ppstroke.h

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// $Id: ppstroke.h 751 2006-03-31 15:43:49Z alex $
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 */
// ppstroke - Definition of rendering PathProcessor classes for path Stroking

#ifndef INC_PPSTROKE
#define INC_PPSTROKE

#include "pathpcs.h"


class TrapsList;
class BecomeA;
class ValueFunction;
class CCAttrMap;

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

>   class PathProcessorStroke : public PathProcessor

    Author:     Jason_Williams (Xara Group Ltd) <camelotdev@xara.com>
    Created:    20/12/96

    Purpose:    This is the abstract base class for all PathProcessors.

                These classes are created by attributes (or similar) when rendered,
                and placed on a stack in the RenderRegion. Whenever RenderRegion::DrawPath
                is invoked to render a path, all stacked PathProcessors will be called in
                turn, and they call back to RenderRegion functions to render whatever they
                wish (usually a modified form of the original path).

                This can be used to "filter" almost any rendering, but is mainly intended
                for use by stroke and fill providers, which replace input paths with more
                suitable shapes to be rendered.

    SeeAlso:    RenderRegion::DrawPath; PathProcessor::ProcessPath

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

class PathProcessorStroke : public PathProcessor
{
friend class RenderRegion;
CC_DECLARE_DYNAMIC(PathProcessorStroke);

public:
    PathProcessorStroke();

public:         // RenderRegion path-processing interface
    virtual void ProcessPath(Path *pPath,
                             RenderRegion *pRender,
                             PathShape ShapePath = PATHSHAPE_PATH);
    virtual BOOL WillChangeFillAndStrokeSeparately(void);

public:         // Specialised interface
    virtual BOOL IsDifferent(PathProcessorStroke *pOther);
            // Returns TRUE if the pOther is considered to be a different processor type

    virtual PathProcessorStroke *Clone(void);
            // Creates a copy of this object. Must be overridden by derived classes!

    virtual BOOL NeedsTransparency() const {return FALSE;};
            // Returns TRUE if this path processor makes use of transparency

    virtual BOOL DoBecomeA(BecomeA* pBecomeA, Path* pPath, Node* pParent);

    virtual BOOL DoesActuallyDoAnything(RenderRegion* pRender);

    virtual BOOL IsAPathProcessorStroke() {return TRUE;}

    NodePath*   GetProcessedPath(Path* pPath, Node* pParent);
    Path*       GetProcessedPath(Path* pPath, CCAttrMap* pAttrMap);

    NodePath* GetSmoothProcessedPath(Path* pPath, Node* pParent);

protected:  // Internal & derived-class helper functions
    TrapsList *PrepareTrapsForStroke(Path *pPath, RenderRegion *pRender, INT32 LineWidth);
            // Prepares a TrapsList structure for use with CreateVarWidthStroke

    Path *CreateVarWidthStroke(Path *pPath, RenderRegion *pRender, INT32 LineWidth,
                                TrapsList *pTrapezoids = NULL);
            // Strokes pPath to produce an outline path for the stroke

    BOOL GetRequiredAttributes( CCAttrMap* pAttrMap,
                                INT32* pLineWidth,
                                LineCapType* pLineCap,
                                ValueFunction** ppValFunc,
                                JointType* pJoinStyle );

    Path *CreateSmoothVarWidthStroke(Path *pPath, RenderRegion *pRender, INT32 LineWidth,
                                TrapsList *pTrapezoids = NULL);
            // As above but creates a smoothed version of the stroke - better but slower

};

#endif

---