Moved all into one package, added png loader.

vec3.go

@@ -0,0 +1,87 @@
+package goga
+
+import (
+	"math"
+)
+
+// A 3D vector.
+type Vec3 struct {
+	X, Y, Z float64
+}
+
+// Creates a copy of actual vector.
+func (v *Vec3) Copy() Vec3 {
+	return Vec3{v.X, v.Y, v.Z}
+}
+
+// Adds and saves the given vector to actual vector.
+func (v *Vec3) Add(vec Vec3) {
+	v.X += vec.X
+	v.Y += vec.Y
+	v.Z += vec.Z
+}
+
+// Subtracts and saves the given vector to actual vector.
+func (v *Vec3) Sub(vec Vec3) {
+	v.X -= vec.X
+	v.Y -= vec.Y
+	v.Z -= vec.Z
+}
+
+// Multiplies and saves the given vector to actual vector.
+func (v *Vec3) Mult(vec Vec3) {
+	v.X *= vec.X
+	v.Y *= vec.Y
+	v.Z *= vec.Z
+}
+
+// Divides and saves the given vector to actual vector.
+func (v *Vec3) Div(vec Vec3) {
+	v.X /= vec.X
+	v.Y /= vec.Y
+	v.Z /= vec.Z
+}
+
+// Calculates and returns the dot product of actual vector.
+func (v *Vec3) Dot() float64 {
+	return v.X*v.X + v.Y*v.Y + v.Z*v.Z
+}
+
+// Calculates and returns the dot product of combination of given vector and actual vector.
+func (v *Vec3) DotVec(vec Vec3) float64 {
+	return v.X*vec.X + v.Y*vec.Y + v.Z*vec.Z
+}
+
+// Returns the length of actual vector.
+func (v *Vec3) Length() float64 {
+	return math.Sqrt(v.Dot())
+}
+
+// Normalizes actual vector to length 1.
+func (v *Vec3) Normalize() {
+	l := v.Length()
+
+	v.X /= l
+	v.Y /= l
+	v.Z /= l
+}
+
+// Calculates and saves cross product of given and actual vector.
+func (v *Vec3) Cross(vec Vec3) {
+	this := Vec3{v.X, v.Y, v.Z}
+
+	v.X = this.Y*vec.Z - this.Z*vec.Y
+	v.Y = this.Z*vec.X - this.X*vec.Z
+	v.Z = this.X*vec.Y - this.Y*vec.X
+}
+
+// Calulates the cross product of given vectors and returns result as a new vector.
+func CrossVec3(a, b Vec3) Vec3 {
+	vec := Vec3{}
+
+	vec.X = (a.Y * b.Z) - (a.Z * b.Y)
+	vec.Y = (a.Z * b.X) - (a.X * b.Z)
+	vec.Z = (a.X * b.Y) - (a.Y * b.X)
+
+	return vec
+}