两个刚性小球在指定范围内碰撞

bouncingball

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+#两个刚性小球在指定范围内碰撞，1个有轨迹，1个没有
+
+from stdpackage import stddraw
+
+stddraw.setXscale(-1.0,1.0)
+stddraw.setYscale(-1.0,1.0)
+
+DT = 20
+RADIUS = 0.1
+r1x = 0.480
+r1y = 0.860
+v1x = 0.015
+v1y = 0.023
+position1 = [(r1x,r1y)]
+r2x = 0.080
+r2y = -0.360
+v2x = 0.03
+v2y = 0.02
+position2 = [(r2x,r2y)]
+changepoint = []
+while True:
+    if (abs(r1x+v1x-r2x-v2x)<2*RADIUS and abs(r1y+v1y-r2y-v2y)<2*RADIUS):
+
+        print(r1x,v1x,r2x,v2x,'change')
+        a = v1x
+        v1x = v2x
+        v2x = a
+        changepoint.append((r1x,r1y,r2x,r2y))
+        # stddraw.line(r1x,r1y,r2x,r2y)
+        # stddraw.show()
+        a = v1y
+        v1y = v2y
+        v2y = a
+        # break
+    if abs(r1x+v1x)+RADIUS>1.0: v1x = -v1x
+    if abs(r1y + v1y)+RADIUS >1.0:v1y = -v1y
+    if abs(r2x+v2x)+RADIUS>1.0: v2x = -v2x
+    if abs(r2y + v2y)+RADIUS >1.0:v2y = -v2y
+    r1x = r1x+v1x
+    r1y = r1y + v1y
+    r2x = r2x+v2x
+    r2y = r2y + v2y
+
+    position1.append((r1x,r1y))
+
+    stddraw.clear(stddraw.LIGHT_GRAY)
+
+    stddraw.setPenColor(stddraw.GRAY)
+    for x,y in position1[-50:]:
+        print(x,y)
+        stddraw.circle(x,y,RADIUS)
+    stddraw.setPenColor(stddraw.BLACK)
+    stddraw.filledCircle(r1x,r1y,RADIUS)
+    stddraw.filledCircle(r2x,r2y,RADIUS)
+    stddraw.show(DT)