public static IEnumerable <Point> GetPointsFromSVGPathsString(string svgPathsString)
{
List <Point> points = new List <Point>();
var svgPaths = GetSVGCommandsFromSVGPathsString(svgPathsString);
Point currentPoint = new Point(0, 0);
foreach (var command in svgPaths)
{
switch (command.SVGCommandType)
{
case SVGCommandType.M:
currentPoint = new Point(command.XYParams.FirstOrDefault(),
command.XYParams.Skip(1).FirstOrDefault());
points.Add(currentPoint);
break;
case SVGCommandType.c:
case SVGCommandType.C:
double dX = (command.SVGCommandType == SVGCommandType.c) ? currentPoint.X : 0;
double dY = (command.SVGCommandType == SVGCommandType.c) ? currentPoint.Y : 0;
Point p0 = currentPoint;
Point p1 = new Point(dX + command.XYParams.FirstOrDefault(),
dY + command.XYParams.Skip(1).FirstOrDefault());
Point p2 = new Point(dX + command.XYParams.Skip(2).FirstOrDefault(),
dY + command.XYParams.Skip(3).FirstOrDefault());
Point p3 = new Point(dX + command.XYParams.Skip(4).FirstOrDefault(),
dY + command.XYParams.Skip(5).FirstOrDefault());
currentPoint = p3;
points.AddRange(SVGMath.CalculateCubicBeizer(p0, p1, p2, p3, 100));
break;
}
}
return(points);
}
/// <summary>
/// Returns a list of XY coordinates for an SVG path string.
///
/// Drawing lines between these coordinates will allow you to draw the SVG image (although you lose fill/colour/line thickness
/// information).
/// </summary>
/// <param name="svgPathsString">SVG Path string</param>
/// <param name="pointsPerBeizerCommand">Number of points to use for Beizer commands</param>
/// <returns>Enumerable list of Points</returns>
public static SVGPathData GetPointsFromSVGPathsString(string svgPathsString, int pointsPerBeizerCommand = 100)
{
SVGPathData pathData = new SVGPathData();
List <Point> points = new List <Point>();
var svgPaths = GetSVGCommandsFromSVGPathsString(svgPathsString);
Point currentPoint = new Point(0, 0);
Point? p0 = null;
Point? p1 = null;
Point? p2 = null;
Point? p3 = null;
Point? q0 = null;
Point? q1 = null;
Point? q2 = null;
foreach (var command in svgPaths)
{
// if lower case use delta values instead of absolute
double dX = (char.IsLower(command.SVGCommandType.ToString().FirstOrDefault())) ? currentPoint.X : 0;
double dY = (char.IsLower(command.SVGCommandType.ToString().FirstOrDefault())) ? currentPoint.Y : 0;
bool keepQValues = false;
bool keepPValues = false;
// Handle commands
switch (command.SVGCommandType)
{
// Fix move, this needs to return an array of SVGPathData if multiple move commands
case SVGCommandType.m:
case SVGCommandType.M:
case SVGCommandType.l:
case SVGCommandType.L:
for (int i = 0; i < command.XYParams.Count(); i += 2)
{
currentPoint = new Point(dX + command.XYParams[i],
dY + command.XYParams[i + 1]);
points.Add(currentPoint);
}
break;
case SVGCommandType.h:
case SVGCommandType.H:
for (int i = 0; i < command.XYParams.Count(); i++)
{
currentPoint = new Point(dX + command.XYParams[i],
currentPoint.Y);
points.Add(currentPoint);
}
break;
case SVGCommandType.v:
case SVGCommandType.V:
for (int i = 0; i < command.XYParams.Count(); i++)
{
currentPoint = new Point(currentPoint.X,
dX + command.XYParams[i]);
points.Add(currentPoint);
}
break;
case SVGCommandType.c:
case SVGCommandType.C:
keepPValues = true;
for (int i = 0; i < command.XYParams.Count(); i += 6)
{
p0 = currentPoint;
p1 = new Point(dX + command.XYParams[i + 0],
dY + command.XYParams[i + 1]);
p2 = new Point(dX + command.XYParams[i + 2],
dY + command.XYParams[i + 3]);
p3 = new Point(dX + command.XYParams[i + 4],
dY + command.XYParams[i + 5]);
currentPoint = p3.Value;
points.AddRange(SVGMath.CalculateCubicBeizer(p0.Value, p1.Value, p2.Value, p3.Value, pointsPerBeizerCommand));
}
break;
case SVGCommandType.s:
case SVGCommandType.S:
keepPValues = true;
for (int i = 0; i < command.XYParams.Count(); i += 4)
{
p0 = currentPoint;
// P1 is calculatd based off of the parameters for the previous curve
p1 = !p2.HasValue ? currentPoint
: new Point((p3.Value.X * 2) - p2.Value.X,
(p3.Value.Y * 2) - p2.Value.Y);
p2 = new Point(dX + command.XYParams[i + 0],
dY + command.XYParams[i + 1]);
p3 = new Point(dX + command.XYParams[i + 2],
dY + command.XYParams[i + 3]);
currentPoint = p3.Value;
points.AddRange(SVGMath.CalculateCubicBeizer(p0.Value, p1.Value, p2.Value, p3.Value, pointsPerBeizerCommand));
}
break;
case SVGCommandType.q:
case SVGCommandType.Q:
keepQValues = true;
for (int i = 0; i < command.XYParams.Count(); i += 4)
{
q0 = currentPoint;
q1 = new Point(dX + command.XYParams[i + 0],
dY + command.XYParams[i + 1]);
q2 = new Point(dX + command.XYParams[i + 2],
dY + command.XYParams[i + 3]);
currentPoint = q2.Value;
points.AddRange(SVGMath.CalculateQuadraticBeizer(q0.Value, q1.Value, q2.Value, pointsPerBeizerCommand));
}
break;
case SVGCommandType.t:
case SVGCommandType.T:
keepQValues = true;
for (int i = 0; i < command.XYParams.Count(); i += 2)
{
q0 = currentPoint;
q1 = !q2.HasValue ? currentPoint
: new Point((q2.Value.X * 2) - q1.Value.X,
(q2.Value.Y * 2) - q1.Value.Y);
q2 = new Point(dX + command.XYParams[i + 0],
dY + command.XYParams[i + 1]);
currentPoint = q2.Value;
points.AddRange(SVGMath.CalculateQuadraticBeizer(q0.Value, q1.Value, q2.Value, pointsPerBeizerCommand));
}
break;
case SVGCommandType.z:
case SVGCommandType.Z:
pathData.IsClosed = true;
break;
case SVGCommandType.invalid:
throw new InvalidOperationException($"Invalid SVG Command {command.SVGCommandString}");
}
// Get rid of Q values if there is a non quadratic beizer command run in between quadratic beizer commands
if (!keepQValues)
{
q0 = null;
q1 = null;
q2 = null;
}
// Get rid of P values if there is a non cubic beizer command run in between cubic beizer commands
if (!keepPValues)
{
p0 = null;
p1 = null;
p2 = null;
p3 = null;
}
}
pathData.Points = points;
return(pathData);
}