LookAt func

README.md

@@ -1,6 +1,6 @@
 # gglm
 
-An OpenGL focused Go mathematics inspired by the C++ glm (OpenGL Mathematics) library
+Fast Go OpenGL Mathematics library inspired by the c++ library [glm](https://github.com/g-truc/glm).
 
 ## Notes
 

gglm/constants.go

@@ -0,0 +1,7 @@
+package gglm
+
+const (
+	Pi      float32 = 3.14159265359
+	Deg2Rad float32 = Pi / 180
+	Rad2Deg float32 = 180 / Pi
+)

gglm/geometric.go

@@ -14,6 +14,10 @@ func DotVec4(v1, v2 *Vec4) float32 {
 	return v1.X()*v2.X() + v1.Y()*v2.Y() + v1.Z()*v2.Z() + v1.W()*v2.W()
 }
 
+func DotQuat(q1, q2 *Quat) float32 {
+	return q1.X()*q2.X() + q1.Y()*q2.Y() + q1.Z()*q2.Z() + q1.W()*q2.W()
+}
+
 func Cross(v1, v2 *Vec3) *Vec3 {
 	return &Vec3{
 		Data: [3]float32{
@@ -73,3 +77,41 @@ func SqrDistVec4(v1, v2 *Vec4) float32 {
 	w := v1.Data[3] - v2.Data[3]
 	return x*x + y*y + z*z + w*w
 }
+
+//ReflectVec2 returns the reflected vector of the incoming vector 'v', and the surface normal 'n'.
+//
+//Note: n must be normalized or you will get wrong results
+func ReflectVec2(v, n *Vec2) *Vec2 {
+
+	//reflectedVec = v − 2*dot(v, norm)*norm
+	d := 2 * (v.Data[0]*n.Data[0] + v.Data[1]*n.Data[1])
+
+	return &Vec2{
+		Data: [2]float32{
+			v.Data[0] - d*n.Data[0],
+			v.Data[1] - d*n.Data[1],
+		},
+	}
+}
+
+//ReflectVec3 returns the reflected vector of the incoming vector 'v', and the surface normal 'n'.
+//
+//Note: n must be normalized or you will get wrong results
+func ReflectVec3(v, n *Vec3) *Vec3 {
+
+	//reflectedVec = v − 2*dot(v, norm)*norm
+	d := 2 * (v.Data[0]*n.Data[0] + v.Data[1]*n.Data[1] + v.Data[2]*n.Data[2])
+
+	return &Vec3{
+		Data: [3]float32{
+			v.Data[0] - d*n.Data[0],
+			v.Data[1] - d*n.Data[1],
+			v.Data[2] - d*n.Data[2],
+		},
+	}
+}
+
+//AngleQuat returns the angle between the two quaternions in radians
+func AngleQuat(q1, q2 *Quat) float32 {
+	return Acos32(DotQuat(q1, q2))
+}

gglm/geometric_test.go

@@ -0,0 +1,139 @@
+package gglm_test
+
+import (
+	"testing"
+
+	"github.com/bloeys/gglm/gglm"
+)
+
+func TestDotVec2(t *testing.T) {
+
+	v1 := gglm.Vec2{Data: [2]float32{1, 2}}
+	v2 := gglm.Vec2{Data: [2]float32{3, 4}}
+	ans := float32(11)
+
+	res := gglm.DotVec2(&v1, &v2)
+	if res != ans {
+		t.Errorf("Got: %v; Expected: %v", res, ans)
+	}
+}
+
+func TestDotVec3(t *testing.T) {
+
+	v1 := gglm.Vec3{Data: [3]float32{1, 2, 3}}
+	v2 := gglm.Vec3{Data: [3]float32{4, 5, 6}}
+	ans := float32(32)
+
+	res := gglm.DotVec3(&v1, &v2)
+	if res != ans {
+		t.Errorf("Got: %v; Expected: %v", res, ans)
+	}
+}
+
+func TestDotVec4(t *testing.T) {
+
+	v1 := gglm.Vec4{Data: [4]float32{1, 2, 3, 4}}
+	v2 := gglm.Vec4{Data: [4]float32{5, 6, 7, 8}}
+	ans := float32(70)
+
+	res := gglm.DotVec4(&v1, &v2)
+	if res != ans {
+		t.Errorf("Got: %v; Expected: %v", res, ans)
+	}
+}
+
+func TestDistVec2(t *testing.T) {
+
+	v1 := gglm.Vec2{Data: [2]float32{1, 2}}
+	v2 := gglm.Vec2{Data: [2]float32{3, 4}}
+	ans := float32(2.828427)
+
+	res := gglm.DistVec2(&v1, &v2)
+	if res != ans {
+		t.Errorf("Got: %v; Expected: %v", res, ans)
+	}
+}
+
+func TestDistVec3(t *testing.T) {
+
+	v1 := gglm.Vec3{Data: [3]float32{1, 2, 3}}
+	v2 := gglm.Vec3{Data: [3]float32{4, 5, 6}}
+	ans := float32(5.196152)
+
+	res := gglm.DistVec3(&v1, &v2)
+	if res != ans {
+		t.Errorf("Got: %v; Expected: %v", res, ans)
+	}
+}
+
+func TestDistVec4(t *testing.T) {
+
+	v1 := gglm.Vec4{Data: [4]float32{1, 2, 3, 4}}
+	v2 := gglm.Vec4{Data: [4]float32{5, 6, 7, 8}}
+	ans := float32(8)
+
+	res := gglm.DistVec4(&v1, &v2)
+	if res != ans {
+		t.Errorf("Got: %v; Expected: %v", res, ans)
+	}
+}
+
+func TestSqrDistVec2(t *testing.T) {
+
+	v1 := gglm.Vec2{Data: [2]float32{1, 2}}
+	v2 := gglm.Vec2{Data: [2]float32{3, 4}}
+	ans := float32(8)
+
+	res := gglm.SqrDistVec2(&v1, &v2)
+	if res != ans {
+		t.Errorf("Got: %v; Expected: %v", res, ans)
+	}
+}
+
+func TestSqrDistVec3(t *testing.T) {
+
+	v1 := gglm.Vec3{Data: [3]float32{1, 2, 3}}
+	v2 := gglm.Vec3{Data: [3]float32{4, 5, 6}}
+	ans := float32(27)
+
+	res := gglm.SqrDistVec3(&v1, &v2)
+	if res != ans {
+		t.Errorf("Got: %v; Expected: %v", res, ans)
+	}
+}
+
+func TestSqrDistVec4(t *testing.T) {
+
+	v1 := gglm.Vec4{Data: [4]float32{1, 2, 3, 4}}
+	v2 := gglm.Vec4{Data: [4]float32{5, 6, 7, 8}}
+	ans := float32(64)
+
+	res := gglm.SqrDistVec4(&v1, &v2)
+	if res != ans {
+		t.Errorf("Got: %v; Expected: %v", res, ans)
+	}
+}
+
+func TestReflectVec2(t *testing.T) {
+
+	v1 := gglm.Vec2{Data: [2]float32{1, 2}}
+	n := gglm.Vec2{Data: [2]float32{0, 1}}
+	ans := gglm.Vec2{Data: [2]float32{1, -2}}
+
+	res := gglm.ReflectVec2(&v1, &n)
+	if !res.Eq(&ans) {
+		t.Errorf("Got: %v; Expected: %v", res, ans)
+	}
+}
+
+func TestReflectVec3(t *testing.T) {
+
+	v1 := gglm.Vec3{Data: [3]float32{1, 2, 3}}
+	n := gglm.Vec3{Data: [3]float32{0, 1, 0}}
+	ans := gglm.Vec3{Data: [3]float32{1, -2, 3}}
+
+	res := gglm.ReflectVec3(&v1, &n)
+	if !res.Eq(&ans) {
+		t.Errorf("Got: %v; Expected: %v", res, ans)
+	}
+}

gglm/mat2.go

@@ -29,23 +29,25 @@ func (m *Mat2) String() string {
 }
 
 //Add m += m2
-func (m *Mat2) Add(m2 *Mat2) {
+func (m *Mat2) Add(m2 *Mat2) *Mat2 {
 	m.Data[0] += m2.Data[0]
 	m.Data[1] += m2.Data[1]
 	m.Data[2] += m2.Data[2]
 	m.Data[3] += m2.Data[3]
+	return m
 }
 
 //Add m -= m2
-func (m *Mat2) Sub(m2 *Mat2) {
+func (m *Mat2) Sub(m2 *Mat2) *Mat2 {
 	m.Data[0] -= m2.Data[0]
 	m.Data[1] -= m2.Data[1]
 	m.Data[2] -= m2.Data[2]
 	m.Data[3] -= m2.Data[3]
+	return m
 }
 
 //Mul m *= m2
-func (m *Mat2) Mul(m2 *Mat2) {
+func (m *Mat2) Mul(m2 *Mat2) *Mat2 {
 	m.Data = [4]float32{
 		m.Data[0]*m2.Data[0] + m.Data[1]*m2.Data[2],
 		m.Data[0]*m2.Data[1] + m.Data[1]*m2.Data[3],
@@ -53,14 +55,20 @@ func (m *Mat2) Mul(m2 *Mat2) {
 		m.Data[2]*m2.Data[0] + m.Data[3]*m2.Data[2],
 		m.Data[2]*m2.Data[1] + m.Data[3]*m2.Data[3],
 	}
+	return m
 }
 
 //Scale m *= x (element wise multiplication)
-func (m *Mat2) Scale(x float32) {
+func (m *Mat2) Scale(x float32) *Mat2 {
 	m.Data[0] *= x
 	m.Data[1] *= x
 	m.Data[2] *= x
 	m.Data[3] *= x
+	return m
+}
+
+func (v *Mat2) Clone() *Mat2 {
+	return &Mat2{Data: v.Data}
 }
 
 func (m *Mat2) Eq(m2 *Mat2) bool {

gglm/mat3.go

@@ -32,7 +32,7 @@ func (m *Mat3) String() string {
 }
 
 //Add m += m2
-func (m *Mat3) Add(m2 *Mat3) {
+func (m *Mat3) Add(m2 *Mat3) *Mat3 {
 
 	m.Data[0] += m2.Data[0]
 	m.Data[1] += m2.Data[1]
@@ -45,10 +45,11 @@ func (m *Mat3) Add(m2 *Mat3) {
 	m.Data[6] += m2.Data[6]
 	m.Data[7] += m2.Data[7]
 	m.Data[8] += m2.Data[8]
+	return m
 }
 
 //Add m -= m2
-func (m *Mat3) Sub(m2 *Mat3) {
+func (m *Mat3) Sub(m2 *Mat3) *Mat3 {
 
 	m.Data[0] -= m2.Data[0]
 	m.Data[1] -= m2.Data[1]
@@ -61,10 +62,11 @@ func (m *Mat3) Sub(m2 *Mat3) {
 	m.Data[6] -= m2.Data[6]
 	m.Data[7] -= m2.Data[7]
 	m.Data[8] -= m2.Data[8]
+	return m
 }
 
 //Mul m *= m2
-func (m *Mat3) Mul(m2 *Mat3) {
+func (m *Mat3) Mul(m2 *Mat3) *Mat3 {
 
 	//Indices:
 	// 0, 1, 2,
@@ -84,10 +86,11 @@ func (m *Mat3) Mul(m2 *Mat3) {
 		m.Data[6]*m2.Data[1] + m.Data[7]*m2.Data[4] + m.Data[8]*m2.Data[7],
 		m.Data[6]*m2.Data[2] + m.Data[7]*m2.Data[5] + m.Data[8]*m2.Data[8],
 	}
+	return m
 }
 
 //Scale m *= x (element wise multiplication)
-func (m *Mat3) Scale(x float32) {
+func (m *Mat3) Scale(x float32) *Mat3 {
 
 	m.Data[0] *= x
 	m.Data[1] *= x
@@ -100,6 +103,11 @@ func (m *Mat3) Scale(x float32) {
 	m.Data[6] *= x
 	m.Data[7] *= x
 	m.Data[8] *= x
+	return m
+}
+
+func (v *Mat3) Clone() *Mat3 {
+	return &Mat3{Data: v.Data}
 }
 
 func (m *Mat3) Eq(m2 *Mat3) bool {

gglm/mat4.go

@@ -33,7 +33,7 @@ func (m *Mat4) String() string {
 }
 
 //Add m += m2
-func (m *Mat4) Add(m2 *Mat4) {
+func (m *Mat4) Add(m2 *Mat4) *Mat4 {
 
 	m.Data[0] += m2.Data[0]
 	m.Data[1] += m2.Data[1]
@@ -54,10 +54,12 @@ func (m *Mat4) Add(m2 *Mat4) {
 	m.Data[13] += m2.Data[13]
 	m.Data[14] += m2.Data[14]
 	m.Data[15] += m2.Data[15]
+
+	return m
 }
 
 //Add m -= m2
-func (m *Mat4) Sub(m2 *Mat4) {
+func (m *Mat4) Sub(m2 *Mat4) *Mat4 {
 
 	m.Data[0] -= m2.Data[0]
 	m.Data[1] -= m2.Data[1]
@@ -78,10 +80,11 @@ func (m *Mat4) Sub(m2 *Mat4) {
 	m.Data[13] -= m2.Data[13]
 	m.Data[14] -= m2.Data[14]
 	m.Data[15] -= m2.Data[15]
+	return m
 }
 
 //Mul m *= m2
-func (m *Mat4) Mul(m2 *Mat4) {
+func (m *Mat4) Mul(m2 *Mat4) *Mat4 {
 
 	//Indices:
 	// 00, 01, 02, 03,
@@ -117,10 +120,12 @@ func (m *Mat4) Mul(m2 *Mat4) {
 		m.Data[12]*m2.Data[2] + m.Data[13]*m2.Data[6] + m.Data[14]*m2.Data[10] + m.Data[15]*m2.Data[14],
 		m.Data[12]*m2.Data[3] + m.Data[13]*m2.Data[7] + m.Data[14]*m2.Data[11] + m.Data[15]*m2.Data[15],
 	}
+
+	return m
 }
 
 //Scale m *= x (element wise multiplication)
-func (m *Mat4) Scale(x float32) {
+func (m *Mat4) Scale(x float32) *Mat4 {
 
 	m.Data[0] *= x
 	m.Data[1] *= x
@@ -141,6 +146,11 @@ func (m *Mat4) Scale(x float32) {
 	m.Data[13] *= x
 	m.Data[14] *= x
 	m.Data[15] *= x
+	return m
+}
+
+func (v *Mat4) Clone() *Mat4 {
+	return &Mat4{Data: v.Data}
 }
 
 func (m *Mat4) Eq(m2 *Mat4) bool {

gglm/quat.go

@@ -0,0 +1,68 @@
+package gglm
+
+import (
+	"fmt"
+)
+
+var _ Swizzle4 = &Quat{}
+var _ fmt.Stringer = &Quat{}
+
+type Quat struct {
+	Vec4
+}
+
+//Eq checks for exact equality
+func (q *Quat) Eq(q2 *Quat) bool {
+	return q.Data == q2.Data
+}
+
+//Euler takes rotations in radians and produces a rotation that
+//rotates around the z-axis, y-axis and lastly x-axis.
+func NewQuatEuler(v *Vec3) *Quat {
+
+	//Some other common terminology: x=roll, y=pitch, z=yaw
+	sinX, cosX := Sincos32(v.Data[0] * 0.5)
+	sinY, cosY := Sincos32(v.Data[1] * 0.5)
+	sinZ, cosZ := Sincos32(v.Data[2] * 0.5)
+
+	//This produces a z->y->x multiply order, but its written as XYZ.
+	//This is due to XYZ meaning independent rotation matrices, so Z is applied
+	//first, then Y matrix and lastly X.
+	//See this for more info: https://github.com/godotengine/godot/issues/6816#issuecomment-254592170
+	//
+	//Note: On most conversion tools putting the multiply order (e.g. ZYX for us) is required.
+	return &Quat{
+		Vec4: Vec4{
+			Data: [4]float32{
+				sinX*cosY*cosZ - cosX*sinY*sinZ,
+				cosX*sinY*cosZ + sinX*cosY*sinZ,
+				cosX*cosY*sinZ - sinX*sinY*cosZ,
+				cosX*cosY*cosZ + sinX*sinY*sinZ,
+			},
+		},
+	}
+}
+
+//AngleAxis rotates rotRad radians around the *normalized* vector rotAxisNorm
+func NewQuatAngleAxis(rotRad float32, rotAxisNorm *Vec3) *Quat {
+
+	s, c := Sincos32(rotRad * 0.5)
+	return &Quat{
+		Vec4: Vec4{
+			Data: [4]float32{
+				rotAxisNorm.Data[0] * s,
+				rotAxisNorm.Data[1] * s,
+				rotAxisNorm.Data[2] * s,
+				c,
+			},
+		},
+	}
+}
+
+func NewQuatId() *Quat {
+	return &Quat{
+		Vec4: Vec4{
+			Data: [4]float32{0, 0, 0, 1},
+		},
+	}
+}

gglm/quat_test.go

@@ -0,0 +1,27 @@
+package gglm_test
+
+import (
+	"testing"
+
+	"github.com/bloeys/gglm/gglm"
+)
+
+func TestNewQuatEuler(t *testing.T) {
+
+	q := gglm.NewQuatEuler(gglm.NewVec3(180, 180, 180).AsRad())
+	ans := &gglm.Quat{Vec4: *gglm.NewVec4(0, 0, 0, 1)}
+
+	if !gglm.EqF32(q.X(), ans.X()) || !gglm.EqF32(q.Y(), ans.Y()) || !gglm.EqF32(q.Z(), ans.Z()) || !gglm.EqF32(q.W(), ans.W()) {
+		t.Errorf("Got: %v; Expected: %v", q.String(), ans.String())
+	}
+}
+
+func TestNewQuatAngleAxis(t *testing.T) {
+
+	q := gglm.NewQuatAngleAxis(180*gglm.Deg2Rad, gglm.NewVec3(0, 1, 0))
+	ans := &gglm.Quat{Vec4: *gglm.NewVec4(0, 1, 0, 0)}
+
+	if !gglm.EqF32(q.X(), ans.X()) || !gglm.EqF32(q.Y(), ans.Y()) || !gglm.EqF32(q.Z(), ans.Z()) || !gglm.EqF32(q.W(), ans.W()) {
+		t.Errorf("Got: %v; Expected: %v", q.String(), ans.String())
+	}
+}

gglm/scalar.go

@@ -0,0 +1,37 @@
+package gglm
+
+import "math"
+
+//F32Epsilon = 0.0000005
+const F32Epsilon float32 = 1e-6
+
+//EqF32 true if abs(f1-f2) <= F32Epsilon
+func EqF32(f1, f2 float32) bool {
+	return math.Abs(float64(f1-f2)) <= float64(F32Epsilon)
+}
+
+//EqF32Epsilon true if abs(f1-f2) <= eps
+func EqF32Epsilon(f1, f2, eps float32) bool {
+	return math.Abs(float64(f1-f2)) <= float64(eps)
+}
+
+func Sin32(x float32) float32 {
+	return float32(math.Sin(float64(x)))
+}
+
+func Asin32(x float32) float32 {
+	return float32(math.Asin(float64(x)))
+}
+
+func Cos32(x float32) float32 {
+	return float32(math.Cos(float64(x)))
+}
+
+func Acos32(x float32) float32 {
+	return float32(math.Acos(float64(x)))
+}
+
+func Sincos32(x float32) (sinx, cosx float32) {
+	a, b := math.Sincos(float64(x))
+	return float32(a), float32(b)
+}

gglm/transform.go

@@ -0,0 +1,123 @@
+package gglm
+
+import (
+	"fmt"
+)
+
+var _ Mat = &TrMat{}
+var _ fmt.Stringer = &TrMat{}
+
+//TrMat represents a transformation matrix
+type TrMat struct {
+	Mat4
+}
+
+//Translate adds the vector to the translation components of the transformation matrix
+func (t *TrMat) Translate(v *Vec3) {
+	t.Data[3] += v.Data[0]
+	t.Data[7] += v.Data[1]
+	t.Data[11] += v.Data[2]
+}
+
+//Scale multiplies the vector by the scale components of the transformation matrix
+func (t *TrMat) Scale(v *Vec3) {
+	t.Data[0] *= v.Data[0]
+	t.Data[5] *= v.Data[1]
+	t.Data[10] *= v.Data[2]
+}
+
+func (t *TrMat) Mul(m *TrMat) *TrMat {
+	t.Mat4.Mul(&m.Mat4)
+	return t
+}
+
+func (t *TrMat) Eq(m *TrMat) bool {
+	return t.Data == m.Data
+}
+
+func (t *TrMat) Clone() *TrMat {
+	return &TrMat{
+		Mat4: *t.Mat4.Clone(),
+	}
+}
+
+func NewTranslationMat(v *Vec3) *TrMat {
+	return &TrMat{
+		Mat4: Mat4{
+			Data: [16]float32{
+				1, 0, 0, v.Data[0],
+				0, 1, 0, v.Data[1],
+				0, 0, 1, v.Data[2],
+				0, 0, 0, 1,
+			},
+		},
+	}
+}
+
+func NewScaleMat(v *Vec3) *TrMat {
+	return &TrMat{
+		Mat4: Mat4{
+			Data: [16]float32{
+				v.Data[0], 0, 0, 0,
+				0, v.Data[1], 0, 0,
+				0, 0, v.Data[2], 0,
+				0, 0, 0, 1,
+			},
+		},
+	}
+}
+
+func NewRotMat(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
+
+	xx := q.Data[0] * q.Data[0]
+	yy := q.Data[1] * q.Data[1]
+	zz := q.Data[2] * q.Data[2]
+	ww := q.Data[3] * q.Data[3]
+
+	xy := q.Data[0] * q.Data[1]
+	xz := q.Data[0] * q.Data[2]
+	xw := q.Data[0] * q.Data[3]
+
+	yz := q.Data[1] * q.Data[2]
+	yw := q.Data[1] * q.Data[3]
+
+	zw := q.Data[2] * q.Data[3]
+
+	return &TrMat{
+		Mat4: Mat4{
+			Data: [16]float32{
+				2*(ww+xx) - 1, 2 * (xy - zw), 2 * (yw + xz), 0,
+				2 * (zw + xy), 2*(ww+yy) - 1, 2 * (yz - xw), 0,
+				2 * (xz - yw), 2 * (xw + yz), 2*(ww+zz) - 1, 0,
+				0, 0, 0, 1,
+			},
+		},
+	}
+}
+
+func LookAt(pos, targetPos, worldUp *Vec3) *TrMat {
+
+	forward := SubVec3(targetPos, pos).Normalize()
+	right := Cross(worldUp, forward).Normalize()
+	up := Cross(forward, right)
+
+	return &TrMat{
+		Mat4: Mat4{
+			Data: [16]float32{
+				right.Data[0], right.Data[1], right.Data[2], -DotVec3(pos, right),
+				up.Data[0], up.Data[1], up.Data[2], -DotVec3(pos, up),
+				forward.Data[0], forward.Data[1], forward.Data[2], -DotVec3(pos, forward),
+				0, 0, 0, 1,
+			},
+		},
+	}
+}
+
+func NewTrMatId() *TrMat {
+	return &TrMat{
+		Mat4: *NewMat4Id(),
+	}
+}

gglm/transform_test.go

@@ -0,0 +1,83 @@
+package gglm_test
+
+import (
+	"testing"
+
+	"github.com/bloeys/gglm/gglm"
+)
+
+func TestNewTrMatId(t *testing.T) {
+
+	m := gglm.NewTrMatId()
+	ans := &gglm.TrMat{
+		Mat4: gglm.Mat4{
+			Data: [16]float32{
+				1, 0, 0, 0,
+				0, 1, 0, 0,
+				0, 0, 1, 0,
+				0, 0, 0, 1,
+			},
+		},
+	}
+
+	if !m.Eq(ans) {
+		t.Errorf("Got: %v; Expected: %v", m.String(), ans.String())
+	}
+}
+
+func TestNewTranslationMat(t *testing.T) {
+
+	m := gglm.NewTranslationMat(gglm.NewVec3(1, 2, 3))
+	ans := &gglm.TrMat{
+		Mat4: gglm.Mat4{
+			Data: [16]float32{
+				1, 0, 0, 1,
+				0, 1, 0, 2,
+				0, 0, 1, 3,
+				0, 0, 0, 1,
+			},
+		},
+	}
+
+	if !m.Eq(ans) {
+		t.Errorf("Got: %v; Expected: %v", m.String(), ans.String())
+	}
+}
+
+func TestNewScaleMat(t *testing.T) {
+
+	m := gglm.NewScaleMat(gglm.NewVec3(1, 2, 3))
+	ans := &gglm.TrMat{
+		Mat4: gglm.Mat4{
+			Data: [16]float32{
+				1, 0, 0, 0,
+				0, 2, 0, 0,
+				0, 0, 3, 0,
+				0, 0, 0, 1,
+			},
+		},
+	}
+
+	if !m.Eq(ans) {
+		t.Errorf("Got: %v; Expected: %v", m.String(), ans.String())
+	}
+}
+
+func TestNewRotMat(t *testing.T) {
+
+	m := gglm.NewRotMat(gglm.NewQuatId())
+	ans := &gglm.TrMat{
+		Mat4: gglm.Mat4{
+			Data: [16]float32{
+				1, 0, 0, 0,
+				0, 1, 0, 0,
+				0, 0, 1, 0,
+				0, 0, 0, 1,
+			},
+		},
+	}
+
+	if !m.Eq(ans) {
+		t.Errorf("Got: %v; Expected: %v", m.String(), ans.String())
+	}
+}

gglm/vec2.go

@@ -51,21 +51,24 @@ func (v *Vec2) String() string {
 }
 
 //Scale v *= x (element wise multiplication)
-func (v *Vec2) Scale(x float32) {
+func (v *Vec2) Scale(x float32) *Vec2 {
 	v.Data[0] *= x
 	v.Data[1] *= x
+	return v
 }
 
 //Add v += v2
-func (v *Vec2) Add(v2 *Vec2) {
+func (v *Vec2) Add(v2 *Vec2) *Vec2 {
 	v.Data[0] += v2.X()
 	v.Data[1] += v2.Y()
+	return v
 }
 
 //SubVec2 v -= v2
-func (v *Vec2) Sub(v2 *Vec2) {
+func (v *Vec2) Sub(v2 *Vec2) *Vec2 {
 	v.Data[0] -= v2.X()
 	v.Data[1] -= v2.Y()
+	return v
 }
 
 //Mag returns the magnitude of the vector
@@ -93,6 +96,10 @@ func (v *Vec2) Normalize() {
 	v.Data[1] /= mag
 }
 
+func (v *Vec2) Clone() *Vec2 {
+	return &Vec2{Data: v.Data}
+}
+
 //AddVec2 v3 = v1 + v2
 func AddVec2(v1, v2 *Vec2) *Vec2 {
 	return &Vec2{
@@ -112,3 +119,12 @@ func SubVec2(v1, v2 *Vec2) *Vec2 {
 		},
 	}
 }
+
+func NewVec2(x, y float32) *Vec2 {
+	return &Vec2{
+		[2]float32{
+			x,
+			y,
+		},
+	}
+}

gglm/vec3.go

@@ -65,24 +65,27 @@ func (v *Vec3) String() string {
 }
 
 //Scale v *= x (element wise multiplication)
-func (v *Vec3) Scale(x float32) {
+func (v *Vec3) Scale(x float32) *Vec3 {
 	v.Data[0] *= x
 	v.Data[1] *= x
 	v.Data[2] *= x
+	return v
 }
 
-func (v *Vec3) Add(v2 *Vec3) {
+func (v *Vec3) Add(v2 *Vec3) *Vec3 {
 
 	v.Data[0] += v2.X()
 	v.Data[1] += v2.Y()
 	v.Data[2] += v2.Z()
+	return v
 }
 
 //SubVec3 v -= v2
-func (v *Vec3) Sub(v2 *Vec3) {
+func (v *Vec3) Sub(v2 *Vec3) *Vec3 {
 	v.Data[0] -= v2.X()
 	v.Data[1] -= v2.Y()
 	v.Data[2] -= v2.Z()
+	return v
 }
 
 //Mag returns the magnitude of the vector
@@ -105,11 +108,29 @@ func (v *Vec3) Set(x, y, z float32) {
 	v.Data[2] = z
 }
 
-func (v *Vec3) Normalize() {
+//Normalize normalizes this vector and returns it (doesn't copy)
+func (v *Vec3) Normalize() *Vec3 {
 	mag := float32(math.Sqrt(float64(v.X()*v.X() + v.Y()*v.Y() + v.Z()*v.Z())))
 	v.Data[0] /= mag
 	v.Data[1] /= mag
 	v.Data[2] /= mag
+
+	return v
+}
+
+func (v *Vec3) Clone() *Vec3 {
+	return &Vec3{Data: v.Data}
+}
+
+//AsRad returns a new vector with all values converted to Radians (i.e. multiplied by gglm.Deg2Rad)
+func (v *Vec3) AsRad() *Vec3 {
+	return &Vec3{
+		Data: [3]float32{
+			v.Data[0] * Deg2Rad,
+			v.Data[1] * Deg2Rad,
+			v.Data[2] * Deg2Rad,
+		},
+	}
 }
 
 //AddVec3 v3 = v1 + v2
@@ -133,3 +154,13 @@ func SubVec3(v1, v2 *Vec3) *Vec3 {
 		},
 	}
 }
+
+func NewVec3(x, y, z float32) *Vec3 {
+	return &Vec3{
+		[3]float32{
+			x,
+			y,
+			z,
+		},
+	}
+}

gglm/vec4.go

@@ -81,27 +81,29 @@ func (v *Vec4) String() string {
 }
 
 //Scale v *= x (element wise multiplication)
-func (v *Vec4) Scale(x float32) {
+func (v *Vec4) Scale(x float32) *Vec4 {
 	v.Data[0] *= x
 	v.Data[1] *= x
 	v.Data[2] *= x
 	v.Data[3] *= x
+	return v
 }
 
-func (v *Vec4) Add(v2 *Vec4) {
-
+func (v *Vec4) Add(v2 *Vec4) *Vec4 {
 	v.Data[0] += v2.X()
 	v.Data[1] += v2.Y()
 	v.Data[2] += v2.Z()
 	v.Data[3] += v2.W()
+	return v
 }
 
 //SubVec4 v -= v2
-func (v *Vec4) Sub(v2 *Vec4) {
+func (v *Vec4) Sub(v2 *Vec4) *Vec4 {
 	v.Data[0] -= v2.X()
 	v.Data[1] -= v2.Y()
 	v.Data[2] -= v2.Z()
 	v.Data[3] -= v2.W()
+	return v
 }
 
 //Mag returns the magnitude of the vector
@@ -133,6 +135,10 @@ func (v *Vec4) Normalize() {
 	v.Data[3] /= mag
 }
 
+func (v *Vec4) Clone() *Vec4 {
+	return &Vec4{Data: v.Data}
+}
+
 //AddVec4 v3 = v1 + v2
 func AddVec4(v1, v2 *Vec4) *Vec4 {
 	return &Vec4{
@@ -156,3 +162,14 @@ func SubVec4(v1, v2 *Vec4) *Vec4 {
 		},
 	}
 }
+
+func NewVec4(x, y, z, w float32) *Vec4 {
+	return &Vec4{
+		[4]float32{
+			x,
+			y,
+			z,
+			w,
+		},
+	}
+}

main.go

@@ -96,4 +96,79 @@ func main() {
 	println("V6: " + v6.String())
 	v6.Normalize()
 	println("V6 Normal: " + v6.String())
+
+	//Mat2Vec2
+	mat2A := gglm.Mat2{
+		Data: [4]float32{
+			1, 2,
+			3, 4,
+		},
+	}
+
+	vec2A := gglm.Vec2{Data: [2]float32{1, 2}}
+	println(gglm.MulMat2Vec2(&mat2A, &vec2A).String())
+
+	//Mat3Vec3
+	mat3A := gglm.Mat3{
+		Data: [9]float32{
+			1, 2, 3,
+			4, 5, 6,
+			7, 8, 9,
+		},
+	}
+
+	vec3A := gglm.Vec3{Data: [3]float32{1, 2, 3}}
+	mm3v3 := gglm.MulMat3Vec3(&mat3A, &vec3A)
+	println(mm3v3.String())
+
+	//ReflectVec2
+	vec2B := &gglm.Vec2{Data: [2]float32{4, 5}}
+	normA := &gglm.Vec2{Data: [2]float32{0, 1}}
+	rVec2A := gglm.ReflectVec2(vec2B, normA)
+	println(rVec2A.String())
+
+	//Quaternion
+	vRot := &gglm.Vec3{Data: [3]float32{60, 30, 20}}
+	q := gglm.NewQuatEuler(vRot.AsRad())
+	println("\n" + vRot.AsRad().String())
+	println(q.String(), "\n", q.Mag())
+
+	q = gglm.NewQuatAngleAxis(60*gglm.Deg2Rad, vRot.Normalize())
+	println("\n" + vRot.Normalize().String())
+	println(q.String())
+
+	//Transform
+	translationMat := gglm.NewTranslationMat(&gglm.Vec3{Data: [3]float32{1, 2, 3}})
+	rotMat := gglm.NewRotMat(gglm.NewQuatEuler(gglm.NewVec3(60, 30, 20).AsRad()))
+	scaleMat := gglm.NewScaleMat(gglm.NewVec3(1, 1, 1))
+
+	modelMat := gglm.NewTrMatId()
+	modelMat.Mul(translationMat.Mul(rotMat.Mul(scaleMat)))
+
+	println("\n\n\n", modelMat.String())
+
+	//Clone Vec2
+	v2Orig := gglm.Vec2{Data: [2]float32{1, 2}}
+	v2Clone := v2Orig.Clone()
+	v2Clone.SetX(99)
+	println("\n\n", v2Orig.String(), "; ", v2Clone.String())
+
+	//Clone TrMat
+	trMatOrig := gglm.NewTranslationMat(gglm.NewVec3(1, 2, 3))
+	trMatClone := trMatOrig.Clone()
+	trMatClone.Scale(gglm.NewVec3(2, 2, 2))
+	trMatClone.Translate(gglm.NewVec3(9, 0, 0))
+	println("\n\n", trMatOrig.String(), "; ", trMatClone.String())
+
+	//Quat geo
+	q1 := gglm.NewQuatEuler(gglm.NewVec3(180, 0, 0).AsRad())
+	q2 := gglm.NewQuatEuler(gglm.NewVec3(0, 180, 0).AsRad())
+	println(gglm.AngleQuat(q1, q2) * gglm.Rad2Deg)
+
+	//LookAt
+	camPos := gglm.NewVec3(0, 0, 3)
+	worldUp := gglm.NewVec3(0, 1, 0)
+	targetPos := gglm.NewVec3(0, 0, 0)
+	viewMat := gglm.LookAt(camPos, targetPos, worldUp)
+	println(viewMat.String())
 }

main_test.go

@@ -7,9 +7,10 @@ import (
 )
 
 var (
-	dotVec2Result float32 = 0
-	dotVec3Result float32 = 0
-	crossResult   *gglm.Vec3
+	dotVec2Result  float32
+	dotVec3Result  float32
+	crossResult    *gglm.Vec3
+	mulMat4Vec4Res *gglm.Vec4
 )
 
 func BenchmarkDotVec2(b *testing.B) {
@@ -71,3 +72,13 @@ func BenchmarkMulMat4(b *testing.B) {
 		m1.Mul(m2)
 	}
 }
+
+func BenchmarkMulMat4Vec4(b *testing.B) {
+
+	m1 := gglm.NewMat4Id()
+	v1 := gglm.Vec4{}
+
+	for i := 0; i < b.N; i++ {
+		mulMat4Vec4Res = gglm.MulMat4Vec4(m1, &v1)
+	}
+}