from OpenGL.GLU import *
from OpenGL.GL import *
from OpenGL.GLUT import *
'''
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定義 init() 函式
設定背景顏色為白(R,G,B = 1)
設定坐標系為2D 範圍X:-10~10, y:-10~10
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'''
def init():
	glClearColor(1.0, 1.0, 1.0, 1.0)
	gluOrtho2D(-10.0, 10.0, -10.0, 10.0)
'''
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定義 drawFunc() 函式
繪製圖形
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'''	
def drawFunc():
	glClear(GL_COLOR_BUFFER_BIT)
#繪製初始三角形 顏色為紅
	
	glColor3f(1, 0, 0)
	glBegin(GL_TRIANGLES)
	glVertex2f(0,0)
	glVertex2f(0,3)
	glVertex2f(3,0)	
	glEnd()	
	glPushMatrix( )
	glPushMatrix( )

#繪製"縮小"後三角形 顏色為綠
	glColor3f(0, 1, 0)	
	glScalef(0.5,0.5,1)
	glBegin(GL_TRIANGLES)
	glVertex2f(0, 0)
	glVertex2f(0, 3)
	glVertex2f(3, 0)
	glEnd()
	glPopMatrix()

#繪製"平移+縮小"後三角形 顏色為藍
	glTranslated(3,3,0)
	glPushMatrix( )
	glScalef(0.5,0.5,1)		
	glColor3f(0, 0, 1)
	glBegin(GL_TRIANGLES)
	glVertex2f(0, 0)
	glVertex2f(0, 3)
	glVertex2f(3, 0)
	glEnd()
	glPopMatrix()
	
#繪製"平移+旋轉+縮小"後三角形 顏色為黃	
	glTranslated(3,3,0)
	glRotatef(90,0,0,1)
	glScalef(0.5,0.5,1)
	glColor3f(1, 1 ,0)
	glBegin(GL_TRIANGLES)
	glVertex2f(0, 0)
	glVertex2f(0, 3)
	glVertex2f(3, 0)
	glEnd()
	glPopMatrix()
	
	
#輔助線的繪製:x,y軸及基準線 顏色為黑
	glColor3f(0, 0, 0)
	glBegin(GL_LINES)
        #X軸
	glVertex2f(-10,0)
	glVertex2f(10,0)
	#y軸
	glVertex2f(0,-10)
	glVertex2f(0,10)
	#原始三角形及縮小三角形的基準範圍
	glVertex2f(3,3)
	glVertex2f(3,0)
	glVertex2f(3,3)
	glVertex2f(0,3)
	#平移+縮小三角形的基準範圍
	glVertex2f(3,3)
	glVertex2f(3,6)
	glVertex2f(3,6)
	glVertex2f(6,6)
	glVertex2f(6,6)
	glVertex2f(6,3)
	glVertex2f(6,3)
	glVertex2f(3,3)
	#原始三角形及縮小三角形的基準範圍
	glVertex2f(6,6)
	glVertex2f(6,9)
	glVertex2f(6,9)
	glVertex2f(9,9)
	glVertex2f(9,9)
	glVertex2f(9,6)
	glVertex2f(9,6)
	glVertex2f(6,6)
	glEnd()
	
#繪製完成執行glFlush顯示在畫面上
	glFlush()

'''
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定義完初始即畫圖函示 下方為執行opengl指令開始繪圖
=======================================
'''	
glutInit()
glutInitDisplayMode(GLUT_RGBA|GLUT_SINGLE)
glutInitWindowSize(800, 800)
glutCreateWindow(b"Sencond")
glutDisplayFunc(drawFunc)
init()
glutMainLoop()