| /* |
| * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved. |
| * Copyright (C) 2008, 2010 Nokia Corporation and/or its subsidiary(-ies) |
| * Copyright (C) 2007 Alp Toker <alp@atoker.com> |
| * Copyright (C) 2008 Eric Seidel <eric@webkit.org> |
| * Copyright (C) 2008 Dirk Schulze <krit@webkit.org> |
| * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved. |
| * Copyright (C) 2012, 2013 Intel Corporation. All rights reserved. |
| * Copyright (C) 2012, 2013 Adobe Systems Incorporated. All rights reserved. |
| * |
| * 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 THE COPYRIGHT HOLDER "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 THE COPYRIGHT HOLDER 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 "core/html/canvas/CanvasPathMethods.h" |
| |
| #include "bindings/v8/ExceptionState.h" |
| #include "core/dom/ExceptionCode.h" |
| #include "platform/geometry/FloatRect.h" |
| #include "platform/transforms/AffineTransform.h" |
| #include "wtf/MathExtras.h" |
| |
| namespace WebCore { |
| |
| void CanvasPathMethods::closePath() |
| { |
| if (m_path.isEmpty()) |
| return; |
| |
| FloatRect boundRect = m_path.boundingRect(); |
| if (boundRect.width() || boundRect.height()) |
| m_path.closeSubpath(); |
| } |
| |
| void CanvasPathMethods::moveTo(float x, float y) |
| { |
| if (!std::isfinite(x) || !std::isfinite(y)) |
| return; |
| if (!isTransformInvertible()) |
| return; |
| m_path.moveTo(FloatPoint(x, y)); |
| } |
| |
| void CanvasPathMethods::lineTo(float x, float y) |
| { |
| if (!std::isfinite(x) || !std::isfinite(y)) |
| return; |
| if (!isTransformInvertible()) |
| return; |
| |
| FloatPoint p1 = FloatPoint(x, y); |
| if (!m_path.hasCurrentPoint()) |
| m_path.moveTo(p1); |
| else if (p1 != m_path.currentPoint()) |
| m_path.addLineTo(p1); |
| } |
| |
| void CanvasPathMethods::quadraticCurveTo(float cpx, float cpy, float x, float y) |
| { |
| if (!std::isfinite(cpx) || !std::isfinite(cpy) || !std::isfinite(x) || !std::isfinite(y)) |
| return; |
| if (!isTransformInvertible()) |
| return; |
| if (!m_path.hasCurrentPoint()) |
| m_path.moveTo(FloatPoint(cpx, cpy)); |
| |
| FloatPoint p1 = FloatPoint(x, y); |
| FloatPoint cp = FloatPoint(cpx, cpy); |
| if (p1 != m_path.currentPoint() || p1 != cp) |
| m_path.addQuadCurveTo(cp, p1); |
| } |
| |
| void CanvasPathMethods::bezierCurveTo(float cp1x, float cp1y, float cp2x, float cp2y, float x, float y) |
| { |
| if (!std::isfinite(cp1x) || !std::isfinite(cp1y) || !std::isfinite(cp2x) || !std::isfinite(cp2y) || !std::isfinite(x) || !std::isfinite(y)) |
| return; |
| if (!isTransformInvertible()) |
| return; |
| if (!m_path.hasCurrentPoint()) |
| m_path.moveTo(FloatPoint(cp1x, cp1y)); |
| |
| FloatPoint p1 = FloatPoint(x, y); |
| FloatPoint cp1 = FloatPoint(cp1x, cp1y); |
| FloatPoint cp2 = FloatPoint(cp2x, cp2y); |
| if (p1 != m_path.currentPoint() || p1 != cp1 || p1 != cp2) |
| m_path.addBezierCurveTo(cp1, cp2, p1); |
| } |
| |
| void CanvasPathMethods::arcTo(float x1, float y1, float x2, float y2, float r, ExceptionState& es) |
| { |
| if (!std::isfinite(x1) || !std::isfinite(y1) || !std::isfinite(x2) || !std::isfinite(y2) || !std::isfinite(r)) |
| return; |
| |
| if (r < 0) { |
| es.throwUninformativeAndGenericDOMException(IndexSizeError); |
| return; |
| } |
| |
| if (!isTransformInvertible()) |
| return; |
| |
| FloatPoint p1 = FloatPoint(x1, y1); |
| FloatPoint p2 = FloatPoint(x2, y2); |
| |
| if (!m_path.hasCurrentPoint()) |
| m_path.moveTo(p1); |
| else if (p1 == m_path.currentPoint() || p1 == p2 || !r) |
| lineTo(x1, y1); |
| else |
| m_path.addArcTo(p1, p2, r); |
| } |
| |
| namespace { |
| |
| float adjustEndAngle(float startAngle, float endAngle, bool anticlockwise) |
| { |
| float twoPi = 2 * piFloat; |
| float newEndAngle = endAngle; |
| /* http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#dom-context-2d-arc |
| * If the anticlockwise argument is false and endAngle-startAngle is equal to or greater than 2pi, or, |
| * if the anticlockwise argument is true and startAngle-endAngle is equal to or greater than 2pi, |
| * then the arc is the whole circumference of this ellipse. |
| */ |
| if (!anticlockwise && endAngle - startAngle >= twoPi) |
| newEndAngle = startAngle + twoPi + fmodf(endAngle - startAngle, twoPi); |
| else if (anticlockwise && startAngle - endAngle >= twoPi) |
| newEndAngle = startAngle - twoPi - fmodf(startAngle - endAngle, twoPi); |
| |
| /* |
| * Otherwise, the arc is the path along the circumference of this ellipse from the start point to the end point, |
| * going anti-clockwise if the anticlockwise argument is true, and clockwise otherwise. |
| * Since the points are on the ellipse, as opposed to being simply angles from zero, |
| * the arc can never cover an angle greater than 2pi radians. |
| */ |
| /* NOTE: When startAngle = 0, endAngle = 2Pi and anticlockwise = true, the spec does not indicate clearly. |
| * We draw the entire circle, because some web sites use arc(x, y, r, 0, 2*Math.PI, true) to draw circle. |
| * We preserve backward-compatibility. |
| */ |
| else if (!anticlockwise && startAngle > endAngle) |
| newEndAngle = startAngle + (twoPi - fmodf(startAngle - endAngle, twoPi)); |
| else if (anticlockwise && startAngle < endAngle) |
| newEndAngle = startAngle - (twoPi - fmodf(endAngle - startAngle, twoPi)); |
| |
| ASSERT(std::abs(newEndAngle - startAngle) < 4 * piFloat); |
| return newEndAngle; |
| } |
| |
| inline void lineToFloatPoint(CanvasPathMethods* path, const FloatPoint& p) |
| { |
| path->lineTo(p.x(), p.y()); |
| } |
| |
| inline FloatPoint getPointOnEllipse(float radiusX, float radiusY, float theta) |
| { |
| return FloatPoint(radiusX * cosf(theta), radiusY * sinf(theta)); |
| } |
| |
| void canonicalizeAngle(float* startAngle, float* endAngle) |
| { |
| // Make 0 <= startAngle < 2*PI |
| float twoPi = 2 * piFloat; |
| float newStartAngle = *startAngle; |
| if (newStartAngle < 0) |
| newStartAngle = twoPi + fmodf(newStartAngle, -twoPi); |
| else |
| newStartAngle = fmodf(newStartAngle, twoPi); |
| |
| float delta = newStartAngle - *startAngle; |
| *startAngle = newStartAngle; |
| *endAngle = *endAngle + delta; |
| ASSERT(newStartAngle >= 0 && newStartAngle < twoPi); |
| } |
| |
| /* |
| * degenerateEllipse() handles a degenerated ellipse using several lines. |
| * |
| * Let's see a following example: line to ellipse to line. |
| * _--^\ |
| * ( ) |
| * -----( ) |
| * ) |
| * /-------- |
| * |
| * If radiusX becomes zero, the ellipse of the example is degenerated. |
| * _ |
| * // P |
| * // |
| * -----// |
| * / |
| * /-------- |
| * |
| * To draw the above example, need to get P that is a local maximum point. |
| * Angles for P are 0.5Pi and 1.5Pi in the ellipse coordinates. |
| * |
| * If radiusY becomes zero, the result is as follows. |
| * -----__ |
| * --_ |
| * ---------- |
| * ``P |
| * Angles for P are 0 and Pi in the ellipse coordinates. |
| * |
| * To handle both cases, degenerateEllipse() lines to start angle, local maximum points(every 0.5Pi), and end angle. |
| * NOTE: Before ellipse() calls this function, adjustEndAngle() is called, so endAngle - startAngle must be less than 4Pi. |
| */ |
| void degenerateEllipse(CanvasPathMethods* path, float x, float y, float radiusX, float radiusY, float rotation, float startAngle, float endAngle, bool anticlockwise) |
| { |
| ASSERT(std::abs(endAngle - startAngle) < 4 * piFloat); |
| ASSERT(startAngle >= 0 && startAngle < 2 * piFloat); |
| ASSERT((anticlockwise && (startAngle - endAngle) >= 0) || (!anticlockwise && (endAngle - startAngle) >= 0)); |
| |
| FloatPoint center(x, y); |
| AffineTransform rotationMatrix; |
| rotationMatrix.rotate(rad2deg(rotation)); |
| // First, if the object's path has any subpaths, then the method must add a straight line from the last point in the subpath to the start point of the arc. |
| lineToFloatPoint(path, center + rotationMatrix.mapPoint(getPointOnEllipse(radiusX, radiusY, startAngle))); |
| if ((!radiusX && !radiusY) || startAngle == endAngle) |
| return; |
| |
| float halfPiFloat = piFloat * 0.5; |
| if (!anticlockwise) { |
| // startAngle - fmodf(startAngle, halfPiFloat) + halfPiFloat is the one of (0, 0.5Pi, Pi, 1.5Pi, 2Pi) |
| // that is the closest to startAngle on the clockwise direction. |
| for (float angle = startAngle - fmodf(startAngle, halfPiFloat) + halfPiFloat; angle < endAngle; angle += halfPiFloat) |
| lineToFloatPoint(path, center + rotationMatrix.mapPoint(getPointOnEllipse(radiusX, radiusY, angle))); |
| } else { |
| for (float angle = startAngle - fmodf(startAngle, halfPiFloat); angle > endAngle; angle -= halfPiFloat) |
| lineToFloatPoint(path, center + rotationMatrix.mapPoint(getPointOnEllipse(radiusX, radiusY, angle))); |
| } |
| |
| lineToFloatPoint(path, center + rotationMatrix.mapPoint(getPointOnEllipse(radiusX, radiusY, endAngle))); |
| } |
| |
| } // namespace |
| |
| void CanvasPathMethods::arc(float x, float y, float radius, float startAngle, float endAngle, bool anticlockwise, ExceptionState& es) |
| { |
| if (!std::isfinite(x) || !std::isfinite(y) || !std::isfinite(radius) || !std::isfinite(startAngle) || !std::isfinite(endAngle)) |
| return; |
| |
| if (radius < 0) { |
| es.throwUninformativeAndGenericDOMException(IndexSizeError); |
| return; |
| } |
| |
| if (!isTransformInvertible()) |
| return; |
| |
| if (!radius || startAngle == endAngle) { |
| // The arc is empty but we still need to draw the connecting line. |
| lineTo(x + radius * cosf(startAngle), y + radius * sinf(startAngle)); |
| return; |
| } |
| |
| canonicalizeAngle(&startAngle, &endAngle); |
| float adjustedEndAngle = adjustEndAngle(startAngle, endAngle, anticlockwise); |
| m_path.addArc(FloatPoint(x, y), radius, startAngle, adjustedEndAngle, anticlockwise); |
| } |
| |
| void CanvasPathMethods::ellipse(float x, float y, float radiusX, float radiusY, float rotation, float startAngle, float endAngle, bool anticlockwise, ExceptionState& es) |
| { |
| if (!std::isfinite(x) || !std::isfinite(y) || !std::isfinite(radiusX) || !std::isfinite(radiusY) || !std::isfinite(rotation) || !std::isfinite(startAngle) || !std::isfinite(endAngle)) |
| return; |
| |
| if (radiusX < 0 || radiusY < 0) { |
| es.throwUninformativeAndGenericDOMException(IndexSizeError); |
| return; |
| } |
| |
| if (!isTransformInvertible()) |
| return; |
| |
| canonicalizeAngle(&startAngle, &endAngle); |
| float adjustedEndAngle = adjustEndAngle(startAngle, endAngle, anticlockwise); |
| if (!radiusX || !radiusY || startAngle == adjustedEndAngle) { |
| // The ellipse is empty but we still need to draw the connecting line to start point. |
| degenerateEllipse(this, x, y, radiusX, radiusY, rotation, startAngle, adjustedEndAngle, anticlockwise); |
| return; |
| } |
| |
| m_path.addEllipse(FloatPoint(x, y), radiusX, radiusY, rotation, startAngle, adjustedEndAngle, anticlockwise); |
| } |
| |
| void CanvasPathMethods::rect(float x, float y, float width, float height) |
| { |
| if (!isTransformInvertible()) |
| return; |
| |
| if (!std::isfinite(x) || !std::isfinite(y) || !std::isfinite(width) || !std::isfinite(height)) |
| return; |
| |
| if (!width && !height) { |
| m_path.moveTo(FloatPoint(x, y)); |
| return; |
| } |
| |
| m_path.addRect(FloatRect(x, y, width, height)); |
| } |
| } |