9 Commits

Author SHA1 Message Date
5ed7ccdded fix: Build Errors 2024-01-23 17:31:32 +03:00
0d29ab066f refactor: Added Static Methods Back 2024-01-23 17:30:46 +03:00
bd03d036aa refactor: Shape 2024-01-23 17:29:55 +03:00
3b299c947c refactor: LineEquation 2024-01-23 17:29:21 +03:00
6a5d10980a refactor: Triangle 2024-01-23 17:28:59 +03:00
dcda78b010 refactor: Line 2024-01-23 17:27:57 +03:00
5170dd0aea refactor: Circle 2024-01-23 17:27:38 +03:00
5c185a664c refactor: AABB 2024-01-23 17:26:45 +03:00
8ccebaa8fb chore: Solution File for Physics2D 2024-01-23 17:24:37 +03:00
12 changed files with 264 additions and 220 deletions

View File

@@ -1,6 +1,6 @@
using System; using System;
using System.Collections.Generic; using System.Collections.Generic;
using Engine.Physics2D;
using Syntriax.Engine.Core; using Syntriax.Engine.Core;
using Syntriax.Engine.Core.Abstract; using Syntriax.Engine.Core.Abstract;
using Syntriax.Engine.Physics2D.Abstract; using Syntriax.Engine.Physics2D.Abstract;

View File

@@ -1,9 +1,10 @@
using Microsoft.Xna.Framework;
using Syntriax.Engine.Core;
namespace Syntriax.Engine.Physics2D; namespace Syntriax.Engine.Physics2D;
public record CollisionInformation public record CollisionInformation
( (
Vector2 Normal, Vector2D Normal,
Vector2 ContactPosition Vector2D ContactPosition
); );

View File

@@ -0,0 +1,31 @@

Microsoft Visual Studio Solution File, Format Version 12.00
# Visual Studio Version 17
VisualStudioVersion = 17.5.002.0
MinimumVisualStudioVersion = 10.0.40219.1
Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Engine.Physics2D", "Engine.Physics2D.csproj", "{88874ADD-23BD-4781-A47C-71B5D4AA9C25}"
EndProject
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Engine.Core", "..\Engine.Core\Engine.Core.csproj", "{A9D6D7DC-4B5A-4D1E-878D-08BA3A871D3A}"
EndProject
Global
GlobalSection(SolutionConfigurationPlatforms) = preSolution
Debug|Any CPU = Debug|Any CPU
Release|Any CPU = Release|Any CPU
EndGlobalSection
GlobalSection(ProjectConfigurationPlatforms) = postSolution
{88874ADD-23BD-4781-A47C-71B5D4AA9C25}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
{88874ADD-23BD-4781-A47C-71B5D4AA9C25}.Debug|Any CPU.Build.0 = Debug|Any CPU
{88874ADD-23BD-4781-A47C-71B5D4AA9C25}.Release|Any CPU.ActiveCfg = Release|Any CPU
{88874ADD-23BD-4781-A47C-71B5D4AA9C25}.Release|Any CPU.Build.0 = Release|Any CPU
{A9D6D7DC-4B5A-4D1E-878D-08BA3A871D3A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
{A9D6D7DC-4B5A-4D1E-878D-08BA3A871D3A}.Debug|Any CPU.Build.0 = Debug|Any CPU
{A9D6D7DC-4B5A-4D1E-878D-08BA3A871D3A}.Release|Any CPU.ActiveCfg = Release|Any CPU
{A9D6D7DC-4B5A-4D1E-878D-08BA3A871D3A}.Release|Any CPU.Build.0 = Release|Any CPU
EndGlobalSection
GlobalSection(SolutionProperties) = preSolution
HideSolutionNode = FALSE
EndGlobalSection
GlobalSection(ExtensibilityGlobals) = postSolution
SolutionGuid = {9C16F1F0-F5F8-4ED9-A3B4-7A0BF8003AA1}
EndGlobalSection
EndGlobal

View File

@@ -0,0 +1,77 @@
using System;
using Syntriax.Engine.Core;
using Syntriax.Engine.Physics2D;
using Syntriax.Engine.Physics2D.Primitives;
namespace Engine.Physics2D;
public static partial class Physics2D
{
public const float RadianToDegree = 57.29577866666166f;
public const float DegreeToRadian = 0.01745329277777778f;
public static bool Overlaps(this Circle left, Circle right)
{
float distanceSquared = left.Position.FromTo(right.Position).LengthSquared();
float radiusSumSquared = left.RadiusSquared + right.RadiusSquared;
return distanceSquared < radiusSumSquared;
}
public static bool Overlaps(this Circle left, Circle right, out Vector2D normal, out float depth)
{
Vector2D distanceVector = left.Position.FromTo(right.Position);
float distanceSquared = distanceVector.LengthSquared();
float radiusSumSquared = left.RadiusSquared + right.RadiusSquared;
bool isOverlapping = distanceSquared < radiusSumSquared;
depth = 0f;
normal = distanceVector.Normalized;
if (isOverlapping)
depth = MathF.Sqrt(radiusSumSquared - distanceSquared);
return isOverlapping;
}
public static bool Overlaps(this Circle circle, Vector2D point) => circle.Position.FromTo(point).LengthSquared() <= circle.RadiusSquared;
public static bool Overlaps(this Circle circle, Vector2D point, out Vector2D normal, out float depth)
{
Vector2D distanceVector = circle.Position.FromTo(point);
float distanceSquared = distanceVector.LengthSquared();
float radiusSquared = circle.RadiusSquared;
bool isOverlapping = distanceSquared < radiusSquared;
depth = 0f;
normal = distanceVector.Normalized;
if (isOverlapping)
depth = MathF.Sqrt(radiusSquared - distanceSquared);
return isOverlapping;
}
public static bool Overlaps(this AABB aabb, Vector2D point)
=> point.X >= aabb.LowerBoundary.X && point.X <= aabb.UpperBoundary.X &&
point.Y >= aabb.LowerBoundary.Y && point.Y <= aabb.UpperBoundary.Y;
public static bool Overlaps(this AABB left, AABB right)
=> left.LowerBoundary.X <= right.UpperBoundary.X && left.UpperBoundary.X >= right.LowerBoundary.X &&
left.LowerBoundary.Y <= right.UpperBoundary.Y && left.UpperBoundary.Y >= right.LowerBoundary.Y;
public static bool Overlaps(Triangle triangle, Vector2D point)
{
float originalTriangleArea = triangle.Area;
float pointTriangleArea1 = new Triangle(point, triangle.B, triangle.C).Area;
float pointTriangleArea2 = new Triangle(triangle.A, point, triangle.C).Area;
float pointTriangleArea3 = new Triangle(triangle.A, triangle.B, point).Area;
float pointTriangleAreasSum = pointTriangleArea1 + pointTriangleArea2 + pointTriangleArea3;
return originalTriangleArea.ApproximatelyEquals(pointTriangleAreasSum, float.Epsilon * 3f);
}
public static bool LaysOn(this Vector2D point, Line line) => Line.Intersects(line, point);
}

View File

@@ -1,7 +1,6 @@
using System; using System;
using System.Collections.Generic; using System.Collections.Generic;
using Microsoft.Xna.Framework;
using Syntriax.Engine.Core; using Syntriax.Engine.Core;
using Syntriax.Engine.Physics2D.Primitives; using Syntriax.Engine.Physics2D.Primitives;
@@ -9,52 +8,6 @@ namespace Syntriax.Engine.Physics2D;
public static class PhysicsMath public static class PhysicsMath
{ {
public static Vector2D Scale(this Vector2D original, Vector2D scale)
=> new Vector2D(original.X * scale.X, original.Y * scale.Y);
public static Triangle ToSuperTriangle(this IList<Vector2D> vertices)
{
float minX = float.MaxValue, minY = float.MaxValue;
float maxX = float.MinValue, maxY = float.MinValue;
foreach (Vector2D point in vertices)
{
minX = MathF.Min(minX, point.X);
minY = MathF.Min(minY, point.Y);
maxX = MathF.Max(maxX, point.X);
maxY = MathF.Max(maxY, point.Y);
}
float dx = maxX - minX;
float dy = maxY - minY;
float deltaMax = MathF.Max(dx, dy);
float midX = (minX + maxX) / 2;
float midY = (minY + maxY) / 2;
Vector2D p1 = new Vector2D((float)midX - 20f * (float)deltaMax, (float)midY - (float)deltaMax);
Vector2D p2 = new Vector2D((float)midX, (float)midY + 20 * (float)deltaMax);
Vector2D p3 = new Vector2D((float)midX + 20 * (float)deltaMax, (float)midY - (float)deltaMax);
return new Triangle(p1, p2, p3);
}
public static IList<Line> ToLines(this IList<Vector2D> vertices)
{
List<Line> lines = new List<Line>(vertices.Count - 1);
ToLines(vertices, lines);
return lines;
}
public static void ToLines(this IList<Vector2D> vertices, IList<Line> lines)
{
lines.Clear();
for (int i = 0; i < vertices.Count - 1; i++)
lines.Add(new(vertices[i], vertices[i + 1]));
lines.Add(new(vertices[^1], vertices[0]));
}
public static bool LaysOn(this Vector2D point, Line line)
=> line.Resolve(point.X).ApproximatelyEquals(point);
// Given three collinear points p, q, r, the function checks if // Given three collinear points p, q, r, the function checks if
@@ -92,10 +45,6 @@ public static class PhysicsMath
public static bool ApproximatelyEquals(this float a, float b) public static bool ApproximatelyEquals(this float a, float b)
=> ApproximatelyEquals(a, b, float.Epsilon); => ApproximatelyEquals(a, b, float.Epsilon);
public static bool ApproximatelyEquals(this Vector2 a, Vector2 b)
=> ApproximatelyEquals(a, b, float.Epsilon);
public static bool ApproximatelyEquals(this Vector2 a, Vector2 b, float epsilon)
=> ApproximatelyEquals(a.X, b.X, epsilon) && ApproximatelyEquals(a.Y, b.Y, epsilon);
public static bool ApproximatelyEquals(this Vector2D a, Vector2D b) public static bool ApproximatelyEquals(this Vector2D a, Vector2D b)
=> ApproximatelyEquals(a, b, float.Epsilon); => ApproximatelyEquals(a, b, float.Epsilon);
public static bool ApproximatelyEquals(this Vector2D a, Vector2D b, float epsilon) public static bool ApproximatelyEquals(this Vector2D a, Vector2D b, float epsilon)

View File

@@ -4,14 +4,11 @@ namespace Syntriax.Engine.Physics2D.Primitives;
public record AABB(Vector2D LowerBoundary, Vector2D UpperBoundary) public record AABB(Vector2D LowerBoundary, Vector2D UpperBoundary)
{ {
public bool Overlaps(Vector2D point) public static bool ApproximatelyEquals(AABB left, AABB right)
=> point.X >= LowerBoundary.X && point.X <= UpperBoundary.X && => left.LowerBoundary.ApproximatelyEquals(right.LowerBoundary) && left.UpperBoundary.ApproximatelyEquals(right.UpperBoundary);
point.Y >= LowerBoundary.Y && point.Y <= UpperBoundary.Y; }
public bool Overlaps(AABB other) public static class AABBExtensions
=> LowerBoundary.X <= other.UpperBoundary.X && UpperBoundary.X >= other.LowerBoundary.X && {
LowerBoundary.Y <= other.UpperBoundary.Y && UpperBoundary.Y >= other.LowerBoundary.Y; public static bool ApproximatelyEquals(this AABB left, AABB right) => AABB.ApproximatelyEquals(left, right);
public bool ApproximatelyEquals(AABB other)
=> LowerBoundary.ApproximatelyEquals(other.LowerBoundary) && UpperBoundary.ApproximatelyEquals(other.UpperBoundary);
} }

View File

@@ -4,15 +4,14 @@ namespace Syntriax.Engine.Physics2D.Primitives;
public record Circle(Vector2D Position, float Radius) public record Circle(Vector2D Position, float Radius)
{ {
public bool Intersects(Circle other) public float RadiusSquared => Radius * Radius;
{ public float Diameter => 2f * Radius;
float distanceSquared = (Position - other.Position).LengthSquared();
float radiusSumSquared = Radius * Radius + other.Radius * other.Radius;
return distanceSquared < radiusSumSquared; public static bool ApproximatelyEquals(Circle left, Circle right)
} => left.Position.ApproximatelyEquals(right.Position) && left.Radius.ApproximatelyEquals(right.Radius);
}
public bool Overlaps(Vector2D point) => (Position - point).LengthSquared() <= Radius * Radius;
public bool ApproximatelyEquals(Circle other) public static class CircleExtensions
=> Position.ApproximatelyEquals(other.Position) && Radius.ApproximatelyEquals(other.Radius); {
public static bool ApproximatelyEquals(this Circle left, Circle right) => Circle.ApproximatelyEquals(left, right);
} }

View File

@@ -9,30 +9,27 @@ namespace Syntriax.Engine.Physics2D.Primitives;
public record Line(Vector2D From, Vector2D To) public record Line(Vector2D From, Vector2D To)
{ {
public Line Reversed => new(To, From); public Line Reversed => new(To, From);
public Vector2D Direction => Vector2D.Normalize(To - From); public Vector2D Direction => From.FromTo(To).Normalize();
public float Length => (From - To).Length(); public float Length => From.FromTo(To).Length();
public float LengthSquared => (From - To).LengthSquared(); public float LengthSquared => From.FromTo(To).LengthSquared();
public LineEquation LineEquation public static LineEquation GetLineEquation(Line line)
{ {
get Vector2D slopeVector = line.From.FromTo(line.To);
{ float slope = slopeVector.Y / slopeVector.X;
Vector2D slopeVector = To - From;
float slope = slopeVector.Y / slopeVector.X;
float yOffset = From.Y - (slope * From.X); float yOffset = line.From.Y - (slope * line.From.X);
return new LineEquation(slope, yOffset); return new LineEquation(slope, yOffset);
}
} }
public bool Intersects(Vector2D point) public static bool Intersects(Line line, Vector2D point)
=> Resolve(point.X).ApproximatelyEquals(point); => LineEquation.Resolve(GetLineEquation(line), point.X).ApproximatelyEquals(point.Y);
public float GetT(Vector2D point) public static float GetT(Line line, Vector2D point)
{ {
float fromX = MathF.Abs(From.X); float fromX = MathF.Abs(line.From.X);
float toX = MathF.Abs(To.X); float toX = MathF.Abs(line.To.X);
float pointX = MathF.Abs(point.X); float pointX = MathF.Abs(point.X);
float min = MathF.Min(fromX, toX); float min = MathF.Min(fromX, toX);
@@ -46,32 +43,32 @@ public record Line(Vector2D From, Vector2D To)
// I don't even know, apparently whatever I wrote up there doesn't take into account of the direction of the line // I don't even know, apparently whatever I wrote up there doesn't take into account of the direction of the line
// Which... I can see how, but I am also not sure how I can make it take into account. Or actually I'm for some reason // Which... I can see how, but I am also not sure how I can make it take into account. Or actually I'm for some reason
// too unmotivated to find a solution. Future me, find a better way if possible, please. // too unmotivated to find a solution. Future me, find a better way if possible, please.
if (!Lerp(t).ApproximatelyEquals(point)) if (!Lerp(line, t).ApproximatelyEquals(point))
return 1f - t; return 1f - t;
return t; return t;
} }
public bool Exist(List<Vector2D> vertices) public static bool Exist(Line line, List<Vector2D> vertices)
{ {
for (int i = 0; i < vertices.Count - 1; i++) for (int i = 0; i < vertices.Count - 1; i++)
{ {
Vector2D vertexCurrent = vertices[i]; Vector2D vertexCurrent = vertices[i];
Vector2D vertexNext = vertices[i]; Vector2D vertexNext = vertices[i];
if (From == vertexCurrent && To == vertexNext) return true; if (line.From == vertexCurrent && line.To == vertexNext) return true;
if (From == vertexNext && To == vertexCurrent) return true; if (line.From == vertexNext && line.To == vertexCurrent) return true;
} }
Vector2D vertexFirst = vertices[0]; Vector2D vertexFirst = vertices[0];
Vector2D vertexLast = vertices[^1]; Vector2D vertexLast = vertices[^1];
if (From == vertexFirst && To == vertexLast) return true; if (line.From == vertexFirst && line.To == vertexLast) return true;
if (From == vertexLast && To == vertexFirst) return true; if (line.From == vertexLast && line.To == vertexFirst) return true;
return false; return false;
} }
public float IntersectionParameterT(Line other) public static float IntersectionParameterT(Line left, Line right)
{ {
float numerator = (From.X - other.From.X) * (other.From.Y - other.To.Y) - (From.Y - other.From.Y) * (other.From.X - other.To.X); float numerator = (left.From.X - right.From.X) * (right.From.Y - right.To.Y) - (left.From.Y - right.From.Y) * (right.From.X - right.To.X);
float denominator = (From.X - To.X) * (other.From.Y - other.To.Y) - (From.Y - To.Y) * (other.From.X - other.To.X); float denominator = (left.From.X - left.To.X) * (right.From.Y - right.To.Y) - (left.From.Y - left.To.Y) * (right.From.X - right.To.X);
// Lines are parallel // Lines are parallel
if (denominator == 0) if (denominator == 0)
@@ -80,20 +77,17 @@ public record Line(Vector2D From, Vector2D To)
return numerator / denominator; return numerator / denominator;
} }
public Vector2D Lerp(float t) public static Vector2D Lerp(Line line, float t)
=> new Vector2D( => new Vector2D(
From.X + (To.X - From.X) * t, line.From.X + (line.To.X - line.From.X) * t,
From.Y + (To.Y - From.Y) * t line.From.Y + (line.To.Y - line.From.Y) * t
); );
public Vector2D Resolve(float x) public static Vector2D ClosestPointTo(Line line, Vector2D point)
=> new Vector2D(x, LineEquation.Resolve(x));
public Vector2D ClosestPointTo(Vector2D point)
{ {
// Convert edge points to vectors // Convert edge points to vectors
var edgeVector = new Vector2D(To.X - From.X, To.Y - From.Y); var edgeVector = new Vector2D(line.To.X - line.From.X, line.To.Y - line.From.Y);
var pointVector = new Vector2D(point.X - From.X, point.Y - From.Y); var pointVector = new Vector2D(point.X - line.From.X, point.Y - line.From.Y);
// Calculate the projection of pointVector onto edgeVector // Calculate the projection of pointVector onto edgeVector
float t = (pointVector.X * edgeVector.X + pointVector.Y * edgeVector.Y) / (edgeVector.X * edgeVector.X + edgeVector.Y * edgeVector.Y); float t = (pointVector.X * edgeVector.X + pointVector.Y * edgeVector.Y) / (edgeVector.X * edgeVector.X + edgeVector.Y * edgeVector.Y);
@@ -102,45 +96,50 @@ public record Line(Vector2D From, Vector2D To)
t = MathF.Max(0, MathF.Min(1, t)); t = MathF.Max(0, MathF.Min(1, t));
// Calculate the closest point on the edge // Calculate the closest point on the edge
float closestX = From.X + t * edgeVector.X; float closestX = line.From.X + t * edgeVector.X;
float closestY = From.Y + t * edgeVector.Y; float closestY = line.From.Y + t * edgeVector.Y;
return new Vector2D((float)closestX, (float)closestY); return new Vector2D((float)closestX, (float)closestY);
} }
public Vector2D IntersectionPoint(Line other) public static Vector2D IntersectionPoint(Line left, Line right)
=> Vector2D.Lerp(From, To, IntersectionParameterT(other)); => Vector2D.Lerp(left.From, left.To, IntersectionParameterT(left, right));
public bool Intersects(Line other) public static bool Intersects(Line left, Line right)
{ {
int o1 = PhysicsMath.Orientation(From, To, other.From); int o1 = PhysicsMath.Orientation(left.From, left.To, right.From);
int o2 = PhysicsMath.Orientation(From, To, other.To); int o2 = PhysicsMath.Orientation(left.From, left.To, right.To);
int o3 = PhysicsMath.Orientation(other.From, other.To, From); int o3 = PhysicsMath.Orientation(right.From, right.To, left.From);
int o4 = PhysicsMath.Orientation(other.From, other.To, To); int o4 = PhysicsMath.Orientation(right.From, right.To, left.To);
if (o1 != o2 && o3 != o4) if (o1 != o2 && o3 != o4)
return true; return true;
if (o1 == 0 && PhysicsMath.OnSegment(From, other.From, To)) return true; if (o1 == 0 && PhysicsMath.OnSegment(left.From, right.From, left.To)) return true;
if (o2 == 0 && PhysicsMath.OnSegment(From, other.To, To)) return true; if (o2 == 0 && PhysicsMath.OnSegment(left.From, right.To, left.To)) return true;
if (o3 == 0 && PhysicsMath.OnSegment(other.From, From, other.To)) return true; if (o3 == 0 && PhysicsMath.OnSegment(right.From, left.From, right.To)) return true;
if (o4 == 0 && PhysicsMath.OnSegment(other.From, To, other.To)) return true; if (o4 == 0 && PhysicsMath.OnSegment(right.From, left.To, right.To)) return true;
return false; return false;
} }
public bool Intersects(Line other, [NotNullWhen(returnValue: true)] out Vector2D? point) public static bool Intersects(Line left, Line right, [NotNullWhen(returnValue: true)] out Vector2D? point)
{ {
point = null; point = null;
bool result = Intersects(other); bool result = Intersects(left, right);
if (result) if (result)
point = IntersectionPoint(other); point = IntersectionPoint(left, right);
return result; return result;
} }
public bool ApproximatelyEquals(Line other) public static bool ApproximatelyEquals(Line left, Line right)
=> From.ApproximatelyEquals(other.From) && To.ApproximatelyEquals(other.To); => left.From.ApproximatelyEquals(right.From) && left.To.ApproximatelyEquals(right.To);
}
public static class LineExtensions
{
public static bool ApproximatelyEquals(this Line left, Line right) => Line.ApproximatelyEquals(left, right);
} }

View File

@@ -2,7 +2,14 @@ namespace Syntriax.Engine.Physics2D.Primitives;
public record LineEquation(float Slope, float OffsetY) public record LineEquation(float Slope, float OffsetY)
{ {
public float Resolve(float x) => Slope * x + OffsetY; // y = mx + b public static float Resolve(LineEquation lineEquation, float x) => lineEquation.Slope * x + lineEquation.OffsetY; // y = mx + b
public bool ApproximatelyEquals(LineEquation other)
=> Slope.ApproximatelyEquals(other.Slope) && OffsetY.ApproximatelyEquals(other.OffsetY); public static bool ApproximatelyEquals(LineEquation left, LineEquation right)
=> left.Slope.ApproximatelyEquals(right.Slope) && left.OffsetY.ApproximatelyEquals(right.OffsetY);
}
public static class LineEquationExtensions
{
public static float Resolve(this LineEquation lineEquation, float x) => LineEquation.Resolve(lineEquation, x);
public static bool ApproximatelyEquals(this LineEquation left, LineEquation right) => LineEquation.ApproximatelyEquals(left, right);
} }

View File

@@ -1,9 +0,0 @@
namespace Syntriax.Engine.Physics2D.Primitives;
public static class Math
{
public const float RadianToDegree = 57.29577866666166f;
public const float DegreeToRadian = 0.01745329277777778f;
public static float Clamp(float value, float min, float max) => (value < min) ? min : (value > max) ? max : value;
}

View File

@@ -7,62 +7,65 @@ namespace Syntriax.Engine.Physics2D.Primitives;
public record Shape(IList<Vector2D> Vertices) public record Shape(IList<Vector2D> Vertices)
{ {
public Triangle SuperTriangle public static Triangle GetSuperTriangle(Shape shape)
{ {
get float minX = float.MaxValue, minY = float.MaxValue;
float maxX = float.MinValue, maxY = float.MinValue;
foreach (Vector2D point in shape.Vertices)
{ {
float minX = float.MaxValue, minY = float.MaxValue; minX = MathF.Min(minX, point.X);
float maxX = float.MinValue, maxY = float.MinValue; minY = MathF.Min(minY, point.Y);
maxX = MathF.Max(maxX, point.X);
foreach (Vector2D point in Vertices) maxY = MathF.Max(maxY, point.Y);
{
minX = MathF.Min(minX, point.X);
minY = MathF.Min(minY, point.Y);
maxX = MathF.Max(maxX, point.X);
maxY = MathF.Max(maxY, point.Y);
}
float dx = maxX - minX;
float dy = maxY - minY;
float deltaMax = MathF.Max(dx, dy);
float midX = (minX + maxX) / 2;
float midY = (minY + maxY) / 2;
Vector2D p1 = new Vector2D((float)midX - 20f * (float)deltaMax, (float)midY - (float)deltaMax);
Vector2D p2 = new Vector2D((float)midX, (float)midY + 20 * (float)deltaMax);
Vector2D p3 = new Vector2D((float)midX + 20 * (float)deltaMax, (float)midY - (float)deltaMax);
return new Triangle(p1, p2, p3);
} }
float dx = maxX - minX;
float dy = maxY - minY;
float deltaMax = MathF.Max(dx, dy);
float midX = (minX + maxX) / 2;
float midY = (minY + maxY) / 2;
Vector2D p1 = new((float)midX - 20f * (float)deltaMax, (float)midY - (float)deltaMax);
Vector2D p2 = new((float)midX, (float)midY + 20 * (float)deltaMax);
Vector2D p3 = new((float)midX + 20 * (float)deltaMax, (float)midY - (float)deltaMax);
return new Triangle(p1, p2, p3);
} }
public List<Line> Lines public static void GetLines(Shape shape, IList<Line> lines)
{
get
{
List<Line> lines = new List<Line>(Vertices.Count - 1);
GetLinesNonAlloc(lines);
return lines;
}
}
public void GetLinesNonAlloc(IList<Line> lines)
{ {
lines.Clear(); lines.Clear();
for (int i = 0; i < Vertices.Count - 1; i++) for (int i = 0; i < shape.Vertices.Count - 1; i++)
lines.Add(new(Vertices[i], Vertices[i + 1])); lines.Add(new(shape.Vertices[i], shape.Vertices[i + 1]));
lines.Add(new(Vertices[^1], Vertices[0])); lines.Add(new(shape.Vertices[^1], shape.Vertices[0]));
} }
public bool ApproximatelyEquals(Shape other) public static List<Line> GetLines(Shape shape)
{ {
if (Vertices.Count != other.Vertices.Count) List<Line> lines = new(shape.Vertices.Count - 1);
GetLines(shape, lines);
return lines;
}
public static bool ApproximatelyEquals(Shape left, Shape right)
{
if (left.Vertices.Count != right.Vertices.Count)
return false; return false;
for (int i = 0; i < Vertices.Count; i++) for (int i = 0; i < left.Vertices.Count; i++)
if (!Vertices[i].ApproximatelyEquals(other.Vertices[i])) if (!left.Vertices[i].ApproximatelyEquals(right.Vertices[i]))
return false; return false;
return true; return true;
} }
} }
public static class ShapeExtensions
{
public static Triangle ToSuperTriangle(this Shape shape) => Shape.GetSuperTriangle(shape);
public static void ToLines(this Shape shape, IList<Line> lines) => Shape.GetLines(shape, lines);
public static List<Line> ToLines(this Shape shape) => Shape.GetLines(shape);
public static bool ApproximatelyEquals(this Shape left, Shape right) => Shape.ApproximatelyEquals(left, right);
}

View File

@@ -6,49 +6,39 @@ namespace Syntriax.Engine.Physics2D.Primitives;
public record Triangle(Vector2D A, Vector2D B, Vector2D C) public record Triangle(Vector2D A, Vector2D B, Vector2D C)
{ {
public float Area => MathF.Abs(( public float Area
A.X * (B.Y - C.Y) + => .5f * MathF.Abs(
B.X * (C.Y - A.Y) + A.X * (B.Y - C.Y) +
C.X * (A.Y - B.Y) B.X * (C.Y - A.Y) +
) * .5f); C.X * (A.Y - B.Y)
);
public Circle CircumCircle public static Circle GetCircumCircle(Triangle triangle)
{ {
get Vector2D midAB = (triangle.A + triangle.B) / 2f;
Vector2D midBC = (triangle.B + triangle.C) / 2f;
float slopeAB = (triangle.B.Y - triangle.A.Y) / (triangle.B.X - triangle.A.X);
float slopeBC = (triangle.C.Y - triangle.B.Y) / (triangle.C.X - triangle.B.X);
Vector2D center;
if (MathF.Abs(slopeAB - slopeBC) > float.Epsilon)
{ {
Vector2D midAB = (A + B) / 2; float x = (slopeAB * slopeBC * (triangle.A.Y - triangle.C.Y) + slopeBC * (triangle.A.X + triangle.B.X) - slopeAB * (triangle.B.X + triangle.C.X)) / (2f * (slopeBC - slopeAB));
Vector2D midBC = (B + C) / 2; float y = -(x - (triangle.A.X + triangle.B.X) / 2f) / slopeAB + (triangle.A.Y + triangle.B.Y) / 2f;
center = new Vector2D(x, y);
float slopeAB = (B.Y - A.Y) / (B.X - A.X);
float slopeBC = (C.Y - B.Y) / (C.X - B.X);
Vector2D center;
if (MathF.Abs(slopeAB - slopeBC) > float.Epsilon)
{
float x = (slopeAB * slopeBC * (A.Y - C.Y) + slopeBC * (A.X + B.X) - slopeAB * (B.X + C.X)) / (2 * (slopeBC - slopeAB));
float y = -(x - (A.X + B.X) / 2) / slopeAB + (A.Y + B.Y) / 2;
center = new Vector2D(x, y);
}
else
center = (midAB + midBC) * .5f;
return new(center, Vector2D.Distance(center, A));
} }
else
center = (midAB + midBC) * .5f;
return new(center, Vector2D.Distance(center, triangle.A));
} }
public bool Overlaps(Vector2D point) public static bool ApproximatelyEquals(Triangle left, Triangle right)
{ => left.A.ApproximatelyEquals(right.A) && left.B.ApproximatelyEquals(right.B) && left.C.ApproximatelyEquals(right.C);
float originalTriangleArea = Area; }
float pointTriangleArea1 = new Triangle(point, B, C).Area; public static class TriangleExtensions
float pointTriangleArea2 = new Triangle(A, point, C).Area; {
float pointTriangleArea3 = new Triangle(A, B, point).Area; public static bool ApproximatelyEquals(this Triangle left, Triangle right) => Triangle.ApproximatelyEquals(left, right);
float pointTriangleAreasSum = pointTriangleArea1 + pointTriangleArea2 + pointTriangleArea3;
return originalTriangleArea.ApproximatelyEquals(pointTriangleAreasSum, float.Epsilon * 3f);
}
public bool ApproximatelyEquals(Triangle other)
=> A.ApproximatelyEquals(other.A) && B.ApproximatelyEquals(other.B) && C.ApproximatelyEquals(other.C);
} }