Module: ChunkyPNGSubimage

Defined in:

lib/chunky_png_subimage/search.rb,
lib/chunky_png_subimage/version.rb,
ext/chunky_png_subimage/chunky_png_subimage.c

Constant Summary

VERSION =

"0.2.0"

Class Method Summary

• ._search_subimage(*args) ⇒ Object

  Exportable function to ruby, to search subimages in the image.

• .search_subimage(img, subimages, single = :single_same_subimage, x = 0, y = 0, width = 0, height = 0) ⇒ Object

  Search subimages on the image.

Class Method Details

._search_subimage(*args) ⇒ Object

Exportable function to ruby, to search subimages in the image

Parameters:

• argc —

  Amount of elements in argv

• argv —

  Parameters: img array of pixels, img width, img height, search offset x, search offset y, search width, search height, singleMode (bit 1 - for subimage search, bit 0 - to stop after 1st found subimage), amount of subimages, for every subimage:

  subimage array of pixels, subimage width, subimage height
  

• self —

  Object

Returns:

• Array of found subimages’ positions

# File 'ext/chunky_png_subimage/chunky_png_subimage.c', line 153

VALUE search_subimages(int argc, VALUE *argv, VALUE self)
{
	/*
	params = [img.pixels, img.width, img.height, x, y, width, height, single, subimages.length]
	subimages.each do |s|
		params << s.pixels
		params << s.width
		params << s.height
	end
	 */

	VALUE result = rb_ary_new();
	const VALUE *imgPixels;
	int imgWidth;
	int imgHeight;
	int searchX;
	int searchY;
	int searchWidth;
	int searchHeight;
	int singleMode;
	int amountSubimages;
	const unsigned int *imgReady;
	int cur = 9;
	int i;

	if (argc < 12 || (argc - 9) % 3 != 0)
		rb_raise(rb_eArgError, "wrong number of arguments");

	imgPixels = RARRAY_PTR(argv[0]);
	imgWidth = NUM2INT(argv[1]);
	imgHeight = NUM2INT(argv[2]);
	searchX = NUM2INT(argv[3]);
	searchY = NUM2INT(argv[4]);
	searchWidth = NUM2INT(argv[5]);
	searchHeight = NUM2INT(argv[6]);
	singleMode = NUM2INT(argv[7]);
	amountSubimages = NUM2INT(argv[8]);

	/* some parameters checks */
	if (searchX < 0)
		searchX = 0;
	if (searchY < 0)
		searchY = 0;
	if (searchX >= imgWidth)
		searchX = imgWidth - 1;
	if (searchY >= imgHeight)
		searchY = imgHeight - 1;
	if (searchWidth <= 0)
		searchWidth = imgWidth;
	if (searchHeight <= 0)
		searchHeight = imgHeight;
	if (searchX + searchWidth >= imgWidth)
		searchWidth = imgWidth - searchX;
	if (searchY + searchHeight >= imgHeight)
		searchHeight = imgHeight - searchY;

	/* prepare image */
	imgReady = convert_image(imgPixels, imgWidth, imgHeight);

	for (i = 0; i < amountSubimages; i++)
	{
		/* cur++ inside RARRAY_PTR might not be used as it is used in the macro multiple times */
		const VALUE *subPixels = RARRAY_PTR(argv[cur]);
		int subWidth = NUM2INT(argv[cur + 1]);
		int subHeight = NUM2INT(argv[cur + 2]);
		const unsigned int *subReady = convert_image(subPixels, subWidth, subHeight);

		VALUE r = search_single_subimage(imgReady, imgWidth, imgHeight,
				searchX, searchY, searchWidth, searchHeight,
				subReady, subWidth, subHeight, singleMode);

		xfree((void *)subReady);

		rb_ary_push(result, r);

		/* stop if the proper single mode and result is found */
		if ((singleMode & 1) && RARRAY_LEN(r) > 0)
			break;

		cur += 3;
	}

	xfree((void *)imgReady);

	return result;
}

.search_subimage(img, subimages, single = :single_same_subimage, x = 0, y = 0, width = 0, height = 0) ⇒ Object

Search subimages on the image.

Attributes

• img - Image where search for subimages will be done

• subimages - Subimage or an array of subimages. Just fully opaque pixels are used from any subimage.

• single - ‘single mode’, when to stop if an subimage is found, possible values: :single_everywhere - fully stop after 1st subimage is found; :single_same_subimage - search maximum 1 subimage position, for every provided subimage; :single_subimage - stop after 1st subimage is found, but find every possible position for that subimage; anything else - search for every possible subimage multiple times.

• x - if find subimages inside some region of image - offset x (0 by default)

• y - if find subimages inside some region of image - offset y (0 by default)

• width - if find subimages inside some region of image - width of that region (full image by default)

• height - if find subimages inside some region of image - height of that region (full image by default)

Output

Method returns:

• An array of arrays with positions of found subimages.

• If just single subimage is provided (without array) - then the output also does not contain outer array.

Examples

ChunkyPNGSubimage.search_subimage img, sub

# File 'lib/chunky_png_subimage/search.rb', line 56

def self.search_subimage img, subimages, single = :single_same_subimage, x = 0, y = 0, width = 0, height = 0
  many_subimages = subimages.is_a? Array
  subimages = [subimages] unless many_subimages
  case single
  when :single_everywhere
    single = 3
  when :single_same_subimage # just 1 result is needed per subimage
    single = 2
  when :single_subimage # single image to find
    single = 1
  else
    single = 0
  end
  params = [img.pixels, img.width, img.height, x, y, width, height, single, subimages.length]
  subimages.each do |s|
    params << s.pixels
    params << s.width
    params << s.height
  end
  res = self._search_subimage *params
  res = res[0] if (!many_subimages && res.is_a?(Array))
  res
end