Discussion :

[lemmanu]

Code :

Sélectionner tout - Visualiser dans une fenêtre à part

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
import math
import cmath
import cairo
 
 
#------ Configuration --------
IMAGE_SIZE = (1000, 1000)
NUM_SUBDIVISIONS = 8
#-----------------------------
 
 
goldenRatio = (1 + math.sqrt(5)) / 2
 
def subdivide(triangles):
    result = []
    for color, A, B, C in triangles:
        if color == 0:
            # Subdivide red triangle
            P = A + (B - A) / goldenRatio
            result += [(0, C, P, B), (1, P, C, A)]
        else:
            # Subdivide blue triangle
            Q = B + (A - B) / goldenRatio
            R = B + (C - B) / goldenRatio
            result += [(1, R, C, A), (1, Q, R, B), (0, R, Q, A)]
    return result
 
# Create wheel of red triangles around the origin
triangles = []
for i in xrange(10):
    B = cmath.rect(1, (2*i - 1) * math.pi / 10)
    C = cmath.rect(1, (2*i + 1) * math.pi / 10)
    if i % 2 == 0:
        B, C = C, B  # Make sure to mirror every second triangle
    triangles.append((0, 0j, B, C))
 
# Perform subdivisions
for i in xrange(NUM_SUBDIVISIONS):
    triangles = subdivide(triangles)
 
# Prepare cairo surface
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, IMAGE_SIZE[0], IMAGE_SIZE[1])
cr = cairo.Context(surface)
cr.translate(IMAGE_SIZE[0] / 2.0, IMAGE_SIZE[1] / 2.0)
wheelRadius = 1.2 * math.sqrt((IMAGE_SIZE[0] / 2.0) ** 2 + (IMAGE_SIZE[1] / 2.0) ** 2)
cr.scale(wheelRadius, wheelRadius)
 
# Draw red triangles
for color, A, B, C in triangles:
    if color == 0:
        cr.move_to(A.real, A.imag)
        cr.line_to(B.real, B.imag)
        cr.line_to(C.real, C.imag)
        cr.close_path()
cr.set_source_rgb(1.0, 0.35, 0.35)
cr.fill()    
 
# Draw blue triangles
for color, A, B, C in triangles:
    if color == 1:
        cr.move_to(A.real, A.imag)
        cr.line_to(B.real, B.imag)
        cr.line_to(C.real, C.imag)
        cr.close_path()
cr.set_source_rgb(0.4, 0.4, 1.0)
cr.fill()
 
# Determine line width from size of first triangle
color, A, B, C = triangles[0]
cr.set_line_width(abs(B - A) / 10.0)
cr.set_line_join(cairo.LINE_JOIN_ROUND)
 
# Draw outlines
for color, A, B, C in triangles:
    cr.move_to(C.real, C.imag)
    cr.line_to(A.real, A.imag)
    cr.line_to(B.real, B.imag)
cr.set_source_rgb(0.2, 0.2, 0.2)
cr.stroke()
 
# Save to PNG
surface.write_to_png('penrose.png')

[__dardanos__]

Salut,
Il faut utiliser la classe PDFSurface pour créer un pdf.
La méthode set_source_rgb sert à définir les composantes RGB d'une couleur.

Code :

Sélectionner tout - Visualiser dans une fenêtre à part

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
#!/usr/bin/env python
# -*- coding:Utf-8 -*-
import math
import cmath
import cairo
 
#------ Configuration --------
IMAGE_SIZE = (1000, 1000)
NUM_SUBDIVISIONS = 5
#-----------------------------
 
goldenRatio = (1 + math.sqrt(5)) / 2
 
def subdivide(triangles):
    result = []
    for color, A, B, C in triangles:
        if color == 0:
            # Subdivide red triangle
            P = A + (B - A) / goldenRatio
            result += [(0, C, P, B), (1, P, C, A)]
        else:
            # Subdivide blue triangle
            Q = B + (A - B) / goldenRatio
            R = B + (C - B) / goldenRatio
            result += [(1, R, C, A), (1, Q, R, B), (0, R, Q, A)]
    return result
 
def penrose( filename, color1, color2):
    # Create wheel of red triangles around the origin
    triangles = []
    for i in xrange(10):
        B = cmath.rect(1, (2*i - 1) * math.pi / 10)
        C = cmath.rect(1, (2*i + 1) * math.pi / 10)
        if i % 2 == 0:
            B, C = C, B  # Make sure to mirror every second triangle
        triangles.append((0, 0j, B, C))
 
    # Perform subdivisions
    for i in xrange(NUM_SUBDIVISIONS):
        triangles = subdivide(triangles)
 
    # Prepare cairo surface
    surface = cairo.PDFSurface(filename, IMAGE_SIZE[0], IMAGE_SIZE[1])
 
    cr = cairo.Context(surface)
    cr.translate(IMAGE_SIZE[0] / 2.0, IMAGE_SIZE[1] / 2.0)
    wheelRadius = 1.2 * math.sqrt((IMAGE_SIZE[0] / 2.0) ** 2 + (IMAGE_SIZE[1] / 2.0) ** 2)
    cr.scale(wheelRadius, wheelRadius)
 
    # Draw red triangles
    for color, A, B, C in triangles:
        if color == 0:
            cr.move_to(A.real, A.imag)
            cr.line_to(B.real, B.imag)
            cr.line_to(C.real, C.imag)
            cr.close_path()
    red, green, blue = color1
    cr.set_source_rgb( red, green, blue)
    cr.fill()    
 
    # Draw blue triangles
    for color, A, B, C in triangles:
        if color == 1:
            cr.move_to(A.real, A.imag)
            cr.line_to(B.real, B.imag)
            cr.line_to(C.real, C.imag)
            cr.close_path()
    red, green, blue = color2
    cr.set_source_rgb( red, green, blue)
    cr.fill()
 
    # Determine line width from size of first triangle
    color, A, B, C = triangles[0]
    cr.set_line_width(abs(B - A) / 10.0)
    cr.set_line_join(cairo.LINE_JOIN_ROUND)
 
    # Draw outlines
    for color, A, B, C in triangles:
        cr.move_to(C.real, C.imag)
        cr.line_to(A.real, A.imag)
        cr.line_to(B.real, B.imag)
    cr.set_source_rgb( 0.2, 0.2, 0.2)
    cr.stroke()
 
 
if __name__ == '__main__':
    filename = 'penrose.pdf'
    # Couleurs RGB
    color1 = 1.0, 0.35, 0.35
    color2 = 0.4, 0.4, 1.0
    penrose( filename, color1, color2)