save_colour_to_disk

	vector<unsigned char> output_pixels(2048*2048*4);

	glReadBuffer(GL_COLOR_ATTACHMENT0);
	glReadPixels(0, 0, 2048, 2048, GL_RGBA, GL_UNSIGNED_BYTE, &output_pixels[0]);


	// Set up Targa TGA image data.
	unsigned char  idlength = 0;
	unsigned char  colourmaptype = 0;
	unsigned char  datatypecode = 2;
	unsigned short int colourmaporigin = 0;
	unsigned short int colourmaplength = 0;
	unsigned char  colourmapdepth = 0;
	unsigned short int x_origin = 0;
	unsigned short int y_origin = 0;

	unsigned short int px = 2048;
	unsigned short int py = 2048;
	unsigned char  bitsperpixel = 32;
	unsigned char  imagedescriptor = 0;
	vector<char> idstring;



	// Write Targa TGA file to disk.
	ofstream out("attachment.tga", ios::binary);

	if (!out.is_open())
	{
		cout << "Failed to open TGA file for writing: attachment.tga" << endl;
		return;
	}

	out.write(reinterpret_cast<char*>(&idlength), 1);
	out.write(reinterpret_cast<char*>(&colourmaptype), 1);
	out.write(reinterpret_cast<char*>(&datatypecode), 1);
	out.write(reinterpret_cast<char*>(&colourmaporigin), 2);
	out.write(reinterpret_cast<char*>(&colourmaplength), 2);
	out.write(reinterpret_cast<char*>(&colourmapdepth), 1);
	out.write(reinterpret_cast<char*>(&x_origin), 2);
	out.write(reinterpret_cast<char*>(&y_origin), 2);
	out.write(reinterpret_cast<char*>(&px), 2);
	out.write(reinterpret_cast<char*>(&py), 2);
	out.write(reinterpret_cast<char*>(&bitsperpixel), 1);
	out.write(reinterpret_cast<char*>(&imagedescriptor), 1);

	out.write(reinterpret_cast<char*>(&output_pixels[0]), 2048*2048 * 4 * sizeof(unsigned char));

	out.close();

	exit(1);