/// <summary>
/// Draw Line with clipping.
/// </summary>
/// <param name="g"></param>
/// <param name="pen"></param>
/// <param name="p1"></param>
/// <param name="p2"></param>
private static void DrawLine(Graphics g, Pen pen, Vector2 p1, Vector2 p2)
{
g.DrawLine(pen, p1.X, p1.Y, p2.X, p2.Y);
}
public static void DrawCurve(this Graphics g,
Curve curve,
float x,
float y,
float width,
float height,
Color curveColor,
float thickness)
{
float lastPosition = curve.Keys[curve.Keys.Count - 1].Position;
// get curve max value
float top = float.MaxValue, bottom = float.MinValue;
foreach (var v in curve.Keys) {
if (v.Value == 0) {
if (v.Value > bottom)
bottom = v.Value;
if (v.Value < top)
top = v.Value;
}
else if (v.Value > 0) {
if (v.Value > bottom)
bottom = v.Value;
}
else {
if (v.Value < top)
top = v.Value;
}
}
// fixed
float curveHeight = bottom + -top;
if (lastPosition == 0) lastPosition = width;
if (curveHeight == 0) curveHeight = height;
Vector2 scale = new Vector2(width / lastPosition,
height / curveHeight);
double dt0 = x;
double dt1 = dt0 + width / scale.X;
double step = scale.X / smoothnessTable[(int)curveSmoothness];
Pen pen0 = new Pen(curveColor, thickness);
if (curve.Keys.Count > 0) {
double kt0 = curve.Keys[0].Position;
double kt1 = curve.Keys[curve.Keys.Count - 1].Position;
double t0 = dt0;
double t1 = Math.Min(dt1, kt0);
// draw fact section
t0 = Math.Max(dt0, kt0);
t1 = Math.Min(dt1, kt1);
if (t0 < t1) {
Vector2[] p = new Vector2[2] { new Vector2(), new Vector2() };
// Search key and next key that includes t0 position.
int keyIndex = 0;
CurveKey key = null, nextKey = null;
for (; keyIndex < curve.Keys.Count; ++keyIndex)
{
key = nextKey; nextKey = curve.Keys[keyIndex];
if (nextKey.Position > t0) break;
}
int pIdx = 0;
p[pIdx] = new Vector2((float)t0 / scale.X, curve.Evaluate((float)t0) * scale.Y + y);
for (double t = t0; t < t1; ) {
double nextT = t1 + step;
if (nextKey != null)
nextT = Math.Min(t1, nextKey.Position);
// Draw current key and next key section.
if (key.Continuity == CurveContinuity.Smooth) {
while (t < nextT) {
// If this line crosses next key position, draw line from
// current position to next key position.
t = (t < nextT && t + step > nextT) ? nextT : t + step;
pIdx = (pIdx + 1) & 1;
p[pIdx] = new Vector2((float)t / scale.X, curve.Evaluate((float)t) / scale.Y + y);
DrawLine(g, pen0, p[0], p[1]);
}
}
else {
// Step case,
// Draw, horizontal line.
pIdx = (pIdx + 1) & 1;
p[pIdx] = new Vector2(nextKey.Position / scale.X, key.Value / scale.Y + y);
DrawLine(g, pen0, p[0], p[1]);
// Draw vertical line.
pIdx = (pIdx + 1) & 1;
p[pIdx] = new Vector2(nextKey.Position / scale.X, nextKey.Value / scale.Y + y);
DrawLine(g, pen0, p[0], p[1]);
t = nextT;
}
// Advance to next key.
key = nextKey;
nextKey = (++keyIndex < curve.Keys.Count) ? curve.Keys[keyIndex] : null;
}
}
}
}
