public static GuiRenderer.TriangleVertex[] GenerateStrips(IList<Vec2> points, Vec2 thickness, ColorValue color)
{
Vec2 halfThickness = thickness * .5f;
GuiRenderer.TriangleVertex[] vertices = new GuiRenderer.TriangleVertex[points.Count * 2];
int writeIndex = 0;
for (int nPoint = 0; nPoint < points.Count; nPoint++)
{
Vec2 point = points[nPoint];
if (nPoint == 0)
{
//first point
Vec2 nextPoint = points[nPoint + 1];
float xDif = nextPoint.X - point.X;
float yDif = nextPoint.Y - point.Y;
if (Math.Abs(yDif) > Math.Abs(xDif))
{
if (yDif > 0)
{
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(new Vec2(point.X - halfThickness.X, point.Y), color);
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(new Vec2(point.X + halfThickness.X, point.Y), color);
}
else
{
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(new Vec2(point.X + halfThickness.X, point.Y), color);
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(new Vec2(point.X - halfThickness.X, point.Y), color);
}
}
else
{
if (xDif < 0)
{
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(new Vec2(point.X, point.Y - halfThickness.Y), color);
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(new Vec2(point.X, point.Y + halfThickness.Y), color);
}
else
{
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(new Vec2(point.X, point.Y + halfThickness.Y), color);
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(new Vec2(point.X, point.Y - halfThickness.Y), color);
}
}
}
else if (nPoint == points.Count - 1)
{
//last point
Vec2 previousPoint = points[nPoint - 1];
float xDif = point.X - previousPoint.X;
float yDif = point.Y - previousPoint.Y;
if (Math.Abs(yDif) > Math.Abs(xDif))
{
if (yDif > 0)
{
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(new Vec2(point.X - halfThickness.X, point.Y), color);
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(new Vec2(point.X + halfThickness.X, point.Y), color);
}
else
{
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(new Vec2(point.X + halfThickness.X, point.Y), color);
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(new Vec2(point.X - halfThickness.X, point.Y), color);
}
}
else
{
if (xDif < 0)
{
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(new Vec2(point.X, point.Y - halfThickness.Y), color);
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(new Vec2(point.X, point.Y + halfThickness.Y), color);
}
else
{
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(new Vec2(point.X, point.Y + halfThickness.Y), color);
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(new Vec2(point.X, point.Y - halfThickness.Y), color);
}
}
}
else
{
Vec2 previousPoint = points[nPoint - 1];
Vec2 nextPoint = points[nPoint + 1];
float angle1 = MathFunctions.ATan(point.Y - previousPoint.Y, point.X - previousPoint.X);
angle1 += MathFunctions.PI * .5f;
float angle2 = MathFunctions.ATan(nextPoint.Y - point.Y, nextPoint.X - point.X);
angle2 += MathFunctions.PI * .5f;
Vec2 offset1 = new Vec2(MathFunctions.Cos(angle1), MathFunctions.Sin(angle1)) * halfThickness;
Vec2 offset2 = new Vec2(MathFunctions.Cos(angle2), MathFunctions.Sin(angle2)) * halfThickness;
Vec2 intersectPoint1;
{
Vec2 line1Start = previousPoint + offset1;
Vec2 line1End = point + offset1;
Vec2 line2Start = nextPoint + offset2;
Vec2 line2End = point + offset2;
if (!MathUtils.IntersectRayRay(line1Start, line1End, line2Start, line2End, out intersectPoint1))
intersectPoint1 = line1End;
}
Vec2 intersectPoint2;
{
Vec2 line1Start = previousPoint - offset1;
Vec2 line1End = point - offset1;
Vec2 line2Start = nextPoint - offset2;
Vec2 line2End = point - offset2;
if (!MathUtils.IntersectRayRay(line1Start, line1End, line2Start, line2End, out intersectPoint2))
intersectPoint2 = line1End;
}
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(intersectPoint1, color);
vertices[writeIndex++] = new GuiRenderer.TriangleVertex(intersectPoint2, color);
}
}
return vertices;
}
public static GuiRenderer.TriangleVertex[] GenerateTriangles(IList<Vec2> points, Vec2 thickness, ColorValue color)
{
GuiRenderer.TriangleVertex[] strips = GenerateStrips(points, thickness, color);
int count = (strips.Length - 2) * 3;
GuiRenderer.TriangleVertex[] triangles = new GuiRenderer.TriangleVertex[count];
int readIndex;
int writeIndex = 0;
for (readIndex = 0; readIndex < 3; readIndex++)
triangles[writeIndex++] = strips[readIndex];
for (; readIndex < strips.Length; readIndex++)
{
GuiRenderer.TriangleVertex v1 = triangles[writeIndex - 2];
GuiRenderer.TriangleVertex v2 = triangles[writeIndex - 1];
triangles[writeIndex++] = v1;
triangles[writeIndex++] = v2;
triangles[writeIndex++] = strips[readIndex];
}
return triangles;
}
