#! /usr/bin/python3
# ===================================================================
# demo combining multiple transformation matrices
# into a single matrix
# ===================================================================
import transformation_matrix as tm
import coordinate_conversion as cc
import user_interface as ui
from graphics import *
import numpy as np
import os, sys
win_width = 801
win_height = 801
# ---- blob (polygon) window coordinates
# ---- blob center is 100,100
blob_w_coords = [ [110,70], [140,70], [110,110], [110,140], [80,110],
[50,110], [70,100], [50,90], [90,90], [110,70] ]
# ---- blob (polygon) center (Cartesian) coordinates
# ---- blob is center around the origin (0.0,0.0)
blob_c_coords = [ [10,-30], [40,-30], [10,10], [10,40], [-20,10],
[-50,10], [-30,0], [-50,-10], [-10,-10], [10,-30] ]
# -------------------------------------------------------------------
# ---- function: draw X,Y axes
# -------------------------------------------------------------------
def draw_xy_axes(win,line_width=1,line_color="black"):
xl = Line(Point(0,win.height/2),Point(win.width-1,win.height/2))
xl.setWidth(line_width)
xl.setFill(line_color)
xl.draw(win)
yl = Line(Point(win.width/2,0),Point(win.width/2,win.height-1))
yl.setWidth(line_width)
yl.setFill(line_color)
yl.draw(win)
# -------------------------------------------------------------------
# ---- function: create a polygon points list in window coordinates
# ---- Note: input coordinates are center (Cartesian) coordinates
# ---- output is window coordinates
# -------------------------------------------------------------------
def create_points_list(tm,coords,winwidth,winheight):
points = []
for c in coords:
xy1 = [c[0],c[1],1]
p = tm @ xy1
xy = cc.center_to_win_coords(p[0],p[1],winwidth,winheight)
points.append(Point(xy[0],xy[1]))
return points
# -------------------------------------------------------------------
# ---- main
# -------------------------------------------------------------------
# ---- do nothing transformation
# ---- in the matrix world the identity matrix is like multiplying by 1
tmi = tm.get_identity_matrix_2d()
dn_points = create_points_list(tmi,blob_c_coords,win_width,win_height)
# ---- rotate/translate transformation
# ---- combine transformations into one
# ---- rotate blob 45 deg then translate 100,100
tm1 = tm.get_translation_matrix_2d(100.0,100.0)
tm2 = tm.get_z_rotation_matrix_2d(45.0)
tm3 = tm1 @ tm2 # order of operations is important
# hint: read operations right to left
rt_points = create_points_list(tm3,blob_c_coords,win_width,win_height)
# ---- create window
win = GraphWin("Rotate/Translate Demo", win_width, win_height)
win.setBackground("white")
# ---- draw center X,Y axes (Cartesian coordinate axes)
draw_xy_axes(win)
# ---- draw blob(s)
# ---- first draw "do nothing" transformation
# ---- second draw rotate/translate transformation
blob = Polygon(dn_points)
blob.setWidth(3)
blob.setOutline("black")
blob.setFill("red")
blob.draw(win)
blob = Polygon(rt_points)
blob.setWidth(3)
blob.setOutline("black")
blob.setFill("red")
blob.draw(win)
# ---- pause and end program
print()
ui.pause()