all: use built-in min and max functions

We can use the built-in `min` and `max` functions since Go 1.21.

Signed-off-by: Eng Zer Jun <[email protected]>

Author: Juneezee

axis.go

@@ -566,17 +566,11 @@ func (DefaultTicks) Ticks(min, max float64) []Tick {
 }
 
 func minInt(a, b int) int {
-	if a < b {
-		return a
-	}
-	return b
+	return min(a, b)
 }
 
 func maxInt(a, b int) int {
-	if a > b {
-		return a
-	}
-	return b
+	return max(a, b)
 }
 
 // LogTicks is suitable for the Tick.Marker field of an Axis,

plotter/image.go

@@ -91,13 +91,13 @@ func (img *Image) transformFor(p *plot.Plot) image.Image {
 		cTrans := int(p.X.Norm(img.x(c)) * float64(img.cols))
 		// Find the equivalent column of the previous image column after applying
 		// axis transforms.
-		cPrevTrans := int(p.X.Norm(img.x(maxInt(c-1, 0))) * float64(img.cols))
+		cPrevTrans := int(p.X.Norm(img.x(max(c-1, 0))) * float64(img.cols))
 		for r := range img.rows {
 			// Find the equivalent image row after applying axis transforms.
 			rTrans := int(p.Y.Norm(img.y(r)) * float64(img.rows))
 			// Find the equivalent row of the previous image row after applying
 			// axis transforms.
-			rPrevTrans := int(p.Y.Norm(img.y(maxInt(r-1, 0))) * float64(img.rows))
+			rPrevTrans := int(p.Y.Norm(img.y(max(r-1, 0))) * float64(img.rows))
 			crColor := img.img.At(c, img.rows-r-1)
 			// Set all the pixels in the new image between (cPrevTrans, rPrevTrans)
 			// and (cTrans, rTrans) to the color at (c,r) in the original image.
@@ -112,13 +112,6 @@ func (img *Image) transformFor(p *plot.Plot) image.Image {
 	return o
 }
 
-func maxInt(a, b int) int {
-	if a > b {
-		return a
-	}
-	return b
-}
-
 func (img *Image) x(c int) float64 {
 	if c >= img.cols || c < 0 {
 		panic("plotter/image: illegal range")

plotter/johnson.go

@@ -114,13 +114,6 @@ func (j *johnson) unblock(u int) {
 	}
 }
 
-func min(a, b int) int {
-	if a < b {
-		return a
-	}
-	return b
-}
-
 // tarjan implements Tarjan's strongly connected component finding
 // algorithm. The implementation is from the pseudocode at
 //

vg/vgimg/vgimg_test.go

@@ -150,13 +150,6 @@ func TestIssue540(t *testing.T) {
 }
 
 func TestIssue687(t *testing.T) {
-	min := func(a, b int) int {
-		if a < b {
-			return a
-		}
-		return b
-	}
-
 	const (
 		fname = "testdata/issue687.png"
 		size  = 500