blob: 4e05609d84e2876024ad7dd4493abb127288b995 [file] [log] [blame]
/*
* Copyright (C) 2008 Apple Inc. All rights reserved.
* Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies)
* Copyright (C) 2013 Xidorn Quan (quanxunzhen@gmail.com)
*
* 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.
* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 OR ITS 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 "third_party/blink/renderer/platform/geometry/float_quad.h"
#include <algorithm>
#include <cmath>
#include <limits>
#include "third_party/blink/renderer/platform/geometry/float_shape_helpers.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
#include "third_party/skia/include/core/SkPoint.h"
namespace blink {
static inline float Min4(float a, float b, float c, float d) {
return std::min(std::min(a, b), std::min(c, d));
}
static inline float Max4(float a, float b, float c, float d) {
return std::max(std::max(a, b), std::max(c, d));
}
inline float Dot(const FloatSize& a, const FloatSize& b) {
return a.Width() * b.Width() + a.Height() * b.Height();
}
inline bool IsPointInTriangle(const FloatPoint& p,
const FloatPoint& t1,
const FloatPoint& t2,
const FloatPoint& t3) {
// Compute vectors
FloatSize v0 = t3 - t1;
FloatSize v1 = t2 - t1;
FloatSize v2 = p - t1;
// Compute dot products
float dot00 = Dot(v0, v0);
float dot01 = Dot(v0, v1);
float dot02 = Dot(v0, v2);
float dot11 = Dot(v1, v1);
float dot12 = Dot(v1, v2);
// Compute barycentric coordinates
float inv_denom = 1.0f / (dot00 * dot11 - dot01 * dot01);
float u = (dot11 * dot02 - dot01 * dot12) * inv_denom;
float v = (dot00 * dot12 - dot01 * dot02) * inv_denom;
// Check if point is in triangle
return (u >= 0) && (v >= 0) && (u + v <= 1);
}
static inline float SaturateInf(float value) {
if (UNLIKELY(std::isinf(value))) {
return std::signbit(value) ? std::numeric_limits<int>::min()
: std::numeric_limits<int>::max();
}
return value;
}
FloatRect FloatQuad::BoundingBox() const {
float left = SaturateInf(Min4(p1_.X(), p2_.X(), p3_.X(), p4_.X()));
float top = SaturateInf(Min4(p1_.Y(), p2_.Y(), p3_.Y(), p4_.Y()));
float right = SaturateInf(Max4(p1_.X(), p2_.X(), p3_.X(), p4_.X()));
float bottom = SaturateInf(Max4(p1_.Y(), p2_.Y(), p3_.Y(), p4_.Y()));
return FloatRect(left, top, right - left, bottom - top);
}
static inline bool WithinEpsilon(float a, float b) {
return fabs(a - b) < std::numeric_limits<float>::epsilon();
}
FloatQuad::FloatQuad(const SkPoint (&quad)[4])
: FloatQuad(FloatPoint(quad[0]),
FloatPoint(quad[1]),
FloatPoint(quad[2]),
FloatPoint(quad[3])) {}
bool FloatQuad::IsRectilinear() const {
return (WithinEpsilon(p1_.X(), p2_.X()) && WithinEpsilon(p2_.Y(), p3_.Y()) &&
WithinEpsilon(p3_.X(), p4_.X()) && WithinEpsilon(p4_.Y(), p1_.Y())) ||
(WithinEpsilon(p1_.Y(), p2_.Y()) && WithinEpsilon(p2_.X(), p3_.X()) &&
WithinEpsilon(p3_.Y(), p4_.Y()) && WithinEpsilon(p4_.X(), p1_.X()));
}
bool FloatQuad::ContainsPoint(const FloatPoint& p) const {
return IsPointInTriangle(p, p1_, p2_, p3_) ||
IsPointInTriangle(p, p1_, p3_, p4_);
}
// Note that we only handle convex quads here.
bool FloatQuad::ContainsQuad(const FloatQuad& other) const {
return ContainsPoint(other.P1()) && ContainsPoint(other.P2()) &&
ContainsPoint(other.P3()) && ContainsPoint(other.P4());
}
static inline FloatPoint RightMostCornerToVector(const FloatRect& rect,
const FloatSize& vector) {
// Return the corner of the rectangle that if it is to the left of the vector
// would mean all of the rectangle is to the left of the vector.
// The vector here represents the side between two points in a clockwise
// convex polygon.
//
// Q XXX
// QQQ XXX If the lower left corner of X is left of the vector that goes
// QQQ from the top corner of Q to the right corner of Q, then all of X
// Q is left of the vector, and intersection impossible.
//
FloatPoint point;
if (vector.Width() >= 0)
point.SetY(rect.MaxY());
else
point.SetY(rect.Y());
if (vector.Height() >= 0)
point.SetX(rect.X());
else
point.SetX(rect.MaxX());
return point;
}
bool FloatQuad::IntersectsRect(const FloatRect& rect) const {
// IntersectsRect is only valid on convex quads which an empty quad is not.
DCHECK(!IsEmpty());
// For each side of the quad clockwise we check if the rectangle is to the
// left of it since only content on the right can onlap with the quad. This
// only works if the quad is convex.
FloatSize v1, v2, v3, v4;
// Ensure we use clockwise vectors.
if (!IsCounterclockwise()) {
v1 = p2_ - p1_;
v2 = p3_ - p2_;
v3 = p4_ - p3_;
v4 = p1_ - p4_;
} else {
v1 = p4_ - p1_;
v2 = p1_ - p2_;
v3 = p2_ - p3_;
v4 = p3_ - p4_;
}
FloatPoint p = RightMostCornerToVector(rect, v1);
if (Determinant(v1, p - p1_) < 0)
return false;
p = RightMostCornerToVector(rect, v2);
if (Determinant(v2, p - p2_) < 0)
return false;
p = RightMostCornerToVector(rect, v3);
if (Determinant(v3, p - p3_) < 0)
return false;
p = RightMostCornerToVector(rect, v4);
if (Determinant(v4, p - p4_) < 0)
return false;
// If not all of the rectangle is outside one of the quad's four sides, then
// that means at least a part of the rectangle is overlapping the quad.
return true;
}
// Tests whether the line is contained by or intersected with the circle.
static inline bool LineIntersectsCircle(const FloatPoint& center,
float radius,
const FloatPoint& p0,
const FloatPoint& p1) {
float x0 = p0.X() - center.X(), y0 = p0.Y() - center.Y();
float x1 = p1.X() - center.X(), y1 = p1.Y() - center.Y();
float radius2 = radius * radius;
if ((x0 * x0 + y0 * y0) <= radius2 || (x1 * x1 + y1 * y1) <= radius2)
return true;
if (p0 == p1)
return false;
float a = y0 - y1;
float b = x1 - x0;
float c = x0 * y1 - x1 * y0;
float distance2 = c * c / (a * a + b * b);
// If distance between the center point and the line > the radius,
// the line doesn't cross (or is contained by) the ellipse.
if (distance2 > radius2)
return false;
// The nearest point on the line is between p0 and p1?
float x = -a * c / (a * a + b * b);
float y = -b * c / (a * a + b * b);
return (((x0 <= x && x <= x1) || (x0 >= x && x >= x1)) &&
((y0 <= y && y <= y1) || (y1 <= y && y <= y0)));
}
bool FloatQuad::IntersectsCircle(const FloatPoint& center, float radius) const {
return ContainsPoint(
center) // The circle may be totally contained by the quad.
|| LineIntersectsCircle(center, radius, p1_, p2_) ||
LineIntersectsCircle(center, radius, p2_, p3_) ||
LineIntersectsCircle(center, radius, p3_, p4_) ||
LineIntersectsCircle(center, radius, p4_, p1_);
}
bool FloatQuad::IntersectsEllipse(const FloatPoint& center,
const FloatSize& radii) const {
// Transform the ellipse to an origin-centered circle whose radius is the
// product of major radius and minor radius. Here we apply the same
// transformation to the quad.
FloatQuad transformed_quad(*this);
transformed_quad.Move(-center.X(), -center.Y());
transformed_quad.Scale(radii.Height(), radii.Width());
FloatPoint origin_point;
return transformed_quad.IntersectsCircle(origin_point,
radii.Height() * radii.Width());
}
bool FloatQuad::IsCounterclockwise() const {
// Return if the two first vectors are turning clockwise. If the quad is
// convex then all following vectors will turn the same way.
return Determinant(p2_ - p1_, p3_ - p2_) < 0;
}
std::ostream& operator<<(std::ostream& ostream, const FloatQuad& quad) {
return ostream << quad.ToString();
}
String FloatQuad::ToString() const {
return String::Format("%s; %s; %s; %s", p1_.ToString().Ascii().data(),
p2_.ToString().Ascii().data(),
p3_.ToString().Ascii().data(),
p4_.ToString().Ascii().data());
}
} // namespace blink