sketch-a-day/2019/sketch_190412a/draw_2D.py

156 wiersze
5.7 KiB
Python

from __future__ import division
from draw_3D import poly_draw
from debug import debug_text
CUT_COLOR = color(200, 0, 0) # Color to mark outline cut
ENG_COLOR = color(0, 0, 200) # Color to mark folding/engraving
TAB_W = 10 # glue tab width
TAB_A = radians(30) # glue tab angle
def draw_unfolded(box_w, box_d, ab_l, cd_l, face_data):
"""
main 2D drawing procedure
takes 2 box dimentions, 2 top point height lists,
and a collection of 3D points (face_data) from the 3D procedure
then draws the unfolded version of the volume with glue tabs
TODO: Remove overlapping lines of triangular faces
"""
ah, bh, ch, dh = ab_l[0], ab_l[-1], cd_l[0], cd_l[-1]
ah_2d, a0_2d = (box_w * 2 + box_d, -ah), (box_w * 2 + box_d, 0)
bh_2d, b0_2d = (0, -bh), (0, 0)
ch_2d, c0_2d = (box_w, -ch), (box_w, 0)
dh_2d, d0_2d = (box_w + box_d, -dh), (box_w + box_d, 0)
noFill()
# Marked for folding
stroke(ENG_COLOR)
# verticals
line_draw(b0_2d, bh_2d)
line_draw(c0_2d, ch_2d)
line_draw(d0_2d, dh_2d)
line_draw(a0_2d, ah_2d)
debug_text("BCDA", (bh_2d, ch_2d, dh_2d, ah_2d))
# divided top face - also draws some CUT_COLOR glue tabs!
start_1, start_2 = bh_2d, ch_2d
for a_3d, b_3d, c_3d, d_3d in face_data:
start_1, start_2 = unfold_tri_face((start_1, start_2),
(a_3d, b_3d, c_3d, d_3d))
# floor face
rect(0, 0, box_w, box_d)
# Marked for cutting
stroke(CUT_COLOR)
# top tab
glue_tab(start_1, start_2, TAB_W, TAB_A)
# middle tab
glue_tab(b0_2d, bh_2d, TAB_W, TAB_A)
# floor tabs
glue_tab((0, box_d), b0_2d, TAB_W, TAB_A)
glue_tab((box_w, box_d), (0, box_d), TAB_W, TAB_A)
glue_tab((box_w, 0), (box_w, box_d), TAB_W, TAB_A)
# main outline cut
num_pts = len(cd_l)
cd_2Dpts = [(box_w + box_d * i / (num_pts - 1), -cd_l[i])
for i in range(num_pts)]
ab_2Dpts = [(box_w * 2 + box_d + box_d * i / (num_pts - 1), -ab_l[i])
for i in range(num_pts)]
main_outline = cd_2Dpts + ab_2Dpts + [(box_w * 2 + box_d * 2, 0), c0_2d]
poly_draw(main_outline, closed=False)
def line_draw(p1, p2, tab=False):
"""
sugar for drawing lines from 2 "points" (tuples or PVectors)
may also draw a glue tab suitably marked for cutting.
"""
line(p1[0], p1[1], p2[0], p2[1])
if tab:
with pushStyle():
stroke(CUT_COLOR)
glue_tab(p1, p2, TAB_W, TAB_A)
def glue_tab(p1, p2, tab_w=10, cut_ang=QUARTER_PI):
"""
draws a trapezoidal or triangular glue tab
along edge defined by p1 and p2, with provided
width (tab_w) and cut angle (cut_ang)
"""
a1 = atan2(p1[0] - p2[0], p1[1] - p2[1]) + cut_ang + PI
a2 = atan2(p1[0] - p2[0], p1[1] - p2[1]) - cut_ang
# calculate cut_len to get the right tab width
cut_len = tab_w / sin(cut_ang)
f1 = (p1[0] + cut_len * sin(a1),
p1[1] + cut_len * cos(a1))
f2 = (p2[0] + cut_len * sin(a2),
p2[1] + cut_len * cos(a2))
edge_len = dist(p1[0], p1[1], p2[0], p2[1])
if edge_len > 2 * cut_len * cos(cut_ang): # 'normal' trapezoidal tab
line_draw(p1, f1)
line_draw(f1, f2)
line_draw(f2, p2)
else: # short triangular tab
fm = ((f1[0] + f2[0]) / 2, (f1[1] + f2[1]) / 2)
line_draw(p1, fm)
line_draw(fm, p2)
def unfold_tri_face(pts_2D, pts_3D):
"""
gets a collection of 2 (B, D) starting 2D points (PVectors or tuples)
Gets a collection of 4 (A, B, C, D) 3D points (PVectors or tuples)
Draws the unfolded face a returns (A, C) 2D positions.
"""
b2D, c2D = pts_2D
a3D, b3D, c3D, d3D = pts_3D
bd_len = dist(b3D[0], b3D[1], b3D[2], d3D[0], d3D[1], d3D[2])
cd_len = dist(c3D[0], c3D[1], c3D[2], d3D[0], d3D[1], d3D[2])
# lower triangle
d2D = third_point(b2D, c2D, bd_len, cd_len)[0] # gets the first solution
line_draw(b2D, c2D)
line_draw(b2D, d2D)
line_draw(d2D, c2D, tab=True)
# upper triangle (fixed from 190408a)
ab_len = dist(b3D[0], b3D[1], b3D[2], a3D[0], a3D[1], a3D[2])
ad_len = dist(a3D[0], a3D[1], a3D[2], d3D[0], d3D[1], d3D[2])
# gets the 1st solution too!
a2D = third_point(b2D, d2D, ab_len, ad_len)[0]
line_draw(b2D, a2D, tab=True)
line_draw(d2D, a2D)
return (a2D, d2D)
def third_point(a, b, ac_len, bc_len):
"""
Adapted from code by Monkut https://stackoverflow.com/users/24718/monkut
at https://stackoverflow.com/questions/4001948/drawing-a-triangle-in-a-coordinate-plane-given-its-three-sides
for use with Processing Python Mode - using PVectors
Returns two point c options given:
point a, point b, ac length, bc length
"""
class NoTrianglePossible(BaseException):
pass
# To allow use of tuples, creates or recreates PVectors
a, b = PVector(*a), PVector(*b)
# check if a triangle is possible
ab_len = a.dist(b)
if ab_len > (ac_len + bc_len) or ab_len < abs(ac_len - bc_len):
raise NoTrianglePossible("The sides do not form a triangle")
# get the length to the vertex of the right triangle formed,
# by the intersection formed by circles a and b
ad_len = (ab_len ** 2 + ac_len ** 2 - bc_len ** 2) / (2.0 * ab_len)
# get the height of the line at a right angle from a_len
h = sqrt(abs(ac_len ** 2 - ad_len ** 2))
# Calculate the mid point d, needed to calculate point c(1|2)
d = PVector(a.x + ad_len * (b.x - a.x) / ab_len,
a.y + ad_len * (b.y - a.y) / ab_len)
# get point c locations
c1 = PVector(d.x + h * (b.y - a.y) / ab_len,
d.y - h * (b.x - a.x) / ab_len)
c2 = PVector(d.y + h * (b.x - a.x) / ab_len,
d.x - h * (b.y - a.y) / ab_len)
return c1, c2