<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE map SYSTEM "http://mapeditor.org/dtd/1.0/map.dtd">
<map version="1.0" orientation="orthogonal" width="10" height="10" tilewidth="32" tileheight="32">
 <properties>
  <property name="Author" value="Silveira Neto"/>
  <property name="Year" value="2009"/>
 </properties>
 <tileset name="mytiles" firstgid="1" tilewidth="32" tileheight="32">
  <image source="free_tileset_version_10.png"/>
 </tileset>
 <layer name="grass" width="10" height="10">
  <data>
   <tile gid="261"/>
   <tile gid="260"/>
    ...
   <tile gid="160"/>
   <tile gid="0"/>
  </data>
 </layer>
</map>

# Author: Silveira Neto
# License: GPLv3
import sys, pygame
from pygame.locals import *
from pygame import Rect
from xml import sax
 
class Tileset:
    def __init__(self, file, tile_width, tile_height):
        image = pygame.image.load(file).convert_alpha()
        if not image:
            print "Error creating new Tileset: file %s not found" % file
        self.tile_width = tile_width
        self.tile_height = tile_height
        self.tiles = []
        for line in xrange(image.get_height()/self.tile_height):
            for column in xrange(image.get_width()/self.tile_width):
                pos = Rect(
                        column*self.tile_width,
                        line*self.tile_height,
                        self.tile_width,
                        self.tile_height )
                self.tiles.append(image.subsurface(pos))
 
    def get_tile(self, gid):
        return self.tiles[gid]
 
class TMXHandler(sax.ContentHandler):
    def __init__(self):
        self.width = 0
        self.height = 0
        self.tile_width = 0
        self.tile_height = 0
        self.columns = 0
        self.lines  = 0
        self.properties = {}
        self.image = None
        self.tileset = None
 
    def startElement(self, name, attrs):
        # get most general map informations and create a surface
        if name == 'map':
            self.columns = int(attrs.get('width', None))
            self.lines  = int(attrs.get('height', None))
            self.tile_width = int(attrs.get('tilewidth', None))
            self.tile_height = int(attrs.get('tileheight', None))
            self.width = self.columns * self.tile_width
            self.height = self.lines * self.tile_height
            self.image = pygame.Surface([self.width, self.height]).convert()
        # create a tileset
        elif name=="image":
            source = attrs.get('source', None)
            self.tileset = Tileset(source, self.tile_width, self.tile_height)
        # store additional properties.
        elif name == 'property':
            self.properties[attrs.get('name', None)] = attrs.get('value', None)
        # starting counting
        elif name == 'layer':
            self.line = 0
            self.column = 0
        # get information of each tile and put on the surface using the tileset
        elif name == 'tile':
            gid = int(attrs.get('gid', None)) - 1
            if gid <0: gid = 0
            tile = self.tileset.get_tile(gid)
            pos = (self.column*self.tile_width, self.line*self.tile_height)
            self.image.blit(tile, pos)
 
            self.column += 1
            if(self.column>=self.columns):
                self.column = 0
                self.line += 1
 
    # just for debugging
    def endDocument(self):
        print self.width, self.height, self.tile_width, self.tile_height
        print self.properties
        print self.image
 
def main():
    if(len(sys.argv)!=2):
        print 'Usage:\n\t{0} filename'.format(sys.argv[0])
        sys.exit(2)
    pygame.init()
    screen = pygame.display.set_mode((800, 480))
    parser = sax.make_parser()
    tmxhandler = TMXHandler()
    parser.setContentHandler(tmxhandler)
    parser.parse(sys.argv[1])
    while 1:
        for event in pygame.event.get():
            if event.type == QUIT:
                return
            elif event.type == KEYDOWN and event.key == K_ESCAPE:
                return
        screen.fill((255,255,255))
        screen.blit(tmxhandler.image, (0,0))
        pygame.display.flip()
        pygame.time.delay(1000/60)
 
if __name__ == "__main__": main()

#include <stdio.h>
#include <cv.h>
#include <highgui.h>
 
int main( int argc, char **argv ){
    IplImage *surfer, *milkyway, *result;
    int key = 0;
    CvSize size;
 
    /* load images, check, get size (both should have the same) */
    surfer = cvLoadImage("surfer.jpg", CV_LOAD_IMAGE_COLOR);
    milkyway = cvLoadImage("milkyway.jpg", CV_LOAD_IMAGE_COLOR);
    if((!surfer)||(!milkyway)){
        printf("Could not open one or more images.");
        exit -1;
    }
    size = cvGetSize(surfer);
 
    /* create a empty image, same size, depth and channels of others */
    result = cvCreateImage(size, surfer->depth, surfer->nChannels);
    cvZero(result);
 
    /* result = surfer + milkyway (NULL mask)*/
    cvAdd(surfer, milkyway, result, NULL);
 
    /* create a window, display the result, wait for a key */
    cvNamedWindow("example", CV_WINDOW_AUTOSIZE);
    cvShowImage("example", result);
    cvWaitKey(0);
 
    /* free memory and get out */
    cvDestroyWindow("example");
    cvReleaseImage(&surfer);
    cvReleaseImage(&milkyway);
    cvReleaseImage(&result);
    return 0;
}
 
/* gcc add.c -o add `pkg-config opencv --libs --cflags` */

#include <highgui.h>
#include <stdio.h>
#include <cv.h>
 
CvHaarClassifierCascade *cascade;
CvMemStorage *storage;
 
int main(int argc, char *argv[]) {
    CvCapture *video = NULL;
    IplImage *frame = NULL;
    int delay = 0, key, i=0;
    char *window_name = "Video";
    char *cascadefile = "haarcascade_frontalface_alt.xml";
 
    /* check for video file passed by command line */
    if (argc>1) {
        video = cvCaptureFromFile(argv[1]);
    }
    else {
        printf("Usage: %s VIDEO_FILE\n", argv[0]);
        return 1;
    }
 
    /* check file was correctly opened */
    if (!video) {
        printf("Unable to open \"%s\"\n", argv[1]);
        return 1;
    }
 
    /* load the classifier */
    cascade = ( CvHaarClassifierCascade* )cvLoad( cascadefile, 0, 0, 0 );
    if(!cascade){
        printf("Error loading the classifier.");
	return 1;
    }
 
    /* setup the memory buffer for the face detector */
    storage = cvCreateMemStorage( 0 );
    if(!storage){
        printf("Error creating the memory storage.");
	return 1;
    }
 
    /* create a video window, auto size */
    cvNamedWindow(window_name, CV_WINDOW_AUTOSIZE);
 
    /* get a frame. Necessary for use the cvGetCaptureProperty */
    frame = cvQueryFrame(video);
 
    /* calculate the delay between each frame and display video's FPS */
    printf("%2.2f FPS\n", cvGetCaptureProperty(video, CV_CAP_PROP_FPS));
    delay = (int) (1000/cvGetCaptureProperty(video, CV_CAP_PROP_FPS));
 
    while (frame) {
	/* show loaded frame */
        cvShowImage(window_name, frame);
 
	/* wait delay and check for the quit key */
        key = cvWaitKey(delay);
        if(key=='q') break;
	/* load and check next frame*/
        frame = cvQueryFrame(video);
	if(!frame) {
		printf("error loading frame.\n");
		return 1;
	}
 
        /* detect faces */
        CvSeq *faces = cvHaarDetectObjects(
            frame, /* image to detect objects in */
            cascade, /* haar classifier cascade */
            storage, /* resultant sequence of the object candidate rectangles */
            1.1, /* increse window by 10% between the subsequent scans*/
            3, /* 3 neighbors makes up an object */
            0 /* flags CV_HAAR_DO_CANNY_PRUNNING */,
            cvSize( 40, 40 )
        );
 
        /* for each face found, draw a red box */
        for( i = 0 ; i < ( faces ? faces->total : 0 ) ; i++ ) {
             CvRect *r = ( CvRect* )cvGetSeqElem( faces, i );
             cvRectangle( frame,
                  cvPoint( r->x, r->y ),
                  cvPoint( r->x + r->width, r->y + r->height ),
                  CV_RGB( 255, 0, 0 ), 1, 8, 0 );
        }
    }
}

int led = 13;                   // LED connected to digital pin 13
int buzzer = 12;                // buzzer connected to digital pin 12
int unit = 50;                  // duration of a pulse
 
char * morsecode[] = {
    "-----",  // 0
    ".----",  // 1
    "..---",  // 2
    "...--",  // 3
    "....-",  // 4
    ".....",  // 5
    "-....",  // 6 
    "--...",  // 7
    "---..",  // 8
    "----.",  // 9
    "---...", // :
    "-.-.-.", // ;
    "",       // < (there's no morse for this simbol)
    "-...-",  // =
    "",       // > (there's no morse for this simbol)
    "..--..", // ?
    ".--._.", // @
    ".-",     // A
    "-...",   // B
    "-.-.",   // C
    "-..",    // D
    ".",      // E
    "..-.",   // F
    "--.",    // G
    "....",   // H
    "..",     // I
    ".---",   // J
    "-.-",    // K
    ".-..",   // L
    "--",     // M
    "-.",     // N
    "---",    // O
    ".--.",   // P
    "--.-",   // Q
    ".-.",    // R
    "...",    // S
    "-",      // T
    "..-",    // U
    "...-",   // V
    ".--",    // W
    "-..-",   // X
    "-.--",   // Y
    "--.."    // Z
};
 
void setup() {
  pinMode(led, OUTPUT);
  pinMode(buzzer, OUTPUT);
  Serial.begin(9600);
}
 
void say_morse_word(char * msg){
  int index = 0;
  while(msg[index]!='\0'){
    // say a dash
    if(msg[index]=='-'){
      dash();
    }
    // say a dot
    if(msg[index]=='.'){
      dot();
    }
    // gap beetween simbols
    intragap();
    index++;
  }
}
 
// beep
void beep(int time){
  int i;
  int t = 100; // period of the wav. bigger means lower pitch.
  int beepduration = (int)((float)time/t*1800);
  digitalWrite(led, HIGH);
  for(i=0;i<beepduration;i++){
    digitalWrite(buzzer, HIGH);
    delayMicroseconds(t);
    digitalWrite(buzzer, LOW);
    delayMicroseconds(t);
  }
  delay(time);
}
 
// silence
void silence(int time){
  digitalWrite(led, LOW);
  delay(time);
}
 
// general procedure for .
void dot() {
  beep(unit);
}
 
// general procedure for -
void dash() {
  beep(unit*3);
}
 
// gap between dots and dashes
void intragap() {
  silence(unit);
}
 
// gap between letters
void shortgap() {
  silence(3*unit);
}
 
// gap be  tween words
void mediumgap() {
  silence(7*unit);
}
 
void say_char(char letter){
  if((letter>='0')&&(letter<='Z')&&(letter!='<')&&(letter!='>')){
    Serial.print(morsecode[letter-'0']);
    Serial.print(' ');
    say_morse_word(morsecode[letter-'0']);
    shortgap();
  } else {
    if(letter==' '){
      Serial.print(" \\ ");
      mediumgap();
    }else{
      Serial.print("X");
    }
  }
}
 
void loop(){
  if(Serial.available()){
    say_char((char)Serial.read());
  }
}

void say_string(char * asciimsg){
  int index = 0;
  char charac;
  charac = asciimsg[index];
  while(charac!='\0'){
    say_char(morsecode[charac-'0']);
    Serial.println(morsecode[charac-'0']);
    charac = asciimsg[++index];
    shortgap();
  }
}

/*
 * Description: Solve a hard coded linear system by gaussian elimination
 * Author: Silveira Neto
 * License: Public Domain
 */
 
#include <stdio.h>
#include <stdlib.h>
 
#define ROWS 4
#define COLS 5
 
/**
 * Linear System, Ax = B
 *
 * 10*x1 +  2*x2 +  3*x3 +  4*x4 = 5
 *  6*x1 + 17*x2 +  8*x3 +  9*x4 = 10
 * 11*x1 + 12*x2 + 23*x3 + 14*x4 = 15
 * 16*x1 + 17*x2 + 18*x3 + 29*x4 = 20
 */
float AB[ROWS][COLS] = {
    {10,  2,  3,  4,  5},
    { 6, 17,  8,  9, 10},
    {11, 12, 23, 14, 15},
    {16, 17, 18, 29, 20}
};
 
/* Answer x from Ax=B */
float X[ROWS] = {0,0,0,0};
 
int main(int argc, char** argv) {
    int row, col, i;
 
    /* gaussian elimination */
    for (col=0; col<COLS-1; col++) {
        for (row=0; row<ROWS; line++){
            float pivot =  AB[row][col]/AB[col][col];
            if(row!=col) {
                for(i=0; i<COLS; i++) {
                    AB[row][i] = AB[row][i] - pivot * AB[col][i];
                }
 
            }
        }
    }
 
    /* X = B/A and show X */
    for(row=0; row<ROWS; line++) {
        X[row] = AB[row][ROWS] / AB[row][row];
        printf("%3.5f ", X[row]);
    }
    printf("n");
 
    return (EXIT_SUCCESS);
}

// returning 0 means collision
int collision(int ax, int ay, int bx, int by, int cx, int cy, int dx, int dy){
	return ((ax > dx)||(bx < cx)||(ay > dy)||(by < cy));
}

import javafx.input.MouseEvent;
import javafx.scene.geometry.Rectangle;
 
public class MovableRectangle extends Rectangle {
    private attribute startX = 0.0;
    private attribute startY = 0.0;
 
    public attribute onMove = function(e:MouseEvent):Void {}
 
    override attribute onMousePressed = function(e:MouseEvent):Void {
        startX = e.getDragX()-translateX;
        startY = e.getDragY()-translateY;
        onMove(e);
    }
 
    override attribute onMouseDragged = function(e:MouseEvent):Void {
        translateX = e.getDragX()-startX;
        translateY = e.getDragY()-startY;
        onMove(e);
    }
}

import javafx.application.Frame;
import javafx.application.Stage;
import javafx.scene.geometry.Rectangle;
import javafx.scene.paint.Color;
import javafx.input.MouseEvent;
 
var colide = Color.WHITE;
 
function checkcollision():Void {
    if (
        (rec1.getBoundsX() > rec2.getBoundsX() + rec2.getWidth()) or
        (rec1.getBoundsX() + rec1.getWidth() < rec2.getBoundsX()) or
        (rec1.getBoundsY() > rec2.getBoundsY() + rec2.getHeight()) or
        (rec1.getBoundsY() + rec1.getHeight() < rec2.getBoundsY())
    ) {
        colide = Color.WHITE
    } else {
        colide = Color.LIGHTGRAY
    }
}
 
var rec1: MovableRectangle = MovableRectangle {
    x: 10, y: 10, width: 50, height: 60, fill: Color.RED
    onMove: function(e:MouseEvent):Void {
        checkcollision()
    }
}
 
var rec2: MovableRectangle = MovableRectangle {
    x: 100, y: 100, width: 70, height: 30, fill: Color.BLUE
    onMove: function(MouseEvent):Void {
        checkcollision()
    }
}
Frame {
    title: "Rectangular Collisions", width: 300, height: 300
    closeAction: function() {
        java.lang.System.exit( 0 );
    }
    visible: true
 
    stage: Stage {
        fill: bind colide
        content: [rec1, rec2]
    }
}

function collission(ax, ay, bx, by, cx, cy, dx, dy): Boolean {
    return not ((ax > dx)or(bx < cx)or(ay > dy)or(by < cy));
}
 
function hitnode(a: Node, b:Node): Boolean{
    return (collission(
        a.getBoundsX(), a.getBoundsY(),
        a.getBoundsX() + a.getWidth(), a.getBoundsY() + a.getHeight(),
        b.getX(), b.getY(),
        b.getX() + b.getWidth(), b.getY() + b.getHeight()
    ));
}

function inside (ax, ay, bx, by, cx, cy, dx, dy):Boolean{
    return ((ax > cx) and (bx < dx) and (ay > cy) and (by < dy));
}
 
function insidenode(a:Node,b:Node):Boolean{
    return (inside(
        a.getBoundsX(), a.getBoundsY(),
        a.getBoundsX() + a.getWidth(), a.getBoundsY() + a.getHeight(),
        b.getBoundsX(), b.getBoundsY(),
        b.getBoundsX() + b.getWidth(), b.getBoundsY() + b.getHeight()
    ));
}

select(X, [X|Xs], Xs).
select(X, [Y|Ys], [Y|Zs]) :- select(X, Ys, Zs).
 
permutar([], []).
permutar(Xs, [Z|Zs]) :-
    select(Z, Xs, Ys),
    permutar(Ys, Zs).

def all_perms(str):
    if len(str) <=1:
        yield str
    else:
        for perm in all_perms(str[1:]):
            for i in range(len(perm)+1):
                yield perm[:i] + str[0:1] + perm[i:]

>>> for p in all_perms(['a','b','c']):
	print p
['a', 'b', 'c']
['b', 'a', 'c']
['b', 'c', 'a']
['a', 'c', 'b']
['c', 'a', 'b']
['c', 'b', 'a']