DZone Snippets: mask code

Generate all subsets of a set

scvalex (Alexandru Scvortov) — Wed, 10 Oct 2007 14:43:25 GMT

This code generates all the subsets of {1, 2, ..., n} and prints them.

This also contains a very fast binary counter implementation.

See this for further explanations.



#include 



/* Applies the mask to a set like {1, 2, ..., n} and prints it */

void printv(int mask[], int n) {

	int i;

	printf("{ ");

	for (i = 0; i < n; ++i)

		if (mask[i])

			printf("%d ", i + 1); /*i+1 is part of the subset*/

	printf("\b }\n");

}



/* Generates the next mask*/

int next(int mask[], int n) {

	int i;

	for (i = 0; (i < n) && mask[i]; ++i)

		mask[i] = 0;



	if (i < n) {

		mask[i] = 1;

		return 1;

	}

	return 0;

}



int main(int argc, char *argv[]) {

	int n = 3;



	int mask[16]; /* Guess what this is */

	int i;

	for (i = 0; i < n; ++i)

		mask[i] = 0;



	/* Print the first set */

	printv(mask, n);



	/* Print all the others */

	while (next(mask, n))

		printv(mask, n);



	return 0;

}

Show all icons in avkon.mbm

korakot (Korakot Chaovavanich) — Tue, 14 Feb 2006 16:41:43 GMT

There are 2 type of mbm files. The following code work with
ROM-type (most mbm on Z:\) only.



>>> from appuifw import *

>>> avkon = u'z:\\system\\data\\avkon.mbm'

>>> def showicon(id_list, maskfunc=lambda x:x):

...     if type(id_list) == int:

...         id_list = [id_list] # one item

...     entries = []

...     if type(maskfunc) == dict:  # allow dict as a func

...         func = lambda id: maskfunc.get(id,id)

...     else:

...         func = maskfunc

...     for id in id_list:

...         item = u'%s, %s' % (id, func(id))

...         icon = Icon(avkon, id, func(id))

...         entries.append((item, u'', icon))

...     app.body = Listbox(entries, lambda: None)

...

>>> showicon(range(503))  # all icons, including mask

>>> showicon(range(0,100,2), lambda x:x+1)  # first 50 icons, with their mask brother

Using transparent gif/png with Image's blitting

korakot (Korakot Chaovavanich) — Thu, 09 Feb 2006 13:03:39 GMT

pys60's Image class will load a transparent gif/png
just like a non-transparent one.
But its blit() method accept a mask paramenter.
I have talked about this in a previous snippet.

The missing link is to create a mask automatically
from the Image. It's typically the top-left pixel.
You can use Image's getpixel() which is undocumented.
I show typical use of getpixel here.

Combine them all, here's the automask function.



def automask(im):

    width, height = im.size

    mask = Image.new(im.size, '1') # black and white

    tran = im.getpixel((0,0))[0]   # transparent top-left

    for y in range(height):

        line = im.getpixel([(x, y) for x in range(width)])

        for x in range(width):

            if line[x] == tran:

                mask.point((x,y), 0)  # mask on the point

    return mask

An example usage



from graphics import Image



ship = Image.open('E:\\Images\\ship.gif')

mask = automask(ship)



canvas.blit(ship, mask=mask)  # don't forget to create canvas first

A Sprite class can be defined based on this too.

Image/canvas bliting

korakot (Korakot Chaovavanich) — Thu, 01 Dec 2005 20:57:55 GMT

I can't remember how to call the blit method.
So, here's just a personal reminder.
(BTW, the pys60 doc has a wrong order between target and source)



app.body = c = Canvas()

w,h = 20,20

im = Image.new(size=(w,h))



# here's prototype

# blit(im, source=(0,0,w,h), target=(0,0), mask=None, scale=0)

# here are examples

c.blit(im)  # put entire image on top-left

c.blit(im, target=(70,70)) # put it about mid-screen

c.blit(im, (0,0,w/2,h/2))  # put a quater image on top-left



# double the image size and put it about mid-screen

c.blit(im, target=(60,60,100,100), scale=1)

If scale is not specified and source <> target, the image
will be clipped instead of resized.

mask is a 1-bit image with the same size as image.
mask = Image.new((w,h),'1')
Pixel on the image will be copied if the same pixel
on the mask is 'white'.
So we can use mask to make 'Sprite'.

Masked Input //Javascript Object

jonasraoni (Jonas Raoni Soares Silva) — Fri, 09 Sep 2005 04:10:55 GMT

Simple and generic mask routine.

[UPDATED CODE AND HELP CAN BE FOUND HERE]

@REQUIRES Event-Listener



// REQUIRES: http://jsfromhell.com/geral/event-listener



//+ Jonas Raoni Soares Silva

//@ http://jsfromhell.com/forms/masked-input [v1.0]



MaskInput = function(f, m){ //v1.0

    function mask(e){

        var patterns = {"1": /[A-Z]/i, "2": /[0-9]/, "4": /[À-ÿ]/i, "8": /./ },

            rules = { "a": 3, "A": 7, "9": 2, "C":5, "c": 1, "*": 8};

        function accept(c, rule){

            for(var i = 1, r = rules[rule] || 0; i <= r; i<<=1)

                if(r & i && patterns[i].test(c))

                    break;

                return i <= r || c == rule;

        }

        var k, mC, r, c = String.fromCharCode(k = e.key), l = f.value.length;

        (!k || k == 8 ? 1 : (r = /^(.)\^(.*)$/.exec(m)) && (r[0] = r[2].indexOf(c) + 1) + 1 ?

            r[1] == "O" ? r[0] : r[1] == "E" ? !r[0] : accept(c, r[1]) || r[0]

            : (l = (f.value += m.substr(l, (r = /[A|9|C|\*]/i.exec(m.substr(l))) ?

            r.index : l)).length) < m.length && accept(c, m.charAt(l))) || e.preventDefault();

    }

    for(var i in !/^(.)\^(.*)$/.test(m) && (f.maxLength = m.length), {keypress: 0, keyup: 1})

        addEvent(f, i, mask);

};



//]]>

Usage (sorry, i'm lazy to write a help hahaha)





telephone "(99)9999-9999"







date "99/99/9999"









máscara = letter + letter withou accent + 2 numbers + "-" + anything + letter "Cc99-*C"









everything, but a, b or c "E^abc"









only a, b or c "O^abc"









just letters "C^"









just letters and also white-space "C^ "









just numbers and also the letters a, b e c "9^abc"