import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as ani
import matplotlib.patches as patches

#紙の準備
fig = plt.figure()
fig.suptitle("2008九大数学　理系第５問",
             color="0.5",ha="right",x=0.96,y=0.96)
ax = fig.add_subplot(111)
ax.set_xlim(-9,9)
ax.set_ylim(-9,9)
ax.set_aspect("equal")
ax.axis("off")

#真ん中の円
c0 = patches.Circle((0,0),radius=2,fc="orangered")
#周りの円
cs = []
for i in range(5):
    alpha = np.pi/2 - i*np.arcsin(24/25)
    c = patches.Circle((5*np.cos(alpha),5*np.sin(alpha)),radius=3,
                       fc=(0.8-0.05*i,0.8,0),alpha=0)
    cs.append(c)
#円を描きます
for c in [c0]+cs:
    ax.add_patch(c)
#「アウト」を書きます
arrow_dict = dict(arrowstyle="-|>",
                  connectionstyle="angle3,angleA=0,angleB=-60",
                  linewidth=2.0,color="r",alpha=0)
out = ax.annotate("アウト！",xy=(-3.0,4.7),xytext=(-12,7.5),
                  size=16,color="r",fontfamily="HGSoeiKakupoptai",
                  arrowprops=arrow_dict,alpha=0)

#減らずグチたち
phrasedic={
"ha" : "center",
"va" : "center",
"size" : 20,
"color" : "white",
"zorder" : 100,
"visible" : False,
"linespacing": 2.4,
"fontfamily": "Meiryo",
}
phrases = []
phrases.append("""
半径２の円の周りに
半径３の円は
最大何個まで置けるのか？
""")
phrases.append("""
レッツ、検証！
""")
phrases.append("""
５個目で重なります
""")
phrases.append("""
というわけで
４個まで置けました
""")
phrases.append("""
END
""")
seq_prs = []
for i in range(len(phrases)):
    prs = fig.text(0.5,0.5,"\n",fontdict=phrasedic,
                   bbox=dict(color="black",pad=300))
    seq_prs.append(prs)

#お気に入りのイージング関数
def easing(x):
    if x<0.5:
        return 2*x**2
    elif x<1:
        return 1-(-2*x+2)**2/2
    else:
        return 1

#オブジェクトを徐々に表示する関数
def show_obj(k,obj):
    alpha = easing(k/39)
    obj.set_alpha(alpha)

#セクションを判定する関数
def section(i): 
    n = np.argmin(~(i<endings))
    keys = list(periods.keys())
    key = keys[n]
    if n == 0:
        k = i
        previous_key = None
    else:
        k = i-endings[n-1]
        previous_key = keys[n-1]
    return k,key,previous_key

#台本の構成
periods = {"P1":140,"P2":60,"S1":20,
           "C1":40,"C2":40,"C3":40,"C4":40,"C5":40,"O1":100,
           "P3":40,"P4":120,"P5":40}
endings = np.cumsum(list(periods.values()))

#上演
def update(i):
    
    k,key,previous_key = section(i)
    #台本のキーには必ず数字をつけます
    index = int(key[1])-1
    
    if "C" in key:
        show_obj(k,cs[index])
    elif "P" in key:
        phrase = phrases[index]
        end = min(k//3+2,len(phrase)-1)
        seq_prs[index].set_text(phrase[1:end])
    elif "O" in key:
        show_obj(k,out)
        show_obj(k,out.arrow_patch)
    
    if k == 0:
        if "P" in key:
            seq_prs[index-1].set_visible(False)
            seq_prs[index].set_visible(True)
        elif "P" in previous_key:
            seq_prs[int(previous_key[1])-1].set_visible(False)

mov = ani.FuncAnimation(fig,update,endings[-1],interval=50)
plt.show()