math: zig fmt
Signed-off-by: Stephen Gutekanst <stephen@hexops.com>
This commit is contained in:
Stephen Gutekanst
parent
12e69752d3
commit
dc5c1f69a6
1 changed files with 123 additions and 169 deletions
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@ -1,9 +1,9 @@
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//! # Collision detection
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//! # Collision detection
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//!
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//! This module provides functions to check for collision between various 2D shape.
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//! This module provides functions to check for collision between various 2D shape.
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//! It also provides functions to determine the contact points of two objects that have collided.
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//! The contact information can be used to resolve the collision.
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//!
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//! The contact information can be used to resolve the collision.
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//!
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const std = @import("std");
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const math = @import("main.zig");
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const testing = @import("../testing.zig");
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@ -11,12 +11,12 @@ const Vec2 = math.Vec2;
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const vec2 = math.vec2;
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/// An axis aligned rectangle.
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///
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///
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/// The boundary of the rectangle is considered inside.
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pub const Rectangle = struct {
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/// Bottom left of the rectangle.
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pos: Vec2,
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/// The size of the rectangle along the x and y axis.
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/// The size of the rectangle along the x and y axis.
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size: Vec2,
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/// Returns true of the two rectangles collide.
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@ -72,27 +72,26 @@ pub const Rectangle = struct {
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b.pos = vec2(5.0, 5.0);
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const r2 = a.collisionRect(b);
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try testing.expect(?Rectangle, r2).eql(null);
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}
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}
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/// Returns vertices for the Rectangle in CCW order.
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pub fn vertices(self: Rectangle) [4]Vec2 {
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return [_]Vec2{
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self.pos,
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self.pos.add(&vec2(self.size.x(), 0.0)),
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self.pos.add(&vec2(self.size.x(), self.size.y())),
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self.pos.add(&vec2(0.0, self.size.y())),
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self.pos,
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self.pos.add(&vec2(self.size.x(), 0.0)),
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self.pos.add(&vec2(self.size.x(), self.size.y())),
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self.pos.add(&vec2(0.0, self.size.y())),
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};
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}
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test vertices {
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const rect = Rectangle{.pos = vec2(0.0, 0.0), .size = vec2(1.0, 1.0)};
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const rect = Rectangle{ .pos = vec2(0.0, 0.0), .size = vec2(1.0, 1.0) };
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const v = rect.vertices();
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try testing.expect(Vec2, vec2(0.0, 0.0)).eql(v[0]);
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try testing.expect(Vec2, vec2(1.0, 0.0)).eql(v[1]);
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try testing.expect(Vec2, vec2(1.0, 1.0)).eql(v[2]);
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try testing.expect(Vec2, vec2(0.0, 1.0)).eql(v[3]);
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}
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};
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// A circle shape defined by position and radius.
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@ -169,16 +168,16 @@ pub const Point = struct {
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test collidesRect {
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const a: Point = .{ .pos = vec2(6, 4) };
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const c = Point{.pos = vec2(6.0, 3.0)};
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const c = Point{ .pos = vec2(6.0, 3.0) };
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var b: Rectangle = .{ .pos = vec2(6, 3), .size = vec2(3, 2) };
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try testing.expect(bool, a.collidesRect(b)).eql(true);
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try testing.expect(bool, a.collidesRect(b)).eql(true);
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try testing.expect(bool, c.collidesRect(b)).eql(true);
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b.pos = vec2(9.1, 4);
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try testing.expect(bool, a.collidesRect(b)).eql(false);
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const p = Point{ .pos = vec2(0.0, 0.0) };
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const r = Rectangle{.pos = vec2(0.0, 0.0), .size = vec2(1.0, 1.0)};
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const r = Rectangle{ .pos = vec2(0.0, 0.0), .size = vec2(1.0, 1.0) };
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try testing.expect(bool, p.collidesRect(r)).eql(true);
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}
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@ -199,8 +198,8 @@ pub const Point = struct {
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try testing.expect(bool, a.collidesCircle(b)).eql(false);
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}
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// Returns true if point is inside polygon.
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// The boundary of the polygon is outside.
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// Returns true if point is inside polygon.
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// The boundary of the polygon is outside.
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// A polygon is specified by a list of the polygon vertices in counter clockwise order.
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pub fn collidesPoly(point: Point, vertices: []const Vec2) bool {
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std.debug.assert(vertices.len > 2);
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@ -225,22 +224,22 @@ pub const Point = struct {
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}
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test collidesPoly {
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const poly = [_]Vec2 {
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vec2(-1.0, -1.0),
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vec2(1.0, -1.0),
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vec2(1.0, 1.0),
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vec2(-1.0, 1.0),
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const poly = [_]Vec2{
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vec2(-1.0, -1.0),
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vec2(1.0, -1.0),
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vec2(1.0, 1.0),
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vec2(-1.0, 1.0),
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};
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try testing.expect(bool, Point.collidesPoly(Point{.pos = vec2(0.0, 0.0)}, &poly)).eql(true);
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try testing.expect(bool, Point.collidesPoly(Point{ .pos = vec2(0.0, 0.0) }, &poly)).eql(true);
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// TODO: decide if boundary is inside or not
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//try testing.expect(bool, Point.collidesPoly(Point{.pos = vec2(1.0, 1.0)}, &poly)).eql(true);
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try testing.expect(bool, Point.collidesPoly(Point{.pos = vec2(2.0, 2.0)}, &poly)).eql(false);
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try testing.expect(bool, Point.collidesPoly(Point{.pos = vec2(-2.0, 2.0)}, &poly)).eql(false);
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try testing.expect(bool, Point.collidesPoly(Point{ .pos = vec2(2.0, 2.0) }, &poly)).eql(false);
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try testing.expect(bool, Point.collidesPoly(Point{ .pos = vec2(-2.0, 2.0) }, &poly)).eql(false);
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}
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/// Returns true if point is inside triangle.
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/// The boundary of the triangle is outside.
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/// The boundary of the triangle is outside.
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/// A triangle is specified by the triangle vertices in counter clockwise order.
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pub fn collidesTriangle(point: Point, vertices: []const Vec2) bool {
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std.debug.assert(vertices.len == 3);
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@ -259,23 +258,23 @@ pub const Point = struct {
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return (alpha > 0) and (beta > 0) and (gamma > 0);
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}
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test collidesTriangle {
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const triangle = [_]Vec2 {
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vec2(-1.0, -1.0),
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vec2(1.0, -1.0),
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vec2(0.0, 1.0),
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const triangle = [_]Vec2{
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vec2(-1.0, -1.0),
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vec2(1.0, -1.0),
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vec2(0.0, 1.0),
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};
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try testing.expect(bool, Point.collidesPoly(Point{.pos = vec2(0.0, 0.0)}, &triangle)).eql(true);
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try testing.expect(bool, Point.collidesPoly(Point{ .pos = vec2(0.0, 0.0) }, &triangle)).eql(true);
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// TODO: decide if boundary is inside or not
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//try testing.expect(bool, Point.collidesPoly(Point{.pos = vec2(0.0, 1.0)}, &triangle)).eql(true);
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try testing.expect(bool, Point.collidesPoly(Point{.pos = vec2(2.0, 2.0)}, &triangle)).eql(false);
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try testing.expect(bool, Point.collidesPoly(Point{.pos = vec2(-2.0, 2.0)}, &triangle)).eql(false);
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try testing.expect(bool, Point.collidesPoly(Point{ .pos = vec2(2.0, 2.0) }, &triangle)).eql(false);
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try testing.expect(bool, Point.collidesPoly(Point{ .pos = vec2(-2.0, 2.0) }, &triangle)).eql(false);
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// TODO: decide if boundary is inside or not
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// const t = [_]Vec2 {
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// vec2(0.0, 0.0),
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// vec2(1.0, 0.0),
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// vec2(1.0, 1.0),
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// vec2(0.0, 0.0),
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// vec2(1.0, 0.0),
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// vec2(1.0, 1.0),
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// };
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// const p = Point{ .pos = vec2(0.0, 0.0) };
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// try testing.expect(bool, p.collidesTriangle(&t)).eql(true);
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@ -314,13 +313,12 @@ pub const Point = struct {
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.end = vec2(1.0, 1.0),
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.threshold = 0.1,
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};
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try testing.expect(bool, Point.collidesLine(Point{.pos = vec2(0.0, 0.0)}, l)).eql(true);
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try testing.expect(bool, Point.collidesLine(Point{ .pos = vec2(0.0, 0.0) }, l)).eql(true);
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// TODO: decide if boundary is inside or not
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//try testing.expect(bool, Point.collidesLine(Point{.pos = vec2(0.0, 0.1)}, l)).eql(true);
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try testing.expect(bool, Point.collidesLine(Point{.pos = vec2(0.0, 0.09)}, l)).eql(true);
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try testing.expect(bool, Point.collidesLine(Point{.pos = vec2(0.0, 1.0)}, l)).eql(false);
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try testing.expect(bool, Point.collidesLine(Point{ .pos = vec2(0.0, 0.09) }, l)).eql(true);
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try testing.expect(bool, Point.collidesLine(Point{ .pos = vec2(0.0, 1.0) }, l)).eql(false);
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}
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};
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/// A line specified by a start and endpoint and a threshold for the line thickness.
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@ -329,7 +327,7 @@ pub const Line = struct {
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end: Vec2,
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threshold: f32,
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/// Return true if line and b intersect.
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/// Return true if line and b intersect.
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/// This function does not take into account the line treshold.
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pub fn collidesLine(a: Line, b: Line) bool {
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const start_dist = a.start.sub(&b.start);
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@ -344,39 +342,32 @@ pub const Line = struct {
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}
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test collidesLine {
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const l0 = Line{.start = vec2(-1.0, -1.0), .end = vec2(1.0, 1.0), .threshold = 0.0};
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try testing.expect(bool, true).eql(
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l0.collidesLine(Line{.start = vec2(-1.0, 1.0), .end = vec2(1.0, -1.0), .threshold=0.0}));
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try testing.expect(bool, true).eql(
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l0.collidesLine(Line{.start = vec2(-10.0, 0.0), .end = vec2(10.0, 0.0), .threshold=0.0}));
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try testing.expect(bool, true).eql(
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l0.collidesLine(Line{.start = vec2(-10.0, 1.0), .end = vec2(10.0, 1.0), .threshold=0.0}));
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try testing.expect(bool, true).eql(
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l0.collidesLine(Line{.start = vec2(-10.0, -1.0), .end = vec2(10.0, -1.0), .threshold=0.0}));
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const l0 = Line{ .start = vec2(-1.0, -1.0), .end = vec2(1.0, 1.0), .threshold = 0.0 };
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try testing.expect(bool, true).eql(l0.collidesLine(Line{ .start = vec2(-1.0, 1.0), .end = vec2(1.0, -1.0), .threshold = 0.0 }));
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try testing.expect(bool, true).eql(l0.collidesLine(Line{ .start = vec2(-10.0, 0.0), .end = vec2(10.0, 0.0), .threshold = 0.0 }));
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try testing.expect(bool, true).eql(l0.collidesLine(Line{ .start = vec2(-10.0, 1.0), .end = vec2(10.0, 1.0), .threshold = 0.0 }));
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try testing.expect(bool, true).eql(l0.collidesLine(Line{ .start = vec2(-10.0, -1.0), .end = vec2(10.0, -1.0), .threshold = 0.0 }));
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// TODO: fails if same line
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//try testing.expect(bool, true).eql(
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// l0.collidesLine(l0));
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try testing.expect(bool, false).eql(
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l0.collidesLine(Line{.start = vec2(-1.1, -1.1), .end = vec2(1.1, 1.1), .threshold=0.0}));
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try testing.expect(bool, false).eql(
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l0.collidesLine(Line{.start = vec2(-10.0, 2.0), .end = vec2(10.0, 2.0), .threshold=0.0}));
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try testing.expect(bool, false).eql(l0.collidesLine(Line{ .start = vec2(-1.1, -1.1), .end = vec2(1.1, 1.1), .threshold = 0.0 }));
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try testing.expect(bool, false).eql(l0.collidesLine(Line{ .start = vec2(-10.0, 2.0), .end = vec2(10.0, 2.0), .threshold = 0.0 }));
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}
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};
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/// Contains the contact information between two convex 2D shapes.
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/// There can be up to two contacts point in case the objects collide
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/// on a paralell line.
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///
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///
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/// The normal points from A to B, so the objects can be separated by moving
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/// B by the vector depth x normal
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///
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///
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pub const Contact = struct {
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/// The contact normal from A to B
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normal: Vec2,
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/// Depth of the peneration.
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/// Depth of the peneration.
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depth: f32,
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/// Contact point 1 on obj A
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cp1: ?Vec2 = null,
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@ -384,7 +375,7 @@ pub const Contact = struct {
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cp2: ?Vec2 = null,
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};
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/// Compute the minimum and maximum projection of vertices in v on the line through v0 with normal n
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/// Compute the minimum and maximum projection of vertices in v on the line through v0 with normal n
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pub fn minmaxProjectionDistance(n: Vec2, v0: Vec2, v: []const Vec2) [2]f32 {
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var max_d = n.dot(&v[0].sub(&v0));
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var min_d = n.dot(&v[0].sub(&v0));
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@ -396,20 +387,14 @@ pub fn minmaxProjectionDistance(n: Vec2, v0: Vec2, v: []const Vec2) [2]f32 {
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max_d = d;
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}
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}
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return [2]f32{min_d, max_d};
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return [2]f32{ min_d, max_d };
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}
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test minmaxProjectionDistance {
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const n_up = vec2(0.0, 1.0);
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const n_right = vec2(1.0, 0.0);
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const v0 = vec2(0.0, 0.0);
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const v = [_]Vec2{
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vec2(2.0, 0.0),
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vec2(1.0, 1.0),
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vec2(0.0, -2.0),
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vec2(-1.0, 2.0),
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vec2(-2.0, 1.0)
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};
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const v = [_]Vec2{ vec2(2.0, 0.0), vec2(1.0, 1.0), vec2(0.0, -2.0), vec2(-1.0, 2.0), vec2(-2.0, 1.0) };
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{
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const minmax = minmaxProjectionDistance(n_up, v0, &v);
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@ -422,22 +407,18 @@ test minmaxProjectionDistance {
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try testing.expect(f32, -2.0).eql(minmax[0]);
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try testing.expect(f32, 2.0).eql(minmax[1]);
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}
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}
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const VertexDepthResult = struct {
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v0: Vec2 = undefined,
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v0: Vec2 = undefined,
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v1: ?Vec2 = null,
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/// Depth of vertex. Positive in the opposite direction of the normal.
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d: f32
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d: f32,
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};
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/// Find the vertex in v that is deepest behind the line defined by the point v0 and normal n.
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pub fn findDeepestVertex(n: Vec2, v0: Vec2, v: []const Vec2) VertexDepthResult {
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var min_depth = VertexDepthResult{
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.v0 = v[0],
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.d = n.dot(&v[0].sub(&v0))
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};
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var min_depth = VertexDepthResult{ .v0 = v[0], .d = n.dot(&v[0].sub(&v0)) };
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for (v[1..]) |vb| {
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const d = n.dot(&vb.sub(&v0));
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if (d < min_depth.d) {
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@ -459,33 +440,33 @@ test findDeepestVertex {
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// Test finding a single deepest vertex
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{
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const v = [_]Vec2{
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vec2(2.0, 0.0),
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vec2(2.0, 0.0),
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vec2(1.0, 1.0),
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vec2(0.0, -2.0), // Deepest
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vec2(-1.0, 2.0),
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vec2(-2.0, 1.0)
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vec2(-2.0, 1.0),
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};
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const depth = findDeepestVertex(n_up, v0, &v);
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try testing.expect(Vec2, vec2(0.0, -2.0)).eql(depth.v0);
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try testing.expect(?Vec2, null).eql(depth.v1);
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try testing.expect(f32, 2.0).eql(depth.d);
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}
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}
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// Test finding two deepest vertices
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{
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const v = [_]Vec2{
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vec2(2.0, 0.0),
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vec2(2.0, 0.0),
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vec2(1.0, 1.0),
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vec2(0.0, -3.0), // Deepest
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vec2(-1.0, -3.0), // Deepest
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vec2(-2.0, 1.0)
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vec2(0.0, -3.0), // Deepest
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vec2(-1.0, -3.0), // Deepest
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vec2(-2.0, 1.0),
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};
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const depth = findDeepestVertex(n_up, v0, &v);
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try testing.expect(Vec2, vec2(0.0, -3.0)).eql(depth.v0);
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try testing.expect(Vec2, vec2(-1.0, -3.0)).eql(depth.v1.?);
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try testing.expect(f32, 3.0).eql(depth.d);
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}
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}
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// No vertex behind edge - will return closest vertex instead
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{
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@ -493,38 +474,37 @@ test findDeepestVertex {
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vec2(2.0, 0.5), // Closest
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vec2(1.0, 1.0),
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vec2(0.0, 3.0),
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vec2(-2.0, 1.0)
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vec2(-2.0, 1.0),
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};
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const depth = findDeepestVertex(n_up, v0, &v);
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try testing.expect(Vec2, vec2(2.0, 0.5)).eql(depth.v0);
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try testing.expect(?Vec2, null).eql(depth.v1);
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try testing.expect(f32, -0.5).eql(depth.d);
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}
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}
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}
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/// Contains information to separate two colliding shapes.
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const SeparationResult = struct {
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// i0: usize = undefined, // Vertex idx
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// i1: ?usize = null,
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v0: Vec2 = undefined,
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// i0: usize = undefined, // Vertex idx
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// i1: ?usize = null,
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v0: Vec2 = undefined,
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v1: ?Vec2 = null,
|
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e: usize = undefined, // Edge idx
|
||||
n: Vec2 = undefined, // Edge normal
|
||||
d: f32 = std.math.floatMax(f32), // Depth
|
||||
e: usize = undefined, // Edge idx
|
||||
n: Vec2 = undefined, // Edge normal
|
||||
d: f32 = std.math.floatMax(f32), // Depth
|
||||
};
|
||||
|
||||
/// Find the edge and vertices for the minimum separation required to
|
||||
/// Find the edge and vertices for the minimum separation required to
|
||||
/// separate vertices in polygon_a from edge in polygon_b.
|
||||
/// Returns null if a separting axis is found.
|
||||
pub fn findMinSeparation(polygon_a: []const Vec2, polygon_b: []const Vec2) ?SeparationResult {
|
||||
var min_result = SeparationResult{};
|
||||
|
||||
var v0 = polygon_b[polygon_b.len-1];
|
||||
var v0 = polygon_b[polygon_b.len - 1];
|
||||
for (polygon_b[0..], 0..) |v1, i| {
|
||||
const edge = v1.sub(&v0);
|
||||
const n = vec2(edge.y(), -edge.x()).normalize(0.0);
|
||||
const n = vec2(edge.y(), -edge.x()).normalize(0.0);
|
||||
const min_depth = findDeepestVertex(n, v0, polygon_a);
|
||||
v0 = v1;
|
||||
if (min_depth.d < 0.0) {
|
||||
|
|
@ -547,19 +527,19 @@ pub fn findMinSeparation(polygon_a: []const Vec2, polygon_b: []const Vec2) ?Sepa
|
|||
|
||||
test findMinSeparation {
|
||||
const triangle_0 = [_]Vec2{
|
||||
vec2(-1.0, -1.0),
|
||||
vec2(-1.0, -1.0),
|
||||
vec2(1.0, -1.0),
|
||||
vec2(0.0, 1.0),
|
||||
vec2(0.0, 1.0),
|
||||
};
|
||||
const triangle_1 = [_]Vec2{
|
||||
vec2(-1.0, -2.75),
|
||||
vec2(-1.0, -2.75),
|
||||
vec2(1.0, -2.75),
|
||||
vec2(0.0, -0.75),
|
||||
vec2(0.0, -0.75),
|
||||
};
|
||||
const triangle_2 = [_]Vec2{
|
||||
vec2(-1.0, -2.75),
|
||||
vec2(-1.0, -2.75),
|
||||
vec2(1.0, -2.75),
|
||||
vec2(0.0, -1.75),
|
||||
vec2(0.0, -1.75),
|
||||
};
|
||||
|
||||
// Top point of triangle_1 intersects with first edge of triangle_0 at depth 0.25
|
||||
|
|
@ -571,10 +551,7 @@ test findMinSeparation {
|
|||
try testing.expect(f32, 0.25).eql(result.?.d);
|
||||
|
||||
// Not colliding - bottom edge of triangle_0 separates the two
|
||||
try testing.expect(?SeparationResult, null).eql(
|
||||
findMinSeparation(&triangle_2, &triangle_0)
|
||||
);
|
||||
|
||||
try testing.expect(?SeparationResult, null).eql(findMinSeparation(&triangle_2, &triangle_0));
|
||||
}
|
||||
|
||||
/// Compute a Contact report between polygon_a and polygon_b if they are colliding.
|
||||
|
|
@ -590,21 +567,21 @@ pub fn polygonPolygonContact(polygon_a: []const Vec2, polygon_b: []const Vec2) ?
|
|||
if (min_separation_a.d < min_separation_b.d) {
|
||||
// Vertex in a passes an edge in b
|
||||
depth = min_separation_a.d;
|
||||
normal = min_separation_a.n.mulScalar(-1.0);
|
||||
normal = min_separation_a.n.mulScalar(-1.0);
|
||||
cp1_a = min_separation_a.v0;
|
||||
cp2_a = min_separation_a.v1;
|
||||
} else if (min_separation_a.d > min_separation_b.d) {
|
||||
// Vertex in b passes an edge in a
|
||||
depth = min_separation_b.d;
|
||||
normal = min_separation_b.n;
|
||||
normal = min_separation_b.n;
|
||||
cp1_a = min_separation_b.v0.add(&normal.mulScalar(depth));
|
||||
if (min_separation_b.v1) |v1| {
|
||||
cp2_a = v1.add(&normal.mulScalar(depth));
|
||||
}
|
||||
} else {
|
||||
cp2_a = v1.add(&normal.mulScalar(depth));
|
||||
}
|
||||
} else {
|
||||
// Two edges
|
||||
depth = min_separation_a.d;
|
||||
normal = min_separation_a.n.mulScalar(-1.0);
|
||||
normal = min_separation_a.n.mulScalar(-1.0);
|
||||
if (@abs(normal.dot(&min_separation_b.n)) != 1.0 or min_separation_a.v1 == null or min_separation_b.v1 == null) {
|
||||
// Edges are not paralell
|
||||
cp1_a = min_separation_b.v0;
|
||||
|
|
@ -612,20 +589,16 @@ pub fn polygonPolygonContact(polygon_a: []const Vec2, polygon_b: []const Vec2) ?
|
|||
} else {
|
||||
// Paralell edges - find two contact points
|
||||
const edge = vec2(min_separation_a.n.y(), -min_separation_a.n.x());
|
||||
const vertices = [_]Vec2{
|
||||
min_separation_a.v0,
|
||||
min_separation_a.v1.?,
|
||||
min_separation_b.v0,
|
||||
min_separation_b.v1.?};
|
||||
const from_a = [4]bool {true, true, false, false};
|
||||
const vertices = [_]Vec2{ min_separation_a.v0, min_separation_a.v1.?, min_separation_b.v0, min_separation_b.v1.? };
|
||||
const from_a = [4]bool{ true, true, false, false };
|
||||
var distances: [4]f32 = undefined;
|
||||
for (vertices, &distances) |v, *d| {
|
||||
d.* = edge.dot(&v);
|
||||
}
|
||||
// Sort vertices along the edge
|
||||
var idx = [_]u8{0,1,2,3};
|
||||
var idx = [_]u8{ 0, 1, 2, 3 };
|
||||
for (0..3) |i| {
|
||||
for (i+1..4) |j| {
|
||||
for (i + 1..4) |j| {
|
||||
if (distances[idx[i]] > distances[idx[j]]) {
|
||||
const t = idx[i];
|
||||
idx[i] = idx[j];
|
||||
|
|
@ -635,11 +608,9 @@ pub fn polygonPolygonContact(polygon_a: []const Vec2, polygon_b: []const Vec2) ?
|
|||
}
|
||||
|
||||
depth = min_separation_a.d;
|
||||
normal = min_separation_a.n.mulScalar(-1.0);
|
||||
cp1_a = if (from_a[idx[1]]) vertices[idx[1]]
|
||||
else vertices[idx[1]].add(&normal.mulScalar(depth));
|
||||
cp2_a = if (from_a[idx[2]]) vertices[idx[2]]
|
||||
else vertices[idx[2]].add(&normal.mulScalar(depth));
|
||||
normal = min_separation_a.n.mulScalar(-1.0);
|
||||
cp1_a = if (from_a[idx[1]]) vertices[idx[1]] else vertices[idx[1]].add(&normal.mulScalar(depth));
|
||||
cp2_a = if (from_a[idx[2]]) vertices[idx[2]] else vertices[idx[2]].add(&normal.mulScalar(depth));
|
||||
}
|
||||
}
|
||||
|
||||
|
|
@ -653,19 +624,19 @@ pub fn polygonPolygonContact(polygon_a: []const Vec2, polygon_b: []const Vec2) ?
|
|||
|
||||
test polygonPolygonContact {
|
||||
const triangle_0 = [_]Vec2{
|
||||
vec2(-1.0, -1.0),
|
||||
vec2(-1.0, -1.0),
|
||||
vec2(1.0, -1.0),
|
||||
vec2(0.0, 1.0),
|
||||
vec2(0.0, 1.0),
|
||||
};
|
||||
const triangle_1 = [_]Vec2{
|
||||
vec2(-1.0, -2.75),
|
||||
vec2(-1.0, -2.75),
|
||||
vec2(1.0, -2.75),
|
||||
vec2(0.0, -0.75),
|
||||
vec2(0.0, -0.75),
|
||||
};
|
||||
const triangle_2 = [_]Vec2{
|
||||
vec2(-1.0, -2.75),
|
||||
vec2(-1.0, -2.75),
|
||||
vec2(1.0, -2.75),
|
||||
vec2(0.0, -1.75),
|
||||
vec2(0.0, -1.75),
|
||||
};
|
||||
|
||||
if (polygonPolygonContact(&triangle_0, &triangle_1)) |contact_0_1| {
|
||||
|
|
@ -689,10 +660,10 @@ test polygonPolygonContact {
|
|||
try testing.expect(?Contact, null).eql(polygonPolygonContact(&triangle_0, &triangle_2));
|
||||
try testing.expect(?Contact, null).eql(polygonPolygonContact(&triangle_2, &triangle_0));
|
||||
|
||||
const rect1 = Rectangle{.pos = vec2(-1.0, -1.0), .size = vec2(2.0, 2.0)};
|
||||
const rect2 = Rectangle{.pos = vec2(-1.5, -2.25), .size = vec2(1.0, 1.5)};
|
||||
const rect3 = Rectangle{.pos = vec2(-0.5, -2.25), .size = vec2(1.0, 1.5)};
|
||||
const rect4 = Rectangle{.pos = vec2( 0.5, -2.25), .size = vec2(1.0, 1.5)};
|
||||
const rect1 = Rectangle{ .pos = vec2(-1.0, -1.0), .size = vec2(2.0, 2.0) };
|
||||
const rect2 = Rectangle{ .pos = vec2(-1.5, -2.25), .size = vec2(1.0, 1.5) };
|
||||
const rect3 = Rectangle{ .pos = vec2(-0.5, -2.25), .size = vec2(1.0, 1.5) };
|
||||
const rect4 = Rectangle{ .pos = vec2(0.5, -2.25), .size = vec2(1.0, 1.5) };
|
||||
const r1 = rect1.vertices();
|
||||
const r2 = rect2.vertices();
|
||||
const r3 = rect3.vertices();
|
||||
|
|
@ -729,16 +700,8 @@ pub fn circlePolygonContact(circle_a: Circle, polygon_b: []const Vec2) ?Contact
|
|||
var depth: f32 = 0.0;
|
||||
var cp1_a: ?Vec2 = null;
|
||||
|
||||
var v0 = polygon_b[polygon_b.len-1];
|
||||
var min_result = struct {
|
||||
n: Vec2,
|
||||
d: f32,
|
||||
i: usize
|
||||
}{
|
||||
.n = vec2(0.0, 0.0),
|
||||
.d = std.math.floatMax(f32),
|
||||
.i = undefined
|
||||
};
|
||||
var v0 = polygon_b[polygon_b.len - 1];
|
||||
var min_result = struct { n: Vec2, d: f32, i: usize }{ .n = vec2(0.0, 0.0), .d = std.math.floatMax(f32), .i = undefined };
|
||||
var closest_vertex = struct {
|
||||
v: Vec2 = undefined,
|
||||
d: f32 = std.math.floatMax(f32),
|
||||
|
|
@ -747,7 +710,7 @@ pub fn circlePolygonContact(circle_a: Circle, polygon_b: []const Vec2) ?Contact
|
|||
|
||||
for (polygon_b[0..], 0..) |v1, i| {
|
||||
const edge = v1.sub(&v0);
|
||||
const n = vec2(edge.y(), -edge.x()).normalize(0.0);
|
||||
const n = vec2(edge.y(), -edge.x()).normalize(0.0);
|
||||
const vc = circle_a.pos.sub(&v0);
|
||||
const d = vc.dot(&n);
|
||||
if (vc.len() < closest_vertex.d) {
|
||||
|
|
@ -773,13 +736,13 @@ pub fn circlePolygonContact(circle_a: Circle, polygon_b: []const Vec2) ?Contact
|
|||
// Check circle to closest point axis
|
||||
{
|
||||
v0 = closest_vertex.v;
|
||||
const n = circle_a.pos.sub(&v0).normalize(0.0);
|
||||
const minmax_b = minmaxProjectionDistance(n, v0, polygon_b);
|
||||
|
||||
const n = circle_a.pos.sub(&v0).normalize(0.0);
|
||||
const minmax_b = minmaxProjectionDistance(n, v0, polygon_b);
|
||||
|
||||
// Circle projects to +- radius
|
||||
const vc = circle_a.pos.sub(&v0);
|
||||
const d = vc.dot(&n);
|
||||
const minmax_a = [2]f32{d - circle_a.radius, d + circle_a.radius};
|
||||
const minmax_a = [2]f32{ d - circle_a.radius, d + circle_a.radius };
|
||||
|
||||
if ((minmax_a[0] > minmax_b[1]) or (minmax_a[1] < minmax_b[0])) {
|
||||
// Circle does not intersect
|
||||
|
|
@ -794,8 +757,8 @@ pub fn circlePolygonContact(circle_a: Circle, polygon_b: []const Vec2) ?Contact
|
|||
}
|
||||
|
||||
depth = -min_result.d;
|
||||
normal = min_result.n.mulScalar(-1.0);
|
||||
cp1_a = circle_a.pos.add(&normal.mulScalar(circle_a.radius));
|
||||
normal = min_result.n.mulScalar(-1.0);
|
||||
cp1_a = circle_a.pos.add(&normal.mulScalar(circle_a.radius));
|
||||
|
||||
return Contact{
|
||||
.normal = normal,
|
||||
|
|
@ -805,9 +768,9 @@ pub fn circlePolygonContact(circle_a: Circle, polygon_b: []const Vec2) ?Contact
|
|||
}
|
||||
|
||||
test circlePolygonContact {
|
||||
const rect1 = Rectangle{.pos = vec2(0.75, -1.0), .size = vec2(2.0, 2.0)};
|
||||
const rect1 = Rectangle{ .pos = vec2(0.75, -1.0), .size = vec2(2.0, 2.0) };
|
||||
const r1 = rect1.vertices();
|
||||
if (circlePolygonContact(Circle{.pos=vec2(0.0, 0.0), .radius = 1.0}, &r1)) |contact| {
|
||||
if (circlePolygonContact(Circle{ .pos = vec2(0.0, 0.0), .radius = 1.0 }, &r1)) |contact| {
|
||||
try testing.expect(Vec2, vec2(1.0, 0.0)).eql(contact.normal);
|
||||
try testing.expect(f32, 0.25).eql(contact.depth);
|
||||
try testing.expect(Vec2, vec2(1.0, 0.0)).eql(contact.cp1.?);
|
||||
|
|
@ -816,20 +779,18 @@ test circlePolygonContact {
|
|||
try testing.expect(bool, true).eql(false);
|
||||
}
|
||||
|
||||
try testing.expect(?Contact, null).eql(
|
||||
circlePolygonContact(Circle{.pos=vec2(-1.0, 0.0), .radius = 1.0}, &r1)
|
||||
);
|
||||
try testing.expect(?Contact, null).eql(circlePolygonContact(Circle{ .pos = vec2(-1.0, 0.0), .radius = 1.0 }, &r1));
|
||||
}
|
||||
|
||||
/// Compute a Contact report between two circles.
|
||||
pub fn circleCircleContact(circle_a: Circle, circle_b: Circle) ?Contact {
|
||||
const delta = circle_b.pos.sub(&circle_a.pos);
|
||||
const distance = delta.len();
|
||||
const depth = circle_a.radius + circle_b.radius - distance;
|
||||
const depth = circle_a.radius + circle_b.radius - distance;
|
||||
if (depth < 0.0) {
|
||||
return null;
|
||||
}
|
||||
// if distance is zero then all separation directions are equivalent. Pick arbitrary one.
|
||||
// if distance is zero then all separation directions are equivalent. Pick arbitrary one.
|
||||
const normal = if (distance > 0.0) delta.mulScalar(1.0 / distance) else vec2(1.0, 0.0);
|
||||
const cp1_a = circle_a.pos.add(&normal.mulScalar(circle_a.radius));
|
||||
|
||||
|
|
@ -841,9 +802,7 @@ pub fn circleCircleContact(circle_a: Circle, circle_b: Circle) ?Contact {
|
|||
}
|
||||
|
||||
test circleCircleContact {
|
||||
if (circleCircleContact(Circle{.pos=vec2(0.0, 0.0), .radius = 1.0},
|
||||
Circle{.pos = vec2(1.75, 0.0), .radius = 1.0})) |contact| {
|
||||
|
||||
if (circleCircleContact(Circle{ .pos = vec2(0.0, 0.0), .radius = 1.0 }, Circle{ .pos = vec2(1.75, 0.0), .radius = 1.0 })) |contact| {
|
||||
try testing.expect(Vec2, vec2(1.0, 0.0)).eql(contact.normal);
|
||||
try testing.expect(f32, 0.25).eql(contact.depth);
|
||||
try testing.expect(Vec2, vec2(1.0, 0.0)).eql(contact.cp1.?);
|
||||
|
|
@ -852,9 +811,7 @@ test circleCircleContact {
|
|||
try testing.expect(bool, true).eql(false);
|
||||
}
|
||||
|
||||
if (circleCircleContact(Circle{.pos=vec2(0.0, 0.0), .radius = 1.0},
|
||||
Circle{.pos = vec2(2.0, 0.0), .radius = 1.0})) |contact| {
|
||||
|
||||
if (circleCircleContact(Circle{ .pos = vec2(0.0, 0.0), .radius = 1.0 }, Circle{ .pos = vec2(2.0, 0.0), .radius = 1.0 })) |contact| {
|
||||
try testing.expect(Vec2, vec2(1.0, 0.0)).eql(contact.normal);
|
||||
try testing.expect(f32, 0.0).eql(contact.depth);
|
||||
try testing.expect(Vec2, vec2(1.0, 0.0)).eql(contact.cp1.?);
|
||||
|
|
@ -863,8 +820,5 @@ test circleCircleContact {
|
|||
try testing.expect(bool, true).eql(false);
|
||||
}
|
||||
|
||||
try testing.expect(?Contact, null).eql(
|
||||
circleCircleContact(Circle{.pos=vec2(0.0, 0.0), .radius = 1.0},
|
||||
Circle{.pos = vec2(2.01, 0.0), .radius = 1.0})
|
||||
);
|
||||
}
|
||||
try testing.expect(?Contact, null).eql(circleCircleContact(Circle{ .pos = vec2(0.0, 0.0), .radius = 1.0 }, Circle{ .pos = vec2(2.01, 0.0), .radius = 1.0 }));
|
||||
}
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue