Function getPixelColorRGBA16

Demo/png/lodepng.cpp:3375–3411

Get RGBA16 color of pixel with index i (y * width + x) from the raw image with given color type, but the given color type must be 16-bit itself.*/

/*Get RGBA16 color of pixel with index i (y * width + x) from the raw image with
given color type, but the given color type must be 16-bit itself.*/
static unsigned getPixelColorRGBA16(unsigned short* r, unsigned short* g, unsigned short* b, unsigned short* a,
                                    const unsigned char* in, size_t i, const LodePNGColorMode* mode)
{
  if(mode->bitdepth != 16) return 85; /*error: this function only supports 16-bit input*/

  if(mode->colortype == LCT_GREY)
  {
    *r = *g = *b = 256 * in[i * 2 + 0] + in[i * 2 + 1];
    if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0;
    else *a = 65535;
  }
  else if(mode->colortype == LCT_RGB)
  {
    *r = 256 * in[i * 6 + 0] + in[i * 6 + 1];
    *g = 256 * in[i * 6 + 2] + in[i * 6 + 3];
    *b = 256 * in[i * 6 + 4] + in[i * 6 + 5];
    if(mode->key_defined && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r
       && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g
       && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0;
    else *a = 65535;
  }
  else if(mode->colortype == LCT_GREY_ALPHA)
  {
    *r = *g = *b = 256 * in[i * 4 + 0] + in[i * 4 + 1];
    *a = 256 * in[i * 4 + 2] + in[i * 4 + 3];
  }
  else if(mode->colortype == LCT_RGBA)
  {
    *r = 256 * in[i * 8 + 0] + in[i * 8 + 1];
    *g = 256 * in[i * 8 + 2] + in[i * 8 + 3];
    *b = 256 * in[i * 8 + 4] + in[i * 8 + 5];
    *a = 256 * in[i * 8 + 6] + in[i * 8 + 7];
  }
  else return 85; /*error: this function only supports 16-bit input, not palettes*/

  return 0; /*no error*/
}

/*
converts from any color type to 24-bit or 32-bit (later maybe more supported). return value = LodePNG error code