public static bool CircleLineIntersection(Circle2D c, Line2D l)
{
var a1 = new Vector2D(c.Point.X - c.Radius, c.Point.Y - c.Radius);
var a2 = new Vector2D(c.Point.X + c.Radius, c.Point.Y + c.Radius);
if (BoundingBoxIntersection(a1, a2, l.A, l.B))
{
var slope = l.Slope;
double inverseSlope;
if (slope == null || (double) slope == 0)
{
// the bounding box already determined that an intersection has been made.
return true;
}
// slightly more complicated... need to create a tangent line. and find the distance.
inverseSlope = 1 / (double)slope;
// y= mx+b
// b = circle.y, x = circle .x
Line2D l2 = new Line2D();
l2.A = new Vector2D(c.Point.X, c.Point.Y);
l2.B.X = c.Point.X + c.Radius;
l2.B.Y = c.Point.Y + inverseSlope * (c.Point.X + c.Radius);
var p = LineLineIntersection(l, l2);
if (p != null)
{
var d = new Line2D(c.Point, p);
if (d.Length < c.Radius)
return true;
return false;
}
Line2D l3 = new Line2D();
l2.A = new Vector2D(c.Point.X, c.Point.Y);
l2.B.X = c.Point.X - c.Radius;
l2.B.Y = c.Point.Y + inverseSlope * (c.Point.X - c.Radius);
var q = LineLineIntersection(l, l2);
if (q != null)
{
var d = new Line2D(c.Point, q);
if (d.Length < c.Radius)
return true;
return false;
}
}
return false;
}
public static bool CircleCircleIntersection(Circle2D a, Circle2D b)
{
var l = new Line2D(a.Point, b.Point);
return l.Length < (a.Radius + b.Radius);
}
public static bool CircleContainsVertex(Circle2D a, Vector2D b)
{
var l = new Line2D(a.Point, b);
return l.Length < a.Radius;
}
public static List<Vector2D> PolygonLineIntersection(Polygon2D polygon, Line2D intersectLine)
{
return
polygon.Lines.Select(line => LineLineIntersection(line, intersectLine)).Where(point => point != null).
ToList();
}
public static Vector2D LineLineIntersection(Line2D l1, Line2D l2)
{
if (BoundingBoxIntersection(l1.A,l1.B, l2.A,l2.B))
{
// if the slopes are not null
if (l1.Slope != null && l2.Slope != null)
{
// and the slopes are not equal
if (Math.Abs((double)l1.Slope - (double)l2.Slope) < double.Epsilon)
{
return null;
}
// if the points form a bounding box
// solve for m1x+b1 = m2x+b2
// m1x = m2x + b2 - b1
// m1x - m2x = b2 - b1
// (m1 - m2)x = b2-b1
// y = mx+b
// m1x+b1 = m2x+b2
// m1x = m2x+b2-b1
// m1x - m2x = b2-b1
// (m1-m2)x = b2-b1
// x = (b2-b1)/(m1-m2)
// x = (b2-b1)/((dy1/dx1)-(dy2-dx2))
double? x = (l2.YIntercept - l1.YIntercept) / ((double)l1.Slope - (double)l2.Slope);
double? y = l1.Slope * x + l1.YIntercept;
if (x != null) if (y != null) return new Vector2D((double)x, (double)y);
}
else if (l1.Slope == null && l2.Slope != null)
{
double? y = l2.Slope * l1.A.X + l2.YIntercept;
if (y != null) return new Vector2D(l1.A.X, (double)y);
}
else if (l1.Slope != null && l2.Slope == null)
{
double? y = l1.Slope * l2.A.X + l1.YIntercept;
if (y != null) return new Vector2D(l2.A.X, (double)y);
}
}
return null;
}
private void DrawWall(Wall w)
{
var wTex = ContentManager.Instance[w.WallTexture.TextureTag];
GL.BindTexture(TextureTarget.Texture2D, wTex.glID);
double total = 0;
foreach (var wx in w.Area.Lines) total += wx.Length;
double runningTotal = 0;
var wt = w.WallTexture;
SetupTexture(wt);
var c = w.Area.Center;
GL.Begin(BeginMode.Quads);
foreach (var wall in w.Area.Lines)
{
var l1 = new Line2D(c, wall.A);
var l2 = new Line2D(c, wall.B);
GL.Normal3(l1.Normal.X, 0, l1.Normal.Y);
GL.TexCoord2((runningTotal / total), _gameInstance.CurrentLevel.BaseFloorHeight / wTex.Height);
GL.Vertex3(wall.A.X, _gameInstance.CurrentLevel.BaseFloorHeight, wall.A.Y);
GL.Normal3(l2.Normal.X, 0, l2.Normal.Y);
GL.TexCoord2(((wall.Length + runningTotal) / total), _gameInstance.CurrentLevel.BaseFloorHeight / wTex.Height);
GL.Vertex3(wall.B.X, _gameInstance.CurrentLevel.BaseFloorHeight, wall.B.Y);
GL.Normal3(l2.Normal.X, 0, l2.Normal.Y);
GL.TexCoord2(((wall.Length + runningTotal) / total), _gameInstance.CurrentLevel.BaseCeilingHeight / wTex.Height);
GL.Vertex3(wall.B.X, _gameInstance.CurrentLevel.BaseCeilingHeight, wall.B.Y);
GL.Normal3(l1.Normal.X, 0, l1.Normal.Y);
GL.TexCoord2((runningTotal / total), _gameInstance.CurrentLevel.BaseCeilingHeight / wTex.Height);
GL.Vertex3(wall.A.X, _gameInstance.CurrentLevel.BaseCeilingHeight, wall.A.Y);
runningTotal += wall.Length;
}
GL.End();
}
private void DrawPlatform(Platform p)
{
var floorTex = ContentManager.Instance[p.FloorTexture.TextureTag];
var ceilingTex = ContentManager.Instance[p.CeilingTexture.TextureTag];
var wallTex = ContentManager.Instance[p.WallTexture.TextureTag];
var area = p.Area.Triangulate();
var center = p.Area.Center;
SetupTexture(p.FloorTexture);
GL.BindTexture(TextureTarget.Texture2D, floorTex.glID);
GL.Begin(BeginMode.Triangles);
foreach (var renderTriangle in area)
{
GL.Normal3(0, 1, 0);
GL.TexCoord2(renderTriangle.Points[0].X / floorTex.Width, renderTriangle.Points[0].Y / floorTex.Height);
GL.Vertex3(renderTriangle.Points[0].X, p.FloorHeight, renderTriangle.Points[0].Y);
GL.TexCoord2(renderTriangle.Points[1].X / floorTex.Width, renderTriangle.Points[1].Y / floorTex.Height);
GL.Vertex3(renderTriangle.Points[1].X, p.FloorHeight, renderTriangle.Points[1].Y);
GL.TexCoord2(renderTriangle.Points[2].X / floorTex.Width, renderTriangle.Points[2].Y / floorTex.Height);
GL.Vertex3(renderTriangle.Points[2].X, p.FloorHeight, renderTriangle.Points[2].Y);
}
GL.End();
SetupTexture(p.CeilingTexture);
GL.BindTexture(TextureTarget.Texture2D, ceilingTex.glID);
GL.Begin(BeginMode.Triangles);
foreach (var renderTriangle in area)
{
GL.Normal3(0, -1, 0);
GL.TexCoord2(renderTriangle.Points[0].X / ceilingTex.Width, renderTriangle.Points[0].Y / ceilingTex.Height);
GL.Vertex3(renderTriangle.Points[0].X, p.CeilingHeight, renderTriangle.Points[0].Y);
GL.TexCoord2(renderTriangle.Points[2].X / ceilingTex.Width, renderTriangle.Points[2].Y / ceilingTex.Height);
GL.Vertex3(renderTriangle.Points[2].X, p.CeilingHeight, renderTriangle.Points[2].Y);
GL.TexCoord2(renderTriangle.Points[1].X / ceilingTex.Width, renderTriangle.Points[1].Y / ceilingTex.Height);
GL.Vertex3(renderTriangle.Points[1].X, p.CeilingHeight, renderTriangle.Points[1].Y);
}
GL.End();
SetupTexture(p.WallTexture);
GL.BindTexture(TextureTarget.Texture2D, ContentManager.Instance[p.WallTexture.TextureTag].glID);
GL.Begin(BeginMode.Quads);
double total = 0;
foreach (var wx in p.Area.Lines) total += wx.Length;
double runningTotal = 0;
foreach (var wall in p.Area.Lines)
{
var l1 = new Line2D(center, wall.A);
var l2 = new Line2D(center, wall.B);
GL.Normal3(l1.Normal.X, 0, l1.Normal.Y);
GL.TexCoord2((runningTotal / total), p.FloorHeight / wallTex.Height);
GL.Vertex3(wall.A.X, p.FloorHeight, wall.A.Y);
GL.Normal3(l2.Normal.X, 0, l2.Normal.Y);
GL.TexCoord2((wall.Length + runningTotal) / total, p.FloorHeight / wallTex.Height);
GL.Vertex3(wall.B.X, p.FloorHeight, wall.B.Y);
GL.Normal3(l2.Normal.X, 0, l2.Normal.Y);
GL.TexCoord2((wall.Length + runningTotal) / total, p.CeilingHeight / wallTex.Height);
GL.Vertex3(wall.B.X, p.CeilingHeight, wall.B.Y);
GL.Normal3(l1.Normal.X, 0, l1.Normal.Y);
GL.TexCoord2((runningTotal / total), p.CeilingHeight / wallTex.Height);
GL.Vertex3(wall.A.X, p.CeilingHeight, wall.A.Y);
runningTotal += wall.Length;
}
GL.End();
}
private void DrawCorridor(Corridor c)
{
var floorTex = ContentManager.Instance[c.FloorTexture.TextureTag];
var ceilingTex = ContentManager.Instance[c.CeilingTexture.TextureTag];
var cWallTex = ContentManager.Instance[c.CeilingWallTexture.TextureTag];
var cFloorTex = ContentManager.Instance[c.FloorWallTexture.TextureTag];
var area = c.Area.Triangulate();
SetupTexture(c.FloorTexture);
GL.BindTexture(TextureTarget.Texture2D, floorTex.glID);
GL.Begin(BeginMode.Triangles);
var center = c.Area.Center;
foreach (var renderTriangle in area)
{
GL.Normal3(0, 1, 0);
GL.TexCoord2(renderTriangle.Points[0].X / floorTex.Width, renderTriangle.Points[0].Y / floorTex.Height);
GL.Vertex3(renderTriangle.Points[0].X, c.FloorHeight, renderTriangle.Points[0].Y);
GL.TexCoord2(renderTriangle.Points[1].X / floorTex.Width, renderTriangle.Points[1].Y / floorTex.Height);
GL.Vertex3(renderTriangle.Points[1].X, c.FloorHeight, renderTriangle.Points[1].Y);
GL.TexCoord2(renderTriangle.Points[2].X / floorTex.Width, renderTriangle.Points[2].Y / floorTex.Height);
GL.Vertex3(renderTriangle.Points[2].X, c.FloorHeight, renderTriangle.Points[2].Y);
}
GL.End();
SetupTexture(c.CeilingTexture);
GL.BindTexture(TextureTarget.Texture2D, ceilingTex.glID);
GL.Begin(BeginMode.Triangles);
foreach (var renderTriangle in area)
{
GL.Normal3(0, -1, 0);
GL.TexCoord2(renderTriangle.Points[0].X / ceilingTex.Width, renderTriangle.Points[0].Y / ceilingTex.Height);
GL.Vertex3(renderTriangle.Points[0].X, c.CeilingHeight, renderTriangle.Points[0].Y);
GL.TexCoord2(renderTriangle.Points[2].X / ceilingTex.Width, renderTriangle.Points[2].Y / ceilingTex.Height);
GL.Vertex3(renderTriangle.Points[2].X, c.CeilingHeight, renderTriangle.Points[2].Y);
GL.TexCoord2(renderTriangle.Points[1].X / ceilingTex.Width, renderTriangle.Points[1].Y / ceilingTex.Height);
GL.Vertex3(renderTriangle.Points[1].X, c.CeilingHeight, renderTriangle.Points[1].Y);
}
GL.End();
SetupTexture(c.CeilingWallTexture);
GL.BindTexture(TextureTarget.Texture2D, cWallTex.glID);
GL.Begin(BeginMode.Quads);
double total = 0;
foreach (var wx in c.Area.Lines) total += wx.Length;
double runningTotal = 0;
foreach (var wall in c.Area.Lines)
{
var l1 = new Line2D(center, wall.A);
var l2 = new Line2D(center, wall.B);
GL.Normal3(l1.Normal.X, 0, l1.Normal.Y);
GL.TexCoord2((runningTotal / total), _gameInstance.CurrentLevel.BaseFloorHeight / cWallTex.Height);
GL.Vertex3(wall.A.X, _gameInstance.CurrentLevel.BaseFloorHeight, wall.A.Y);
GL.Normal3(l2.Normal.X, 0, l2.Normal.Y);
GL.TexCoord2((wall.Length + runningTotal) / total, _gameInstance.CurrentLevel.BaseFloorHeight / cWallTex.Height);
GL.Vertex3(wall.B.X, _gameInstance.CurrentLevel.BaseFloorHeight, wall.B.Y);
GL.Normal3(l2.Normal.X, 0, l2.Normal.Y);
GL.TexCoord2((wall.Length + runningTotal) / total, c.FloorHeight / cWallTex.Height);
GL.Vertex3(wall.B.X, c.FloorHeight, wall.B.Y);
GL.Normal3(l1.Normal.X, 0, l1.Normal.Y);
GL.TexCoord2(runningTotal / total, c.FloorHeight / cWallTex.Height);
GL.Vertex3(wall.A.X, c.FloorHeight, wall.A.Y);
}
GL.End();
SetupTexture(c.FloorWallTexture);
GL.BindTexture(TextureTarget.Texture2D, cFloorTex.glID);
GL.Begin(BeginMode.Quads);
foreach (var wall in c.Area.Lines)
{
var l1 = new Line2D(center, wall.A);
var l2 = new Line2D(center, wall.B);
GL.Normal3(l1.Normal.X, 0, l1.Normal.Y);
GL.TexCoord2((runningTotal) / total, c.CeilingHeight / cFloorTex.Height);
GL.Vertex3(wall.A.X, c.CeilingHeight, wall.A.Y);
GL.Normal3(l2.Normal.X, 0, l2.Normal.Y);
GL.TexCoord2((wall.Length + runningTotal) / total, c.CeilingHeight / cFloorTex.Height);
GL.Vertex3(wall.B.X, c.CeilingHeight, wall.B.Y);
GL.Normal3(l2.Normal.X, 0, l2.Normal.Y);
GL.TexCoord2((wall.Length + runningTotal) / total, _gameInstance.CurrentLevel.BaseCeilingHeight / cFloorTex.Height);
GL.Vertex3(wall.B.X, _gameInstance.CurrentLevel.BaseCeilingHeight, wall.B.Y);
GL.Normal3(l1.Normal.X, 0, l1.Normal.Y);
GL.TexCoord2((runningTotal) / total, _gameInstance.CurrentLevel.BaseCeilingHeight / cFloorTex.Height);
GL.Vertex3(wall.A.X, _gameInstance.CurrentLevel.BaseCeilingHeight, wall.A.Y);
runningTotal += wall.Length;
}
GL.End();
}