streamtools/rescalers/changestack.cpp

   1 #include "rescalers/simple.hpp"
   2 #include <stdint.h>
   3 #include <cmath>
   4 #include <stdexcept>
   5
   6 namespace
   7 {
   8         void do_changestack(uint8_t* target, uint32_t twidth, uint32_t theight,
   9                 const uint8_t* source, uint32_t swidth, uint32_t sheight)
  10         {
  11                 uint32_t* __restrict__ src = (uint32_t*)source;
  12                 uint32_t* __restrict__ dest = (uint32_t*)target;
  13                 bool horizontal_to_vertical;
  14                 uint32_t ratio;
  15
  16                 if(swidth < twidth) {
  17                         //Vertical to horizontal.
  18                         horizontal_to_vertical = false;
  19                         if(twidth % swidth || sheight % theight)
  20                                 throw std::runtime_error("Bad size change for stacking change");
  21                         ratio = twidth / swidth;
  22                         if(theight * ratio != sheight)
  23                                 throw std::runtime_error("Bad size change for stacking change");
  24                 } else {
  25                         //Horizontal to vertical.
  26                         horizontal_to_vertical = true;
  27                         if(swidth % twidth || theight % sheight)
  28                                 throw std::runtime_error("Bad size change for stacking change");
  29                         ratio = swidth / twidth;
  30                         if(sheight * ratio != theight)
  31                                 throw std::runtime_error("Bad size change for stacking change");
  32                 }
  33
  34                 for(uint32_t y = 0; y < sheight; y++)
  35                         for(uint32_t x = 0; x < swidth; x++) {
  36                                 uint32_t _x, _y;
  37                                 if(horizontal_to_vertical) {
  38                                         _x = x % twidth;
  39                                         _y = y + x / twidth * sheight;
  40                                 } else {
  41                                         _x = x + y / theight * swidth;
  42                                         _y = y % theight;
  43                                 }
  44                                 dest[_y * twidth + _x] = src[y * swidth + x];
  45                         }
  46         }
  47
  48         simple_rescaler factory("changestacking", make_bound_method(do_changestack));
  49 }