I am however getting errors in my prototype shader code when trying to compile with fxc. I am getting an Illegal character code when I compile and I don't know why. Also if you are a HLSL guru please look over my code and make any comments that strike you. Note I got the HLSL random function from an answer to this question.

http://stackoverflow.com/questions/5149544/can-i-generate-a-random-number-inside-a-pixel-shader

Below is my shader code. Please forgive me if there a many mistakes as its my first HLSL code:

float4 DitherByChance(float2 coords : TEXCOORD0) : COLOR { float4 newColor; // The pixel color to return float4 oldColor = tex2D(s0, coords); // Note I know that as the code stands now rCutOff = gCutOff = bCutOff I will sort a fix for this out later float rCutOff = random(coords); // A random float that determines if the red channel will be rounded up or down float gCutOff = random(coords); // A random float that determines if the green channel will be rounded up or down float bCutOff = random(coords); // A random float that determines if the blue channel will be rounded up or down float rPercentChance = frac(oldColor.r * 255); //Chance to round red channel up float gPercentChance = frac(oldColor.g * 255); //Chance to round green channel up float bPercentChance = frac(oldColor.b * 255); //Chance to round blue channel up //In the code below (1/255) is the floating point represntaion of an incress of one on the 0-255 RGB scale if (rCutOff <= rPercentChance) newColor.r = oldColor.r + ((1 - rPercentChance) / 255); //Bump up one r value else newColor.r = oldColor.r - rPercentChance * (1 / 255); //Bump down to ensure r is not rounded up if (gCutOff <= gPercentChance) newColor.g = oldColor.g + ((1 - gPercentChance) / 255); //Bump up one g value else newColor.b = oldColor.b - bPercentChance * (1 / 255); //Bump down to ensure g is not rounded up if (bCutOff <= bPercentChance) newColor.b = oldColor.b + ((1 - bPercentChance) / 255); //Bump up one b value else newColor.b = oldColor.b - bPercentChance * (1 / 255); //Bump down to ensure b is not rounded up return newColor; } // Input: It uses texture coords as the random number seed. // Output: Random number: [0,1), that is between 0.0 and 0.999999... inclusive. // Author: Michael Pohoreski // Copyright: Copyleft 2012 :-) float random( vec2 p ) { // We need irrationals for pseudo randomness. // Most (all?) known transcendental numbers will (generally) work. const vec2 r = vec2( 23.1406926327792690, // e^pi (Gelfond's constant) 2.6651441426902251); // 2^sqrt(2) (Gelfond–Schneider constant) return fract( cos( mod( 123456789., 1e-7 + 256. * dot(p,r) ) ) ); }

**Edited by vanattab, 04 October 2012 - 04:16 PM.**