Creating a common numbers.Abs function for code reuse.

area/area.go

@@ -18,6 +18,8 @@ package area
 import (
 	"fmt"
 	"image"
+
+	"github.com/mum4k/termdash/numbers"
 )
 
 // Size returns the size of the provided area.
@@ -76,14 +78,6 @@ func VSplit(area image.Rectangle, widthPerc int) (left image.Rectangle, right im
 	return left, right, nil
 }
 
-// abs returns the absolute value of x.
-func abs(x int) int {
-	if x < 0 {
-		return -x
-	}
-	return x
-}
-
 // ExcludeBorder returns a new area created by subtracting a border around the
 // provided area. Return the zero area if there isn't enough space to exclude
 // the border.
@@ -95,10 +89,10 @@ func ExcludeBorder(area image.Rectangle) image.Rectangle {
 		return image.ZR
 	}
 	return image.Rect(
-		abs(area.Min.X+1),
-		abs(area.Min.Y+1),
-		abs(area.Max.X-1),
-		abs(area.Max.Y-1),
+		numbers.Abs(area.Min.X+1),
+		numbers.Abs(area.Min.Y+1),
+		numbers.Abs(area.Max.X-1),
+		numbers.Abs(area.Max.Y-1),
 	)
 }
 

draw/braille_line.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/mum4k/termdash/canvas/braille"
 	"github.com/mum4k/termdash/cell"
+	"github.com/mum4k/termdash/numbers"
 )
 
 // braillePixelChange represents an action on a pixel on the braille canvas.
@@ -133,8 +134,8 @@ func brailleLinePoints(start, end image.Point) []image.Point {
 	// Implements Bresenham's line algorithm.
 	// https://en.wikipedia.org/wiki/Bresenham%27s_line_algorithm
 
-	vertProj := abs(end.Y - start.Y)
-	horizProj := abs(end.X - start.X)
+	vertProj := numbers.Abs(end.Y - start.Y)
+	horizProj := numbers.Abs(end.X - start.X)
 	if vertProj < horizProj {
 		if start.X > end.X {
 			return lineLow(end.X, end.Y, start.X, start.Y)
@@ -201,11 +202,3 @@ func lineHigh(x0, y0, x1, y1 int) []image.Point {
 	}
 	return res
 }
-
-// abs returns the absolute value of x.
-func abs(x int) int {
-	if x < 0 {
-		return -x
-	}
-	return x
-}

numbers/numbers.go

@@ -162,3 +162,11 @@ func RadiansToDegrees(radians float64) int {
 	}
 	return d
 }
+
+// Abs returns the absolute value of x.
+func Abs(x int) int {
+	if x < 0 {
+		return -x
+	}
+	return x
+}

numbers/numbers_test.go

@@ -327,3 +327,25 @@ func TestRadiansToDegrees(t *testing.T) {
 		})
 	}
 }
+
+func TestAbs(t *testing.T) {
+	tests := []struct {
+		input int
+		want  int
+	}{
+		{0, 0},
+		{1, 1},
+		{2, 2},
+		{-1, 1},
+		{-2, 2},
+	}
+
+	for _, tc := range tests {
+		t.Run(fmt.Sprintf("%d", tc.input), func(t *testing.T) {
+			got := Abs(tc.input)
+			if got != tc.want {
+				t.Errorf("Abs(%d) => %v, want %v", tc.input, got, tc.want)
+			}
+		})
+	}
+}