WebCore/svg/SVGPreserveAspectRatio.cpp

   1 /*
   2  * Copyright (C) 2004, 2005, 2008 Nikolas Zimmermann <zimmermann@kde.org>
   3  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
   4  * Copyright (C) 2010 Dirk Schulze <krit@webkit.org>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Library General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Library General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Library General Public License
  17  * along with this library; see the file COPYING.LIB.  If not, write to
  18  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  19  * Boston, MA 02110-1301, USA.
  20  */
  21
  22 #include "config.h"
  23
  24 #if ENABLE(SVG)
  25 #include "SVGPreserveAspectRatio.h"
  26
  27 #include "AffineTransform.h"
  28 #include "FloatRect.h"
  29 #include "SVGParserUtilities.h"
  30 #include <wtf/text/StringConcatenate.h>
  31
  32 namespace WebCore {
  33
  34 SVGPreserveAspectRatio::SVGPreserveAspectRatio()
  35     : m_align(SVG_PRESERVEASPECTRATIO_XMIDYMID)
  36     , m_meetOrSlice(SVG_MEETORSLICE_MEET)
  37 {
  38 }
  39
  40 void SVGPreserveAspectRatio::setAlign(unsigned short align, ExceptionCode& ec)
  41 {
  42     if (align == SVG_PRESERVEASPECTRATIO_UNKNOWN || align > SVG_PRESERVEASPECTRATIO_XMAXYMAX) {
  43         ec = NOT_SUPPORTED_ERR;
  44         return;
  45     }
  46
  47     m_align = static_cast<SVGPreserveAspectRatioType>(align);
  48 }
  49
  50 void SVGPreserveAspectRatio::setMeetOrSlice(unsigned short meetOrSlice, ExceptionCode& ec)
  51 {
  52     if (meetOrSlice == SVG_MEETORSLICE_UNKNOWN || meetOrSlice > SVG_MEETORSLICE_SLICE) {
  53         ec = NOT_SUPPORTED_ERR;
  54         return;
  55     }
  56
  57     m_meetOrSlice = static_cast<SVGMeetOrSliceType>(meetOrSlice);
  58 }
  59
  60 SVGPreserveAspectRatio SVGPreserveAspectRatio::parsePreserveAspectRatio(const UChar*& currParam, const UChar* end, bool validate, bool& result)
  61 {
  62     SVGPreserveAspectRatio aspectRatio;
  63     aspectRatio.m_align = SVG_PRESERVEASPECTRATIO_NONE;
  64     aspectRatio.m_meetOrSlice = SVG_MEETORSLICE_MEET;
  65     result = false;
  66
  67     // FIXME: Rewrite this parser, without gotos!
  68     if (!skipOptionalSpaces(currParam, end))
  69         goto bail_out;
  70
  71     if (*currParam == 'd') {
  72         if (!skipString(currParam, end, "defer"))
  73             goto bail_out;
  74         // FIXME: We just ignore the "defer" here.
  75         if (!skipOptionalSpaces(currParam, end))
  76             goto bail_out;
  77     }
  78
  79     if (*currParam == 'n') {
  80         if (!skipString(currParam, end, "none"))
  81             goto bail_out;
  82         skipOptionalSpaces(currParam, end);
  83     } else if (*currParam == 'x') {
  84         if ((end - currParam) < 8)
  85             goto bail_out;
  86         if (currParam[1] != 'M' || currParam[4] != 'Y' || currParam[5] != 'M')
  87             goto bail_out;
  88         if (currParam[2] == 'i') {
  89             if (currParam[3] == 'n') {
  90                 if (currParam[6] == 'i') {
  91                     if (currParam[7] == 'n')
  92                         aspectRatio.m_align = SVG_PRESERVEASPECTRATIO_XMINYMIN;
  93                     else if (currParam[7] == 'd')
  94                         aspectRatio.m_align = SVG_PRESERVEASPECTRATIO_XMINYMID;
  95                     else
  96                         goto bail_out;
  97                 } else if (currParam[6] == 'a' && currParam[7] == 'x')
  98                      aspectRatio.m_align = SVG_PRESERVEASPECTRATIO_XMINYMAX;
  99                 else
 100                      goto bail_out;
 101              } else if (currParam[3] == 'd') {
 102                 if (currParam[6] == 'i') {
 103                     if (currParam[7] == 'n')
 104                         aspectRatio.m_align = SVG_PRESERVEASPECTRATIO_XMIDYMIN;
 105                     else if (currParam[7] == 'd')
 106                         aspectRatio.m_align = SVG_PRESERVEASPECTRATIO_XMIDYMID;
 107                     else
 108                         goto bail_out;
 109                 } else if (currParam[6] == 'a' && currParam[7] == 'x')
 110                     aspectRatio.m_align = SVG_PRESERVEASPECTRATIO_XMIDYMAX;
 111                 else
 112                     goto bail_out;
 113             } else
 114                 goto bail_out;
 115         } else if (currParam[2] == 'a' && currParam[3] == 'x') {
 116             if (currParam[6] == 'i') {
 117                 if (currParam[7] == 'n')
 118                     aspectRatio.m_align = SVG_PRESERVEASPECTRATIO_XMAXYMIN;
 119                 else if (currParam[7] == 'd')
 120                     aspectRatio.m_align = SVG_PRESERVEASPECTRATIO_XMAXYMID;
 121                 else
 122                     goto bail_out;
 123             } else if (currParam[6] == 'a' && currParam[7] == 'x')
 124                 aspectRatio.m_align = SVG_PRESERVEASPECTRATIO_XMAXYMAX;
 125             else
 126                 goto bail_out;
 127         } else
 128             goto bail_out;
 129         currParam += 8;
 130         skipOptionalSpaces(currParam, end);
 131     } else
 132         goto bail_out;
 133
 134     if (currParam < end) {
 135         if (*currParam == 'm') {
 136             if (!skipString(currParam, end, "meet"))
 137                 goto bail_out;
 138             skipOptionalSpaces(currParam, end);
 139         } else if (*currParam == 's') {
 140             if (!skipString(currParam, end, "slice"))
 141                 goto bail_out;
 142             skipOptionalSpaces(currParam, end);
 143             if (aspectRatio.m_align != SVG_PRESERVEASPECTRATIO_NONE)
 144                 aspectRatio.m_meetOrSlice = SVG_MEETORSLICE_SLICE;
 145         }
 146     }
 147
 148     if (end != currParam && validate) {
 149 bail_out:
 150         // FIXME: Should the two values be set to UNKNOWN instead?
 151         aspectRatio.m_align = SVG_PRESERVEASPECTRATIO_NONE;
 152         aspectRatio.m_meetOrSlice = SVG_MEETORSLICE_MEET;
 153     } else
 154         result = true;
 155
 156     return aspectRatio;
 157 }
 158
 159 void SVGPreserveAspectRatio::transformRect(FloatRect& destRect, FloatRect& srcRect)
 160 {
 161     FloatSize imageSize = srcRect.size();
 162     float origDestWidth = destRect.width();
 163     float origDestHeight = destRect.height();
 164     switch (m_meetOrSlice) {
 165     case SVGPreserveAspectRatio::SVG_MEETORSLICE_UNKNOWN:
 166         break;
 167     case SVGPreserveAspectRatio::SVG_MEETORSLICE_MEET:
 168     {
 169         float widthToHeightMultiplier = srcRect.height() / srcRect.width();
 170         if (origDestHeight > origDestWidth * widthToHeightMultiplier) {
 171             destRect.setHeight(origDestWidth * widthToHeightMultiplier);
 172             switch (m_align) {
 173             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMINYMID:
 174             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMID:
 175             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMID:
 176                 destRect.setY(destRect.y() + origDestHeight / 2 - destRect.height() / 2);
 177                 break;
 178             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMINYMAX:
 179             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMAX:
 180             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMAX:
 181                 destRect.setY(destRect.y() + origDestHeight - destRect.height());
 182                 break;
 183             default:
 184                 break;
 185             }
 186         }
 187         if (origDestWidth > origDestHeight / widthToHeightMultiplier) {
 188             destRect.setWidth(origDestHeight / widthToHeightMultiplier);
 189             switch (m_align) {
 190             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMIN:
 191             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMID:
 192             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMAX:
 193                 destRect.setX(destRect.x() + origDestWidth / 2 - destRect.width() / 2);
 194                 break;
 195             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMIN:
 196             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMID:
 197             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMAX:
 198                 destRect.setX(destRect.x() + origDestWidth - destRect.width());
 199                 break;
 200             default:
 201                 break;
 202             }
 203         }
 204         break;
 205     }
 206     case SVGPreserveAspectRatio::SVG_MEETORSLICE_SLICE:
 207     {
 208         float widthToHeightMultiplier = srcRect.height() / srcRect.width();
 209         // if the destination height is less than the height of the image we'll be drawing
 210         if (origDestHeight < origDestWidth * widthToHeightMultiplier) {
 211             float destToSrcMultiplier = srcRect.width() / destRect.width();
 212             srcRect.setHeight(destRect.height() * destToSrcMultiplier);
 213             switch (m_align) {
 214             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMINYMID:
 215             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMID:
 216             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMID:
 217                 srcRect.setY(destRect.y() + imageSize.height() / 2 - srcRect.height() / 2);
 218                 break;
 219             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMINYMAX:
 220             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMAX:
 221             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMAX:
 222                 srcRect.setY(destRect.y() + imageSize.height() - srcRect.height());
 223                 break;
 224             default:
 225                 break;
 226             }
 227         }
 228         // if the destination width is less than the width of the image we'll be drawing
 229         if (origDestWidth < origDestHeight / widthToHeightMultiplier) {
 230             float destToSrcMultiplier = srcRect.height() / destRect.height();
 231             srcRect.setWidth(destRect.width() * destToSrcMultiplier);
 232             switch (m_align) {
 233             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMIN:
 234             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMID:
 235             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMAX:
 236                 srcRect.setX(destRect.x() + imageSize.width() / 2 - srcRect.width() / 2);
 237                 break;
 238             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMIN:
 239             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMID:
 240             case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMAX:
 241                 srcRect.setX(destRect.x() + imageSize.width() - srcRect.width());
 242                 break;
 243             default:
 244                 break;
 245             }
 246         }
 247         break;
 248     }
 249     }
 250 }
 251
 252 // FIXME: We should use floats here, like everywhere else!
 253 AffineTransform SVGPreserveAspectRatio::getCTM(double logicX, double logicY, double logicWidth, double logicHeight, double physWidth, double physHeight) const
 254 {
 255     AffineTransform transform;
 256     if (m_align == SVG_PRESERVEASPECTRATIO_UNKNOWN)
 257         return transform;
 258
 259     double logicalRatio = logicWidth / logicHeight;
 260     double physRatio = physWidth / physHeight;
 261
 262     if (m_align == SVG_PRESERVEASPECTRATIO_NONE) {
 263         transform.scaleNonUniform(physWidth / logicWidth, physHeight / logicHeight);
 264         transform.translate(-logicX, -logicY);
 265         return transform;
 266     }
 267
 268     if ((logicalRatio < physRatio && (m_meetOrSlice == SVG_MEETORSLICE_MEET)) || (logicalRatio >= physRatio && (m_meetOrSlice == SVG_MEETORSLICE_SLICE))) {
 269         transform.scaleNonUniform(physHeight / logicHeight, physHeight / logicHeight);
 270
 271         if (m_align == SVG_PRESERVEASPECTRATIO_XMINYMIN || m_align == SVG_PRESERVEASPECTRATIO_XMINYMID || m_align == SVG_PRESERVEASPECTRATIO_XMINYMAX)
 272             transform.translate(-logicX, -logicY);
 273         else if (m_align == SVG_PRESERVEASPECTRATIO_XMIDYMIN || m_align == SVG_PRESERVEASPECTRATIO_XMIDYMID || m_align == SVG_PRESERVEASPECTRATIO_XMIDYMAX)
 274             transform.translate(-logicX - (logicWidth - physWidth * logicHeight / physHeight) / 2, -logicY);
 275         else
 276             transform.translate(-logicX - (logicWidth - physWidth * logicHeight / physHeight), -logicY);
 277
 278         return transform;
 279     }
 280
 281     transform.scaleNonUniform(physWidth / logicWidth, physWidth / logicWidth);
 282
 283     if (m_align == SVG_PRESERVEASPECTRATIO_XMINYMIN || m_align == SVG_PRESERVEASPECTRATIO_XMIDYMIN || m_align == SVG_PRESERVEASPECTRATIO_XMAXYMIN)
 284         transform.translate(-logicX, -logicY);
 285     else if (m_align == SVG_PRESERVEASPECTRATIO_XMINYMID || m_align == SVG_PRESERVEASPECTRATIO_XMIDYMID || m_align == SVG_PRESERVEASPECTRATIO_XMAXYMID)
 286         transform.translate(-logicX, -logicY - (logicHeight - physHeight * logicWidth / physWidth) / 2);
 287     else
 288         transform.translate(-logicX, -logicY - (logicHeight - physHeight * logicWidth / physWidth));
 289
 290     return transform;
 291 }
 292
 293 String SVGPreserveAspectRatio::valueAsString() const
 294 {
 295     String alignType;
 296
 297     switch (m_align) {
 298     case SVG_PRESERVEASPECTRATIO_NONE:
 299         alignType = "none";
 300         break;
 301     case SVG_PRESERVEASPECTRATIO_XMINYMIN:
 302         alignType = "xMinYMin";
 303         break;
 304     case SVG_PRESERVEASPECTRATIO_XMIDYMIN:
 305         alignType = "xMidYMin";
 306         break;
 307     case SVG_PRESERVEASPECTRATIO_XMAXYMIN:
 308         alignType = "xMaxYMin";
 309         break;
 310     case SVG_PRESERVEASPECTRATIO_XMINYMID:
 311         alignType = "xMinYMid";
 312         break;
 313     case SVG_PRESERVEASPECTRATIO_XMIDYMID:
 314         alignType = "xMidYMid";
 315         break;
 316     case SVG_PRESERVEASPECTRATIO_XMAXYMID:
 317         alignType = "xMaxYMid";
 318         break;
 319     case SVG_PRESERVEASPECTRATIO_XMINYMAX:
 320         alignType = "xMinYMax";
 321         break;
 322     case SVG_PRESERVEASPECTRATIO_XMIDYMAX:
 323         alignType = "xMidYMax";
 324         break;
 325     case SVG_PRESERVEASPECTRATIO_XMAXYMAX:
 326         alignType = "xMaxYMax";
 327         break;
 328     case SVG_PRESERVEASPECTRATIO_UNKNOWN:
 329         alignType = "unknown";
 330         break;
 331     };
 332
 333     switch (m_meetOrSlice) {
 334     default:
 335     case SVG_MEETORSLICE_UNKNOWN:
 336         return alignType;
 337     case SVG_MEETORSLICE_MEET:
 338         return makeString(alignType, " meet");
 339     case SVG_MEETORSLICE_SLICE:
 340         return makeString(alignType, " slice");
 341     };
 342 }
 343
 344 }
 345
 346 #endif // ENABLE(SVG)