Function rotsprite_image

src/doc/algorithm/rotsprite.cpp:166–229

}

void rotsprite_image(Image* bmp, const Image* spr, const Image* mask,
  int x1, int y1, int x2, int y2,
  int x3, int y3, int x4, int y4)
{
  static ImageBufferPtr buf[3]; // TODO non-thread safe

  for (int i=0; i<3; ++i)
    if (!buf[i])
      buf[i].reset(new ImageBuffer(1));

  int xmin = MIN(x1, MIN(x2, MIN(x3, x4)));
  int xmax = MAX(x1, MAX(x2, MAX(x3, x4)));
  int ymin = MIN(y1, MIN(y2, MIN(y3, y4)));
  int ymax = MAX(y1, MAX(y2, MAX(y3, y4)));
  int rot_width = xmax - xmin;
  int rot_height = ymax - ymin;

  if (rot_width == 0 || rot_height == 0)
    return;

  int scale = 8;
  std::unique_ptr<Image> bmp_copy(Image::create(bmp->pixelFormat(), rot_width*scale, rot_height*scale, buf[0]));
  std::unique_ptr<Image> tmp_copy(Image::create(spr->pixelFormat(), spr->width()*scale, spr->height()*scale, buf[1]));
  std::unique_ptr<Image> spr_copy(Image::create(spr->pixelFormat(), spr->width()*scale, spr->height()*scale, buf[2]));
  std::unique_ptr<Image> msk_copy;

  color_t maskColor = spr->maskColor();

  bmp_copy->setMaskColor(maskColor);
  tmp_copy->setMaskColor(maskColor);
  spr_copy->setMaskColor(maskColor);

  spr_copy->clear(maskColor);
  spr_copy->copy(spr, gfx::Clip(spr->bounds()));

  for (int i=0; i<3; ++i) {
    // clear_image(tmp_copy, maskColor);
    image_scale2x(tmp_copy.get(), spr_copy.get(), spr->width()*(1<<i), spr->height()*(1<<i));
    spr_copy->copy(tmp_copy.get(), gfx::Clip(tmp_copy->bounds()));
  }

  if (mask) {
    // Same ImageBuffer than tmp_copy
    msk_copy.reset(Image::create(IMAGE_BITMAP, mask->width()*scale, mask->height()*scale, buf[1]));
    clear_image(msk_copy.get(), 0);
    scale_image(msk_copy.get(), mask,
                0, 0, msk_copy->width(), msk_copy->height(),
                0, 0, mask->width(), mask->height());
  }

  clear_image(bmp_copy.get(), maskColor);
  scale_image(bmp_copy.get(), bmp,
              0, 0, bmp_copy->width(), bmp_copy->height(),
              xmin, ymin, rot_width, rot_height);

  parallelogram(
    bmp_copy.get(), spr_copy.get(), msk_copy.get(),
    (x1-xmin)*scale, (y1-ymin)*scale, (x2-xmin)*scale, (y2-ymin)*scale,