Initial

g3d/vectors.lua

@@ -0,0 +1,42 @@
+-- written by groverbuger for g3d
+-- september 2021
+-- MIT license
+
+----------------------------------------------------------------------------------------------------
+-- vector functions
+----------------------------------------------------------------------------------------------------
+-- some basic vector functions that don't use tables
+-- because these functions will happen often, this is done to avoid frequent memory allocation
+
+local vectors = {}
+
+function vectors.subtract(v1,v2,v3, v4,v5,v6)
+    return v1-v4, v2-v5, v3-v6
+end
+
+function vectors.add(v1,v2,v3, v4,v5,v6)
+    return v1+v4, v2+v5, v3+v6
+end
+
+function vectors.scalarMultiply(scalar, v1,v2,v3)
+    return v1*scalar, v2*scalar, v3*scalar
+end
+
+function vectors.crossProduct(a1,a2,a3, b1,b2,b3)
+    return a2*b3 - a3*b2, a3*b1 - a1*b3, a1*b2 - a2*b1
+end
+
+function vectors.dotProduct(a1,a2,a3, b1,b2,b3)
+    return a1*b1 + a2*b2 + a3*b3
+end
+
+function vectors.normalize(x,y,z)
+    local mag = math.sqrt(x^2 + y^2 + z^2)
+    return x/mag, y/mag, z/mag
+end
+
+function vectors.magnitude(x,y,z)
+    return math.sqrt(x^2 + y^2 + z^2)
+end
+
+return vectors