| /* |
| * 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 "modules/canvas2d/CanvasPathMethods.h" |
| |
| #include "bindings/core/v8/ExceptionState.h" |
| #include "core/dom/ExceptionCode.h" |
| #include "platform/geometry/FloatRect.h" |
| #include "platform/transforms/AffineTransform.h" |
| #include "wtf/MathExtras.h" |
| |
| namespace blink { |
| |
| 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); |
| |
| 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); |
| |
| 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); |
| |
| m_path.addBezierCurveTo(cp1, cp2, p1); |
| } |
| |
| void CanvasPathMethods::arcTo(float x1, |
| float y1, |
| float x2, |
| float y2, |
| float r, |
| ExceptionState& exceptionState) { |
| if (!std::isfinite(x1) || !std::isfinite(y1) || !std::isfinite(x2) || |
| !std::isfinite(y2) || !std::isfinite(r)) |
| return; |
| |
| if (r < 0) { |
| exceptionState.throwDOMException( |
| IndexSizeError, |
| "The radius provided (" + String::number(r) + ") is negative."); |
| 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 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, and the point at |
| * startAngle along this circle's circumference, measured in radians clockwise |
| * from the ellipse's semi-major axis, acts as both the start point and the |
| * end point. |
| */ |
| if (!anticlockwise && endAngle - startAngle >= twoPiFloat) |
| newEndAngle = startAngle + twoPiFloat; |
| else if (anticlockwise && startAngle - endAngle >= twoPiFloat) |
| newEndAngle = startAngle - twoPiFloat; |
| |
| /* |
| * 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 + (twoPiFloat - fmodf(startAngle - endAngle, twoPiFloat)); |
| else if (anticlockwise && startAngle < endAngle) |
| newEndAngle = |
| startAngle - (twoPiFloat - fmodf(endAngle - startAngle, twoPiFloat)); |
| |
| ASSERT(ellipseIsRenderable(startAngle, newEndAngle)); |
| 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 newStartAngle = fmodf(*startAngle, twoPiFloat); |
| |
| if (newStartAngle < 0) { |
| newStartAngle += twoPiFloat; |
| // Check for possible catastrophic cancellation in cases where |
| // newStartAngle was a tiny negative number (c.f. crbug.com/503422) |
| if (newStartAngle >= twoPiFloat) |
| newStartAngle -= twoPiFloat; |
| } |
| |
| float delta = newStartAngle - *startAngle; |
| *startAngle = newStartAngle; |
| *endAngle = *endAngle + delta; |
| |
| ASSERT(newStartAngle >= 0 && newStartAngle < twoPiFloat); |
| } |
| |
| /* |
| * 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 equal to or less than 2Pi. |
| */ |
| void degenerateEllipse(CanvasPathMethods* path, |
| float x, |
| float y, |
| float radiusX, |
| float radiusY, |
| float rotation, |
| float startAngle, |
| float endAngle, |
| bool anticlockwise) { |
| ASSERT(ellipseIsRenderable(startAngle, endAngle)); |
| ASSERT(startAngle >= 0 && startAngle < twoPiFloat); |
| ASSERT((anticlockwise && (startAngle - endAngle) >= 0) || |
| (!anticlockwise && (endAngle - startAngle) >= 0)); |
| |
| FloatPoint center(x, y); |
| AffineTransform rotationMatrix; |
| rotationMatrix.rotateRadians(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; |
| |
| if (!anticlockwise) { |
| // startAngle - fmodf(startAngle, piOverTwoFloat) + piOverTwoFloat 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, piOverTwoFloat) + piOverTwoFloat; |
| angle < endAngle; angle += piOverTwoFloat) |
| lineToFloatPoint(path, center + |
| rotationMatrix.mapPoint(getPointOnEllipse( |
| radiusX, radiusY, angle))); |
| } else { |
| for (float angle = startAngle - fmodf(startAngle, piOverTwoFloat); |
| angle > endAngle; angle -= piOverTwoFloat) |
| 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& exceptionState) { |
| if (!std::isfinite(x) || !std::isfinite(y) || !std::isfinite(radius) || |
| !std::isfinite(startAngle) || !std::isfinite(endAngle)) |
| return; |
| |
| if (radius < 0) { |
| exceptionState.throwDOMException( |
| IndexSizeError, |
| "The radius provided (" + String::number(radius) + ") is negative."); |
| 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& exceptionState) { |
| 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) { |
| exceptionState.throwDOMException( |
| IndexSizeError, "The major-axis radius provided (" + |
| String::number(radiusX) + ") is negative."); |
| return; |
| } |
| if (radiusY < 0) { |
| exceptionState.throwDOMException( |
| IndexSizeError, "The minor-axis radius provided (" + |
| String::number(radiusY) + ") is negative."); |
| 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; |
| |
| m_path.addRect(FloatRect(x, y, width, height)); |
| } |
| } // namespace blink |
