GLSL pack floats in texture

// GLSL 
		const float pixelDepth = 256.0f;
		const vec4 bitSh = vec4(
			pixelDepth * pixelDepth * pixelDepth, 
			pixelDepth * pixelDepth, 
			pixelDepth, 
			1.);
		const vec4 bitShifts = vec4(1.) / bitSh;

    vec2 decodeFloats16()
		{
			vec2 coord;
			vec4 color = texture2D(lookUpX, texCoordVar);

			// Denormalize
			float r = color.r * 255.0f;
			float g = color.g * 255.0f;
			float b = color.b * 255.0f;
			float a = color.a * 255.0f;

			coord.x = (r * 255.0f + g) / float(inputWidth) + uPixelWidth/2.0f;
			coord.y = (b * 255.0f + a) / float(inputHeight) + uPixelHeight/2.0f;
			return coord;
		}
		
		float decodeFloatRGBA(vec4 rgba)
		{
			return dot(rgba, bitShifts);
		}

		vec2 getTrueTexCoord()
		{
			vec4 colX = texture2D(lookUpX, texCoordVar);
			vec4 colY = texture2D(lookUpY, texCoordVar);

			return vec2(
				decodeFloatRGBA(colX),
				decodeFloatRGBA(colY));
		}
		
		
		
		//////////////////////////////////////////////////////////////////////////////////// C++
		// NOTE: Need to add half pixel width to the encoded tex coord either from cpu or in shader
		
		
		// TODO: 
ofFloatColor encodeFloat32(float value)
{
	static const float pd = 255.; // pixel depth
	static const ofVec4f bitSh( pd*pd*pd, pd*pd, pd, 1.);
	static const ofVec4f bitMsk(0.0f, 1.0f/pd, 1.0f/pd, 1.0f/pd);

	float aux;
	ofVec4f enc(
		modf(value * bitSh.x, &aux),
		modf(value * bitSh.y, &aux),
		modf(value * bitSh.z, &aux),
		modf(value * bitSh.w, &aux));
	ofVec4f encXXYZ(enc.x, enc.x, enc.y, enc.z);
	enc -= encXXYZ * bitMsk;
	return ofFloatColor(enc.x, enc.y, enc.z, enc.w);
}


ofColor encodeFloat16(int x, int y)
{
	ofColor color;
	color.r = x / 255;
	color.g = x % 255;
	color.b = y / 255;
	color.a = y % 255;
	return color;
}