MPC Curves 2

sampler s0 : register(s0);
float4 p0 :  register(c0);
float4 p1 :  register(c1);

#define width  (p0[0])
#define height  (p0[1])
#define counter (p0[2])
#define clock  (p0[3])
#define one_over_width  (p1[0])
#define one_over_height (p1[1])
#define PI acos(-1)

#define Curves_contrast 1.0
#define Curves_formula 2

float4 main(float2 tex : TEXCOORD0) : COLOR {
  float4 c0 = tex2D(s0, tex);

  float3 color = c0.rgb; //original input color
  float3 lumCoeff = float3(0.2126, 0.7154, 0.0721);  //Values to calculate luma with
  float Curves_contrast_blend = Curves_contrast;

  float redChannel = color.r;
  float greenChannel = color.g;
  float blueChannel = color.b;

  // -- Curve 2 --
  #if Curves_formula == 2
    // Applies Curve to all 3 individual channels
    redChannel = ( (redChannel - 0.5) / (0.5 + abs(redChannel-0.5)) ) + 0.5; // 717 amd fps
    greenChannel = ( (greenChannel - 0.5) / (0.5 + abs(greenChannel-0.5)) ) + 0.5; // 717 amd fps
    blueChannel = ( (blueChannel - 0.5) / (0.5 + abs(blueChannel-0.5)) ) + 0.5; // 717 amd fps
  #endif

  // Blends the original color with the new processed colors
  float3 newColor = lerp(color, float3(redChannel, greenChannel, blueChannel), Curves_contrast_blend);

  //Blend by Curves_contrast
  c0.rgb = lerp(c0.rgb, newColor, Curves_contrast_blend);

  return c0;
}