Moved all into one package, added png loader.

vec4.go

@@ -0,0 +1,72 @@
+package goga
+
+import (
+	"math"
+)
+
+// A 4D vector.
+type Vec4 struct {
+	X, Y, Z, W float64
+}
+
+// Creates a copy of actual vector.
+func (v *Vec4) Copy() Vec4 {
+	return Vec4{v.X, v.Y, v.Z, v.W}
+}
+
+// Adds and saves the given vector to actual vector.
+func (v *Vec4) Add(vec Vec4) {
+	v.X += vec.X
+	v.Y += vec.Y
+	v.Z += vec.Z
+	v.W += vec.W
+}
+
+// Subracts and saves the given vector to actual vector.
+func (v *Vec4) Sub(vec Vec4) {
+	v.X -= vec.X
+	v.Y -= vec.Y
+	v.Z -= vec.Z
+	v.W -= vec.W
+}
+
+// Multiplies and saves the given vector to actual vector.
+func (v *Vec4) Mult(vec Vec4) {
+	v.X *= vec.X
+	v.Y *= vec.Y
+	v.Z *= vec.Z
+	v.W *= vec.W
+}
+
+// Divides and saves the given vector to actual vector.
+func (v *Vec4) Div(vec Vec4) {
+	v.X /= vec.X
+	v.Y /= vec.Y
+	v.Z /= vec.Z
+	v.W /= vec.W
+}
+
+// Calculates and returns the dot product of actual vector.
+func (v *Vec4) Dot() float64 {
+	return v.X*v.X + v.Y*v.Y + v.Z*v.Z + v.W*v.W
+}
+
+// Calculates and returns the dot product of combination of given vector and actual vector.
+func (v *Vec4) DotVec(vec Vec4) float64 {
+	return v.X*vec.X + v.Y*vec.Y + v.Z*vec.Z + v.W*vec.W
+}
+
+// Returns the length of actual vector.
+func (v *Vec4) Length() float64 {
+	return math.Sqrt(v.Dot())
+}
+
+// Normalizes actual vector to length 1.
+func (v *Vec4) Normalize() {
+	l := v.Length()
+
+	v.X /= l
+	v.Y /= l
+	v.Z /= l
+	v.W /= l
+}