#
#    w3d2 exporter for Blender v2.11+
#    Based on Flure's w3d script; exports raw data in easy to parse format
#    Press alt-p in this window and each mesh will be exported to a file
#    Comment out corresponding FILE.write lines for info you don't want/need
#

import Blender
from math import sqrt

version = "W3D24"

def calcNormal(face, verts, n):
    # If it's a quad, calculate normal from diagonal instead
    # Assume verts are sorted in circular fasion (i.e. next to each other)
    m = (3 * n) | 1    # when n=0 (tri), m=1; when n=1 (quad), m=3
    vectorU = [verts[face[0]][0] - verts[face[2]][0],    \
               verts[face[0]][1] - verts[face[2]][1],    \
               verts[face[0]][2] - verts[face[2]][2]]
    vectorV = [verts[face[n]][0] - verts[face[m]][0],    \
               verts[face[n]][1] - verts[face[m]][1],    \
               verts[face[n]][2] - verts[face[m]][2]]
    normal = [(vectorU[1] * vectorV[2]) - (vectorU[2] * vectorV[1]),    \
              (vectorU[2] * vectorV[0]) - (vectorU[0] * vectorV[2]),    \
              (vectorU[0] * vectorV[1]) - (vectorU[1] * vectorV[0])]
    nLength = sqrt((normal[0] ** 2) + (normal[1] ** 2) + (normal[2] ** 2))
    return (normal[0]/nLength, normal[1]/nLength, normal[2]/nLength)

scene = Blender.getCurrentScene()
for name in scene.objects:
    if Blender.isMesh(name):
        print("Writing %s...\n" % name)
        fileName = "%s.w3d" % name
        FILE = open(fileName, "w")
        FILE.write("%s\n\n" % version)
        FILE.write("MESH\t%s\n\n" % name)

        object = Blender.getObject(name)
        mesh = Blender.getMesh(name)
        faces = mesh.faces
        materials = object.materials
        vertices = mesh.vertices
        vnormals = mesh.normals
        texcoords = mesh.texcoords
        vcolors = mesh.colors

        # Total vertices and faces; comment if not useful
        FILE.write("TOTALFACES\t%s\n" % len(faces))
        FILE.write("TOTALVERTS\t%s\n\n" % len(vertices))

        # the j is to keep track what iteration I'm on in the
        # "for face in faces" loop so I can make sure I'm on the
        # right set of UV coords
        j = 0
        for face in faces:
            if face[3]: totalVerts = 4
            else: totalVerts = 3

            # 1 for quad, 0 for triangle
            FILE.write("QUAD\t%s\n" % (totalVerts - 3))

            # 1 to smooth, 0 to not smooth
            FILE.write("SMOOTH\t%s\n" % face[4])

            # print face's "natual" material info
            matIndex = face[5]
            if materials and materials[matIndex]:
                material = Blender.getMaterial(materials[matIndex])
                FILE.write("COLOR\t%s\t%s\t%s\n" % (material.R, material.G, material.B))
                try:
                    FILE.write("SPECCOLOR\t%s\t%s\t%s\n" % (material.SpecR, material.SpecG, material.SpecB))
                    FILE.write("SPEC\t%s\n" % material.Spec)
                    FILE.write("HARD\t%s\n" % material.Hard)
                    FILE.write("ALPHA\t%s\n" % material.Alpha)
                    FILE.write("DIFFUSE\t%s\n" % material.Ref)
                except:
                    print "Blender Version < 2.12, skipping most material properties\n\n"

            # normal caculation
            normal = calcNormal(face, vertices, totalVerts - 3)
            FILE.write("NORMAL\t%s\t%s\t%s\n" % (normal[0], normal[1], normal[2]))

            # loop to keep uv, vertex, vertex normal, and vertex colors
            # grouped per set
            for i in range(totalVerts):
                if texcoords:
                    FILE.write("UVCOORD\t%s\t%s\n" % (texcoords[j][i][0], texcoords[j][i][1]))
                FILE.write("VERTEX\t%s\t%s\t%s\n" % (vertices[face[i]][0], vertices[face[i]][1], vertices[face[i]][2]))
                FILE.write("VNORMAL\t%s\t%s\t%s\n" % (vnormals[face[i]][0], vnormals[face[i]][1], vnormals[face[i]][2]))
                if vcolors:
                    FILE.write("VCOLOR\t%s\t%s\t%s\n" % (vcolors[face[i]][0], vcolors[face[i]][1], vcolors[face[i]][2]))

            # print first image map for uvcoords to use
            # to be updated when we get access to other textures
            if mesh.texture: FILE.write("UVTEXTURE\t%s\n" % mesh.texture)

            FILE.write("\n")
            j = j + 1

        FILE.close()

print scene