// Draw function
public void DrawFunction(Canvas graphFunctions, string function, Color functionColor)
{
// creates syntax tree
SyntaxTree calculator = new SyntaxTree(function);
GeometryGroup g = new GeometryGroup();
Point currentPoint = new Point();
Point previousPoint = new Point();
bool isCurrentPoint = false;
bool isPreviousPoint = false;
Brush brush = new SolidColorBrush(functionColor);
// for each x point calclulates y with step of range x divided by canvas width => x+=step of each point
for (double x = minX; x < maxX; x += (maxX - minX) / graphFunctions.Width)
{
// calculates y value for each x point
double y = calculator.Calculate(x, out isCurrentPoint);
if (Math.Abs(y) > maxY * 2)
{
isCurrentPoint = false;
}
if (isCurrentPoint)
{
currentPoint.X = (x / ((maxY - minX) / graphFunctions.Width) -
minX / ((maxX - minX) / graphFunctions.Width));
currentPoint.Y = (graphFunctions.Height -
(y / ((maxY - minY) / graphFunctions.Height) -
minY / ((maxY - minY) / graphFunctions.Height)));
if (isPreviousPoint)
{
// connect prev and current point with line
g.Children.Add(new LineGeometry(
previousPoint,
currentPoint));
Path functionPath = new Path();
functionPath.StrokeThickness = 1;
functionPath.Stroke = brush;
functionPath.Data = g;
graphFunctions.Children.Add(functionPath);
}
}
// set current point to previous till the end of canvas
previousPoint = currentPoint;
isPreviousPoint = isCurrentPoint;
}
}
