From 286731aa626b44d4ea73d441ab7197a6b2b20f5d Mon Sep 17 00:00:00 2001
From: Jakub Sobon <jakub.sobon@elohim.sk>
Date: Mon, 21 Jan 2019 00:51:33 -0500
Subject: [PATCH] Moving some functions from numbers -> trig.

---
 numbers/numbers.go      | 29 ----------------------
 numbers/numbers_test.go | 53 -----------------------------------------
 2 files changed, 82 deletions(-)

diff --git a/numbers/numbers.go b/numbers/numbers.go
index ca28e0f..5aafbd1 100644
--- a/numbers/numbers.go
+++ b/numbers/numbers.go
@@ -16,7 +16,6 @@
 package numbers
 
 import (
-	"image"
 	"math"
 )
 
@@ -163,31 +162,3 @@ func RadiansToDegrees(radians float64) int {
 	}
 	return d
 }
-
-// CirclePointAtAngle given an angle in degrees and a circle midpoint and
-// radius, calculates coordinates of a point on the circle at that angle.
-// Angles are zero at the X axis and grow counter-clockwise.
-func CirclePointAtAngle(degrees int, mid image.Point, radius int) image.Point {
-	angle := DegreesToRadians(degrees)
-	r := float64(radius)
-	x := mid.X + int(Round(r*math.Cos(angle)))
-	// Y coordinates grow down on the canvas.
-	y := mid.Y - int(Round(r*math.Sin(angle)))
-	return image.Point{x, y}
-}
-
-// CircleAngleAtPoint given a point on a circle and its midpoint,
-// calculates the angle in degrees.
-// Angles are zero at the X axis and grow counter-clockwise.
-func CircleAngleAtPoint(point, mid image.Point) int {
-	adj := float64(point.X - mid.X)
-	opp := float64(mid.Y - point.Y)
-	if opp != 0 {
-		angle := math.Atan2(opp, adj)
-		return RadiansToDegrees(angle)
-	} else if adj >= 0 {
-		return 0
-	} else {
-		return 180
-	}
-}
diff --git a/numbers/numbers_test.go b/numbers/numbers_test.go
index 20c0574..ae9dbfe 100644
--- a/numbers/numbers_test.go
+++ b/numbers/numbers_test.go
@@ -16,7 +16,6 @@ package numbers
 
 import (
 	"fmt"
-	"image"
 	"math"
 	"testing"
 )
@@ -328,55 +327,3 @@ func TestRadiansToDegrees(t *testing.T) {
 		})
 	}
 }
-
-func TestCirclePointAtAngleAndAngle(t *testing.T) {
-	tests := []struct {
-		degrees int
-		mid     image.Point
-		radius  int
-		want    image.Point
-	}{
-		{0, image.Point{0, 0}, 1, image.Point{1, 0}},
-		{90, image.Point{0, 0}, 1, image.Point{0, -1}},
-		{180, image.Point{0, 0}, 1, image.Point{-1, 0}},
-		{270, image.Point{0, 0}, 1, image.Point{0, 1}},
-
-		// Non-zero mid point.
-		{0, image.Point{5, 5}, 1, image.Point{6, 5}},
-		{90, image.Point{5, 5}, 1, image.Point{5, 4}},
-		{180, image.Point{5, 5}, 1, image.Point{4, 5}},
-		{270, image.Point{5, 5}, 1, image.Point{5, 6}},
-		{0, image.Point{1, 1}, 1, image.Point{2, 1}},
-		{90, image.Point{1, 1}, 1, image.Point{1, 0}},
-		{180, image.Point{1, 1}, 1, image.Point{0, 1}},
-		{270, image.Point{1, 1}, 1, image.Point{1, 2}},
-
-		// Larger radius.
-		{0, image.Point{0, 0}, 11, image.Point{11, 0}},
-		{90, image.Point{0, 0}, 11, image.Point{0, -11}},
-		{180, image.Point{0, 0}, 11, image.Point{-11, 0}},
-		{270, image.Point{0, 0}, 11, image.Point{0, 11}},
-
-		// Other angles.
-		{27, image.Point{0, 0}, 11, image.Point{10, -5}},
-		{68, image.Point{0, 0}, 11, image.Point{4, -10}},
-		{333, image.Point{2, 2}, 2, image.Point{4, 3}},
-		{153, image.Point{2, 2}, 2, image.Point{0, 1}},
-	}
-
-	for _, tc := range tests {
-		t.Run(fmt.Sprintf("CirclePointAtAngle %v %v %v", tc.degrees, tc.mid, tc.radius), func(t *testing.T) {
-			got := CirclePointAtAngle(tc.degrees, tc.mid, tc.radius)
-			if got != tc.want {
-				t.Errorf("CirclePointAtAngle(%v, %v, %v) => %v, want %v", tc.degrees, tc.mid, tc.radius, got, tc.want)
-			}
-		})
-		t.Run(fmt.Sprintf("CircleAngleAtPoint %v %v", tc.want, tc.mid), func(t *testing.T) {
-			got := CircleAngleAtPoint(tc.want, tc.mid)
-			want := tc.degrees
-			if got != want {
-				t.Errorf("CircleAngleAtPoint(%v, %v) => %v, want %v", tc.want, tc.mid, got, want)
-			}
-		})
-	}
-}