public void Remove(GraphItemViewModel exp)
{
listOfGraphs.Remove(exp);
view.Graphs = listOfGraphs.AsReadOnly();
}
private void DrawFunc(GraphItemViewModel graph)
{
var exp = graph.Expression;
var geometry = new StreamGeometry();
using (var context = geometry.Open())
{
bool startFlag = true;
double y;
double tempY;
for (double x = -centerX / cm; x <= (currentWidth - centerX) / cm; x += 0.03 * slider.Value)
{
parameters.Parameters["x"] = x;
y = (double)exp.Calculate(parameters);
tempY = centerY - (y * cm);
if (double.IsNaN(y) || tempY < 0 || tempY > currentHeight)
{
startFlag = true;
}
else
{
if (startFlag)
{
context.BeginFigure(new Point(centerX + (x * cm), tempY), false, false);
startFlag = false;
}
context.LineTo(new Point(centerX + (x * cm), tempY), true, false);
}
}
}
geometry.Freeze();
var funcVisual = new DrawingVisual();
var pen = new Pen(Brushes.Red, 1);
pen.Freeze();
using (DrawingContext context = funcVisual.RenderOpen())
{
context.DrawGeometry(Brushes.Red, pen, geometry);
}
graph.Visual = funcVisual;
canvas.AddVisual(funcVisual);
}