Blur_Vanilla.cpp

#include <algorithm>
#include "Blur.h"
#include "Context.h"
 
using namespace Cogs::Core;
 
namespace {
 
  void boxFilterScanline(float* dst,
                         const float* src,
                         const uint32_t N,
                         const float radius)
  {
    auto s = 1.f / (2.f*radius + 1.f);
    auto n = static_cast<uint32_t>(radius);
    auto f = radius - n;
 
    auto sum = src[0];
    for (uint32_t k = 1; k <= n; k++) {
      sum += src[k];
    }
    sum += f*src[n + 1];
 
    for (uint32_t i = 0; i < N; i++) {
      dst[i] = s*sum;
      if (i + n + 1 < N) sum += (1.f - f)*src[i + n + 1];
      if (i + n + 2 < N) sum += f*src[i + n + 2];
      if (i - n < N) sum -= (1.f - f)*src[i - n];
      if (i - n - 1 < N) sum -= f*src[i - n - 1];
    }
 
  }
}
 
void Blur::BoxFilterPassXTask::operator()()
{
  for (uint32_t k = a; k < b; k++) {
    for (uint32_t j = 0; j < size.y; j++) {
      for (uint32_t i = 0; i < size.x; i++) {
        ptrA[i] = src[(k*size.y + j)*size.x + i];
      }
      for (uint32_t l = 0; l < iterations; l++) {
        boxFilterScanline(ptrB, ptrA, size.x, radius);
        std::swap(ptrA, ptrB);
      }
      for (uint32_t i = 0; i < size.x; i++) {
        dst[(k*size.y + j)*size.x + i] = ptrA[i];
      }
    }
  }
}
 
void Blur::BoxFilterPassYTask::operator()()
{
  for (uint32_t k = a; k < b; k++) {
    for (uint32_t i = 0; i < size.x; i++) {
      for (uint32_t j = 0; j < size.y; j++) {
        ptrA[j] = src[(k*size.y + j)*size.x + i];
      }
      for (uint32_t l = 0; l < iterations; l++) {
        boxFilterScanline(ptrB, ptrA, size.y, radius);
        std::swap(ptrA, ptrB);
      }
      for (uint32_t j = 0; j < size.y; j++) {
        dst[(k*size.y + j)*size.x + i] = ptrA[j];
      }
    }
  }
}
 
void Blur::BoxFilterPassZTask::operator()()
{
  for (uint32_t j = a; j < b; j++) {
    for (uint32_t i = 0; i < size.x; i++) {
 
      for (uint32_t k = 0; k < size.z; k++) {
        ptrA[k] = src[(k*size.y + j)*size.x + i];
      }
      for (uint32_t l = 0; l < iterations; l++) {
        boxFilterScanline(ptrB, ptrA, size.z, radius);
        std::swap(ptrA, ptrB);
      }
      for (uint32_t k = 0; k < size.z; k++) {
        dst[(k*size.y + j)*size.x + i] = ptrA[k];
      }
    }
  }
}