Miscellany

void main()
{	
	gl_TexCoord[0] = gl_MultiTexCoord0;
	gl_Position = ftransform();
} 


uniform sampler2D opacityMap;
uniform sampler2D source0, source1, source2, source3;

void main()
{
	opacity	= texture2D(opacityMap,	gl_TexCoord[0].st);
	texel0	= texture2D(source0,	gl_TexCoord[0].st);
	texel1	= texture2D(source1,	gl_TexCoord[0].st);
	texel2	= texture2D(source2,	gl_TexCoord[0].st);
	texel3	= texture2D(source3,	gl_TexCoord[0].st);
	
	gl_FragColor = 	texel0.rgb * opacity.r +
					texel1.rgb * opacity.g +
					texel2.rgb * opacity.b +
					texel3.rgb * opacity.a;
}