Add Clamp

README.md

@@ -20,6 +20,8 @@ gglm currently has the following:
 
 ## Installation
 
+Note: gglm requires Go 1.18 or higher.
+
 `go get github.com/bloeys/gglm`
 
 ## Usage
@@ -54,5 +56,5 @@ func main() {
 
 ## Notes
 
-You can check compiler inlining decisions using `go run -gcflags "-m" .`. Some functions look a bit weird compared to similar ones
+You can check compiler inlining decisions using `go run -gcflags "-m" .`. Some functions look a bit weird
 because we are trying to reduce function complexity so the compiler inlines.

gglm/scalar.go

@@ -1,6 +1,10 @@
 package gglm
 
-import "math"
+import (
+	"math"
+
+	"golang.org/x/exp/constraints"
+)
 
 // EqF32 true if abs(f1-f2) <= F32Epsilon
 func EqF32(f1, f2 float32) bool {
@@ -52,3 +56,21 @@ func Abs32(x float32) float32 {
 func Sqrt32(x float32) float32 {
 	return float32(math.Sqrt(float64(x)))
 }
+
+// Clamp returns:
+//
+//	min if x<min
+//	max if x>max
+//	x   if x>=min && x<=max
+func Clamp[T constraints.Ordered](x, min, max T) T {
+
+	if x < min {
+		return min
+	}
+
+	if x > max {
+		return max
+	}
+
+	return x
+}

gglm/scalar_test.go

@@ -0,0 +1,64 @@
+package gglm_test
+
+import (
+	"testing"
+
+	"github.com/bloeys/gglm/gglm"
+)
+
+func TestClamp(t *testing.T) {
+
+	x := 5
+	ans := 5
+	if gglm.Clamp(x, 0, 10) != ans {
+		t.Errorf("Got: %v; Expected: %v", x, ans)
+	}
+
+	x = 10
+	ans = 10
+	if gglm.Clamp(x, 0, 10) != ans {
+		t.Errorf("Got: %v; Expected: %v", x, ans)
+	}
+
+	x = 20
+	ans = 10
+	if gglm.Clamp(x, 0, 10) != ans {
+		t.Errorf("Got: %v; Expected: %v", x, ans)
+	}
+
+	x = -10
+	ans = 0
+	if gglm.Clamp(x, 0, 10) != ans {
+		t.Errorf("Got: %v; Expected: %v", x, ans)
+	}
+
+	xf := 1.5
+	ansf := 1.5
+	if gglm.Clamp(xf, 0, 10) != ansf {
+		t.Errorf("Got: %v; Expected: %v", xf, ansf)
+	}
+
+	xf = 15
+	ansf = 10
+	if gglm.Clamp(xf, 0, 10) != ansf {
+		t.Errorf("Got: %v; Expected: %v", xf, ansf)
+	}
+
+	xf = -1.5
+	ansf = 0
+	if gglm.Clamp(xf, 0, 10) != ansf {
+		t.Errorf("Got: %v; Expected: %v", xf, ansf)
+	}
+
+	xf = 2
+	ansf = 1.5
+	if gglm.Clamp(xf, 0.5, 1.5) != ansf {
+		t.Errorf("Got: %v; Expected: %v", xf, ansf)
+	}
+
+	xf = 1.2
+	ansf = 1.2
+	if gglm.Clamp(xf, 0.5, 1.5) != ansf {
+		t.Errorf("Got: %v; Expected: %v", xf, ansf)
+	}
+}

gglm/transform.go

@@ -13,24 +13,36 @@ type TrMat struct {
 	Mat4
 }
 
+// TranslateVec adds v to the translation components of the transformation matrix
+func (t *TrMat) TranslateVec(v *Vec3) *TrMat {
+	return t.Translate(v.X(), v.Y(), v.Z())
+}
+
 // Translate adds v to the translation components of the transformation matrix
-func (t *TrMat) Translate(v *Vec3) *TrMat {
-	t.Data[3][0] += v.Data[0]
-	t.Data[3][1] += v.Data[1]
-	t.Data[3][2] += v.Data[2]
+func (t *TrMat) Translate(x, y, z float32) *TrMat {
+	t.Data[3][0] += x
+	t.Data[3][1] += y
+	t.Data[3][2] += z
 	return t
 }
 
+// ScaleVec multiplies the scale components of the transformation matrix by v
+func (t *TrMat) ScaleVec(v *Vec3) *TrMat {
+	return t.Scale(v.X(), v.Y(), v.Z())
+}
+
 // Scale multiplies the scale components of the transformation matrix by v
-func (t *TrMat) Scale(v *Vec3) *TrMat {
-	t.Data[0][0] *= v.Data[0]
-	t.Data[1][1] *= v.Data[1]
-	t.Data[2][2] *= v.Data[2]
+func (t *TrMat) Scale(x, y, z float32) *TrMat {
+	t.Data[0][0] *= z
+	t.Data[1][1] *= y
+	t.Data[2][2] *= z
 	return t
 }
 
-// Rotate takes a *normalized* axis and angles in radians to rotate around the given axis
-func (t *TrMat) Rotate(rads float32, axis *Vec3) *TrMat {
+// RotateVec takes a *normalized* axis and angles in radians to rotate around the given axis
+func (t *TrMat) RotateVec(rads float32, axis *Vec3) *TrMat {
+
+	// Manually inlined
 
 	s := Sin32(rads)
 	c := Cos32(rads)
@@ -83,6 +95,61 @@ func (t *TrMat) Rotate(rads float32, axis *Vec3) *TrMat {
 	return t
 }
 
+// Rotate takes a *normalized* axis and angles in radians to rotate around the given axis
+func (t *TrMat) Rotate(rads float32, axisX, axisY, axisZ float32) *TrMat {
+
+	s := Sin32(rads)
+	c := Cos32(rads)
+
+	axis := NewVec3(axisX, axisY, axisZ)
+	axis.Normalize()
+	temp := axis.Clone().Scale(1 - c)
+
+	rotate := TrMat{}
+	rotate.Data[0][0] = c + temp.Data[0]*axis.Data[0]
+	rotate.Data[0][1] = temp.Data[0]*axis.Data[1] + s*axis.Data[2]
+	rotate.Data[0][2] = temp.Data[0]*axis.Data[2] - s*axis.Data[1]
+
+	rotate.Data[1][0] = temp.Data[1]*axis.Data[0] - s*axis.Data[2]
+	rotate.Data[1][1] = c + temp.Data[1]*axis.Data[1]
+	rotate.Data[1][2] = temp.Data[1]*axis.Data[2] + s*axis.Data[0]
+
+	rotate.Data[2][0] = temp.Data[2]*axis.Data[0] + s*axis.Data[1]
+	rotate.Data[2][1] = temp.Data[2]*axis.Data[1] - s*axis.Data[0]
+	rotate.Data[2][2] = c + temp.Data[2]*axis.Data[2]
+
+	result := Mat4{}
+
+	col0 := t.Col(0)
+	col1 := t.Col(1)
+	col2 := t.Col(2)
+	result.Data[0] = col0.Scale(rotate.Data[0][0]).
+		Add(col1.Scale(rotate.Data[0][1])).
+		Add(col2.Scale(rotate.Data[0][2])).
+		Data
+
+	col0 = t.Col(0)
+	col1 = t.Col(1)
+	col2 = t.Col(2)
+	result.Data[1] = col0.Scale(rotate.Data[1][0]).
+		Add(col1.Scale(rotate.Data[1][1])).
+		Add(col2.Scale(rotate.Data[1][2])).
+		Data
+
+	col0 = t.Col(0)
+	col1 = t.Col(1)
+	col2 = t.Col(2)
+	result.Data[2] = col0.Scale(rotate.Data[2][0]).
+		Add(col1.Scale(rotate.Data[2][1])).
+		Add(col2.Scale(rotate.Data[2][2])).
+		Data
+
+	t.Data[0] = result.Data[0]
+	t.Data[1] = result.Data[1]
+	t.Data[2] = result.Data[2]
+	return t
+}
+
 func (t *TrMat) Mul(m *TrMat) *TrMat {
 	t.Mat4.Mul(&m.Mat4)
 	return t
@@ -98,8 +165,8 @@ func (t *TrMat) Clone() *TrMat {
 	}
 }
 
-func NewTranslationMat(v *Vec3) *TrMat {
-	return &TrMat{
+func NewTranslationMatVec(v *Vec3) TrMat {
+	return TrMat{
 		Mat4: Mat4{
 			Data: [4][4]float32{
 				{1, 0, 0, 0},
@@ -111,8 +178,21 @@ func NewTranslationMat(v *Vec3) *TrMat {
 	}
 }
 
-func NewScaleMat(v *Vec3) *TrMat {
-	return &TrMat{
+func NewTranslationMat(posX, posY, posZ float32) TrMat {
+	return TrMat{
+		Mat4: Mat4{
+			Data: [4][4]float32{
+				{1, 0, 0, 0},
+				{0, 1, 0, 0},
+				{0, 0, 1, 0},
+				{posX, posY, posZ, 1},
+			},
+		},
+	}
+}
+
+func NewScaleMatVec(v *Vec3) TrMat {
+	return TrMat{
 		Mat4: Mat4{
 			Data: [4][4]float32{
 				{v.Data[0], 0, 0, 0},
@@ -124,7 +204,20 @@ func NewScaleMat(v *Vec3) *TrMat {
 	}
 }
 
-func NewRotMat(q *Quat) *TrMat {
+func NewScaleMat(scaleX, scaleY, scaleZ float32) TrMat {
+	return TrMat{
+		Mat4: Mat4{
+			Data: [4][4]float32{
+				{scaleX, 0, 0, 0},
+				{0, scaleY, 0, 0},
+				{0, 0, scaleZ, 0},
+				{0, 0, 0, 1},
+			},
+		},
+	}
+}
+
+func NewRotMatQuat(q *Quat) TrMat {
 
 	//Based on: https://www.weizmann.ac.il/sci-tea/benari/sites/sci-tea.benari/files/uploads/softwareAndLearningMaterials/quaternion-tutorial-2-0-1.pdf
 	//Note: in the reference p0,p1,p2,p3 == w,x,y,z
@@ -143,7 +236,7 @@ func NewRotMat(q *Quat) *TrMat {
 
 	zw := q.Data[2] * q.Data[3]
 
-	return &TrMat{
+	return TrMat{
 		Mat4: Mat4{
 			Data: [4][4]float32{
 				{2*(ww+xx) - 1, 2 * (zw + xy), 2 * (xz - yw), 0},
@@ -157,7 +250,7 @@ func NewRotMat(q *Quat) *TrMat {
 
 // LookAtRH does a right-handed coordinate system lookAt (RH is the default for OpenGL).
 // Can be used to create the view matrix
-func LookAtRH(pos, targetPos, worldUp *Vec3) *TrMat {
+func LookAtRH(pos, targetPos, worldUp *Vec3) TrMat {
 
 	forward := SubVec3(targetPos, pos)
 	forward.Normalize()
@@ -165,7 +258,7 @@ func LookAtRH(pos, targetPos, worldUp *Vec3) *TrMat {
 	right.Normalize()
 	up := Cross(&right, &forward)
 
-	return &TrMat{
+	return TrMat{
 		Mat4: Mat4{
 			Data: [4][4]float32{
 				{right.Data[0], up.Data[0], -forward.Data[0], 0},
@@ -179,7 +272,7 @@ func LookAtRH(pos, targetPos, worldUp *Vec3) *TrMat {
 
 // LookAtLH does a left-handed coordinate system lookAt.
 // Can be used to create the view matrix
-func LookAtLH(pos, targetPos, worldUp *Vec3) *TrMat {
+func LookAtLH(pos, targetPos, worldUp *Vec3) TrMat {
 
 	forward := SubVec3(targetPos, pos)
 	forward.Normalize()
@@ -187,7 +280,7 @@ func LookAtLH(pos, targetPos, worldUp *Vec3) *TrMat {
 	right.Normalize()
 	up := Cross(&forward, &right)
 
-	return &TrMat{
+	return TrMat{
 		Mat4: Mat4{
 			Data: [4][4]float32{
 				{right.Data[0], up.Data[0], forward.Data[0], 0},
@@ -200,9 +293,9 @@ func LookAtLH(pos, targetPos, worldUp *Vec3) *TrMat {
 }
 
 // Perspective creates a perspective projection matrix
-func Perspective(fov, aspectRatio, nearClip, farClip float32) *Mat4 {
+func Perspective(fov, aspectRatio, nearClip, farClip float32) Mat4 {
 	halfFovTan := float32(math.Tan(float64(fov * 0.5)))
-	return &Mat4{
+	return Mat4{
 		Data: [4][4]float32{
 			{1 / (aspectRatio * halfFovTan), 0, 0, 0},
 			{0, 1 / halfFovTan, 0, 0},
@@ -213,8 +306,8 @@ func Perspective(fov, aspectRatio, nearClip, farClip float32) *Mat4 {
 }
 
 // Perspective creates an orthographic projection matrix
-func Ortho(left, right, top, bottom, nearClip, farClip float32) *TrMat {
-	return &TrMat{
+func Ortho(left, right, top, bottom, nearClip, farClip float32) TrMat {
+	return TrMat{
 		Mat4: Mat4{
 			Data: [4][4]float32{
 				{2 / (right - left), 0, 0, 0},
@@ -231,3 +324,21 @@ func NewTrMatId() TrMat {
 		Mat4: NewMat4Id(),
 	}
 }
+
+func NewTrMatWithPos(x, y, z float32) TrMat {
+	tr := TrMat{
+		Mat4: NewMat4Id(),
+	}
+
+	tr.Translate(x, y, z)
+	return tr
+}
+
+func NewTrMatWithPosVec(pos *Vec3) TrMat {
+	tr := TrMat{
+		Mat4: NewMat4Id(),
+	}
+
+	tr.TranslateVec(pos)
+	return tr
+}

gglm/transform_test.go

@@ -27,8 +27,7 @@ func TestNewTrMatId(t *testing.T) {
 
 func TestNewTranslationMat(t *testing.T) {
 
-	pos := gglm.NewVec3(1, 2, 3)
-	m := gglm.NewTranslationMat(&pos)
+	m := gglm.NewTranslationMat(1, 2, 3)
 	ans := &gglm.TrMat{
 		Mat4: gglm.Mat4{
 			Data: [4][4]float32{
@@ -47,8 +46,7 @@ func TestNewTranslationMat(t *testing.T) {
 
 func TestNewScaleMat(t *testing.T) {
 
-	pos := gglm.NewVec3(1, 2, 3)
-	m := gglm.NewScaleMat(&pos)
+	m := gglm.NewScaleMat(1, 2, 3)
 	ans := &gglm.TrMat{
 		Mat4: gglm.Mat4{
 			Data: [4][4]float32{
@@ -68,7 +66,7 @@ func TestNewScaleMat(t *testing.T) {
 func TestNewRotMat(t *testing.T) {
 
 	quat := gglm.NewQuatId()
-	m := gglm.NewRotMat(&quat)
+	m := gglm.NewRotMatQuat(&quat)
 	ans := &gglm.TrMat{
 		Mat4: gglm.Mat4{
 			Data: [4][4]float32{

go.mod

@@ -1,3 +1,5 @@
 module github.com/bloeys/gglm
 
-go 1.17
+go 1.18
+
+require golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842

go.sum

@@ -0,0 +1,2 @@
+golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842 h1:vr/HnozRka3pE4EsMEg1lgkXJkTFJCVUX+S/ZT6wYzM=
+golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842/go.mod h1:XtvwrStGgqGPLc4cjQfWqZHG1YFdYs6swckp8vpsjnc=

main.go

@@ -152,17 +152,16 @@ func main() {
 	println(q.String())
 
 	// Transform
-	translationMat := gglm.NewTranslationMat(&gglm.Vec3{Data: [3]float32{1, 2, 3}})
+	translationMat := gglm.NewTranslationMatVec(&gglm.Vec3{Data: [3]float32{1, 2, 3}})
 
 	rotDegs := gglm.NewVec3(60, 30, 20)
 	quat := gglm.NewQuatEulerVec(rotDegs.AsRad())
-	rotMat := gglm.NewRotMat(&quat)
+	rotMat := gglm.NewRotMatQuat(&quat)
 
-	scale := gglm.NewVec3(1, 1, 1)
-	scaleMat := gglm.NewScaleMat(&scale)
+	scaleMat := gglm.NewScaleMat(1, 1, 1)
 
 	modelMat := gglm.NewTrMatId()
-	modelMat.Mul(translationMat.Mul(rotMat.Mul(scaleMat)))
+	modelMat.Mul(translationMat.Mul(rotMat.Mul(&scaleMat)))
 
 	println("\n\n\n", modelMat.String())
 
@@ -173,15 +172,13 @@ func main() {
 	println("\n\n", v2Orig.String(), "; ", v2Clone.String())
 
 	// Clone TrMat
-	pos := gglm.NewVec3(1, 2, 3)
-	trMatOrig := gglm.NewTranslationMat(&pos)
+	trMatOrig := gglm.NewTranslationMat(1, 2, 3)
 	trMatClone := trMatOrig.Clone()
 
 	trMatCloneScale := gglm.NewVec3(2, 2, 2)
-	trMatClone.Scale(&trMatCloneScale)
+	trMatClone.ScaleVec(&trMatCloneScale)
 
-	pos = gglm.NewVec3(9, 0, 0)
-	trMatClone.Translate(&pos)
+	trMatClone.Translate(9, 0, 0)
 	println("\n\n", trMatOrig.String(), "; ", trMatClone.String())
 
 	// Quat geo