public static Intersection QuadraticBezierSegmentQuadraticBezierSegmentIntersection00(
double a1X, double a1Y, double a2X, double a2Y, double a3X, double a3Y,
double b1X, double b1Y, double b2X, double b2Y, double b3X, double b3Y,
double epsilon = Epsilon)
{
// Initialize the intersection.
var result = new Intersection(IntersectionStates.NoIntersection);
// ToDo: Break early if the AABB of the ends and handles do not intersect.
// ToDo: Break early if the AABB of the curve does not intersect.
// Parametric matrix form of the Bézier curve
var xCoeffA = QuadraticBezierBernsteinBasisTests.QuadraticBezierBernsteinBasis(a1X, a2X, a3X);
var yCoeffA = QuadraticBezierBernsteinBasisTests.QuadraticBezierBernsteinBasis(a1Y, a2Y, a3Y);
var xCoeffB = QuadraticBezierBernsteinBasisTests.QuadraticBezierBernsteinBasis(b1X, b2X, b3X);
var yCoeffB = QuadraticBezierBernsteinBasisTests.QuadraticBezierBernsteinBasis(b1Y, b2Y, b3Y);
IList <double> roots = new List <double>();
if (yCoeffA.C == 0)
{
var v0 = xCoeffA.C * (yCoeffA.A - yCoeffB.A);
var v1 = v0 - (xCoeffA.B * yCoeffA.B);
var v2 = v0 + v1;
var v3 = yCoeffA.B * yCoeffA.B;
roots = QuarticRootsTests.QuarticRoots(
/* t^4 */ xCoeffA.C * yCoeffB.C * yCoeffB.C,
/* t^3 */ 2 * xCoeffA.C * yCoeffB.B * yCoeffB.C,
/* t^2 */ (xCoeffA.C * yCoeffB.B * yCoeffB.B) - (xCoeffB.C * v3) - (yCoeffB.C * v0) - (yCoeffB.C * v1),
/* t^1 */ (-xCoeffB.B * v3) - (yCoeffB.B * v0) - (yCoeffB.B * v1),
/* C^0 */ ((xCoeffA.A - xCoeffB.A) * v3) + ((yCoeffA.A - yCoeffB.A) * v1),
epsilon);
}
else
{
var v0 = (xCoeffA.C * yCoeffB.C) - (yCoeffA.C * xCoeffB.C);
var v1 = (xCoeffA.C * yCoeffB.B) - (xCoeffB.B * yCoeffA.C);
var v2 = (xCoeffA.B * yCoeffA.C) - (yCoeffA.B * xCoeffA.C);
var v3 = yCoeffA.A - yCoeffB.A;
var v4 = (yCoeffA.C * (xCoeffA.A - xCoeffB.A)) - (xCoeffA.C * v3);
var v5 = (-yCoeffA.B * v2) + (yCoeffA.C * v4);
var v6 = v2 * v2;
roots = QuarticRootsTests.QuarticRoots(
/* t^4 */ v0 * v0,
/* t^3 */ 2 * v0 * v1,
/* t^2 */ ((-yCoeffB.C * v6) + (yCoeffA.C * v1 * v1) + (yCoeffA.C * v0 * v4) + (v0 * v5)) / yCoeffA.C,
/* t^1 */ ((-yCoeffB.B * v6) + (yCoeffA.C * v1 * v4) + (v1 * v5)) / yCoeffA.C,
/* C^0 */ ((v3 * v6) + (v4 * v5)) / yCoeffA.C,
epsilon);
}
foreach (var s in roots)
{
var point = new Point2D(
(xCoeffB.C * s * s) + (xCoeffB.B * s) + xCoeffB.A,
(yCoeffB.C * s * s) + (yCoeffB.B * s) + yCoeffB.A);
if (s >= 0 && s <= 1)
{
var xRoots = QuadraticRootsTests.QuadraticRoots(
/* t^2 */ -xCoeffA.C,
/* t^1 */ -xCoeffA.B,
/* C^0 */ -xCoeffA.A + point.X,
epsilon);
var yRoots = QuadraticRootsTests.QuadraticRoots(
/* t^2 */ -yCoeffA.C,
/* t^1 */ -yCoeffA.B,
/* C^0 */ -yCoeffA.A + point.Y,
epsilon);
if (xRoots.Count > 0 && yRoots.Count > 0)
{
// Find the nearest matching x and y roots in the ranges 0 < x < 1; 0 < y < 1.
foreach (var xRoot in xRoots)
{
if (xRoot >= 0 && xRoot <= 1)
{
foreach (var yRoot in yRoots)
{
var t = xRoot - yRoot;
if ((t >= 0 ? t : -t) < epsilon)
{
result.AppendPoint(point);
goto checkRoots; // Break through two levels of foreach loops to exit early. Using goto for performance.
}
}
}
}
checkRoots :;
}
}
}
if (result.Items.Count > 0)
{
result.State = IntersectionStates.Intersection;
}
return(result);
}
public static Intersection QuadraticBezierSegmentQuadraticBezierSegmentIntersection3(
double a1X, double a1Y, double a2X, double a2Y, double a3X, double a3Y,
double b1X, double b1Y, double b2X, double b2Y, double b3X, double b3Y,
double epsilon = Epsilon)
{
var result = new Intersection(IntersectionStates.NoIntersection);
// ToDo: Break early if the AABB bounding box of the curve does not intersect.
var c12 = new Vector2D(a1X - (a2X * 2) + a3X, a1Y - (a2Y * 2) + a3Y);
var c11 = new Vector2D(2 * (a2X - a1X), 2 * (a2Y - a1Y));
var c22 = new Vector2D(b1X - (b2X * 2) + b3X, b1Y - (b2Y * 2) + b3Y);
var c21 = new Vector2D(2 * (b2X - b1X), 2 * (b2Y - b1Y));
var a = (c12.I * c11.J) - (c11.I * c12.J);
var b = (c22.I * c11.J) - (c11.I * c22.J);
var c = (c21.I * c11.J) - (c11.I * c21.J);
var d = (c11.I * (a1Y - b1Y)) + (c11.J * (b1X - a1X));
var e = (c22.I * c12.J) - (c12.I * c22.J);
var f = (c21.I * c12.J) - (c12.I * c21.J);
var g = (c12.I * (a1Y - b1Y)) + (c12.J * (b1X - a1X));
var roots = QuarticRootsTests.QuarticRoots(
/* C */ -e * e,
/* t^1 */ -2 * e * f,
/* t^2 */ (a * b) - (f * f) - (2 * e * g),
/* t^3 */ (a * c) - (2 * f * g),
/* t^4 */ (a * d) - (g * g),
epsilon);
foreach (var s in roots)
{
var point = new Point2D((c22.I * s * s) + (c21.I * s) + b1X, (c22.J * s * s) + (c21.J * s) + b1Y);
if (0 <= s && s <= 1)
{
var xRoots = QuadraticRootsTests.QuadraticRoots(
/* C */ -c12.I,
/* t^1 */ -c11.I,
/* t^2 */ -a1X + point.X,
epsilon);
var yRoots = QuadraticRootsTests.QuadraticRoots(
/* C */ -c12.J,
/* t^1 */ -c11.J,
/* t^2 */ -a1Y + point.Y,
epsilon);
if (xRoots.Count > 0 && yRoots.Count > 0)
{
// Find the nearest matching x and y roots in the ranges 0 < x < 1; 0 < y < 1.
foreach (var xRoot in xRoots)
{
if (xRoot >= 0 && xRoot <= 1)
{
foreach (var yRoot in yRoots)
{
var t = xRoot - yRoot;
if ((t >= 0 ? t : -t) < epsilon)
{
result.Items.Add(point);
goto checkRoots; // Break through two levels of foreach loops. Using goto for performance.
}
}
}
}
checkRoots :;
}
}
}
if (result.Items.Count > 0)
{
result.State = IntersectionStates.Intersection;
}
return(result);
}
public static Intersection QuadraticBezierSegmentQuadraticBezierSegmentIntersection1(
double a1X, double a1Y, double a2X, double a2Y, double a3X, double a3Y,
double b1X, double b1Y, double b2X, double b2Y, double b3X, double b3Y,
double epsilon = Epsilon)
{
var result = new Intersection(IntersectionStates.NoIntersection);
// ToDo: Break early if the AABB bounding box of the curve does not intersect.
// ToDo: Figure out if the following can be broken out of the vector structs.
var c12 = new Vector2D(a1X - (a2X * 2) + a3X, a1Y - (a2Y * 2) + a3Y);
var c11 = new Vector2D(2 * (a2X - a1X), 2 * (a2Y - a1Y));
// c10 is a1X and a1Y
var c22 = new Vector2D(b1X - (b2X * 2) + b3X, b1Y - (b2Y * 2) + b3Y);
var c21 = new Vector2D(2 * (b2X - b1X), 2 * (b2Y - b1Y));
// c20 is b1X and b1Y
var a = (c12.I * c11.J) - (c11.I * c12.J);
var b = (c22.I * c11.J) - (c11.I * c22.J);
var c = (c21.I * c11.J) - (c11.I * c21.J);
var d = (c11.I * (a1Y - b1Y)) - (c11.J * (b1X - a1X));
var e = (-c22.I * c12.J) - (c12.I * c22.J);
var f = (c21.I * c12.J) - (c12.I * c21.J);
var g = (c12.I * (a1Y - b1Y)) - (c12.J * (b1X - a1X));
IList <double> roots;
if ((a * d) - (g * g) == 0)
{
var v0 = (a * c) - (2 * f * g);
var v1 = (a * b) - (f * f) - (2 * e * g);
var v2 = -2 * e * f;
var v3 = -e * e;
roots = CubicRootsTests.CubicRoots(
/* t^3 */ -v3,
/* t^2 */ -v2,
/* t^1 */ -v1,
/* C */ -v0,
epsilon);
}
else
{
var v0 = (a * d) - (g * g);
var v1 = (a * c) - (2 * f * g);
var v2 = (a * b) - (f * f) - (2 * e * g);
var v3 = -2 * e * f;
var v4 = -e * e;
roots = QuarticRootsTests.QuarticRoots(
/* t^4 */ -v4,
/* t^3 */ -v3,
/* t^2 */ -v2,
/* t^1 */ -v1,
/* C */ -v0,
epsilon);
}
//roots.Reverse();
foreach (var s in roots)
{
var point = new Point2D(
(c22.I * s * s) + (c21.I * s) + b1X,
(c22.J * s * s) + (c21.J * s) + b1Y);
if (s >= 0 && s <= 1)
{
var v0 = a1X - point.X;
var v1 = c11.I;
var v2 = c12.I;
var xRoots = QuadraticRootsTests.QuadraticRoots(
/* t^2 */ -v2,
/* t^1 */ -v1,
/* C */ -v0,
epsilon);
v0 = a1Y - point.Y;
v1 = c11.J;
v2 = c12.J;
var yRoots = QuadraticRootsTests.QuadraticRoots(
/* t^2 */ -v2,
/* t^1 */ -v1,
/* C */ -v0,
epsilon);
if (xRoots.Count > 0 && yRoots.Count > 0)
{
// Find the nearest matching x and y roots in the ranges 0 < x < 1; 0 < y < 1.
foreach (var xRoot in xRoots)
{
if (xRoot >= 0 && xRoot <= 1)
{
foreach (var yRoot in yRoots)
{
var t = xRoot - yRoot;
if ((t >= 0 ? t : -t) < 0.1)
{
result.AppendPoint(point);
goto checkRoots; // Break through two levels of foreach loops. Using goto for performance.
}
}
}
}
checkRoots :;
}
}
}
if (result.Items.Count > 0)
{
result.State = IntersectionStates.Intersection;
}
return(result);
}
public static Intersection QuadraticBezierSegmentQuadraticBezierSegmentIntersection2(
double a1X, double a1Y, double a2X, double a2Y, double a3X, double a3Y,
double b1X, double b1Y, double b2X, double b2Y, double b3X, double b3Y,
double epsilon = Epsilon)
{
var va = new Vector2D(a2X, a2Y) * -2;
var c12 = new Vector2D(a1X, a1Y) + va + new Vector2D(a3X, a3Y);
va = new Vector2D(a1X, a1Y) * -2;
var vb = new Vector2D(a2X, a2Y) * 2;
var c11 = va + vb;
var c10 = new Vector2D(a1X, a1Y);
va = new Vector2D(b2X, b2Y) * -2;
var c22 = new Vector2D(b1X, b1Y) + va + new Vector2D(b3X, b3Y);
va = new Vector2D(b1X, b1Y) * -2;
vb = new Vector2D(b2X, b2Y) * 2;
var c21 = va + vb;
var c20 = new Vector2D(b1X, b1Y);
var a = (c12.I * c11.J) - (c11.I * c12.J);
var b = (c22.I * c11.J) - (c11.I * c22.J);
var c = (c21.I * c11.J) - (c11.I * c21.J);
var d = (c11.I * (c10.J - c20.J)) + (c11.J * (-c10.I + c20.I));
var e = (c22.I * c12.J) - (c12.I * c22.J);
var f = (c21.I * c12.J) - (c12.I * c21.J);
var g = (c12.I * (c10.J - c20.J)) + (c12.J * (-c10.I + c20.I));
var roots = QuarticRootsTests.QuarticRoots(
-e * e,
-2 * e * f,
(a * b) - (f * f) - (2 * e * g),
(a * c) - (2 * f * g),
(a * d) - (g * g),
epsilon);
var result = new Intersection(IntersectionStates.NoIntersection);
for (var i = 0; i < roots.Count; i++)
{
var s = roots[i];
if (0 <= s && s <= 1)
{
var xRoots = QuadraticRootsTests.QuadraticRoots(
-c12.I,
-c11.I,
-c10.I + c20.I + (s * c21.I) + (s * s * c22.I),
epsilon);
var yRoots = QuadraticRootsTests.QuadraticRoots(
-c12.J,
-c11.J,
-c10.J + c20.J + (s * c21.J) + (s * s * c22.J),
epsilon);
if (xRoots.Count > 0 && yRoots.Count > 0)
{
for (var j = 0; j < xRoots.Count; j++)
{
var xRoot = xRoots[j];
if (0 <= xRoot && xRoot <= 1)
{
for (var k = 0; k < yRoots.Count; k++)
{
if (Abs(xRoot - yRoots[k]) < epsilon)
{
result.Items.Add(((Point2D)c22 * s * s) + ((c21 * s) + c20));
goto checkRoots;
}
}
}
}
checkRoots :;
}
}
}
if (result.Items.Count > 0)
{
result.State = IntersectionStates.Intersection;
}
return(result);
}
public static Intersection QuadraticBezierSegmentQuadraticBezierSegmentIntersection0(
double a1X, double a1Y, double a2X, double a2Y, double a3X, double a3Y,
double b1X, double b1Y, double b2X, double b2Y, double b3X, double b3Y,
double epsilon = Epsilon)
{
// Initialize the intersection.
var result = new Intersection(IntersectionStates.NoIntersection);
var xCoeffA = QuadraticBezierBernsteinBasisTests.QuadraticBezierBernsteinBasis(a1X, a2X, a3X);
var yCoeffA = QuadraticBezierBernsteinBasisTests.QuadraticBezierBernsteinBasis(a1Y, a2Y, a3Y);
var xCoeffB = QuadraticBezierBernsteinBasisTests.QuadraticBezierBernsteinBasis(b1X, b2X, b3X);
var yCoeffB = QuadraticBezierBernsteinBasisTests.QuadraticBezierBernsteinBasis(b1Y, b2Y, b3Y);
var a = (xCoeffA.C * yCoeffA.B) - (xCoeffA.B * yCoeffA.C);
var b = (xCoeffB.C * yCoeffA.B) - (xCoeffA.B * yCoeffB.C);
var c = (xCoeffB.B * yCoeffA.B) - (xCoeffA.B * yCoeffB.B);
var d = (xCoeffA.B * (yCoeffA.A - yCoeffB.A)) - (yCoeffA.B * (xCoeffB.A - xCoeffA.A));
var e = (xCoeffB.C * yCoeffA.C) - (xCoeffA.C * yCoeffB.C);
var f = (xCoeffB.B * yCoeffA.C) - (xCoeffA.C * yCoeffB.B);
var g = (xCoeffA.C * (yCoeffA.A - yCoeffB.A)) - (yCoeffA.C * (yCoeffB.A - xCoeffA.A));
var roots = QuarticRootsTests.QuarticRoots(
/* t^4 */ e * e,
/* t^3 */ 2 * e * f,
/* t^2 */ (-a * b) + (f * f) + (2 * e * g),
/* t^1 */ (-a * c) + (2 * f * g),
/* C */ (-a * d) + (g * g),
epsilon);
foreach (var s in roots)
{
var point = new Point2D(
(xCoeffB.C * s * s) + (xCoeffB.B * s) + xCoeffB.A,
(yCoeffB.C * s * s) + (yCoeffB.B * s) + yCoeffB.A);
if (s >= 0 && s <= 1)
{
var xRoots = QuadraticRootsTests.QuadraticRoots(
/* t^2 */ -xCoeffA.C,
/* t^1 */ -xCoeffA.B,
/* C */ -xCoeffA.A + point.X,
epsilon);
var yRoots = QuadraticRootsTests.QuadraticRoots(
/* t^2 */ -yCoeffA.C,
/* t^1 */ -yCoeffA.B,
/* C */ -yCoeffA.A + point.Y,
epsilon);
if (xRoots.Count > 0 && yRoots.Count > 0)
{
// Find the nearest matching x and y roots in the ranges 0 < x < 1; 0 < y < 1.
foreach (var xRoot in xRoots)
{
if (xRoot >= 0 && xRoot <= 1)
{
foreach (var yRoot in yRoots)
{
var t = xRoot - yRoot;
if ((t >= 0 ? t : -t) < 0.06) // ToDo: Find the error and replace 0.06 with epsilon.
{
result.AppendPoint(point);
goto checkRoots; // Break through two levels of foreach loops. Using goto for performance.
}
}
}
}
checkRoots :;
}
}
}
if (result.Items.Count > 0)
{
result.State = IntersectionStates.Intersection;
}
return(result);
}