ppvecstr.cpp

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// $Id: ppvecstr.cpp 1282 2006-06-09 09:46:49Z alex $
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 */
// ppvecstr - Implemenbtation of rendering PathProcessor classes for Vector Path Stroking

#include "camtypes.h"

#include "ppvecstr.h"

//#include "attrmgr.h" - in camtypes.h [AUTOMATICALLY REMOVED]
//#include "docview.h" - in camtypes.h [AUTOMATICALLY REMOVED]
//#include "document.h" - in camtypes.h [AUTOMATICALLY REMOVED]
//#include "fillattr.h" - in camtypes.h [AUTOMATICALLY REMOVED]
//#include "fixmem.h" - in camtypes.h [AUTOMATICALLY REMOVED]
//#include "grndbmp.h"
#include "nodepath.h"
//#include "paths.h" - in camtypes.h [AUTOMATICALLY REMOVED]
#include "pathstrk.h"
#include "pathtrap.h"
#include "qualattr.h"
//#include "rndrgn.h" - in camtypes.h [AUTOMATICALLY REMOVED]
//#include "spread.h" - in camtypes.h [AUTOMATICALLY REMOVED]
#include "strkattr.h"
#include "valfunc.h"


/***********************************************************************************************

>   class VectorStrokeSubRenderContext : public SubRenderContext

    Author:     Jason_Williams (Xara Group Ltd) <camelotdev@xara.com>
    Created:    6/3/97
    Purpose:    Used during rendering to store the render context of a repeating vector stroke
                if it has taken too long to render so far.

    Notes:      pOutputTraps will be auto-deleted on destruct. pValFunc will NOT be deleted.

***********************************************************************************************/

PORTNOTE("other","Removed VectorStrokeSubRenderContext - derived from SubRenderContext")
#ifndef EXCLUDE_FROM_XARALX
class VectorStrokeSubRenderContext : public SubRenderContext
{
CC_DECLARE_DYNCREATE(VectorStrokeSubRenderContext);
public:
    VectorStrokeSubRenderContext();
    ~VectorStrokeSubRenderContext();

    TrapsList       *pOutputTraps;          // The output trapezoids we've generated for stroking
    ValueFunction   *pValFunc;              // The width function for the stroke
    JointType       JoinStyle;              // The stroke's join style
    INT32           LineWidth;              // The stroke's line width
    INT32           RepeatDist;             // The distance for each repeat (or 0 if non-repeating)
    UINT32          Index;                  // The index of the next TrapEdgeList to be stroked (in pOutputTraps)
};

VectorStrokeSubRenderContext::VectorStrokeSubRenderContext()
{
    LineWidth    = 5000;
    JoinStyle    = RoundJoin;
    pValFunc     = NULL;
    RepeatDist   = 0;
    pOutputTraps = NULL;
    Index        = 0;
}

VectorStrokeSubRenderContext::~VectorStrokeSubRenderContext()
{
    pValFunc = NULL;        // Set it to NULL because it's a public var

    if (pOutputTraps != NULL)
        delete pOutputTraps;
    pOutputTraps = NULL;    // Set it to NULL because it's a public var
}

CC_IMPLEMENT_DYNCREATE(VectorStrokeSubRenderContext, SubRenderContext);
#endif

CC_IMPLEMENT_DYNAMIC(PathProcessorStrokeVector, PathProcessorStroke);

// Declare smart memory handling in Debug builds
#define new CAM_DEBUG_NEW




/********************************************************************************************

>   virtual BOOL PathProcessorStrokeVector::WillChangeFillAndStrokeSeparately(void)

    Author:     Jason_Williams (Xara Group Ltd) <camelotdev@xara.com>
    Created:    17/2/97

    Returns:    TRUE

    Purpose:    Called by the RenderRegion to determine if this PathProcessorStrokeVector affects
                the "fill" and "stroke" portions of the path separately. (Generally
                speaking, only fill/stroke providers will cause these two different
                "bits" of a path to be rendered separately). This call is made BEFORE
                this Processor's ProcessPath function will be called.

                If the caller gets a TRUE back, the stroke and fill paths will be
                rendered separately.

    Notes:      Base class implementation returns FALSE. Derived Stroke and Fill
                processors (such as this one) override this method to return TRUE.

********************************************************************************************/

BOOL PathProcessorStrokeVector::WillChangeFillAndStrokeSeparately(void)
{
    return(TRUE);
}



/********************************************************************************************

>   virtual BOOL PathProcessorStrokeVector::NeedsTransparency() const

    Author:     Jason_Williams (Xara Group Ltd) <camelotdev@xara.com>
    Created:    4/3/97

    Returns:    TRUE if this stroke type needs transparency in order to render

    Purpose:    Determine if this stroke type needs transparency in order to render.
                Vector strokes 

********************************************************************************************/

BOOL PathProcessorStrokeVector::NeedsTransparency() const
{
    StrokeDefinition *pStrokeDef = StrokeComponent::FindStroke(StrokeID);
    if (pStrokeDef == NULL)
    {
        return(FALSE);
    }

    return(pStrokeDef->NeedsTransparency());
}




/********************************************************************************************

>   virtual void PathProcessorStrokeVector::ProcessPath(Path *pPath,
                                                        RenderRegion *pRender,
                                                        PathShape ShapePath = PATHSHAPE_PATH);

    Author:     Jason_Williams (Xara Group Ltd) <camelotdev@xara.com>
    Created:    17/2/97

    Purpose:    Called by the RenderRegion to apply the path processing operation to 
                the given path.

                The PathProcessorStrokeVector class changes the stroking (only) of paths
                passed into it.

    Notes:      * When rendering a path, always pass in your 'this' pointer to
                  RenderRegion::DrawPath, so that you don't start an infinite
                  recursion!

                * To stop rendering of the path, simply return without calling the RR

                * To render this path unchanged, simply call directly back to the RR:
                    pRender->DrawPath(pPath, this);
                
                * Only affect the fill of this path if pPath->IsFilled

                * Only affect the stroke of this path if pPath->IsStroked

                * If converting a path into a "filled path" for stroking, the output
                  path should be rendered with IsStroked=FALSE or it'll get a line
                  around the outside!               

********************************************************************************************/

void PathProcessorStrokeVector::ProcessPath(Path *pPath,
                                            RenderRegion *pRender,
                                            PathShape ShapePath)
{
    PORTNOTETRACE("other","PathProcessorStrokeVector::ProcessPath - do nothing");
#ifndef EXCLUDE_FROM_XARALX
    ERROR3IF(pPath == NULL || pRender == NULL, "Illegal NULL Params");

    // Get the RenderRegion SubRenderContext and see if we're returning part-way through a background render
    VectorStrokeSubRenderContext *pSubRenderContext = (VectorStrokeSubRenderContext *)pRender->GetSubRenderState();
    if (pSubRenderContext != NULL && !IS_A(pSubRenderContext, VectorStrokeSubRenderContext))
    {
        // We can't use the sub render context, because it's not ours!
        pSubRenderContext = NULL;
    }

    // --- If we don't have a valid stroke definition, then get the base class to render
    // the stroke as a simple flat-filled stroke.
    StrokeDefinition *pStrokeDef = StrokeComponent::FindStroke(StrokeID);
    if (pStrokeDef == NULL)
    {
        PathProcessorStroke::ProcessPath(pPath, pRender);
        return;
    }

    // --- See if we have to create a new SubRenderContext, or if we can use the one passed in.
    // We always store all relevant variables in a SubRenderContext object so that we can easily
    // return control to the RenderRegion without having to copy lots of local values in/out.
    const BOOL CreateSubRenderContext = (pSubRenderContext == NULL);
    if (CreateSubRenderContext)
    {
        pSubRenderContext = new VectorStrokeSubRenderContext;
        if (pSubRenderContext == NULL)
        {
            pRender->DrawPath(pPath, this, ShapePath);
            return;
        }

        // --- If the provided path is not stroked, then we'll just pass it straight through
        // We also don't touch it if we're doing EOR rendering, or click hit detection
        if (!pPath->IsStroked || pRender->DrawingMode != DM_COPYPEN || pRender->IsHitDetect())
        {
            delete pSubRenderContext;
            pRender->DrawPath(pPath, this, ShapePath);
            return;
        }

        // --- If the quality is set low, or if the current stroke attribute is not our "parent"
        // attribute (so we're not the "current" stroker) then strokes are just rendered as centrelines
        // BLOCK
        {
            QualityAttribute *pQuality = (QualityAttribute *) pRender->GetCurrentAttribute(ATTR_QUALITY);
            StrokeTypeAttrValue *pTypeAttr = (StrokeTypeAttrValue *) pRender->GetCurrentAttribute(ATTR_STROKETYPE);

            if ((pQuality != NULL && pQuality->QualityValue.GetLineQuality() != Quality::FullLine) ||
                (pTypeAttr != NULL && pTypeAttr != GetParentAttr()))
            {
                delete pSubRenderContext;
                pRender->DrawPath(pPath, this, ShapePath);
                return;
            }
        }

        // --- We don't expect the input path to be stroked AND filled on entry
        ERROR3IF(pPath->IsFilled, "PathProcessor expected RenderRegion to handle IsFilled case");

        // --- Get the current line width & Join Style from the render region
        // BLOCK
        {
            LineWidthAttribute *pWidthAttr = (LineWidthAttribute *) pRender->GetCurrentAttribute(ATTR_LINEWIDTH);
            if (pWidthAttr != NULL)
                pSubRenderContext->LineWidth = pWidthAttr->LineWidth;

            JoinTypeAttribute *pJoinAttr = (JoinTypeAttribute *) pRender->GetCurrentAttribute(ATTR_JOINTYPE);
            if (pJoinAttr != NULL)
                pSubRenderContext->JoinStyle = pJoinAttr->JoinType;
        }
    }

    // --- Create a new path to be rendered in place of the provided path
    // Note that I use a large allocation size so that reallocation need not be done
    // frequently, which also helps reduce memory fragmentation.
    Path *pOutput = new Path;
    if (pOutput == NULL)
    {
        if (!pRender->IsSubRenderStateLocked())
            pRender->SetSubRenderState(NULL);
        delete pSubRenderContext;
        pRender->DrawPath(pPath, this, ShapePath);
        return;
    }

    pOutput->Initialise(128, 128);


    // --- Find our Variable Width function
    if (CreateSubRenderContext)
    {
        // --- Get the variable line width descriptor from the render region
        VariableWidthAttrValue *pVarWidthAttr = (VariableWidthAttrValue *) pRender->GetCurrentAttribute(ATTR_VARWIDTH);
        if (pVarWidthAttr != NULL)
            pSubRenderContext->pValFunc = pVarWidthAttr->GetWidthFunction();
    }

    ValueFunction *pValFunc = pSubRenderContext->pValFunc;

    // If we couldn't find a proper value function, then we'll default to constant-width.
    // We keep a static Constant function around always, because it's thread-safe and because
    // that saves us the overhead of creating and deleting it on the stack each time we're called
    static ValueFunctionConstant Constant(1.0);
    if (pValFunc == NULL)
        pValFunc = &Constant;


    // --- Find our brush clipart tree
    Node *pBrush = pStrokeDef->GetStrokeTree();
    ERROR3IF(!IS_A(pBrush, Spread), "Brush does not start with a Spread Node!");
    DocRect BrushBounds = ((Spread *)pBrush)->GetBoundingRect();

    // Get a PathStroker to map paths onto the destination stroke with
    PathStrokerVector Stroker(pValFunc, pSubRenderContext->LineWidth,
                                LineCapButt, &BrushBounds);

    // Work out if this is a repeating stroke, and if so, how often it repeats
    if (CreateSubRenderContext)
    {
        if (pStrokeDef->IsRepeating())
        {
            // The repeat distance is calculated as a number of millipoints per repeat of the
            // stroke, such that it retains the correct aspect ratio. That is, the ratio of
            // brush width to height is the same as RepeatDist to LineWidth
            pSubRenderContext->RepeatDist = (INT32) (Stroker.GetScaleFactor() * (double)BrushBounds.Width());
            if (pSubRenderContext->RepeatDist < 1000)       // I absolutely refuse to repeat it more than
                pSubRenderContext->RepeatDist = 1000;       // once every 1pt, as this is plenty small enough

            // Suss the path length out
            ProcessLength GenerateLength(100);
            double Length = 0;
            BOOL ok = GenerateLength.PathLength(pPath, &Length);

            // Ask the stroke def for its number of brush repeats - 0 means work it out
            INT32 NumberOfRepeats = pStrokeDef->NumRepeats();
            if(NumberOfRepeats == 0 && pSubRenderContext->RepeatDist > 0)
            {
                // Work out the optimal number of repeats along the path
                NumberOfRepeats = (INT32)(floor((Length/pSubRenderContext->RepeatDist) + 0.5));
            }

            // Don't got dividing by zero now...            
            if(NumberOfRepeats <= 0)
                NumberOfRepeats = 1;
        
            // Alter the repeat distance to accomodate this number of repeats
            pSubRenderContext->RepeatDist = (INT32)(Length / (double)NumberOfRepeats);
        }

        // Generate the set of trapezoids for the dest path
        ProcessPathToTrapezoids GenerateTraps(100);
        pSubRenderContext->pOutputTraps = new TrapsList(pSubRenderContext->RepeatDist);

        BOOL Failed = (pSubRenderContext->pOutputTraps == NULL);
        if (!Failed && !GenerateTraps.Init(pPath, pSubRenderContext->pOutputTraps))
            Failed = TRUE;

        ProcessFlags PFlags(TRUE, FALSE, FALSE);    // Flags are: Flatten, !QuantiseLines, !QuantiseAll
        if (!Failed && !GenerateTraps.Process(PFlags, TrapTravel_Parametric, pSubRenderContext->JoinStyle))
            Failed = TRUE;

        if (Failed)
        {
            pRender->DrawPath(pPath, this, ShapePath);
            if (!pRender->IsSubRenderStateLocked())
                pRender->SetSubRenderState(NULL);
            delete pSubRenderContext;
            return;
        }
    }

    ERROR3IF(pSubRenderContext->pOutputTraps == NULL || pValFunc == NULL,
                "Vector stroke SubRenderContext was not properly uninitialised!");

    // --- Handle background rendering. We always store all critical information in a SubRenderContext.
    // If we have to break into rendering because of background rendering, we give the context to the RndRgn
    // to keep for next time. However, when we finish rendering everything, we need to clean up - we will
    // assume that we'll make it to the end, and chnage this variable if we get interrupted.
    BOOL DeleteSubRenderContext = TRUE;

    // Lock the sub-render context so that nobody "inside" the brush uses it
    const BOOL SRContextLocked = pRender->IsSubRenderStateLocked();
    if (!SRContextLocked)
        pRender->LockSubRenderState(TRUE);

    // --- Now "render" the brush clipart tree via our Stroker
    for ( ;
            pSubRenderContext->Index < pSubRenderContext->pOutputTraps->GetNumTraps() && DeleteSubRenderContext;
            pSubRenderContext->Index++)
    {
        // Find the trapezoid edge list for this pass
        TrapEdgeList *pEdgeList = pSubRenderContext->pOutputTraps->GetTrapEdgeList(pSubRenderContext->Index);
        if (pEdgeList->GetNumEdges() < 2)
        {
            ERROR3("No map traps when stroking! Subpath stripped\n");
            continue;
        }

        // And render away
        pRender->SaveContext();

        Node* pNode = pBrush->FindFirstForUnclippedInkRender(pRender);
        while (pNode)
        {
            // Prepare the stroker to stroke this sub-stroke
            Stroker.PrepareToStroke(pEdgeList);

            if (pNode->IsAnAttribute())
            {
                // If we are overriding the fill/transparency with the one applied to the stroke,
                // then we simply throw away all fill/transparency attributes as we render
                // (We do this on the fly rather than as we make the brush so that the user can
                // toggle this mode on and off at any time if they change their mind)
                BOOL RenderIt = TRUE;
                if ( (pStrokeDef->OverrideFill()  && ((NodeAttribute *)pNode)->IsAColourFill()) ||
                     (pStrokeDef->OverrideFill()  && ((NodeAttribute *)pNode)->IsAStrokeColour()) ||
                     (pStrokeDef->OverrideTrans() && ((NodeAttribute *)pNode)->IsAStrokeTransp()) ||
                     (pStrokeDef->OverrideTrans() && ((NodeAttribute *)pNode)->IsATranspFill()) )
                {
                    RenderIt = FALSE;
                }

                if (RenderIt)
                {
                    // We must modify all attributes to lie in the destination stroke.
                    // This includes fill/trans geometry endpoints, line widths, and
                    // also possibly modifying transparency levels to allow a flat transparency
                    // to be applied to the whole stroke.
                    AttributeValue *pAttrValue = ((NodeAttribute *)pNode)->GetAttributeValue();
                    AttributeValue *pNewValue  = pAttrValue->MouldIntoStroke(&Stroker, 1.0);
                    //****!!!!TODO - Just above, we have the chance to handle transparency better
                    // - we could at least scale all transparencies by passing a flat scale factor into
                    // the MouldIntoStroke call.

                    if (pNewValue != NULL)
                        pNewValue->Render(pRender, TRUE);       // The RndRgn will delete this when it's done with
                    else
                        pNode->Render(pRender);                 // No change, so render the original attribute
                }
            }
            else if (pNode->IsNodePath())
            {
                // Stroke the trapezoids into the output path
                pOutput->ClearPath();
                if (!Stroker.StrokePath(&((NodePath *)pNode)->InkPath, pOutput))
                    break;

                pRender->SetWindingRule(NonZeroWinding);
                pRender->DrawPath(pOutput, this, ShapePath);
            }
//              else
//                  TRACEUSER( "Jason", _T("\nBrush node %s not rendered\n"), pNode->GetRuntimeClass()->m_lpszClassName);

            pNode = pNode->FindNextForUnclippedInkRender(pRender);
        }

        pRender->RestoreContext();

        // --- Now check if we should break into rendering for background rendering purposes
        // If the Sub-render-context is locked, then we're inside a blend or something, and it's too dangerous
        // for us to store our sub-render state, so we have no choice but to render until we finish.
        // BLOCK
        if (!SRContextLocked && IS_A(pRender, GRenderDIB))
        {
            View *pView = pRender->GetRenderView();
            if (pView != NULL && !pRender->RenderTreeCanContinue())
            {
                // We have been interrupted by the background redraw system.
                // We will immediately exit, storing our SubRenderContext away into the
                // RenderRegion for the next time it calls us (see below).
                DeleteSubRenderContext = FALSE;

                // Drop through and let the loop condition handle exit
            }
        }
    }

    // If we locked the sub-render context, then we must restore it
    if (!SRContextLocked)
        pRender->LockSubRenderState(FALSE);

    // If we have finished rendering everything, then we vape our sub render context.
    // (We even check if we were interrupted just as we finished the final iteration)
    if (DeleteSubRenderContext || pSubRenderContext->Index >= pSubRenderContext->pOutputTraps->GetNumTraps())
    {
        if (!SRContextLocked)
            pRender->SetSubRenderState(NULL);
        delete pSubRenderContext;
        pSubRenderContext = NULL;
    }
    else
    {
        if (!SRContextLocked)
            pRender->SetSubRenderState(pSubRenderContext);
    }

    delete pOutput;
    pOutput = NULL;
#endif
}



/********************************************************************************************

>   virtual BOOL PathProcessorStrokeVector::IsDifferent(PathProcessorStroke *pOther);

    Author:     Jason_Williams (Xara Group Ltd) <camelotdev@xara.com>
    Created:    17/2/97

    Inputs:     pOther - The other PathProcessorStroke

    Returns:    TRUE if they're considered different, FALSE if they are equivalent

    Purpose:    Equality operator

    Notes:      The base class implementation compares the runtime classes of the
                2 objects to see if they are different classes. If they are the same
                class, it assumes they're considered equal - derived classes should
                override this behaviour if further comparisons are necessary.

********************************************************************************************/

BOOL PathProcessorStrokeVector::IsDifferent(PathProcessorStroke *pOther)
{
    ERROR3IF(pOther == NULL, "Illegal NULL param");

    if (GetRuntimeClass() != pOther->GetRuntimeClass())
        return(TRUE);

    // We're different if we use different stroke definitions
    return(StrokeID != ((PathProcessorStrokeVector *)pOther)->StrokeID);
}



/********************************************************************************************

>   virtual PathProcessorStroke *PathProcessorStrokeVector::Clone(void)

    Author:     Jason_Williams (Xara Group Ltd) <camelotdev@xara.com>
    Created:    17/2/97

    Returns:    NULL if we're out of memory, else
                a pointer to a clone (exact copy) of this object

    Purpose:    To copy PathProcessorStroke or derived-class object

********************************************************************************************/

PathProcessorStroke *PathProcessorStrokeVector::Clone(void)
{
    // Clone this object - this can be done by just creating a new one
    PathProcessorStrokeVector *pClone = new PathProcessorStrokeVector;

    // And copy the (base class) parent-attribute pointer so we know when our
    // parent attribute is "current" in the render region.
    if (pClone != NULL)
    {
        pClone->SetParentAttr(GetParentAttr());
        pClone->StrokeID = StrokeID;
    }

    return(pClone);
}



/********************************************************************************************

>   void PathProcessorStrokeVector::SetStrokeDefinition(StrokeHandle Handle)

    Author:     Jason_Williams (Xara Group Ltd) <camelotdev@xara.com>
    Created:    29/2/97

    Purpose:    Sets this path processor up to use the given vector stroke definition
                in all future rendering. 

    Notes:      If not set, or if set to StrokeHandle_NoStroke, the stroke processor
                will render its strokes as simple (flat filled) strokes by calling the
                base class ProcessPath method.

********************************************************************************************/

void PathProcessorStrokeVector::SetStrokeDefinition(StrokeHandle Handle)
{
    ERROR3IF(Handle != StrokeHandle_NoStroke && StrokeComponent::FindStroke == NULL,
                "Trying to set a Stroke PathProcessor to use a deleted stroke!");

    StrokeID = Handle;
}

---