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Cube.py
# coding: utf-8
import math
from operator import itemgetter
import console
from PIL import Image, ImageDraw
import scene
class Point3D:
def __init__(self, x = 0, y = 0, z = 0):
self.x, self.y, self.z = float(x), float(y), float(z)
def rotateX(self, angle):
""" Rotates the point around the X axis by the given angle in degrees. """
rad = angle * math.pi / 180
cosa = math.cos(rad)
sina = math.sin(rad)
y = self.y * cosa - self.z * sina
z = self.y * sina + self.z * cosa
return Point3D(self.x, y, z)
def rotateY(self, angle):
""" Rotates the point around the Y axis by the given angle in degrees. """
rad = angle * math.pi / 180
cosa = math.cos(rad)
sina = math.sin(rad)
z = self.z * cosa - self.x * sina
x = self.z * sina + self.x * cosa
return Point3D(x, self.y, z)
def rotateZ(self, angle):
""" Rotates the point around the Z axis by the given angle in degrees. """
rad = angle * math.pi / 180
cosa = math.cos(rad)
sina = math.sin(rad)
x = self.x * cosa - self.y * sina
y = self.x * sina + self.y * cosa
return Point3D(x, y, self.z)
def project(self, win_width, win_height, fov, viewer_distance):
""" Transforms this 3D point to 2D using a perspective projection. """
factor = fov / (viewer_distance + self.z)
x = self.x * factor + win_width / 2
y = -self.y * factor + win_height / 2
return Point3D(x, y, self.z)
class Cube(scene.Scene):
def setup(self, win_width = 640, win_height = 480):
self.vertices = [
Point3D(-1,1,-1),
Point3D(1,1,-1),
Point3D(1,-1,-1),
Point3D(-1,-1,-1),
Point3D(-1,1,1),
Point3D(1,1,1),
Point3D(1,-1,1),
Point3D(-1,-1,1)
]
# Define the vertices that compose each of the 6 faces. These numbers are
# indices to the vertices list defined above.
self.faces = [(0,1,2,3),(1,5,6,2),(5,4,7,6),(4,0,3,7),(0,4,5,1),(3,2,6,7)]
# Define colors for each face
colors = [
'#FFEC94',
'#FFAEAE',
'#404040',
'#B0E57C',
'#B4D8E7',
'#7BC8A4']
self.colors = [scene.load_pil_image(Image.new('RGBA',(10,10),color)) for color in colors]
self.angle = 0
def draw(self):
angle = self.angle
self.angle += .5
scene.background(0,0,0)
# It will hold transformed vertices.
t = []
for v in self.vertices:
# Rotate the point around X axis, then around Y axis, and finally around Z axis.
r = v.rotateX(angle).rotateY(angle).rotateZ(angle)
# Transform the point from 3D to 2D
p = r.project(self.size.w, self.size.h, 256, 3)
# Put the point in the list of transformed vertices
t.append(p)
# Calculate the average Z values of each face.
avg_z = []
i = 0
for f in self.faces:
z = (t[f[0]].z + t[f[1]].z + t[f[2]].z + t[f[3]].z) / 4.0
avg_z.append([i,z])
i = i + 1
# Draw the faces using the Painter's algorithm:
# Distant faces are drawn before the closer ones.
for tmp in sorted(avg_z,key=itemgetter(1),reverse=True):
face_index = tmp[0]
f = self.faces[face_index]
pointlist = [
t[f[1]].x, t[f[1]].y,
t[f[0]].x, t[f[0]].y,
t[f[2]].x, t[f[2]].y,
t[f[3]].x, t[f[3]].y,]
scene.image_quad(self.colors[face_index], *pointlist)
scene.run(Cube())
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