private void OnLoad(object sender, EventArgs e)
{
Application.Idle += OnApplicationIdle;
GL.ClearColor(Color.CornflowerBlue);
GL.Enable(EnableCap.DepthTest);
SetupViewport();
Context.VSync = true;
_window = new Window3D(-50, 50, -50, 50, -50, 50);
Calculator calc = new Calculator();
CompiledExpression expr = ExpressionCompiler.CompileInfix("sin(x)+cos(y)", false);
var mesh = LineCalculator3D.Calculate(calc, expr, _window, 0.5F);
// Vertices
GL.GenBuffers(1, out _bufferInfo.VertexId);
GL.BindBuffer(BufferTarget.ArrayBuffer, _bufferInfo.VertexId);
GL.BufferData(BufferTarget.ArrayBuffer, mesh.VertexArraySize, mesh.Vertices, BufferUsageHint.StaticDraw);
// Indices
GL.GenBuffers(1, out _bufferInfo.IndexId);
GL.BindBuffer(BufferTarget.ElementArrayBuffer, _bufferInfo.IndexId);
GL.BufferData(BufferTarget.ElementArrayBuffer, mesh.IndexArraySize, mesh.Indices, BufferUsageHint.StaticDraw);
// Colors
GL.GenBuffers(1, out _bufferInfo.ColorId);
GL.BindBuffer(BufferTarget.ArrayBuffer, _bufferInfo.ColorId);
GL.BufferData(BufferTarget.ArrayBuffer, mesh.ColorArraySize, mesh.Colors, BufferUsageHint.StaticDraw);
_bufferInfo.IndexCount = mesh.Indices.Length;
}
public static ConstructedMatrix Calculate(Calculator calc, CompiledExpression expr, Window3D window, float step)
{
float lowZ = float.MaxValue, highZ = float.MinValue;
List<Vector3> results = new List<Vector3>();
List<int> startPoints = new List<int>();
int i = 0;
for (float x = window.MinimumX; x < window.MaximumX; x += step)
{
startPoints.Add(i);
calc.SetArgument("x", x);
bool outsideGraph = true;
Vector3? last = null;
for (float y = window.MinimumY; y < window.MaximumY; y += step)
{
calc.SetArgument("y", y);
float z = (float)calc.Evaluate(expr);
Vector3 result = new Vector3(x, y, z);
results.Add(result);
bool includeResult = false, includeLast = false;
if (z > window.MaximumZ || z < window.MinimumZ)
{
// Outside the window
if (!outsideGraph)
{
// First point outside the window
includeResult = true;
outsideGraph = true;
}
}
else
{
// Inside the window
if (outsideGraph)
{
// First point inside the window, include the last vertex as well
includeLast = true;
}
includeResult = true;
outsideGraph = false;
}
if (includeResult)
{
if (z < lowZ)
{
lowZ = includeLast && last.HasValue ? Math.Min(z, last.Value.Z) : z;
}
if (z > highZ)
{
highZ = includeLast && last.HasValue ? Math.Max(z, last.Value.Z) : z;
}
}
last = result;
i++;
}
}
List<int> indices = new List<int>();
for (int x = 0; x < startPoints.Count - 1; x++)
{
int currentX = startPoints[x];
int nextX = startPoints[x + 1];
for (int y = 0; y < startPoints[x + 1] - startPoints[x] - 1; y++)
{
indices.AddRange(new[] { currentX + y, nextX + y, nextX + y + 1, currentX + y, nextX + y + 1, currentX + y + 1 });
}
}
int[] colors = new int[results.Count];
float absLowZ = Math.Abs(lowZ);
float mulFactor = 255F / (absLowZ + Math.Abs(highZ));
for (int j = 0; j < results.Count; j++)
{
float z = results[j].Z;
int normalized = Math.Max(0, Math.Min(255, (int)Math.Round((z + absLowZ) * mulFactor)));
colors[j] = Color.FromArgb(normalized, normalized, normalized).ToArgb();
}
return new ConstructedMatrix(results.ToArray(), indices.ToArray(), colors.ToArray());
}