[PyOpenGL-Users] glColor problem

[Greg H. <gho...@co...>]

I'm trying to write a simple app using PyOpenG, unfortunately the 
glColor*() function seems to have no effect.  I'm sure I'm just missing 
something.  Any help would be appreciated.  The following source code 
only shows the 2 classes used to extend the wxGLCanvas...the remaining 
code simply adds a Contour canvas to a Frame and shows the Frame.  A 
polygon shows up, but only in gray.  I've tried many variations, all 
resulting in only a gray polygon.  Thank you.



class MyCanvasBase(wxGLCanvas):
  	def __init__(self, parent, size, pos = wxDefaultPosition):
		wxGLCanvas.__init__(self, parent, -1, size = size, pos = pos, 
attribList = WX_GL_RGBA)
		self.parent = parent
		self.size = size
		self.init = False
		# initial mouse position
		self.lastx = self.x = 30
		self.lasty = self.y = 30
		self.SetColour('white')
		
		self.SetCurrent()
		glViewport(0, 0, self.size.width, self.size.height)
		
		
		EVT_ERASE_BACKGROUND(self, self.OnEraseBackground)
		EVT_SIZE(self, self.OnSize)
		EVT_PAINT(self, self.OnPaint)
		EVT_LEFT_DOWN(self, self.OnMouseDown)  # needs fixing...
		EVT_LEFT_UP(self, self.OnMouseUp)
		EVT_MOTION(self, self.OnMouseMotion)



	def OnEraseBackground(self, event):
		pass # Do nothing, to avoid flashing on MSW.

	def OnSize(self, event):
		#size = self.GetClientSize()
		if self.GetContext():
			self.SetCurrent()
			glViewport(0, 0, self.size.width, self.size.height)

	def OnPaint(self, event):
		dc = wxPaintDC(self)
		self.SetCurrent()
		glViewport(0, 0, self.size.width, self.size.height)
		if not self.init:
			self.InitGL()
			self.init = True
		self.OnDraw()

	def OnMouseDown(self, evt):
		self.x, self.y = evt.GetPosition()
		self.CaptureMouse()

	def OnMouseUp(self, evt):
		self.ReleaseMouse()

	def OnMouseMotion(self, evt):
		if evt.Dragging() and evt.LeftIsDown():
			self.lastx, self.lasty = self.x, self.y
			#self.x, self.y = self.lastx, self.lasty
			self.x, self.y = evt.GetPosition()
			self.Refresh(False)




class Contourcanvas(MyCanvasBase):
	def InitGL(self):
		# set viewing projection
		glMatrixMode(GL_PROJECTION)
		glFrustum(-0.5, 0.5, -0.5, 0.5, 1.0, 3.0)

		# position viewer
		glMatrixMode(GL_MODELVIEW)
		glTranslatef(0.0, 0.0, -2.0)

		# position object
		glRotatef(self.y, 1.0, 0.0, 0.0)
		glRotatef(self.x, 0.0, 1.0, 0.0)
		
		glEnable(GL_DEPTH_TEST)
		glEnable(GL_LIGHTING)
		
		glEnable(GL_LIGHT0)
	
		
	def OnDraw(self):

		max = 0;
		
		for i in range(NUM_ROWS):
			for j in range(NUM_COLS):
				
				val = int(self.parent.mappanel.grid.GetCellValue(i, j))
				
				if max < val:
					max = val
					
	
		# clear color and depth buffers
		glClearColor(1.0, 1.0, 1.0, 1.0)
		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
		
		
		glBegin(GL_QUADS)
		
		glColor3f(1.0, 0.0, 0.0)
		
		glVertex3f(0.0, 1.0, 1.0)
		glVertex3f(0.0, -1.0, -1.0)
		
		glColor3f(0.0, 0.0, 1.0)
		glVertex3f(0.0, -1.0, 1.0)
		glVertex3f(0.0, 1.0, -1.0)
		
		glEnd()
		
		glFlush()

		glRotatef((self.lasty - self.y)/10., 1.0, 0.0, 0.0);
		glRotatef((self.lastx - self.x)/10., 0.0, 1.0, 0.0);

		self.SwapBuffers()



--Greg