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Diffstat (limited to 'WebCore/platform/graphics/Path.cpp')
-rw-r--r-- | WebCore/platform/graphics/Path.cpp | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/WebCore/platform/graphics/Path.cpp b/WebCore/platform/graphics/Path.cpp new file mode 100644 index 0000000..f3450be --- /dev/null +++ b/WebCore/platform/graphics/Path.cpp @@ -0,0 +1,276 @@ +/* + * 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> + +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; +} + +} |