WebCore/platform/graphics/cairo/PathCairo.cpp

   1 /*
   2     Copyright (C) 2007 Krzysztof Kowalczyk <kkowalczyk@gmail.com>
   3     Copyright (C) 2004, 2005, 2006 Nikolas Zimmermann <wildfox@kde.org>
   4                   2004, 2005, 2006 Rob Buis <buis@kde.org>
   5                   2005, 2007 Apple Inc. All Rights reserved.
   6                   2007 Alp Toker <alp@atoker.com>
   7
   8     This library is free software; you can redistribute it and/or
   9     modify it under the terms of the GNU Library General Public
  10     License as published by the Free Software Foundation; either
  11     version 2 of the License, or (at your option) any later version.
  12
  13     This library is distributed in the hope that it will be useful,
  14     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16     Library General Public License for more details.
  17
  18     You should have received a copy of the GNU Library General Public License
  19     aint with this library; see the file COPYING.LIB.  If not, write to
  20     the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21     Boston, MA 02110-1301, USA.
  22 */
  23
  24 #include "config.h"
  25 #include "Path.h"
  26
  27 #include "AffineTransform.h"
  28 #include "CairoPath.h"
  29 #include "FloatRect.h"
  30 #include "GraphicsContext.h"
  31 #include "NotImplemented.h"
  32 #include "PlatformString.h"
  33 #include "StrokeStyleApplier.h"
  34
  35 #include <cairo.h>
  36 #include <math.h>
  37 #include <wtf/MathExtras.h>
  38
  39 namespace WebCore {
  40
  41 Path::Path()
  42     : m_path(new CairoPath())
  43 {
  44 }
  45
  46 Path::~Path()
  47 {
  48     delete m_path;
  49 }
  50
  51 Path::Path(const Path& other)
  52     : m_path(new CairoPath())
  53 {
  54     cairo_t* cr = platformPath()->m_cr;
  55     cairo_path_t* p = cairo_copy_path(other.platformPath()->m_cr);
  56     cairo_append_path(cr, p);
  57     cairo_path_destroy(p);
  58 }
  59
  60 Path& Path::operator=(const Path& other)
  61 {
  62     if (&other == this)
  63         return *this;
  64
  65     clear();
  66     cairo_t* cr = platformPath()->m_cr;
  67     cairo_path_t* p = cairo_copy_path(other.platformPath()->m_cr);
  68     cairo_append_path(cr, p);
  69     cairo_path_destroy(p);
  70     return *this;
  71 }
  72
  73 void Path::clear()
  74 {
  75     cairo_t* cr = platformPath()->m_cr;
  76     cairo_new_path(cr);
  77 }
  78
  79 bool Path::isEmpty() const
  80 {
  81     cairo_t* cr = platformPath()->m_cr;
  82 #if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1,5,10)
  83     return !cairo_has_current_point(cr);
  84 #else
  85     cairo_path_t* p = cairo_copy_path(cr);
  86     bool hasData = p->num_data;
  87     cairo_path_destroy(p);
  88     return !hasData;
  89 #endif
  90 }
  91
  92 void Path::translate(const FloatSize& p)
  93 {
  94     cairo_t* cr = platformPath()->m_cr;
  95     cairo_translate(cr, p.width(), p.height());
  96 }
  97
  98 void Path::moveTo(const FloatPoint& p)
  99 {
 100     cairo_t* cr = platformPath()->m_cr;
 101     cairo_move_to(cr, p.x(), p.y());
 102 }
 103
 104 void Path::addLineTo(const FloatPoint& p)
 105 {
 106     cairo_t* cr = platformPath()->m_cr;
 107     cairo_line_to(cr, p.x(), p.y());
 108 }
 109
 110 void Path::addRect(const FloatRect& rect)
 111 {
 112     cairo_t* cr = platformPath()->m_cr;
 113     cairo_rectangle(cr, rect.x(), rect.y(), rect.width(), rect.height());
 114 }
 115
 116 /*
 117  * inspired by libsvg-cairo
 118  */
 119 void Path::addQuadCurveTo(const FloatPoint& controlPoint, const FloatPoint& point)
 120 {
 121     cairo_t* cr = platformPath()->m_cr;
 122     double x, y;
 123     double x1 = controlPoint.x();
 124     double y1 = controlPoint.y();
 125     double x2 = point.x();
 126     double y2 = point.y();
 127     cairo_get_current_point(cr, &x, &y);
 128     cairo_curve_to(cr,
 129                    x  + 2.0 / 3.0 * (x1 - x),  y  + 2.0 / 3.0 * (y1 - y),
 130                    x2 + 2.0 / 3.0 * (x1 - x2), y2 + 2.0 / 3.0 * (y1 - y2),
 131                    x2, y2);
 132 }
 133
 134 void Path::addBezierCurveTo(const FloatPoint& controlPoint1, const FloatPoint& controlPoint2, const FloatPoint& controlPoint3)
 135 {
 136     cairo_t* cr = platformPath()->m_cr;
 137     cairo_curve_to(cr, controlPoint1.x(), controlPoint1.y(),
 138                    controlPoint2.x(), controlPoint2.y(),
 139                    controlPoint3.x(), controlPoint3.y());
 140 }
 141
 142 void Path::addArc(const FloatPoint& p, float r, float sa, float ea, bool anticlockwise)
 143 {
 144     // http://bugs.webkit.org/show_bug.cgi?id=16449
 145     // cairo_arc() functions hang or crash when passed inf as radius or start/end angle
 146     if (!isfinite(r) || !isfinite(sa) || !isfinite(ea))
 147         return;
 148
 149     cairo_t* cr = platformPath()->m_cr;
 150     if (anticlockwise)
 151         cairo_arc_negative(cr, p.x(), p.y(), r, sa, ea);
 152     else
 153         cairo_arc(cr, p.x(), p.y(), r, sa, ea);
 154 }
 155
 156 void Path::addArcTo(const FloatPoint& p1, const FloatPoint& p2, float radius)
 157 {
 158     // FIXME: cairo_arc_to not yet in cairo see cairo.h
 159     // cairo_arc_to(m_cr, p1.x(), p1.y(), p2.x(), p2.y());
 160     notImplemented();
 161 }
 162
 163 void Path::addEllipse(const FloatRect& rect)
 164 {
 165     cairo_t* cr = platformPath()->m_cr;
 166     cairo_save(cr);
 167     float yRadius = .5 * rect.height();
 168     float xRadius = .5 * rect.width();
 169     cairo_translate(cr, rect.x() + xRadius, rect.y() + yRadius);
 170     cairo_scale(cr, xRadius, yRadius);
 171     cairo_arc(cr, 0., 0., 1., 0., 2 * piDouble);
 172     cairo_restore(cr);
 173 }
 174
 175 void Path::closeSubpath()
 176 {
 177     cairo_t* cr = platformPath()->m_cr;
 178     cairo_close_path(cr);
 179 }
 180
 181 FloatRect Path::boundingRect() const
 182 {
 183     cairo_t* cr = platformPath()->m_cr;
 184     double x0, x1, y0, y1;
 185 #if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1, 6, 0)
 186     cairo_path_extents(cr, &x0, &y0, &x1, &y1);
 187 #else
 188     cairo_stroke_extents(cr, &x0, &y0, &x1, &y1);
 189 #endif
 190     return FloatRect(x0, y0, x1 - x0, y1 - y0);
 191 }
 192
 193 FloatRect Path::strokeBoundingRect(StrokeStyleApplier* applier)
 194 {
 195     cairo_t* cr = platformPath()->m_cr;
 196     if (applier) {
 197         GraphicsContext gc(cr);
 198         applier->strokeStyle(&gc);
 199     }
 200
 201     double x0, x1, y0, y1;
 202     cairo_stroke_extents(cr, &x0, &y0, &x1, &y1);
 203     return FloatRect(x0, y0, x1 - x0, y1 - y0);
 204 }
 205
 206 bool Path::contains(const FloatPoint& point, WindRule rule) const
 207 {
 208     if (!boundingRect().contains(point))
 209         return false;
 210
 211     cairo_t* cr = platformPath()->m_cr;
 212     cairo_fill_rule_t cur = cairo_get_fill_rule(cr);
 213     cairo_set_fill_rule(cr, rule == RULE_EVENODD ? CAIRO_FILL_RULE_EVEN_ODD : CAIRO_FILL_RULE_WINDING);
 214     bool contains = cairo_in_fill(cr, point.x(), point.y());
 215     cairo_set_fill_rule(cr, cur);
 216     return contains;
 217 }
 218
 219 void Path::apply(void* info, PathApplierFunction function) const
 220 {
 221     cairo_t* cr = platformPath()->m_cr;
 222     cairo_path_t* path = cairo_copy_path(cr);
 223     cairo_path_data_t* data;
 224     PathElement pelement;
 225     FloatPoint points[3];
 226     pelement.points = points;
 227
 228     for (int i = 0; i < path->num_data; i += path->data[i].header.length) {
 229         data = &path->data[i];
 230         switch (data->header.type) {
 231         case CAIRO_PATH_MOVE_TO:
 232             pelement.type = PathElementMoveToPoint;
 233             pelement.points[0] = FloatPoint(data[1].point.x,data[1].point.y);
 234             function(info, &pelement);
 235             break;
 236         case CAIRO_PATH_LINE_TO:
 237             pelement.type = PathElementAddLineToPoint;
 238             pelement.points[0] = FloatPoint(data[1].point.x,data[1].point.y);
 239             function(info, &pelement);
 240             break;
 241         case CAIRO_PATH_CURVE_TO:
 242             pelement.type = PathElementAddCurveToPoint;
 243             pelement.points[0] = FloatPoint(data[1].point.x,data[1].point.y);
 244             pelement.points[1] = FloatPoint(data[2].point.x,data[2].point.y);
 245             pelement.points[2] = FloatPoint(data[3].point.x,data[3].point.y);
 246             function(info, &pelement);
 247             break;
 248         case CAIRO_PATH_CLOSE_PATH:
 249             pelement.type = PathElementCloseSubpath;
 250             function(info, &pelement);
 251             break;
 252         }
 253     }
 254     cairo_path_destroy(path);
 255 }
 256
 257 void Path::transform(const AffineTransform& trans)
 258 {
 259     cairo_t* m_cr = platformPath()->m_cr;
 260     cairo_matrix_t c_matrix = cairo_matrix_t(trans);
 261     cairo_matrix_invert(&c_matrix);
 262     cairo_transform(m_cr, &c_matrix);
 263 }
 264
 265 String Path::debugString() const
 266 {
 267     if (isEmpty())
 268         return String();
 269
 270     String pathString;
 271     cairo_path_t* path = cairo_copy_path(platformPath()->m_cr);
 272     cairo_path_data_t* data;
 273
 274     for (int i = 0; i < path->num_data; i += path->data[i].header.length) {
 275         data = &path->data[i];
 276         switch (data->header.type) {
 277         case CAIRO_PATH_MOVE_TO:
 278             if (i < (path->num_data - path->data[i].header.length))
 279                 pathString += String::format("M%.2f,%.2f ",
 280                                       data[1].point.x, data[1].point.y);
 281             break;
 282         case CAIRO_PATH_LINE_TO:
 283             pathString += String::format("L%.2f,%.2f ",
 284                                       data[1].point.x, data[1].point.y);
 285             break;
 286         case CAIRO_PATH_CURVE_TO:
 287             pathString += String::format("C%.2f,%.2f,%.2f,%.2f,%.2f,%.2f ",
 288                                       data[1].point.x, data[1].point.y,
 289                                       data[2].point.x, data[2].point.y,
 290                                       data[3].point.x, data[3].point.y);
 291             break;
 292         case CAIRO_PATH_CLOSE_PATH:
 293             pathString += "Z ";
 294             break;
 295         }
 296     }
 297
 298     cairo_path_destroy(path);
 299     return pathString.simplifyWhiteSpace();
 300 }
 301
 302 } // namespace WebCore