/*
* Copyright (C) 2003, 2006 Apple Computer, Inc. All rights reserved.
* 2006 Rob Buis <buis@kde.org>
* Copyright (C) 2007 Eric Seidel <eric@webkit.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "Path.h"
#include "FloatPoint.h"
#include "FloatRect.h"
#include "PathTraversalState.h"
#include <math.h>
#include <wtf/MathExtras.h>
static const float QUARTER = 0.552f; // approximation of control point positions on a bezier
// to simulate a quarter of a circle.
namespace WebCore {
static void pathLengthApplierFunction(void* info, const PathElement* element)
{
PathTraversalState& traversalState = *static_cast<PathTraversalState*>(info);
if (traversalState.m_success)
return;
traversalState.m_previous = traversalState.m_current;
FloatPoint* points = element->points;
float segmentLength = 0.0f;
switch (element->type) {
case PathElementMoveToPoint:
segmentLength = traversalState.moveTo(points[0]);
break;
case PathElementAddLineToPoint:
segmentLength = traversalState.lineTo(points[0]);
break;
case PathElementAddQuadCurveToPoint:
segmentLength = traversalState.quadraticBezierTo(points[0], points[1]);
break;
case PathElementAddCurveToPoint:
segmentLength = traversalState.cubicBezierTo(points[0], points[1], points[2]);
break;
case PathElementCloseSubpath:
segmentLength = traversalState.closeSubpath();
break;
}
traversalState.m_totalLength += segmentLength;
if ((traversalState.m_action == PathTraversalState::TraversalPointAtLength ||
traversalState.m_action == PathTraversalState::TraversalNormalAngleAtLength) &&
(traversalState.m_totalLength >= traversalState.m_desiredLength)) {
FloatSize change = traversalState.m_current - traversalState.m_previous;
float slope = atan2f(change.height(), change.width());
if (traversalState.m_action == PathTraversalState::TraversalPointAtLength) {
float offset = traversalState.m_desiredLength - traversalState.m_totalLength;
traversalState.m_current.move(offset * cosf(slope), offset * sinf(slope));
} else {
static const float rad2deg = 180.0f / piFloat;
traversalState.m_normalAngle = slope * rad2deg;
}
traversalState.m_success = true;
}
}
float Path::length()
{
PathTraversalState traversalState(PathTraversalState::TraversalTotalLength);
apply(&traversalState, pathLengthApplierFunction);
return traversalState.m_totalLength;
}
FloatPoint Path::pointAtLength(float length, bool& ok)
{
PathTraversalState traversalState(PathTraversalState::TraversalPointAtLength);
traversalState.m_desiredLength = length;
apply(&traversalState, pathLengthApplierFunction);
ok = traversalState.m_success;
return traversalState.m_current;
}
float Path::normalAngleAtLength(float length, bool& ok)
{
PathTraversalState traversalState(PathTraversalState::TraversalNormalAngleAtLength);
traversalState.m_desiredLength = length;
apply(&traversalState, pathLengthApplierFunction);
ok = traversalState.m_success;
return traversalState.m_normalAngle;
}
Path Path::createRoundedRectangle(const FloatRect& rectangle, const FloatSize& roundingRadii)
{
Path path;
float x = rectangle.x();
float y = rectangle.y();
float width = rectangle.width();
float height = rectangle.height();
float rx = roundingRadii.width();
float ry = roundingRadii.height();
if (width <= 0.0f || height <= 0.0f)
return path;
float dx = rx, dy = ry;
// If rx is greater than half of the width of the rectangle
// then set rx to half of the width (required in SVG spec)
if (dx > width * 0.5f)
dx = width * 0.5f;
// If ry is greater than half of the height of the rectangle
// then set ry to half of the height (required in SVG spec)
if (dy > height * 0.5f)
dy = height * 0.5f;
path.moveTo(FloatPoint(x + dx, y));
if (dx < width * 0.5f)
path.addLineTo(FloatPoint(x + width - rx, y));
path.addBezierCurveTo(FloatPoint(x + width - dx * (1 - QUARTER), y), FloatPoint(x + width, y + dy * (1 - QUARTER)), FloatPoint(x + width, y + dy));
if (dy < height * 0.5)
path.addLineTo(FloatPoint(x + width, y + height - dy));
path.addBezierCurveTo(FloatPoint(x + width, y + height - dy * (1 - QUARTER)), FloatPoint(x + width - dx * (1 - QUARTER), y + height), FloatPoint(x + width - dx, y + height));
if (dx < width * 0.5)
path.addLineTo(FloatPoint(x + dx, y + height));
path.addBezierCurveTo(FloatPoint(x + dx * (1 - QUARTER), y + height), FloatPoint(x, y + height - dy * (1 - QUARTER)), FloatPoint(x, y + height - dy));
if (dy < height * 0.5)
path.addLineTo(FloatPoint(x, y + dy));
path.addBezierCurveTo(FloatPoint(x, y + dy * (1 - QUARTER)), FloatPoint(x + dx * (1 - QUARTER), y), FloatPoint(x + dx, y));
path.closeSubpath();
return path;
}
Path Path::createRoundedRectangle(const FloatRect& rectangle, const FloatSize& topLeftRadius, const FloatSize& topRightRadius, const FloatSize& bottomLeftRadius, const FloatSize& bottomRightRadius)
{
Path path;
float width = rectangle.width();
float height = rectangle.height();
if (width <= 0.0 || height <= 0.0)
return path;
if (width < topLeftRadius.width() + topRightRadius.width()
|| width < bottomLeftRadius.width() + bottomRightRadius.width()
|| height < topLeftRadius.height() + bottomLeftRadius.height()
|| height < topRightRadius.height() + bottomRightRadius.height())
// If all the radii cannot be accommodated, return a rect.
return createRectangle(rectangle);
float x = rectangle.x();
float y = rectangle.y();
path.moveTo(FloatPoint(x + topLeftRadius.width(), y));
path.addLineTo(FloatPoint(x + width - topRightRadius.width(), y));
path.addBezierCurveTo(FloatPoint(x + width - topRightRadius.width() * (1 - QUARTER), y), FloatPoint(x + width, y + topRightRadius.height() * (1 - QUARTER)), FloatPoint(x + width, y + topRightRadius.height()));
path.addLineTo(FloatPoint(x + width, y + height - bottomRightRadius.height()));
path.addBezierCurveTo(FloatPoint(x + width, y + height - bottomRightRadius.height() * (1 - QUARTER)), FloatPoint(x + width - bottomRightRadius.width() * (1 - QUARTER), y + height), FloatPoint(x + width - bottomRightRadius.width(), y + height));
path.addLineTo(FloatPoint(x + bottomLeftRadius.width(), y + height));
path.addBezierCurveTo(FloatPoint(x + bottomLeftRadius.width() * (1 - QUARTER), y + height), FloatPoint(x, y + height - bottomLeftRadius.height() * (1 - QUARTER)), FloatPoint(x, y + height - bottomLeftRadius.height()));
path.addLineTo(FloatPoint(x, y + topLeftRadius.height()));
path.addBezierCurveTo(FloatPoint(x, y + topLeftRadius.height() * (1 - QUARTER)), FloatPoint(x + topLeftRadius.width() * (1 - QUARTER), y), FloatPoint(x + topLeftRadius.width(), y));
path.closeSubpath();
return path;
}
Path Path::createRectangle(const FloatRect& rectangle)
{
Path path;
float x = rectangle.x();
float y = rectangle.y();
float width = rectangle.width();
float height = rectangle.height();
if (width <= 0.0f || height <= 0.0f)
return path;
path.moveTo(FloatPoint(x, y));
path.addLineTo(FloatPoint(x + width, y));
path.addLineTo(FloatPoint(x + width, y + height));
path.addLineTo(FloatPoint(x, y + height));
path.closeSubpath();
return path;
}
Path Path::createEllipse(const FloatPoint& center, float rx, float ry)
{
float cx = center.x();
float cy = center.y();
Path path;
if (rx <= 0.0f || ry <= 0.0f)
return path;
float x = cx;
float y = cy;
unsigned step = 0, num = 100;
bool running = true;
while (running)
{
if (step == num)
{
running = false;
break;
}
float angle = static_cast<float>(step) / static_cast<float>(num) * 2.0f * piFloat;
x = cx + cosf(angle) * rx;
y = cy + sinf(angle) * ry;
step++;
if (step == 1)
path.moveTo(FloatPoint(x, y));
else
path.addLineTo(FloatPoint(x, y));
}
path.closeSubpath();
return path;
}
Path Path::createCircle(const FloatPoint& center, float r)
{
return createEllipse(center, r, r);
}
Path Path::createLine(const FloatPoint& start, const FloatPoint& end)
{
Path path;
if (start.x() == end.x() && start.y() == end.y())
return path;
path.moveTo(start);
path.addLineTo(end);
return path;
}
}