// Draw a red Quad that covers all the view port, and the when space is pressed
// the viewport gets expanded to the whole screen and stretch the contents inside
var mat : Material;
private var stretch : boolean = false;

function Update() {
if(Input.GetKeyDown(KeyCode.Space)) {
if(stretch) {
stretch = false;
} else {
stretch = true;
}
}
}

function OnPostRender() {
if (!mat) {
Debug.LogError("Please Assign a material on the inspector");
return;
}
GL.PushMatrix();
mat.SetPass(0);
GL.LoadPixelMatrix();
if(stretch) {
GL.Viewport(Rect(0,0,Screen.width,Screen.height));
} else {
GL.Viewport(Rect(0,0,Screen.width/2,Screen.height));
}
GL.Color(Color.red);
GL.Begin(GL.QUADS);
GL.Vertex3(0,0,0);
GL.Vertex3(0,Screen.height,0);
GL.Vertex3(Screen.width,Screen.height,0);
GL.Vertex3(Screen.width,0,0);
GL.Color(Color.yellow);
GL.End();
GL.Begin(GL.TRIANGLES);
GL.Vertex3(Screen.width/2,Screen.height/4,1);
GL.Vertex3(Screen.width/4,Screen.height/2,1);
GL.Vertex3(Screen.width - Screen.width/4,Screen.height/2,1);
GL.End();
GL.PopMatrix();
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
public Material mat;
private bool stretch = false;
void Update() {
if (Input.GetKeyDown(KeyCode.Space))
if (stretch)
stretch = false;
else
stretch = true;

}
void OnPostRender() {
if (!mat) {
Debug.LogError("Please Assign a material on the inspector");
return;
}
GL.PushMatrix();
mat.SetPass(0);
GL.LoadPixelMatrix();
if (stretch)
GL.Viewport(new Rect(0, 0, Screen.width, Screen.height));
else
GL.Viewport(new Rect(0, 0, Screen.width / 2, Screen.height));
GL.Color(Color.red);
GL.Begin(GL.QUADS);
GL.Vertex3(0, 0, 0);
GL.Vertex3(0, Screen.height, 0);
GL.Vertex3(Screen.width, Screen.height, 0);
GL.Vertex3(Screen.width, 0, 0);
GL.Color(Color.yellow);
GL.End();
GL.Begin(GL.TRIANGLES);
GL.Vertex3(Screen.width / 2, Screen.height / 4, 1);
GL.Vertex3(Screen.width / 4, Screen.height / 2, 1);
GL.Vertex3(Screen.width - Screen.width / 4, Screen.height / 2, 1);
GL.End();
GL.PopMatrix();
}
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

public mat as Material

private stretch as bool = false

def Update():
if Input.GetKeyDown(KeyCode.Space):
if stretch:
stretch = false
else:
stretch = true

def OnPostRender():
if not mat:
Debug.LogError('Please Assign a material on the inspector')
return
GL.PushMatrix()
mat.SetPass(0)
GL.LoadPixelMatrix()
if stretch:
GL.Viewport(Rect(0, 0, Screen.width, Screen.height))
else:
GL.Viewport(Rect(0, 0, (Screen.width / 2), Screen.height))
GL.Color(Color.red)
GL.Begin(GL.QUADS)
GL.Vertex3(0, 0, 0)
GL.Vertex3(0, Screen.height, 0)
GL.Vertex3(Screen.width, Screen.height, 0)
GL.Vertex3(Screen.width, 0, 0)
GL.Color(Color.yellow)
GL.End()
GL.Begin(GL.TRIANGLES)
GL.Vertex3((Screen.width / 2), (Screen.height / 4), 1)
GL.Vertex3((Screen.width / 4), (Screen.height / 2), 1)
GL.Vertex3((Screen.width - (Screen.width / 4)), (Screen.height / 2), 1)
GL.End()
GL.PopMatrix()