Ensure Dist/SqrDist funcs inline + DistVec4 + SqrDistVec4

.gitignore

@@ -12,4 +12,5 @@
 *.out
 
 # Dependency directories (remove the comment below to include it)
-# vendor/
+vendor/
+.vscode

README.md

@@ -1,2 +1,8 @@
 # gglm
+
 An OpenGL focused Go mathematics inspired by the C++ glm (OpenGL Mathematics) library
+
+## Notes
+
+You can check compiler inlining decisions using `go run -gcflags "-m" .`. Some functions look a bit weird compared to similar ones
+because we are trying to reduce function complexity so the compiler inlines.

gglm/geometric.go

@@ -1,5 +1,7 @@
 package gglm
 
+import "math"
+
 func DotVec2(v1, v2 *Vec2) float32 {
 	return v1.X()*v2.X() + v1.Y()*v2.Y()
 }
@@ -24,54 +26,50 @@ func Cross(v1, v2 *Vec3) *Vec3 {
 
 //DistVec2 returns euclidean distance between v1 and v2
 func DistVec2(v1, v2 *Vec2) float32 {
-
-	diff := Vec2{
-		Data: [2]float32{
-			v1.X() - v2.X(),
-			v1.Y() - v2.Y(),
-		},
-	}
-
-	return diff.Mag()
+	x := v1.X() - v2.X()
+	y := v1.Y() - v2.Y()
+	return float32(math.Sqrt(float64(x*x + y*y)))
 }
 
 //DistVec3 returns euclidean distance between v1 and v2
 func DistVec3(v1, v2 *Vec3) float32 {
+	x := v1.X() - v2.X()
+	y := v1.Y() - v2.Y()
+	z := v1.Z() - v2.Z()
+	return float32(math.Sqrt(float64(x*x + y*y + z*z)))
+}
 
-	diff := Vec3{
-		Data: [3]float32{
-			v1.X() - v2.X(),
-			v1.Y() - v2.Y(),
-			v1.Z() - v2.Z(),
-		},
-	}
+//DistVec4 returns euclidean distance between v1 and v2
+func DistVec4(v1, v2 *Vec4) float32 {
 
-	return diff.Mag()
+	//Using X() etc won't let the function inline
+	x := v1.Data[0] - v2.Data[0]
+	y := v1.Data[1] - v2.Data[1]
+	z := v1.Data[2] - v2.Data[2]
+	w := v1.Data[3] - v2.Data[3]
+	return float32(math.Sqrt(float64(x*x + y*y + z*z + w*w)))
 }
 
 //DistVec2 returns the squared euclidean distance between v1 and v2 (avoids a sqrt)
 func SqrDistVec2(v1, v2 *Vec2) float32 {
-
-	diff := Vec2{
-		Data: [2]float32{
-			v1.X() - v2.X(),
-			v1.Y() - v2.Y(),
-		},
-	}
-
-	return diff.SqrMag()
+	x := v1.X() - v2.X()
+	y := v1.Y() - v2.Y()
+	return x*x + y*y
 }
 
 //DistVec3 returns the squared euclidean distance between v1 and v2 (avoids a sqrt)
 func SqrDistVec3(v1, v2 *Vec3) float32 {
-
-	diff := Vec3{
-		Data: [3]float32{
-			v1.X() - v2.X(),
-			v1.Y() - v2.Y(),
-			v1.Z() - v2.Z(),
-		},
-	}
-
-	return diff.SqrMag()
+	x := v1.X() - v2.X()
+	y := v1.Y() - v2.Y()
+	z := v1.Z() - v2.Z()
+	return x*x + y*y + z*z
+}
+
+//DistVec4 returns the squared euclidean distance between v1 and v2 (avoids a sqrt)
+func SqrDistVec4(v1, v2 *Vec4) float32 {
+	x := v1.Data[0] - v2.Data[0]
+	y := v1.Data[1] - v2.Data[1]
+	z := v1.Data[2] - v2.Data[2]
+	w := v1.Data[3] - v2.Data[3]
+	return x*x + y*y + z*z + w*w
 }

main.go

@@ -51,12 +51,36 @@ func main() {
 	println(m6.String())
 	println(m4.Eq(m6))
 
+	//Vec2
 	v1 := &gglm.Vec2{Data: [2]float32{1, 2}}
 	v2 := &gglm.Vec2{Data: [2]float32{3, 4}}
 	println(gglm.DistVec2(v1, v2))
 	println(gglm.SqrDistVec2(v2, v1))
-
 	println(v1.Eq(v2))
 	v2.Set(1, 2)
 	println(v1.Eq(v2))
+
+	//Vec3
+	v3 := &gglm.Vec3{Data: [3]float32{1, 2, 3}}
+	v4 := &gglm.Vec3{Data: [3]float32{4, 5, 6}}
+	println(gglm.DistVec3(v3, v4))
+	println(gglm.SqrDistVec3(v4, v3))
+
+	println(v3.Eq(v4))
+	v4.Set(1, 2, 3)
+	println(v3.Eq(v4))
+
+	println(gglm.DotVec3(v3, v4))
+
+	//Vec4
+	v5 := &gglm.Vec4{Data: [4]float32{1, 2, 3, 4}}
+	v6 := &gglm.Vec4{Data: [4]float32{5, 6, 7, 8}}
+	println(gglm.DistVec4(v5, v6))
+	println(gglm.SqrDistVec4(v5, v6))
+
+	println(v5.Eq(v6))
+	v6.Set(1, 2, 3, 4)
+	println(v5.Eq(v6))
+
+	println(gglm.DotVec4(v5, v6))
 }