triangle tests

CHANGELOG.md

@@ -1,11 +1,12 @@
 # Changelog
 
-## [v2.7.0] - January 2021 probably.
+## [v2.7.0] - January 7 2021
 
 ### Added
 
 - triangle functions
 - perpendicular() bisector
+- macros allow variables (thanks Mason!)
 
 ### Changed
 

src/point.jl

@@ -307,88 +307,23 @@ function ispointonline(pt::Point, pt1::Point, pt2::Point;
     end
 end
 
-# """
-#     intersection(p1::Point, p2::Point, p3::Point, p4::Point;
-#         commonendpoints = false,
-#         crossingonly = false,
-#         collinearintersect = false)
-#
-# Find intersection of two lines `p1`-`p2` and `p3`-`p4`
-#
-# Deprecated. Use `intersectionlines().`
-# """
-# function intersection(A::Point, B::Point, C::Point, D::Point;
-#         commonendpoints = false,
-#         crossingonly = false,
-#         collinearintersect = false
-#         )
-#     # false if either line is undefined
-#     if (A == B) || (C == D)
-#         return (false, Point(0, 0))
-#     end
-#
-#     # false if the lines share a common end point
-#     if commonendpoints
-#         if (A == C) || (B == C) || (A == D) || (B == D)
-#             return (false, Point(0, 0))
-#         end
-#     end
-#
-#     # Cramer's ?
-#     A1 = (A.y - B.y)
-#     B1 = (B.x - A.x)
-#     C1 = (A.x * B.y - B.x * A.y)
-#
-#     L1 = (A1, B1, -C1)
-#
-#     A2 = (C.y - D.y)
-#     B2 = (D.x - C.x)
-#     C2 = (C.x * D.y - D.x * C.y)
-#
-#     L2 = (A2, B2, -C2)
-#
-#     d  = L1[1] * L2[2] - L1[2] * L2[1]
-#     dx = L1[3] * L2[2] - L1[2] * L2[3]
-#     dy = L1[1] * L2[3] - L1[3] * L2[1]
-#
-#     # if you ask me collinear points don't really intersect
-#     if (C1 == C2) && (collinearintersect == false)
-#         return (false, Point(0, 0))
-#     end
-#
-#     if d != 0
-#         pt = Point(dx/d, dy/d)
-#         if crossingonly == true
-#             if ispointonline(pt, A, B) && ispointonline(pt, C, D)
-#                return (true, pt)
-#             else
-#                return (false, pt)
-#             end
-#         else
-#             if ispointonline(pt, A, B, extended=true) && ispointonline(pt, C, D, extended=true)
-#                 return (true, pt)
-#             else
-#                return (false, pt)
-#             end
-#         end
-#     else
-#         return (false, Point(0, 0))
-#     end
-# end
-
 """
     slope(pointA::Point, pointB::Point)
 
 Find angle of a line starting at `pointA` and ending at `pointB`.
 
 Return a value between 0 and 2pi. Value will be relative to the current axes.
 
-    slope(O, Point(0, 100)) |> rad2deg # y is positive down the page
-    90.0
+```
+slope(O, Point(0, 100)) |> rad2deg # y is positive down the page
+90.0
 
-    slope(Point(0, 100), O) |> rad2deg
-    270.0
+slope(Point(0, 100), O) |> rad2deg
+270.0
+```
 
+The slope isn't the same as the gradient. A vertical line going up has a
+slope of 3π/2.
 """
 function slope(pointA, pointB)
     return mod2pi(atan(pointB.y - pointA.y, pointB.x - pointA.x))

test/runtests.jl

@@ -154,6 +154,7 @@ function run_all_tests()
         include("boxmaptest.jl")
         include("noise-test.jl")
         include("dashtests.jl")
+        include("triangles.jl")
     end
 end
 

test/triangles.jl

@@ -0,0 +1,58 @@
+#!/usr/bin/env julia
+
+using Luxor
+
+using Test
+
+using Random
+Random.seed!(42)
+
+function triangle_tests(fname)
+    Drawing(800, 800, fname)
+    origin()
+    background("white")
+    fontsize(10)
+
+    panes = Tiler(500, 500, 1, 2)
+
+    @layer begin
+        translate(first(panes[1]))
+        # equilateral
+        tri1 = [polar(100, θ) for θ in (0, 2π/3, 4π/3)]
+        prettypoly(tri1, :stroke, close=true)
+
+        orthocenter = triangleorthocenter(tri1...)
+        incenter = triangleincenter(tri1...)
+        center = trianglecenter(tri1...)
+        circumcenter = trianglecircumcenter(tri1...)
+        circle.((orthocenter, incenter, center, circumcenter), 2, :fill)
+
+        # all centers are the same
+        @test isapprox(orthocenter, incenter)
+        @test isapprox(orthocenter, center)
+        @test isapprox(orthocenter, circumcenter)
+    end
+
+    @layer begin
+        translate(first(panes[2]))
+        # isosceles
+        tri2 = [Point(0, 0), Point(80, -80), Point(160, 0)]
+        prettypoly(tri2, :stroke, close=true)
+
+        orthocenter = triangleorthocenter(tri2...)
+        incenter = triangleincenter(tri2...)
+        center = trianglecenter(tri2...)
+        circumcenter = trianglecircumcenter(tri2...)
+        circle.((orthocenter, incenter, center, circumcenter), 2, :fill)
+
+        # all centers lie on the same vetical line
+        @test isapprox(orthocenter.x, incenter.x)
+        @test isapprox(orthocenter.x, center.x)
+        @test isapprox(orthocenter.x, circumcenter.x)
+    end
+
+    @test finish() == true
+    println("...finished test: output in $(fname)")
+end
+
+triangle_tests("triangle-tests.svg")