CK_01_Rolloff.dctl

/*
  Smooth rolloff
*/
DEFINE_UI_PARAMS(p_max,     Max,         DCTLUI_SLIDER_FLOAT,  1.0f,  1.3f, 0.6f, 0.01f)
DEFINE_UI_PARAMS(p_max_r,   Max Range,   DCTLUI_SLIDER_FLOAT,  0.2f,  0.0f, 0.4f, 0.01f)
DEFINE_UI_PARAMS(p_min,     Min,         DCTLUI_SLIDER_FLOAT,  0.0f, -0.3f, 0.4f, 0.01f)
DEFINE_UI_PARAMS(p_min_r,   Min Range,   DCTLUI_SLIDER_FLOAT,  0.2f,  0.0f, 0.4f, 0.01f)
DEFINE_UI_PARAMS(p_depth,   Depth,       DCTLUI_SLIDER_FLOAT,  1.0f,  0.1f, 2.0f, 0.01f)
DEFINE_UI_PARAMS(p_bend,    Tilt,        DCTLUI_SLIDER_FLOAT,  0.0f, -0.5f, 0.5f, 0.01f)

__DEVICE__ inline float depth (float p, float t)
{
  if (t != 1.0f)
    return  _powf(p, t);
  else 
    return p;
}

__DEVICE__ inline float bend (float p, float t)
{
  float adjust = 0.5f - 0.5f/_powf(1.5f, t);
  if (t != 0.0f)
    return  p * 1.0f/_powf(p + 1.0f, t) + adjust;
  else 
    return p;
}

__DEVICE__ inline float rolloff (float p, float max, float max_r)
{
  if (p <= max - max_r)
    return p;
  else if (p >= max + max_r)
    return max;
  else
    return -1/(4*max_r)*(p*p - 2*(max + max_r)*p + (max - max_r)*(max - max_r));
}

__DEVICE__ inline float split (float p, float max, float max_r, float min, float min_r, float t, float b)
{
   float p2;
   if (p >= 0.5f)
   {
      p2 = bend(p, b);
      p2 = depth(p2, 1.0f/t);
      p2 = rolloff(p2, max, max_r);
      p2 = depth(p2, t);
   }
   else 
   {
      p2 = bend(1.0f - p, b);
      p2 = depth(p2, 1.0f/t);
      p2 = rolloff(p2, 1.0f - min, min_r);
      p2 = depth(p2, t);
      p2 = 1.0f - p2;
   }
   return p2;
}

__DEVICE__ float3 transform(int p_Width, int p_Height, int p_X, int p_Y, __TEXTURE__ p_TexR, __TEXTURE__ p_TexG, __TEXTURE__ p_TexB)
{
   float3 p = make_float3(
                     _tex2D(p_TexR, p_X, p_Y),
                     _tex2D(p_TexG, p_X, p_Y),
                     _tex2D(p_TexB, p_X, p_Y));
   p.x = split(p.x, p_max, p_max_r, p_min, p_min_r, p_depth, p_bend);
   p.y = split(p.y, p_max, p_max_r, p_min, p_min_r, p_depth, p_bend);
   p.z = split(p.z, p_max, p_max_r, p_min, p_min_r, p_depth, p_bend);
   return p;
}