Mat*Vec mul

gglm/mat2.go

@@ -104,6 +104,16 @@ func MulMat2(m1, m2 *Mat2) *Mat2 {
 	}
 }
 
+//MulMat2Vec2 v2 = m1 * v1
+func MulMat2Vec2(m1 *Mat2, v1 *Vec2) *Vec2 {
+	return &Vec2{
+		Data: [2]float32{
+			m1.Data[0]*v1.Data[0] + m1.Data[1]*v1.Data[1],
+			m1.Data[2]*v1.Data[0] + m1.Data[3]*v1.Data[1],
+		},
+	}
+}
+
 //NewMat2Id returns the 2x2 identity matrix
 func NewMat2Id() *Mat2 {
 	return &Mat2{

gglm/mat2_test.go

@@ -0,0 +1,24 @@
+package gglm_test
+
+import (
+	"testing"
+
+	"github.com/bloeys/gglm/gglm"
+)
+
+func TestMulMat2Vec2(t *testing.T) {
+
+	m := &gglm.Mat2{
+		Data: [4]float32{
+			1, 2,
+			3, 4,
+		}}
+	v := &gglm.Vec2{Data: [2]float32{1, 2}}
+
+	result := gglm.MulMat2Vec2(m, v)
+	correctAns := gglm.Vec2{Data: [2]float32{5, 11}}
+
+	if !result.Eq(&correctAns) {
+		t.Errorf("Got: %v; Expected: %v", result.String(), correctAns.String())
+	}
+}

gglm/mat3.go

@@ -163,6 +163,17 @@ func MulMat3(m1, m2 *Mat3) *Mat3 {
 	}
 }
 
+//MulMat3Vec3 v2 = m1 * v1
+func MulMat3Vec3(m1 *Mat3, v1 *Vec3) *Vec3 {
+	return &Vec3{
+		Data: [3]float32{
+			m1.Data[0]*v1.Data[0] + m1.Data[1]*v1.Data[1] + m1.Data[2]*v1.Data[2],
+			m1.Data[3]*v1.Data[0] + m1.Data[4]*v1.Data[1] + m1.Data[5]*v1.Data[2],
+			m1.Data[6]*v1.Data[0] + m1.Data[7]*v1.Data[1] + m1.Data[8]*v1.Data[2],
+		},
+	}
+}
+
 //NewMat3Id returns the 3x3 identity matrix
 func NewMat3Id() *Mat3 {
 	return &Mat3{

gglm/mat3_test.go

@@ -0,0 +1,25 @@
+package gglm_test
+
+import (
+	"testing"
+
+	"github.com/bloeys/gglm/gglm"
+)
+
+func TestMulMat3Vec3(t *testing.T) {
+
+	m := &gglm.Mat3{
+		Data: [9]float32{
+			1, 2, 3,
+			4, 5, 6,
+			7, 8, 9,
+		}}
+	v := &gglm.Vec3{Data: [3]float32{1, 2, 3}}
+
+	result := gglm.MulMat3Vec3(m, v)
+	correctAns := gglm.Vec3{Data: [3]float32{14, 32, 50}}
+
+	if !result.Eq(&correctAns) {
+		t.Errorf("Got: %v; Expected: %v", result.String(), correctAns.String())
+	}
+}

gglm/mat4.go

@@ -234,6 +234,18 @@ func MulMat4(m1, m2 *Mat4) *Mat4 {
 	}
 }
 
+//MulMat4Vec4 v2 = m1 * v1
+func MulMat4Vec4(m1 *Mat4, v1 *Vec4) *Vec4 {
+	return &Vec4{
+		Data: [4]float32{
+			m1.Data[0]*v1.Data[0] + m1.Data[1]*v1.Data[1] + m1.Data[2]*v1.Data[2] + m1.Data[3]*v1.Data[3],
+			m1.Data[4]*v1.Data[0] + m1.Data[5]*v1.Data[1] + m1.Data[6]*v1.Data[2] + m1.Data[7]*v1.Data[3],
+			m1.Data[8]*v1.Data[0] + m1.Data[9]*v1.Data[1] + m1.Data[10]*v1.Data[2] + m1.Data[11]*v1.Data[3],
+			m1.Data[12]*v1.Data[0] + m1.Data[13]*v1.Data[1] + m1.Data[14]*v1.Data[2] + m1.Data[15]*v1.Data[3],
+		},
+	}
+}
+
 //NewMat4Id returns the 4x4 identity matrix
 func NewMat4Id() *Mat4 {
 	return &Mat4{

gglm/mat4_test.go

@@ -0,0 +1,26 @@
+package gglm_test
+
+import (
+	"testing"
+
+	"github.com/bloeys/gglm/gglm"
+)
+
+func TestMulMat4Vec4(t *testing.T) {
+
+	m := &gglm.Mat4{
+		Data: [16]float32{
+			1, 2, 3, 4,
+			5, 6, 7, 8,
+			9, 10, 11, 12,
+			13, 14, 15, 16,
+		}}
+	v := &gglm.Vec4{Data: [4]float32{1, 2, 3, 4}}
+
+	result := gglm.MulMat4Vec4(m, v)
+	correctAns := gglm.Vec4{Data: [4]float32{30, 70, 110, 150}}
+
+	if !result.Eq(&correctAns) {
+		t.Errorf("Got: %v; Expected: %v", result.String(), correctAns.String())
+	}
+}