blender projects: view3d openGL overlay

Just brushing up my OpenGL programming skills by programming a simple overlay script in the 3D viewport. I am planning to implement a custom panel fro the viewport.

First try

 Second try

WIP Code

• In the above screenshot, the vertical yellow bar and the mouse position inside the 3d view are created by my script.
  

• I am currently developing a  framework for quickly writing OpenGL overlay scripts to be displayed in the 3D view.
  

========================================== 

# SPACEHANDLER.VIEW3D.DRAW

import Blender
from Blender.BGL import *
from Blender.Draw import *
from Blender.Window import *

# Aliases
v3 = glVertex3f

#--------------------------------------------------------------

def Bounds(pt, ptmin, ptmax):
    return pt >= ptmin and pt <= ptmax

#--------------------------------------------------------------

def TransformMouseCoords(view):
    view['moux'], view['mouy'] = GetMouseCoords()
    vieworigin = view['vertices'][:2]
    view['vmoux'] = view['moux']-vieworigin[0]
    view['vmouy'] = view['mouy']-vieworigin[1]

#--------------------------------------------------------------

def GetExtents(rect):
    return ((rect[2] - rect[0]), (rect[3] - rect[1]))

#--------------------------------------------------------------

def Inside(view):
    x, y = view['moux'], view['mouy']
    rect = view['vertices']
    return (Bounds(x, rect[0], rect[2]) and Bounds(y, rect[1], rect[3]))

#--------------------------------------------------------------

def GetViewInfo():
    view3ds = GetScreenInfo(Types.VIEW3D)
    for view in view3ds:
        if view['id'] == GetAreaID():
            return view
    return None

#--------------------------------------------------------------

def UpdateInfo(view):
    TransformMouseCoords(view)
    view['width'], view['height'] = GetExtents(view['vertices'])    

#--------------------------------------------------------------

def InitGL():
    glEnable(GL_BLEND)
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
    glShadeModel(GL_FLAT)
    glClearColor(0,0,0,1)

#--------------------------------------------------------------

def InitGLOverlay(view):
    x, y, = view['vertices'][:2]
    w, h = view['width'], view['height']
    glViewport(x, y, w, h)
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    gluOrtho2D(0, w, 0, h)
    glMatrixMode(GL_MODELVIEW)
    glLoadIdentity()

#--------------------------------------------------------------

def DeInitGLOVerlay():
    pass

#--------------------------------------------------------------

def DrawWidgets():
    glBegin(GL_POLYGON)
    v3(0, 0, 0)
    v3(100, 0, 0)
    v3(100, 100, 0)
    v3(0, 100, 0)    
    glEnd()

#--------------------------------------------------------------

view = GetViewInfo()

if not view:
    print "Could not retrieve view info. something's wrong"
else:
    UpdateInfo(view)
    if not Inside(view):
        print "Mouse outside of view3d"
    else:
        print view['vmoux'],view['vmouy']
    InitGL()
    InitGLOverlay(view)
    DrawWidgets()
    DeInitGLOVerlay()