abs(delta) > 90d && Math.Abs(delta) < (360d - 90d);
                        bool directionChangedOverOverlapThreshold = overlap && !(ignorePressure || strokeNode.PressureFactor == 1f) && Math.Abs(delta) > 30d && Math.Abs(delta) < (360d - 30d);

                        double prevArea = prevStrokeNodeBounds.Height * prevStrokeNodeBounds.Width;
                        double currArea = strokeNodeBounds.Height * strokeNodeBounds.Width;

                        bool areaChanged = !(prevArea == currArea && prevArea == (prevPrevStrokeNodeBounds.Height * prevPrevStrokeNodeBounds.Width));
                        bool areaChangeOverThreshold = false;
                        if (overlap && areaChanged)
                        {
                            if ((Math.Min(prevArea, currArea) / Math.Max(prevArea, currArea)) <= 0.90d)
                            {
                                //the min area is < 70% of the max area
                                areaChangeOverThreshold = true;
                            }
                        }

                        if (areaChanged || delta != 0.0d || index >= iteratorCount)
                        {
                            //the area changed between the three nodes OR there was an angle delta OR we're at the end 
                            //of the stroke...  either way, this is a significant node.  If not, we're going to drop it.
                            if ((overlap && (directionChangedOverOverlapThreshold || areaChangeOverThreshold)) ||
                                directionChangedOverAbsoluteThreshold)
                            {
                                //
                                // we need to stop the pathfigure at P
                                // and render the pathfigure
                                //
                                //  |--|      |--|    |--||--|   |------|
                                //  |PP|------|P |    |PP||P |   |PP P C| 
                                //  |--|      |--|    |--||--|   |------|
                                //           /           |C |          
                                //      |--|             |--|         
                                //      |C |               
                                //      |--|               


#if DEBUG_RENDERING_FEEDBACK
                                prevStrokeNode.GetPointsAtEndOfSegment(pathFigureABSide, pathFigureDCSide, debugDC, feedbackSize, showFeedback);
#else
                                //end the figure
                                prevStrokeNode.GetPointsAtEndOfSegment(pathFigureABSide, pathFigureDCSide);
#endif
                                //render
                                ReverseDCPointsRenderAndClear(context, pathFigureABSide, pathFigureDCSide, polyLinePoints, isEllipse, true/*clear the point collections*/);

                                if (areaChangeOverThreshold)
                                {
                                    //render a complete stroke node or we can get artifacts
                                    prevStrokeNode.GetContourPoints(polyLinePoints);
                                    AddFigureToStreamGeometryContext(context, polyLinePoints, prevStrokeNode.IsEllipse/*isBezierFigure*/);
                                    polyLinePoints.Clear();
                                }
                            }
                            else
                            {
                                //
                                // direction didn't change over the threshold, add the midpoint data
                                //  |--|      |--|
                                //  |PP|------|P | 
                                //  |--|      |--|
                                //                \
                                //                  |--| 
                                //                  |C | 
                                //                  |--| 
                                bool endSegment; //flag that tell us if we missed an intersection
#if DEBUG_RENDERING_FEEDBACK
                                strokeNode.GetPointsAtMiddleSegment(prevStrokeNode, delta, pathFigureABSide, pathFigureDCSide, out endSegment, debugDC, feedbackSize, showFeedback);
#else
                                strokeNode.GetPointsAtMiddleSegment(prevStrokeNode, delta, pathFigureABSide, pathFigureDCSide, out endSegment);
#endif
                                if (endSegment)
                                {
                                    //we have a missing intersection, we need to end the 
                                    //segment at P
#if DEBUG_RENDERING_FEEDBACK
                                    prevStrokeNode.GetPointsAtEndOfSegment(pathFigureABSide, pathFigureDCSide, debugDC, feedbackSize, showFeedback);
#else
                                    //end the figure
                                    prevStrokeNode.GetPointsAtEndOfSegment(pathFigureABSide, pathFigureDCSide);
#endif
                                    //render
                                    ReverseDCPointsRenderAndClear(context, pathFigureABSide, pathFigureDCSide, polyLinePoints, isEllipse, true/*clear the point collections*/);
                                }
                             }
                        }

                        //
                        // either way... slide our pointers forward, to do this, we simply mark 
                        // our first pointer as 'empty'
                        //
                        prevPrevStrokeNode = emptyStrokeNode;
                        prevPrevStrokeNodeBounds = empty;

                        
                    }

                    //
                    // anything left to render?
                    //
                    if (prevPrevStrokeNode.IsValid)
                    {
                        if (prevStrokeNode.IsValid)
                        {
                            if (calculateBounds)
                            {
                                bounds.Union(prevPrevStrokeNodeBounds);
                                bounds.Union(prevStrokeNodeBounds);
                            }
                            Debug.Assert(!strokeNode.IsValid);
                            //
                            // we never made it to strokeNode, render two points, OR 
                            // strokeNode was a dupe
                            //
                            if (pathFigureABSide.Count > 0)
                            {
#if DEBUG_RENDERING_FEEDBACK
                                prevStrokeNode.GetPointsAtEndOfSegment(pathFigureABSide, pathFigureDCSide, debugDC, feedbackSize, showFeedback);
#else
                                //
                                // strokeNode was a dupe, we just need to render the end of the stroke
                                // which is at prevStrokeNode
                                //
                                prevStrokeNode.GetPointsAtEndOfSegment(pathFigureABSide, pathFigureDCSide);
#endif
                                //render
                                ReverseDCPointsRenderAndClear(context, pathFigureABSide, pathFigureDCSide, polyLinePoints, isEllipse, false/*clear the point collections*/);
                            }
                            else
                            {
                                // we've only seen two points to render
                                Debug.Assert(pathFigureDCSide.Count == 0);
                                //contains all the logic to render two stroke nodes
                                RenderTwoStrokeNodes(   context,
                                                        prevPrevStrokeNode,
                                                        prevPrevStrokeNodeBounds,
                                                        prevStrokeNode,
                                                        prevStrokeNodeBounds,
                                                        pathFigureABSide,
                                                        pathFigureDCSide,
                                                        polyLinePoints
#if DEBUG_RENDERING_FEEDBACK
                                                       ,debugDC,
                                                       feedbackSize,
                                                       showFeedback
#endif
                                                    );

                            }
                        }
                        else
                        {
                            if (calculateBounds)
                            {
                                bounds.Union(prevPrevStrokeNodeBounds);
                            }

                            // we only have a single point to render
                            Debug.Assert(pathFigureABSide.Count == 0);
                            prevPrevStrokeNode.GetContourPoints(pathFigureABSide);
                            AddFigureToStreamGeometryContext(context, pathFigureABSide, prevPrevStrokeNode.IsEllipse/*isBezierFigure*/);

                        }
                    }
                    else if (prevStrokeNode.IsValid && strokeNode.IsValid)
                    {
                        if (calculateBounds)
                        {
                            bounds.Union(prevStrokeNodeBounds);
                            bounds.Union(strokeNodeBounds);
                        }

                        // typical case, we hit the end of the stroke
                        // see if we need to start a stroke, or just end one
                        if (pathFigureABSide.Count > 0)
                        {
#if DEBUG_RENDERING_FEEDBACK
                            strokeNode.GetPointsAtEndOfSegment(pathFigureABSide, pathFigureDCSide, debugDC, feedbackSize, showFeedback);
#else
                            strokeNode.GetPointsAtEndOfSegment(pathFigureABSide, pathFigureDCSide);
#endif

                            //render
                            ReverseDCPointsRenderAndClear(context, pathFigureABSide, pathFigureDCSide, polyLinePoints, isEllipse, false/*clear the point collections*/);

                            if (FuzzyContains(strokeNodeBounds, prevStrokeNodeBounds, 70d) != RectCompareResult.NoItersection)
                            {
                                //render a complete stroke node or we can get artifacts
                                strokeNode.GetContourPoints(polyLinePoints);
                                AddFigureToStreamGeometryContext(context, polyLinePoints, strokeNode.IsEllipse/*isBezierFigure*/);
                            }
                        }
                        else
                        {
                            Debug.Assert(pathFigureDCSide.Count == 0);
                            //contains all the logic to render two stroke nodes
                            RenderTwoStrokeNodes(   context,
                                                    prevStrokeNode,
                                                    prevStrokeNodeBounds,
                                                    strokeNode,
                                                    strokeNodeBounds,
                                                    pathFigureABSide,
                                                    pathFigureDCSide,
                                                    polyLinePoints
#if DEBUG_RENDERING_FEEDBACK
                                                   ,debugDC,
                                                   feedbackSize,
                                                   showFeedback
#endif
                                                );

                        } 
                    }
                }
                finally
                {
                    context.Close();
                    geometry.Freeze();
                }
            }
        }