3dFolding.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

# Copyright 2010 British Broadcasting Corporation and Kamaelia Contributors(1)
#
# (1) Kamaelia Contributors are listed in the AUTHORS file and at
#     http://www.kamaelia.org/AUTHORS - please extend this file,
#     not this notice.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# loadTexture function and event handling based on code from THF

from Kamaelia.UI.OpenGL.Vector import Vector
from Kamaelia.UI.OpenGL.Transform import Transform
from Kamaelia.UI.OpenGL.Intersect import Intersect

from Kamaelia.UI.OpenGL.OpenGLComponent import OpenGLComponent

import Axon
import pygame
from pygame.locals import *
from OpenGL.GL import *
from OpenGL.GLU import *


import time,math

class Simple3dFold(OpenGLComponent):

    def __init__(self, **argd):
        super(Simple3dFold, self).__init__(**argd)
        self.radius = max(0.001, argd.get("radius", 1.0))
        self.segments = max(2, argd.get("segments", 15))

    def setup(self):
        self.tex = "../../CE/characters/OLIVIA.jpg"
        self.loadTexture()

        # adjust aspect ratio
        if self.tex_w < self.tex_h:
            self.size.x = self.size.x * self.tex_w/self.tex_h
        else:
            self.size.y = self.size.y * self.tex_h/self.tex_w

        size = self.size/2.0
        
        shape = "CONCENTRIC"
        if shape == "SQUARE":
            #                  vertex-x  vertex-y   texture-x   texture-y
            self.polys = [
                           [ ((-size.x,  -size.y), (0.0,        1.0-self.tex_h)),
                             ((-size.x,  +size.y), (0.0,        1.0           )),
                             ((+size.x,  +size.y), (self.tex_w, 1.0           )),
                             ((+size.x,  -size.y), (self.tex_w, 1.0-self.tex_h)),
                           ],
                        ]
        elif shape == "STAR":
            #                  vertex-x  vertex-y      texture-x   texture-y
            self.polys = [
                           [ ((-size.x, -0.5*size.y), (0.0,        1.0-self.tex_h*0.75)),
                             ((0.0,     +size.y    ), (0.5,        1.0                )),
                             ((+size.x, -0.5*size.y), (1.0,        1.0-self.tex_h*0.75)),
                           ],
                           [ ((-size.x, +0.5*size.y), (0.0,        1.0-self.tex_h*0.25)),
                             ((0.0,     -size.y    ), (0.5,        1.0-self.tex_h     )),
                             ((+size.x, +0.5*size.y), (1.0,        1.0-self.tex_h*0.25)),
                           ],
                         ]
        elif shape == "CONCENTRIC":
            #                  vertex-x    vertex-y       texture-x         texture-y
            self.polys = [
                           [ ((-size.x,     -size.y    ), (0.0,             1.0-self.tex_h     )),
                             ((-size.x,     -size.y*0.6), (0.0,             1.0-self.tex_h*0.80)),
                             ((+size.x,     -size.y*0.6), (self.tex_w,      1.0-self.tex_h*0.80)),
                             ((+size.x,     -size.y),     (self.tex_w,      1.0-self.tex_h     )),
                           ],
                           [ ((-size.x,     +size.y    ), (0.0,             1.0                )),
                             ((-size.x,     +size.y*0.6), (0.0,             1.0-self.tex_h*0.20)),
                             ((+size.x,     +size.y*0.6), (self.tex_w,      1.0-self.tex_h*0.20)),
                             ((+size.x,     +size.y),     (self.tex_w,      1.0                )),
                           ],
                           [ ((-size.x,     -size.y    ), (0.0,             1.0-self.tex_h     )),
                             ((-size.x,     +size.y    ), (0.0,             1.0                )),
                             ((-size.x*0.6, +size.y    ), (self.tex_w*0.20, 1.0                )),
                             ((-size.x*0.6, -size.y    ), (self.tex_w*0.20, 1.0-self.tex_h     )),
                           ],
                           [ ((+size.x,     -size.y    ), (self.tex_w,      1.0-self.tex_h     )),
                             ((+size.x,     +size.y    ), (self.tex_w,      1.0                )),
                             ((+size.x*0.6, +size.y    ), (self.tex_w*0.80, 1.0                )),
                             ((+size.x*0.6, -size.y    ), (self.tex_w*0.80, 1.0-self.tex_h     )),
                           ],
                           [ ((-size.x*0.4, -size.y*0.4), (self.tex_w*0.30, 1.0-self.tex_h*0.70)),
                             ((-size.x*0.4, +size.y*0.4), (self.tex_w*0.30, 1.0-self.tex_h*0.30)),
                             ((+size.x*0.4, +size.y*0.4), (self.tex_w*0.70, 1.0-self.tex_h*0.30)),
                             ((+size.x*0.4, -size.y*0.4), (self.tex_w*0.70, 1.0-self.tex_h*0.70)),
                           ],
                        ]
        else:
            raise "No shape"

        self.starttime = time.time()
        self.foldpoint = (0.0, 0.0)
        self.folddelta = (0.0, 0.0)

        self.addListenEvents( [pygame.MOUSEBUTTONDOWN, pygame.MOUSEMOTION, pygame.MOUSEBUTTONUP ])
        self.pulling = False


    def draw(self):

        polys3d = []
        for poly in self.polys:
            curledpoly = curl( poly,
                               (self.foldpoint, self.folddelta), 
                               self.radius,
                               self.segments
                             )
            polys3d.extend(curledpoly)

        glEnable(GL_TEXTURE_2D)
        glBindTexture(GL_TEXTURE_2D, self.texID)
        glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE)

        val=0
        for poly in polys3d:
            glBegin(GL_POLYGON)
            for ((x,y,z),(tx,ty), fade) in poly:
                shade = fade**2
                glColor3f(shade,shade,shade)
                glTexCoord2f(tx,ty)
                glVertex3f(x, y, z)
            glEnd()

        glDisable(GL_TEXTURE_2D)

    def frame(self):
        size = self.size/2.0

        angle = (time.time()-self.starttime) / 2.0
#        self.folddelta = math.cos(angle*0.2), math.sin(angle*0.2)

#        self.radius = 2.0*math.cos(angle)+2.2
#        cossquared = (math.cos(angle)**2)
#        moveto = interpolate(self.poly[1][0],self.poly[3][0],2.0*cossquared)
#        movefrom = self.poly[1][0]
#        moveto = rotate(angle*0.1, moveto)
#        movefrom = rotate(angle*0.1, movefrom)
#        self.foldpoint, self.folddelta = calcFoldLine(movefrom, moveto, self.radius)

        self.redraw()

    def loadTexture(self):
        """ Loads texture from specified image file. """
        from math import ceil, log
        if self.tex is not None:
            # load image
            image = pygame.image.load(self.tex)
            # create power of 2 dimensioned surface
            pow2size = (int(2**(ceil(log(image.get_width(), 2)))), int(2**(ceil(log(image.get_height(), 2)))))
            if pow2size != image.get_size():
                textureSurface = pygame.Surface(pow2size, pygame.SRCALPHA, 32)
                # determine texture coordinates
                self.tex_w = float(image.get_width())/pow2size[0]
                self.tex_h = float(image.get_height())/pow2size[1]
                # copy image data to pow2surface
                textureSurface.blit(image, (0,0))
            else:
                textureSurface = image
                self.tex_w = 1.0
                self.tex_h = 1.0
            # read pixel data
            textureData = pygame.image.tostring(textureSurface, "RGBX", 1)
            # gen tex name
            self.texID = glGenTextures(1)
            # create texture
            glEnable(GL_TEXTURE_2D)
            glBindTexture(GL_TEXTURE_2D, self.texID)
            glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
            glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
            glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA, textureSurface.get_width(), textureSurface.get_height(), 0,
                            GL_RGBA, GL_UNSIGNED_BYTE, textureData );
            glDisable(GL_TEXTURE_2D)

    def handleEvents(self):
        while self.dataReady("events"):
            setPullPoint=False
            event = self.recv("events")
            if (event.type == pygame.MOUSEBUTTONDOWN and event.button==1 and self.identifier in event.hitobjects):
                self.pulling=True
                setPullPoint=True

            if (event.type == pygame.MOUSEBUTTONUP and self.pulling):
                self.pulling=False
                self.foldpoint, self.folddelta = calcFoldLine((0.0, 0.0), (0.0, 0.0), self.radius)

            if self.pulling:

                # transform vertices for intersection test
                transformedPoly = [ self.transform.transformVector(Vector(x,y,0.0))
                                    for ((x,y),_) in self.polys[0] ]
                # calculate distance of intersection
                t = Intersect.ray_Plane(Vector(0,0,0), event.direction, transformedPoly[0:3]);
                # point of intersection
                p = event.direction*t

                point = mapPlaneToPoly( transformedPoly[0].toTuple(),
                                        transformedPoly[1].toTuple(),
                                        transformedPoly[2].toTuple(),
                                        self.polys[0][0][0],
                                        self.polys[0][1][0],
                                        self.polys[0][2][0],
                                        p.toTuple(),
                                        )
                if setPullPoint:
                    self.pullpoint = point[0], point[1]
                self.foldpoint, self.folddelta = calcFoldLine(self.pullpoint, point, self.radius)



def mapPlaneToPoly(A,B,C,AA,BB,CC,P):
    # A, B, C are points on the poly as (x,y,z) tuples
    # P is a point in the plane as (x,y,z) tuple
    # AA,BB,CC are the corresponding (x,y) tuple points for A,B,C

    # we'll calculate p and q where P = A + pAB + qAC

    AB = B[0]-A[0], B[1]-A[1], B[2]-A[2]
    AC = C[0]-A[0], C[1]-A[1], C[2]-A[2]

    components = [ (0,1), (0,2), (1,2), (1,0), (2,0), (2,1) ]  # different choices of component pairs to use
    for x,y in components:

        # check we're not going to get division by zero errors
        # otherwise move onto a different pair of components
        if AC[y] == 0:
            continue
        divisor = AB[y]*AC[x] - AB[x]*AC[y]
        if divisor == 0:
            continue

        # p = (xA*yAC - xD*yAC + yD*xAC - yA*xAC) / (yAB*xAC - xAB*yAC)
        p = ( AC[y]*(A[x]-P[x]) + AC[x]*(P[y]-A[y]) ) / divisor

        # q = (yD - yA - p*yAB)/yAC
        q = (P[y] - A[y] - p*AB[y]) / AC[y]

        # now we have p and q, we can do P = A + pAB + qAC in the AA,BB,CC domain
        AABB = BB[0]-AA[0], BB[1]-AA[1]
        AACC = CC[0]-AA[0], CC[1]-AA[1]

        return ( AA[0] + p*AABB[0] + q*AACC[0],
                 AA[1] + p*AABB[1] + q*AACC[1] )


def calcFoldLine(oldPos, newPos, foldradius):
    # calculate what fold line is needed to move the specified point to the specified new location

    ox,oy = oldPos
    nx,ny = newPos

    delta = (nx-ox, ny-oy)

    if delta == (0.0, 0.0):
        return (0.0, 0.0), (0.0, 0.0)

    folddelta = right90(delta)
    foldpoint = ( (ox+nx)/2.0, (oy+ny)/2.0 )
    adjust = normalise(left90(folddelta), foldradius*(math.pi/2.0 - 1.0))
    foldpoint = ( foldpoint[0] + adjust[0],
                  foldpoint[1] + adjust[1] )

    return (foldpoint,folddelta)

def curl(poly, foldline, radius, segments):
    # curls a 2d convex polygon in an X-Y plane about a foldline, giving a pageturn/peel effect
    # poly = list of points, of the form ((X,Y),(textureX,textureY))
    # foldline = ((x,y),(dx,dy)) defining a line
    # radius and segments controls the shape and rendering quality of the curl
    #
    # returns list of polys
    # each poly is a list of points, of the form ((X,Y,Z),(textureX,textureY),fade)
    # Z=0 for uncurled parts of the polygon
    # Z=2*radius for fully curled over parts
    # fade=1.0 for fully uncurled or fully curled parts
    # fade=0.0 for points on the midpoint of the curl
    # (use fade to control shaing to darken the curled parts of the polygon)

    foldpoint, folddelta = foldline

    if folddelta == (0.0, 0.0):
        return [ [ ((x,y,0.0),texP,1.0) for ((x,y),texP) in poly ] ]


    # we're going the transform the foldline from being on the midpoint of the fold
    # to where the curl starts
    foldpoint = (foldpoint[0] + normalise(left90(folddelta), radius)[0],
                 foldpoint[1] + normalise(left90(folddelta), radius)[1] )

    # generate the set of lines through the polygon with which we need to slice
    # it up in order to make the polygons for each segment of the curl
    slicelines = []
    distance = radius*math.pi
    for slicenum in range(0,segments):
        folddist = distance/segments*slicenum
        slicepoint = right90(normalise(folddelta, folddist))
        slicepoint = ( slicepoint[0] + foldpoint[0],
                       slicepoint[1] + foldpoint[1] )
        slicelines.append( (slicepoint, folddelta) )

    # slice the polygon into segments using the slicelines we defined
    slices = segmentIntoSlices(poly, slicelines)

    # tag each point with vector-from-start-of-folding
    # first part (non folded part) will be zero distance
    polys=[]
    polys.append( [ (point,(0,0),texpoint) for point,texpoint in slices[0] ] )
    for slice in slices[1:]:
        polys.append( [ (point,
                         vector_from_line(point,(foldpoint, folddelta)),
                         texpoint)
                         for point,texpoint in slice ]
                    )

    # now curl the polys
    curledpolys = []
    foldpointoffset = normalise(right90(folddelta), (math.pi*radius/2.0))
    reflectionpoint = ( foldpoint[0] + foldpointoffset[0],
                        foldpoint[1] + foldpointoffset[1] )
    for poly in polys:
        curledpoly = []
        for (point,vec,texpoint) in poly:
            if vec==(0,0):
                x,y,z = (point[0],point[1], 0.0)
                fade = 1.0
            else:
                angle = dist(vec) / radius  # goes 0..pi over a half circle
                if angle <= math.pi:
                    cos = math.cos(angle)
                    sin = math.sin(angle)
                    nvec = normalise(vec, radius)
                    x = point[0]-vec[0] + sin*nvec[0]
                    y = point[1]-vec[1] + sin*nvec[1]
                    z = radius - radius*cos
                else:
                    z = 2.0*radius
                    x,y = reflect(point, (reflectionpoint, folddelta))
                fade = abs(radius-z)/radius
            curledpoly.append(((x,y,z),texpoint,fade))

        curledpolys.append(curledpoly)

    return curledpolys


def segmentIntoSlices(poly, slicelines):
    # slices a polygon into a set of polygons, by slicing it using, in order
    # the set of supplied lines.
    slices = [ poly ]
    oldpoly = poly[:]

    # slices the polygon using the first line; then slices what is left using the next
    # and then what is left again using the next, etc...

    for sliceline in slicelines:
        if len(oldpoly):
            oldpoly, newpoly = slicepoly(oldpoly, sliceline)
        else:
            break
        slices[-1] = oldpoly
        oldpoly = newpoly

        slices.append(newpoly)
    return slices

def slicepoly(poly, foldline):
    """\
    Slice a 2d poly CONVEX (not concave) across a line.

    Takes in a list of (X,Y) points reresenting a poly and a line (point_on_line, delta)
    and returns a list of [poly,poly]
    first poly is the poly for the left side of the line. 2nd slice is the right side.
    """
    foldpoint = foldline[0]
    folddelta = foldline[1]

    (prev, prevtex) = poly[-1]

    normpoly = []
    foldpoly = []

    subpoly = []
    currentside = whichSide(prev, foldline)

    for (point,texpoint) in poly:

        intersect = bisect(prev, point, foldline)
        pointside = whichSide(point, foldline)

        if intersect>=0.0 and intersect<=1.0:
            ipoint = interpolate(prev,point,intersect)
            itexpoint = interpolate(prevtex,texpoint,intersect)
        else:
            ipoint = tuple(point)
            itexpoint = tuple(texpoint)
        subpoly.append( (ipoint,itexpoint) )

        if currentside==0:
            currentside = pointside

        if pointside * currentside < 0.0:  # different signs, we've switched sides
            if currentside<0.0:
                normpoly.extend(subpoly)
            else:
                foldpoly.extend(subpoly)

            subpoly = [(ipoint,itexpoint),(point,texpoint)]
            currentside = pointside

        prev,prevtex = point,texpoint

    if currentside<0.0:
        normpoly.extend(subpoly)
    else:
        foldpoly.extend(subpoly)

    return normpoly,foldpoly


def whichSide(point,line):
    """Returns -ve, 0, +ve if point is on LHS, ontop, or RHS of line"""

    linepoint, linedelta = line

    # determine which side of the fold line this initial point is on
    # which side of the line is it on? right hand side, or left?
    pdx = point[0]-linepoint[0]
    pdy = point[1]-linepoint[1]

    if linedelta[0]==0:
        return pdx
    elif linedelta[0]>0:
        return (linedelta[1]/linedelta[0])*pdx - pdy
    elif linedelta[0]<0:
        return pdy - (linedelta[1]/linedelta[0])*pdx




def bisect(start,end,line):
    """Returns the point of intersection of a line between start and end
    and an infinite line (defined by a point and delta vector).
    0 = intersects at start
    0.5 = intersects half way between start and end
    1 = intersects at end
    <0 or >1 = intersects outside of those bounds
    None = lines are parallel
    """
    point,delta = line

    divisor = ( (end[1]-start[1])*delta[0] - (end[0]-start[0])*delta[1] )
    if divisor != 0.0:
        intersect = ( (point[1]-start[1])*delta[0] - (point[0]-start[0])*delta[1] ) / divisor
    else:
        return None

    return intersect

def interpolate(start,end,val):
    return [ start*(1.0-val) + end*val for (start,end) in zip(start,end) ]

def reflect(point,foldline):
    foldpoint = foldline[0]
    dx,dy = foldline[1]

    # move line (and therefore the point) so the line passes through (0,0)
    px = point[0]-foldpoint[0]
    py = point[1]-foldpoint[1]

    # find closest point on the line
    if dx == 0.0:
        cx = 0
        cy = py
    elif dy == 0.0:
        cx = px
        cy = 0
    else:
        cx = (py + px*dx/dy)/(dy/dx + dx/dy)
        cy = py + (dx/dy)*(px-cx)

    # reflect
    rx = point[0] - 2.0*(px-cx)
    ry = point[1] - 2.0*(py-cy)

    return rx,ry

def vector_from_line(point,line):
    """returns the shortest vector from the line to the point"""
    linepoint = line[0]
    dx,dy = line[1]

    # move line (and therefore the point) so the line passes through (0,0)
    px = point[0] - linepoint[0]
    py = point[1] - linepoint[1]

    # find closest point on the line
    if dx == 0.0:
        cx = 0
        cy = py
    elif dy == 0.0:
        cx = px
        cy = 0
    else:
        cx = (py + px*dx/dy)/(dy/dx + dx/dy)
        cy = py + (dx/dy)*(px-cx)

    return px-cx,py-cy

def normalise(vector, toLen=1.0):
    lenSquared = sum([v*v for v in vector])
    scaling = toLen/(lenSquared**0.5)
    return [v*scaling for v in vector]

def left90(vector):
    return (-vector[1],vector[0])

def right90(vector):
    return (vector[1],-vector[0])

def rotate(angle, vector):
    cos = math.cos(angle)
    sin = math.sin(angle)
    return ( cos*vector[0]+sin*vector[1],
            -sin*vector[0]+cos*vector[1] )

def dist(vector):
    return (vector[0]*vector[0] + vector[1]*vector[1])**0.5

if __name__ == '__main__':
    import Axon

    from Kamaelia.UI.OpenGL.OpenGLDisplay import OpenGLDisplay
    from Kamaelia.UI.OpenGL.SimpleRotationInteractor import SimpleRotationInteractor

    display = OpenGLDisplay(background_colour=(0.75, 0.75, 1.0)).activate()
    OpenGLDisplay.setDisplayService(display)

    FOLD = Simple3dFold(position=(0,0,-22), size=(15,15,2), rotation=(-30,0,0),radius=1.0,segments=15).activate()
#    SimpleRotationInteractor(target=FOLD).activate()

    print "Grab close to a corner and drag!"

    Axon.Scheduler.scheduler.run.runThreads()