I want to calculate the distance from the viewpoint/eyepoint to each vertex in my scene then store that value in the r,g,b and a components of a RGBA8 texture… I have gone round in circles trying to figure out how to go from a single 32 bit number to 4 - 8bit numbers. Is the following reasonable? That is… should it work? If not, does anyone know what would?

Fragment Shader:

```
// Calculate Distance To Each Vertex from vertex position
// in eyespace passed as varying from vertex shader
float distance = length(eyepoint);
// convert distance from floating point to fixed point
// with 8 fractional bits
float fixedPointDistance = distance * pow(2, 8);
// get upper 16 bits
int upper16Bits = int(fixedPointDistance/65536);
// get lower 16 bits
int lower16Bits = int(fixedPointDistance);
// get byte1 (or bits 23-31)
int byte1 = int(upper16Bits/256);
// get byte2 (or bits 16-23)
int byte2 = int(upper16Bits*256)/256);
// get byte3 (or bits 8-15)
int byte3 = int(lower16Bits/256);
// get byte1 (or bits 0-7)
int byte4 = int(lower16Bits*256)/256);
float red = float(byte1/256);
float green = float(byte2/256);
float blue = float(byte3/256);
float alpha = float(byte4/256);
gl_FragColor = vec4(red, green, blue, alpha);
```

CD