/layout/svg/base/src/nsSVGPathFrame.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ----- BEGIN LICENSE BLOCK -----
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is the Mozilla SVG project.
 *
 * The Initial Developer of the Original Code is 
 * Crocodile Clips Ltd..
 * Portions created by the Initial Developer are Copyright (C) 2001
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *    Alex Fritze <alex.fritze@crocodile-clips.com> (original author)
 *    Daniele Nicolodi <daniele@grinta.net> 
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or 
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the NPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ----- END LICENSE BLOCK ----- */

#include <math.h>

#include "nsSVGPathGeometryFrame.h"
#include "nsIDOMSVGAnimatedPathData.h"
#include "nsIDOMSVGPathSegList.h"
#include "nsIDOMSVGPathSeg.h"
#include "nsIDOMSVGMatrix.h"
#include "nsISVGRendererPathBuilder.h"

class nsSVGPathFrame : public nsSVGPathGeometryFrame
{
protected:
  friend nsresult
  NS_NewSVGPathFrame(nsIPresShell* aPresShell, nsIContent* aContent, nsIFrame** aNewFrame);

  ~nsSVGPathFrame();
  virtual nsresult Init();
  
public:
  // nsISVGValueObserver interface:
  NS_IMETHOD DidModifySVGObservable(nsISVGValue* observable);

  // nsISVGPathGeometrySource interface:
  NS_IMETHOD ConstructPath(nsISVGRendererPathBuilder *pathBuilder);

private:  
  nsCOMPtr<nsIDOMSVGPathSegList> mSegments;
};

//----------------------------------------------------------------------
// Implementation

nsresult
NS_NewSVGPathFrame(nsIPresShell* aPresShell, nsIContent* aContent, nsIFrame** aNewFrame)
{
  *aNewFrame = nsnull;
  
  nsCOMPtr<nsIDOMSVGAnimatedPathData> anim_data = do_QueryInterface(aContent);
  if (!anim_data) {
#ifdef DEBUG
    printf("warning: trying to construct an SVGPathFrame for a content element that doesn't support the right interfaces\n");
#endif
    return NS_ERROR_FAILURE;
  }
  
  nsSVGPathFrame* it = new (aPresShell) nsSVGPathFrame;
  if (nsnull == it)
    return NS_ERROR_OUT_OF_MEMORY;

  *aNewFrame = it;
  return NS_OK;
}

nsSVGPathFrame::~nsSVGPathFrame()
{
  nsCOMPtr<nsISVGValue> value;
  if (mSegments && (value = do_QueryInterface(mSegments)))
      value->RemoveObserver(this);
}

nsresult nsSVGPathFrame::Init()
{
  nsresult rv = nsSVGPathGeometryFrame::Init();
  if (NS_FAILED(rv)) return rv;
  
  nsCOMPtr<nsIDOMSVGAnimatedPathData> anim_data = do_QueryInterface(mContent);
  NS_ASSERTION(anim_data,"wrong content element");
  anim_data->GetAnimatedPathSegList(getter_AddRefs(mSegments));
  NS_ASSERTION(mSegments, "no pathseglist");
  if (!mSegments) return NS_ERROR_FAILURE;
  nsCOMPtr<nsISVGValue> value = do_QueryInterface(mSegments);
  if (value)
    value->AddObserver(this);
  
  return NS_OK;
}  

//----------------------------------------------------------------------
// nsISVGValueObserver methods:

NS_IMETHODIMP
nsSVGPathFrame::DidModifySVGObservable(nsISVGValue* observable)
{
  nsCOMPtr<nsIDOMSVGPathSegList> l = do_QueryInterface(observable);
  if (l && mSegments==l) {
    UpdateGraphic(nsISVGPathGeometrySource::UPDATEMASK_PATH);
    return NS_OK;
  }
  // else
  return nsSVGPathGeometryFrame::DidModifySVGObservable(observable);
}

//----------------------------------------------------------------------
// nsISVGPathGeometrySource methods:

/* void constructPath (in nsISVGRendererPathBuilder pathBuilder); */
NS_IMETHODIMP nsSVGPathFrame::ConstructPath(nsISVGRendererPathBuilder* pathBuilder)
{
  PRUint32 count;
  mSegments->GetNumberOfItems(&count);
  if (count == 0) return NS_OK;
  
  float cx = 0.0f; // current point
  float cy = 0.0f;
  
  float cx1 = 0.0f; // last controlpoint (for s,S,t,T)
  float cy1 = 0.0f;

  PRUint16 lastSegmentType = nsIDOMSVGPathSeg::PATHSEG_UNKNOWN;
  
  PRUint32 i;
  for (i = 0; i < count; ++i) {
    nsCOMPtr<nsIDOMSVGPathSeg> segment;
    mSegments->GetItem(i, getter_AddRefs(segment));

    PRUint16 type = nsIDOMSVGPathSeg::PATHSEG_UNKNOWN;
    segment->GetPathSegType(&type);

    PRBool absCoords = PR_FALSE;
    
    switch (type) {
      case nsIDOMSVGPathSeg::PATHSEG_CLOSEPATH:
        pathBuilder->ClosePath(&cx,&cy);
        break;
        
      case nsIDOMSVGPathSeg::PATHSEG_MOVETO_ABS:
        absCoords = PR_TRUE;
      case nsIDOMSVGPathSeg::PATHSEG_MOVETO_REL:
        {
          float x, y;
          if (!absCoords) {
            nsCOMPtr<nsIDOMSVGPathSegMovetoRel> moveseg = do_QueryInterface(segment);
            NS_ASSERTION(moveseg, "interface not implemented");
            moveseg->GetX(&x);
            moveseg->GetY(&y);
            x += cx;
            y += cy;
          } else {
            nsCOMPtr<nsIDOMSVGPathSegMovetoAbs> moveseg = do_QueryInterface(segment);
            NS_ASSERTION(moveseg, "interface not implemented");
            moveseg->GetX(&x);
            moveseg->GetY(&y);
          }            
          cx = x;
          cy = y;
          pathBuilder->Moveto(x,y);
        }
        break;
        
      case nsIDOMSVGPathSeg::PATHSEG_LINETO_ABS:
        absCoords = PR_TRUE;
      case nsIDOMSVGPathSeg::PATHSEG_LINETO_REL:
        {
          float x, y;
          if (!absCoords) {
            nsCOMPtr<nsIDOMSVGPathSegLinetoRel> lineseg = do_QueryInterface(segment);
            NS_ASSERTION(lineseg, "interface not implemented");
            lineseg->GetX(&x);
            lineseg->GetY(&y);
            x += cx;
            y += cy;
          } else {
            nsCOMPtr<nsIDOMSVGPathSegLinetoAbs> lineseg = do_QueryInterface(segment);
            NS_ASSERTION(lineseg, "interface not implemented");
            lineseg->GetX(&x);
            lineseg->GetY(&y);
          }            
          cx = x;
          cy = y;
          pathBuilder->Lineto(x,y);
        }
        break;        

      case nsIDOMSVGPathSeg::PATHSEG_CURVETO_CUBIC_ABS:
        absCoords = PR_TRUE;
      case nsIDOMSVGPathSeg::PATHSEG_CURVETO_CUBIC_REL:
        {
          float x, y, x1, y1, x2, y2;
          if (!absCoords) {
            nsCOMPtr<nsIDOMSVGPathSegCurvetoCubicRel> curveseg = do_QueryInterface(segment);
            NS_ASSERTION(curveseg, "interface not implemented");
            curveseg->GetX(&x);
            curveseg->GetY(&y);
            curveseg->GetX1(&x1);
            curveseg->GetY1(&y1);
            curveseg->GetX2(&x2);
            curveseg->GetY2(&y2);
            x  += cx;
            y  += cy;
            x1 += cx;
            y1 += cy;
            x2 += cx;
            y2 += cy;
          } else {
            nsCOMPtr<nsIDOMSVGPathSegCurvetoCubicAbs> curveseg = do_QueryInterface(segment);
            NS_ASSERTION(curveseg, "interface not implemented");
            curveseg->GetX(&x);
            curveseg->GetY(&y);
            curveseg->GetX1(&x1);
            curveseg->GetY1(&y1);
            curveseg->GetX2(&x2);
            curveseg->GetY2(&y2);
          }            
          cx = x;
          cy = y;
          cx1 = x2;
          cy1 = y2;
          pathBuilder->Curveto(x, y, x1, y1, x2, y2);
        }
        break;
        
      case nsIDOMSVGPathSeg::PATHSEG_CURVETO_QUADRATIC_ABS:
        absCoords = PR_TRUE;
      case nsIDOMSVGPathSeg::PATHSEG_CURVETO_QUADRATIC_REL:
        {
          float x, y, x1, y1, x31, y31, x32, y32;
          if (!absCoords) {
            nsCOMPtr<nsIDOMSVGPathSegCurvetoQuadraticRel> curveseg = do_QueryInterface(segment);
            NS_ASSERTION(curveseg, "interface not implemented");
            curveseg->GetX(&x);
            curveseg->GetY(&y);
            curveseg->GetX1(&x1);
            curveseg->GetY1(&y1);
            x  += cx;
            y  += cy;
            x1 += cx;
            y1 += cy;
          } else {
            nsCOMPtr<nsIDOMSVGPathSegCurvetoQuadraticAbs> curveseg = do_QueryInterface(segment);
            NS_ASSERTION(curveseg, "interface not implemented");
            curveseg->GetX(&x);
            curveseg->GetY(&y);
            curveseg->GetX1(&x1);
            curveseg->GetY1(&y1);
          }    

          // conversion of quadratic bezier curve to cubic bezier curve:
          x31 = cx + (x1 - cx) * 2 / 3;
          y31 = cy + (y1 - cy) * 2 / 3;
          x32 = x1 + (x - x1) / 3;
          y32 = y1 + (y - y1) / 3;

          cx  = x;
          cy  = y;
          cx1 = x1;
          cy1 = y1;

          pathBuilder->Curveto(x, y, x31, y31, x32, y32);
        }
        break;

      case nsIDOMSVGPathSeg::PATHSEG_ARC_ABS:
        absCoords = PR_TRUE;
      case nsIDOMSVGPathSeg::PATHSEG_ARC_REL:
        {
          float x0, y0, x, y, r1, r2, angle;
          PRBool largeArcFlag, sweepFlag;

          x0 = cx;
          y0 = cy;
          
          if (!absCoords) {
            nsCOMPtr<nsIDOMSVGPathSegArcRel> arcseg = do_QueryInterface(segment);
            NS_ASSERTION(arcseg, "interface not implemented");
            arcseg->GetX(&x);
            arcseg->GetY(&y);
            arcseg->GetR1(&r1);
            arcseg->GetR2(&r2);
            arcseg->GetAngle(&angle);
            arcseg->GetLargeArcFlag(&largeArcFlag);
            arcseg->GetSweepFlag(&sweepFlag);

            x  += cx;
            y  += cy;
          } else {
            nsCOMPtr<nsIDOMSVGPathSegArcAbs> arcseg = do_QueryInterface(segment);
            NS_ASSERTION(arcseg, "interface not implemented");
            arcseg->GetX(&x);
            arcseg->GetY(&y);
            arcseg->GetR1(&r1);
            arcseg->GetR2(&r2);
            arcseg->GetAngle(&angle);
            arcseg->GetLargeArcFlag(&largeArcFlag);
            arcseg->GetSweepFlag(&sweepFlag);
          }            
          cx = x;
          cy = y;
          
          pathBuilder->Arcto(x, y, r1, r2, angle, largeArcFlag, sweepFlag);
        }
        break;

      case nsIDOMSVGPathSeg::PATHSEG_LINETO_HORIZONTAL_ABS:
        absCoords = PR_TRUE;
      case nsIDOMSVGPathSeg::PATHSEG_LINETO_HORIZONTAL_REL:
        {
          float x;
          float y = cy;
          if (!absCoords) {
            nsCOMPtr<nsIDOMSVGPathSegLinetoHorizontalRel> lineseg = do_QueryInterface(segment);
            NS_ASSERTION(lineseg, "interface not implemented");
            lineseg->GetX(&x);
            x += cx;
          } else {
            nsCOMPtr<nsIDOMSVGPathSegLinetoHorizontalAbs> lineseg = do_QueryInterface(segment);
            NS_ASSERTION(lineseg, "interface not implemented");
            lineseg->GetX(&x);
          }
          cx = x;
          pathBuilder->Lineto(x,y);
        }
        break;        

      case nsIDOMSVGPathSeg::PATHSEG_LINETO_VERTICAL_ABS:
        absCoords = PR_TRUE;
      case nsIDOMSVGPathSeg::PATHSEG_LINETO_VERTICAL_REL:
        {
          float x = cx;
          float y;
          if (!absCoords) {
            nsCOMPtr<nsIDOMSVGPathSegLinetoVerticalRel> lineseg = do_QueryInterface(segment);
            NS_ASSERTION(lineseg, "interface not implemented");
            lineseg->GetY(&y);
            y += cy;
          } else {
            nsCOMPtr<nsIDOMSVGPathSegLinetoVerticalAbs> lineseg = do_QueryInterface(segment);
            NS_ASSERTION(lineseg, "interface not implemented");
            lineseg->GetY(&y);
          }
          cy = y;
          pathBuilder->Lineto(x,y);
        }
        break;

      case nsIDOMSVGPathSeg::PATHSEG_CURVETO_CUBIC_SMOOTH_ABS:
        absCoords = PR_TRUE;
      case nsIDOMSVGPathSeg::PATHSEG_CURVETO_CUBIC_SMOOTH_REL:
        {
          float x, y, x1, y1, x2, y2;

          if (lastSegmentType == nsIDOMSVGPathSeg::PATHSEG_CURVETO_CUBIC_REL        ||
              lastSegmentType == nsIDOMSVGPathSeg::PATHSEG_CURVETO_CUBIC_ABS        ||
              lastSegmentType == nsIDOMSVGPathSeg::PATHSEG_CURVETO_CUBIC_SMOOTH_REL ||
              lastSegmentType == nsIDOMSVGPathSeg::PATHSEG_CURVETO_CUBIC_SMOOTH_ABS ) {
            // the first controlpoint is the reflection of the last one about the current point:
            x1 = 2*cx - cx1;
            y1 = 2*cy - cy1;
          }
          else {
            // the first controlpoint is equal to the current point:
            x1 = cx;
            y1 = cy;
          }
          
          if (!absCoords) {
            nsCOMPtr<nsIDOMSVGPathSegCurvetoCubicSmoothRel> curveseg = do_QueryInterface(segment);
            NS_ASSERTION(curveseg, "interface not implemented");
            curveseg->GetX(&x);
            curveseg->GetY(&y);
            curveseg->GetX2(&x2);
            curveseg->GetY2(&y2);
            x  += cx;
            y  += cy;
            x2 += cx;
            y2 += cy;
          } else {
            nsCOMPtr<nsIDOMSVGPathSegCurvetoCubicSmoothAbs> curveseg = do_QueryInterface(segment);
            NS_ASSERTION(curveseg, "interface not implemented");
            curveseg->GetX(&x);
            curveseg->GetY(&y);
            curveseg->GetX2(&x2);
            curveseg->GetY2(&y2);
          }            
          cx  = x;
          cy  = y;
          cx1 = x2;
          cy1 = y2;
          pathBuilder->Curveto(x, y, x1, y1, x2, y2);
        }
        break;

      case nsIDOMSVGPathSeg::PATHSEG_CURVETO_QUADRATIC_SMOOTH_ABS:
        absCoords = PR_TRUE;
      case nsIDOMSVGPathSeg::PATHSEG_CURVETO_QUADRATIC_SMOOTH_REL:
        {
          float x, y, x1, y1, x31, y31, x32, y32;

          if (lastSegmentType == nsIDOMSVGPathSeg::PATHSEG_CURVETO_QUADRATIC_REL        ||
              lastSegmentType == nsIDOMSVGPathSeg::PATHSEG_CURVETO_QUADRATIC_ABS        ||
              lastSegmentType == nsIDOMSVGPathSeg::PATHSEG_CURVETO_QUADRATIC_SMOOTH_REL ||
              lastSegmentType == nsIDOMSVGPathSeg::PATHSEG_CURVETO_QUADRATIC_SMOOTH_ABS ) {
            // the first controlpoint is the reflection of the last one about the current point:
            x1 = 2*cx - cx1;
            y1 = 2*cy - cy1;
          }
          else {
            // the first controlpoint is equal to the current point:
            x1 = cx;
            y1 = cy;
          }
          
          if (!absCoords) {
            nsCOMPtr<nsIDOMSVGPathSegCurvetoQuadraticSmoothRel> curveseg = do_QueryInterface(segment);
            NS_ASSERTION(curveseg, "interface not implemented");
            curveseg->GetX(&x);
            curveseg->GetY(&y);
            x  += cx;
            y  += cy;
          } else {
            nsCOMPtr<nsIDOMSVGPathSegCurvetoQuadraticSmoothAbs> curveseg = do_QueryInterface(segment);
            NS_ASSERTION(curveseg, "interface not implemented");
            curveseg->GetX(&x);
            curveseg->GetY(&y);
          }            

          // conversion of quadratic bezier curve to cubic bezier curve:
          x31 = cx + (x1 - cx) * 2 / 3;
          y31 = cy + (y1 - cy) * 2 / 3;
          x32 = x1 + (x - x1) / 3;
          y32 = y1 + (y - y1) / 3;

          cx  = x;
          cy  = y;
          cx1 = x1;
          cy1 = y1;

          pathBuilder->Curveto(x, y, x31, y31, x32, y32);
        }
        break;

      default:
        NS_ASSERTION(1==0, "unknown path segment");
        break;
    }
    lastSegmentType = type;
  }
  
  return NS_OK;  
}

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