public static void DrawCircle(this Texture2D texture, IntVertex2 v0, int radius, Color color)
{
Action <int, int> draw = (x, y) => texture.SetPixel(x, y, color);
BresenhamCircle(v0.x, v0.y, radius, draw);
texture.Apply();
}
public static IntersectionType IntSegmentToIntSegmentE(IntVertex2 start0, IntVertex2 end0, IntVertex2 start1,
IntVertex2 end1, bool testBoundingBox = false)
{
IntSegment2 intersection;
return(IntSegmentToIntSegmentE(start0.x, start0.y, end0.x, end0.y, start1.x, start1.y, end1.x, end1.y,
out intersection, testBoundingBox));
}
public static bool IntSegmentToRay(IntVertex2 segmentStart, IntVertex2 segmentEnd, Vertex2 rayStart,
Vertex2 rayEnd, out IntVertex2 intersection)
{
intersection = IntVertex2.zero;
float r, s;
if (LineToLine(rayStart, rayEnd, (Vertex2)segmentStart, (Vertex2)segmentEnd, out r, out s))
{
if (r >= 0)
{
if (s >= 0 && s <= 1)
{
var inter = rayStart + (rayEnd - rayStart) * r;
intersection = new IntVertex2(inter.x, inter.y);
return(true);
}
}
}
return(false);
}
public static IntVertex2 Perp(IntVertex2 vector)
{
return(new IntVertex2(-vector.y, vector.x));
}
public static void DrawGradientLine(this Texture2D texture, IntVertex2 v0, IntVertex2 v1, Color color0,
Color color1)
{
DrawGradientLine(texture, v0.x, v0.y, v1.x, v1.y, color0, color1);
}
public static void DrawLine(this Texture2D texture, IntVertex2 v0, IntVertex2 v1, Color color, bool AA = false)
{
DrawLine(texture, v0.x, v0.y, v1.x, v1.y, color, AA);
}
private static void WuLine(IntVertex2 v0, IntVertex2 v1, Action <int, int, float> draw)
{
WuLine(v0.x, v0.y, v1.x, v1.y, draw);
}
public static void BresenhamLine(IntVertex2 v0, IntVertex2 v1, Action <int, int> draw)
{
BresenhamLine(v0.x, v0.y, v1.x, v1.y, draw);
}
public static bool IntSegmentToIntSegment(IntVertex2 start0, IntVertex2 end0, IntVertex2 start1, IntVertex2 end1,
out IntSegment2 intersection, bool testBoundingBox = false)
{
return(IntSegmentToIntSegmentE(start0.x, start0.y, end0.x, end0.y, start1.x, start1.y, end1.x, end1.y,
out intersection, testBoundingBox) != IntersectionType.None);
}
public IntSegment2(IntVertex2 b)
{
a = IntVertex2.zero;
this.b = b;
}
public IntSegment2(IntVertex2 a, IntVertex2 b)
{
this.a = a;
this.b = b;
}
public IntSegment2(IntSegment2 segment)
{
a = segment.a;
b = segment.b;
}
public static bool IntSegmentToRay(IntVertex2 v0, IntVertex2 v1, Ray2D ray, out IntVertex2 intersection)
{
return(IntSegmentToRay(v0, v1, ray.origin, ray.origin + ray.direction, out intersection));
}
public static bool IntSegmentToRay(IntSegment2 segment, Ray2D ray, out IntVertex2 intersection)
{
return(IntSegmentToRay(segment.a, segment.b, ray, out intersection));
}
public static int PerpDot(IntVertex2 a, IntVertex2 b)
{
return(a.x * b.y - a.y * b.x);
}
public IntSegment2(int x0, int y0, int x1, int y1)
{
a = new IntVertex2(x0, y0);
b = new IntVertex2(x1, y1);
}
/// <summary>
/// More than 0 - left, less than 0 - right, equals 0 - on line
/// </summary>
public static int LocatePointOnLine(IntVertex2 line1, IntVertex2 line2, IntVertex2 point)
{
return((line2.x - line1.x) * (point.y - line1.y) - (point.x - line1.x) * (line2.y - line1.y));
}
public static float IntLineSegmentToIntLineSegment(IntSegment2 S1, IntSegment2 S2)
{
IntVertex2 u = S1.b - S1.a;
IntVertex2 v = S2.b - S2.a;
IntVertex2 w = S1.a - S2.a;
float a = IntVertex2.Dot(u, u); // always >= 0
float b = IntVertex2.Dot(u, v);
float c = IntVertex2.Dot(v, v); // always >= 0
float d = IntVertex2.Dot(u, w);
float e = IntVertex2.Dot(v, w);
float D = a * c - b * b; // always >= 0
float sN, sD = D; // sc = sN / sD, default sD = D >= 0
float tN, tD = D; // tc = tN / tD, default tD = D >= 0
// compute the line parameters of the two closest points
if (D < Mathf.Epsilon)
{
// the lines are almost parallel
sN = 0; // force using point P0 on segment S1
sD = 1; // to prevent possible division by 0.0 later
tN = e;
tD = c;
}
else
{
// get the closest points on the infinite lines
sN = (b * e - c * d);
tN = (a * e - b * d);
if (sN < 0)
{
// sc < 0 => the s=0 edge is visible
sN = 0;
tN = e;
tD = c;
}
else if (sN > sD)
{
// sc > 1 => the s=1 edge is visible
sN = sD;
tN = e + b;
tD = c;
}
}
if (tN < 0)
{
// tc < 0 => the t=0 edge is visible
tN = 0;
// recompute sc for this edge
if (-d < 0)
{
sN = 0;
}
else if (-d > a)
{
sN = sD;
}
else
{
sN = -d;
sD = a;
}
}
else if (tN > tD)
{
// tc > 1 => the t=1 edge is visible
tN = tD;
// recompute sc for this edge
if ((-d + b) < 0)
{
sN = 0;
}
else if ((-d + b) > a)
{
sN = sD;
}
else
{
sN = (-d + b);
sD = a;
}
}
// finally do the division to get sc and tc
float sc = (Mathf.Abs(sN) < Mathf.Epsilon ? 0 : sN / sD);
float tc = (Mathf.Abs(tN) < Mathf.Epsilon ? 0 : tN / tD);
// get the difference of the two closest points
IntVertex2 dP = w + (sc * u) - (tc * v); // = S1(sc) - S2(tc)
return(dP.magnitude); // return the closest distance
}
