From c67cb58c42668f8110692b5a315d36c4d1935e9f Mon Sep 17 00:00:00 2001
From: og76 <ovidiu.grigorescu@gmail.com>
Date: Fri, 25 Mar 2016 21:48:15 +0200
Subject: [PATCH] Create rotation.py

vector / rotation algo
---
 algorithms/rotation.py | 94 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)
 create mode 100644 algorithms/rotation.py

diff --git a/algorithms/rotation.py b/algorithms/rotation.py
new file mode 100644
index 000000000..f671cf9b3
--- /dev/null
+++ b/algorithms/rotation.py
@@ -0,0 +1,94 @@
+
+
+#### RotationToDirection 
+'''
+Converts euler to vector (direction or normal) with custom length
+
+required arguments (as strings):
+    input socket name: rotation (euler), length (float),
+    output socket name: direction (vector)
+    axis in ("X", "Y", "Z", "-X", "-Y", "-Z")
+'''
+
+def generateRotationToDirectionCode(rotationName, lengthName, directionOutputName, axis):
+    directionAxisTuple = {"X": "({}, 0, 0)", "Y": "(0, {}, 0)", "Z": "(0, 0, {})",
+                         "-X":"(-{}, 0, 0)","-Y": "(0,-{}, 0)","-Z": "(0, 0,-{})"}
+    axisTuple = directionAxisTuple[axis].format(lengthName)
+    
+    return "{} = {}.to_matrix() * mathutils.Vector({})".format(directionOutputName, rotationName, axisTuple)
+
+##############################
+
+
+#### DirectionToRotation 
+'''
+Converts vector to rotation, with an extra guide vector 
+(like to_track_quat(), but can specify custom UP axis (as guide))
+
+required arguments (as strings):
+    input socket name: direction (vector), guide (vector),
+    trackAxis in ("X", "Y", "Z", "-X", "-Y", "-Z")
+    guideAxis in ("X", "Y", "Z")
+optional outputs / types (as strings):
+    output socket names : matrix (matrix), rotation (euler), quaternion (quaternion)
+     - will generate that output type if respective name is other than ""
+    if no output is specified (all to ""), code will be ""
+    this allows to generate that output only if needed (ex if respective socket is linked (isLinked dict))
+needs mathutils module
+'''
+
+def generateDirectionToRotationCode(directionName, guideName, trackAxis, guideAxis, matrixOutputName = "", rotationOutputName = "", quaternionOutputName = ""):
+    
+    def getAxesChange(track, guide):
+        if track == "X":    a = "( z,-y, x)" if guide == "Z" else "( z, x, y)"
+        elif track == "Y":  a = "( y, z, x)" if guide == "Z" else "( x, z,-y)"
+        elif track == "Z":  a = "( x, y, z)" if guide == "X" else "(-y, x, z)"
+        elif track == "-X": a = "(-z, y, x)" if guide == "Z" else "(-z, x,-y)"
+        elif track == "-Y": a = "(-y,-z, x)" if guide == "Z" else "( x,-z, y)"
+        elif track == "-Z": a = "( x,-y,-z)" if guide == "X" else "( y, x,-z)"
+        return a
+    
+    outputMatrix, outputEuler, outputQuaternion = False, False, False
+    if matrixOutputName != "": outputMatrix = True
+    if rotationOutputName != "": outputEuler = True
+    if quaternionOutputName != "": outputQuaternion = True
+    
+    #### exception 0
+    if not any([outputMatrix, outputEuler, outputQuaternion]):
+        return ""
+    
+    #### exception 1
+    if trackAxis[-1:] == guideAxis[-1:]:
+        if outputMatrix: yield "{} = mathutils.Matrix()".format(matrixOutputName)
+        if outputEuler: yield "{} = mathutils.Euler((0, 0, 0), 'XYZ')".format(rotationOutputName)
+        if outputQuaternion: yield "{} = mathutils.Quaternion((1, 0, 0, 0))".format(quaternionOutputName)
+        return
+
+    #### exception 2
+    yield "zero = mathutils.Vector((0, 0, 0))"
+
+    yield "if {} == zero:".format(directionName)
+    if outputMatrix: yield "    {} = mathutils.Matrix()".format(matrixOutputName)
+    if outputEuler: yield "    {} = mathutils.Euler((0, 0, 0), 'XYZ')".format(rotationOutputName)
+    if outputQuaternion: yield "    {} = mathutils.Quaternion((1, 0, 0, 0))".format(quaternionOutputName)
+
+    # always same
+    yield "else:"
+    yield "    z = {}.normalized()".format(directionName)
+    yield "    if {} != zero and z.cross({}) != zero: y = z.cross({}.normalized())".format(guideName, guideName, guideName)
+    if "X" == guideAxis: yield "    else: y = z.cross(mathutils.Vector((1, 0, 0))) if z.cross(mathutils.Vector((1, 0, 0))) != zero else mathutils.Vector((0, 0, 1))"
+    if "Y" == guideAxis: yield "    else: y = z.cross(mathutils.Vector((0, 1, 0))) if z.cross(mathutils.Vector((0, 1, 0))) != zero else mathutils.Vector((0, 0, 1))"
+    if "Z" == guideAxis: yield "    else: y = z.cross(mathutils.Vector((0, 0, 1))) if z.cross(mathutils.Vector((0, 0, 1))) != zero else mathutils.Vector((0, 1, 0))"
+    yield "    x = y.cross(z)"
+
+    yield "    mx, my, mz = " + getAxesChange(trackAxis, guideAxis)
+
+    yield "    mat = mathutils.Matrix()"
+    yield "    mat.col[0].xyz, mat.col[1].xyz, mat.col[2].xyz = mx, my, mz"
+                
+    #### outputs
+    if outputMatrix: yield "    {} = mat.normalized()".format(matrixOutputName)
+    if outputEuler: yield "    {} = mat.to_euler()".format(rotationOutputName)
+    if outputQuaternion: yield "    {} = mat.to_quaternion()".format(quaternionOutputName)
+
+##############################