new:CubeWithoutPerspective

src/python/CubeWithoutPerspective.py

@@ -0,0 +1,107 @@
+# coding:utf-8
+
+from tkinter import Tk, Canvas
+import math, threading, time
+
+
+class TkCube(object):
+    def __init__(self):
+        self.points = [[-1, 1, -1],  # LeftFrontDown
+                       [1, 1, -1],  # RFD
+                       [-1, -1, -1],  # LBD
+                       [1, -1, -1],  # RBD
+                       [-1, 1, 1],  # LFU
+                       [1, 1, 1],  # RFU
+                       [-1, -1, 1],  # LBU
+                       [1, -1, 1]]  # RBU
+        self.pit = [[0, 0], [0, 0], [0, 0], [0, 0], [0, 0], [0, 0], [0, 0], [0, 0]]  # point in 2d
+        self.angle = 0
+        self.speed = 1  # π/s
+        self.fps = 60
+        self.dist = [5, 4]  # distance between the cube's center and focal point/canvas
+        self.st = 1 / self.fps  # sleep time
+        self.apf = math.pi * self.speed / self.fps  # angle per frame
+        # init canvas
+        self.tkroot = Tk()
+        self.cvs = [Canvas(self.tkroot, bg='white', width=800, height=600),
+                    Canvas(self.tkroot, bg='white', width=800, height=600)]
+        self.cvs[0].pack()
+        self.showingCv = 0
+        self.hiddenCv = 1
+        self.runThread = threading.Thread(target=self.run)
+
+    def rotate(self):
+        self.angle += self.apf
+        if self.angle > 2 * math.pi:
+            self.angle -= 2 * math.pi
+        radius = math.sqrt(2)  # 点旋转的半径
+        for pair in [[0, 4, -math.pi / 4],
+                     [1, 5, math.pi / 4],
+                     [2, 6, -math.pi * 3 / 4],
+                     [3, 7, math.pi * 3 / 4]]:  # rotate in pairs
+            center = [radius * math.cos(self.angle + pair[2]), radius * math.sin(self.angle + pair[2])]
+            # x
+            self.points[pair[0]][0] = center[0]
+            self.points[pair[1]][0] = center[0]
+            # y
+            self.points[pair[0]][1] = center[1]
+            self.points[pair[1]][1] = center[1]
+
+    def draw(self):
+        # 按照Y轴排序,筛去最远的点
+        self.points.sort(key=lambda t: t[1])
+        # 按Z轴排序,下层的点在前面,方便后面作画
+        self.points.sort(key=lambda t: t[2], reverse=True)
+        # project points into 2D canvas 投影到2D
+        for pt in range(8):
+            rate = self.dist[1] / (self.dist[0] + self.points[pt][1])
+            scale = 200
+            self.pit[pt][0] = self.points[pt][0] * rate * scale + 400  # 因为坐标原点在左上角,让x和y分别加400和300让画面在窗口中心
+            self.pit[pt][1] = self.points[pt][2] * rate * scale + 300
+        self.cvs[self.hiddenCv].delete('all')
+        for dcp, nps in [[1, [0, 3, 5]],  # drawing central point:以1,2,4,7四个点为中心,分别连接相邻的三个点即可绘成正方体
+                         [2, [0, 3, 6]],
+                         [4, [0, 5, 6]],
+                         [7, [3, 5, 6]]]:
+            for np in nps:  # nearby point
+                self.cvs[self.hiddenCv].create_line(self.pit[dcp][0], self.pit[dcp][1],
+                                                    self.pit[np][0],
+                                                    self.pit[np][1])
+        # for pt in self.pit:
+        #     self.cvs[self.hiddenCv].create_text(int(pt[0])+400,int(pt[1])+300,text=str(self.pit.index(pt)))
+        self.cvs[self.hiddenCv].create_polygon(self.pit[0][0], self.pit[0][1], self.pit[4][0], self.pit[4][1],
+                                               self.pit[5][0], self.pit[5][1], self.pit[1][0], self.pit[1][1],
+                                               fill='blue')
+        self.cvs[self.hiddenCv].create_polygon(self.pit[0][0], self.pit[0][1], self.pit[4][0], self.pit[4][1],
+                                               self.pit[6][0], self.pit[6][1], self.pit[2][0], self.pit[2][1],
+                                               fill='blue')
+        # self.cvs[self.hiddenCv].create_polygon(self.pit[0][0]-1, self.pit[0][1]-1, self.pit[4][0]-1, self.pit[4][1]+1,
+        #                                        self.pit[5][0]+1, self.pit[5][1]+1, self.pit[1][0]+1, self.pit[1][1]-1,
+        #                                        fill='blue')
+        # self.cvs[self.hiddenCv].create_polygon(self.pit[0][0]+1, self.pit[0][1]-1, self.pit[4][0]+1, self.pit[4][1]+1,
+        #                                        self.pit[6][0]-1, self.pit[6][1]+1, self.pit[2][0]-1, self.pit[2][1]-1,
+        #                                        fill='blue')
+        # 切换canvas
+        self.cvs[self.showingCv].pack_forget()
+        self.cvs[self.hiddenCv].pack()
+        self.showingCv, self.hiddenCv = self.hiddenCv, self.showingCv
+
+    def run(self):
+        while True:
+            # self.rotateThread = threading.Thread(target=self.rotate)
+            # self.rotateThread.run()
+            # self.drawThread = threading.Thread(target=self.draw)
+            # self.drawThread.run()
+            self.rotate()
+            self.draw()
+            # print(self.points)
+            time.sleep(self.st)
+
+    def start(self):
+        self.runThread.start()
+        self.tkroot.mainloop()
+
+
+if __name__ == '__main__':
+    tc = TkCube()
+    tc.start()