using System.Collections.Generic;
using System.Drawing;
using System.Linq;
namespace DrawGraph
{
internal class Drawer
{
private const int WheelConstant = 120;
private const int ZoomMultiplier = 4;
private readonly Pen _axesPen;
private readonly Color _backColor;
private readonly List<Function> _currentFunctions;
private readonly Graph _graph;
public Drawer(Graph graph, Pen graphPen, Pen axesPen, Pen functionPen, Color backColor)
{
_graph = graph;
GraphPen = graphPen;
FunctionPen = functionPen;
_axesPen = axesPen;
_backColor = backColor;
_currentFunctions
= new List
<Function
>(); DrawGrid = DrawTicks = DrawAxes = true;
}
public Drawer(Graph graph)
: this(graph,
new Pen
(Brushes.
Black, 2
),
new Pen
(Brushes.
Black, 2
),
new Pen
(Brushes.
Black, 2
), Color.
White) {
}
public Drawer(Graph graph, Color backColor)
: this(graph,
new Pen
(Brushes.
Black, 2
),
new Pen
(Brushes.
Black, 2
),
new Pen
(Brushes.
Black, 2
), backColor
) {
}
public Drawer(Graph graph, Pen functionPen)
: this(graph,
new Pen
(Brushes.
Black, 2
),
new Pen
(Brushes.
Black, 2
), functionPen, Color.
White) {
}
public Drawer(Graph graph, Pen functionPen, Color backColor)
: this(graph,
new Pen
(Brushes.
Black, 2
),
new Pen
(Brushes.
Black, 2
), functionPen, backColor
) {
}
public Pen GraphPen { get; set; }
public Pen FunctionPen { get; set; }
public Graph Graph
{
get { return _graph; }
}
public bool DrawGrid { get; set; }
public bool DrawTicks { get; set; }
public bool DrawAxes { get; set; }
private PointF TransformPoint(PointF point)
{
//the point (0,0) of the form is the upper left corner, so every graph point needs a conversion
return new PointF
(point.
X*Graph.
CellSize + Graph.
Center.
X,
-point.
Y*Graph.
CellSize + Graph.
Center.
Y); }
// draw a single function
private void DrawFunction(Graphics g, Function f)
{
// a list of list of points is required to properly skip imaginary number(e.g sqrt(-1))
var pointsList
= new List
<List
<PointF
>> {new List
<PointF
>()};
bool lastNan = false;
for (float x = -Graph.NumOfCells/2; x < Graph.NumOfCells/2; x += Graph.Step)
// from -X border to X border og the graph
{
float y = f.Apply(x); // the y value of x is calculated thanks to reflection
PointF point
= TransformPoint
(new PointF
(x, y
)); // then the point obtained is converted to "real" coordinates
//when an imaginary number is discovered it creates a new separated list of points to draw
//every list of points will be drawn singularly
if (double.IsNaN(y))
{
if (!lastNan) // it creates a new list of points only if the last number wasn't imaginary
{
pointsList.
Add(new List
<PointF
>()); lastNan = true;
}
}
// if a point exceeds the borders of the graph his Y components is set to not visible, to prevent overflow.
else if (point.Y > Graph.Heigth)
{
pointsList
[pointsList.
Count - 1
].
Add(new PointF
(point.
X, Graph.
Heigth + FunctionPen.
Width)); }
else if (point.Y < 0)
{
pointsList
[pointsList.
Count - 1
].
Add(new PointF
(point.
X,
-FunctionPen.
Width)); }
else
{
lastNan = false;
pointsList[pointsList.Count - 1].Add(point); //
}
}
//draws each list of points only if the list has a number of elements > 1
foreach (var list in pointsList.Where(list => list.Count > 1))
{
g.DrawLines(FunctionPen, list.ToArray());
}
}
public void DrawGraph(Graphics g)
{
g.Clear(_backColor);
if (DrawGrid || DrawTicks)
{
for (int i = 0; i <= Graph.NumOfCells; i++)
{
if (DrawGrid)
{
//draw grid
g.DrawLine(Pens.Gray, i*Graph.CellSize, 0, i*Graph.CellSize, Graph.NumOfCells*Graph.CellSize);
g.DrawLine(Pens.Gray, 0, i*Graph.CellSize, Graph.NumOfCells*Graph.CellSize, i*Graph.CellSize);
}
if (DrawTicks)
{
//draw tick marks
g.DrawLine(_axesPen, Graph.Center.X - Graph.TickSize/2, i*Graph.CellSize,
Graph.Center.X + Graph.TickSize/2, i*Graph.CellSize);
g.DrawLine(_axesPen, i*Graph.CellSize, Graph.Center.Y - Graph.TickSize/2, i*Graph.CellSize,
Graph.Center.Y + Graph.TickSize/2);
}
}
}
if (DrawAxes)
{
//draw axes
g.DrawLine(_axesPen, 0, Graph.Center.Y, Graph.Width, Graph.Center.Y);
g.DrawLine(_axesPen, Graph.Center.X, 0, Graph.Center.X, Graph.Heigth);
}
}
public void DrawFunctions(Graphics g)
{
// draw all the current functions
foreach (Function f in _currentFunctions)
{
DrawFunction(g, f);
}
}
public void Zoom(int delta)
{
int value = (delta/WheelConstant)*ZoomMultiplier;
if (Graph.NumOfCells - value <= Graph.MinNumOfCells)
{
Graph.NumOfCells = Graph.MinNumOfCells;
}
else if (Graph.NumOfCells - value >= Graph.MaxNumOfCells)
{
Graph.NumOfCells = Graph.MaxNumOfCells;
}
else
{
Graph.NumOfCells -= value;
}
}
public void AddFunction(Function f)
{
_currentFunctions.Add(f);
}
public void ClearFunctionList()
{
if (_currentFunctions.Count > 0)
_currentFunctions.Clear();
}
}
}
