the world is a pixel
Posts tagged Java
Java Font List
Jan 5th
Here’s a program that lists fonts available in your JVM. You can also set the environment variable JAVA_FONTS to specify the font directory.
import java.awt.GraphicsEnvironment; public class ListFonts { public static void main(String args[]){ GraphicsEnvironment e = GraphicsEnvironment.getLocalGraphicsEnvironment(); for(String font:e.getAvailableFontFamilyNames()){ System.out.println(font); } } }
By using pipes you can count how many fonts you have:
java ListFonts|wc -l
On my Ubuntu machine here I got 556 because I use those excellent, free and indispensable Larabie Fonts.
For looking up for a font with “sans” in its name, using a case insensitive grep:
java ListFonts|grep -i “sans”
I get a list like this:
DejaVu Sans
DejaVu Sans Condensed
DejaVu Sans Light
DejaVu Sans Mono
FreeSans
Tiled TMX Map Loader for Pygame
Dec 19th
I’m using the Tiled Map Editor for a while, I even wrote that tutorial about it. It’s a general purpose tile map editor, written in Java but now migrating to C++ with Qt, that can be easily used with my set of free pixelart tiles.
A map done with Tiled is stored in a file with TMX extension. It’s just a XML file, easy to understand.
As I’m creating a map loader for my owns purposes, the procedure I’m doing here works we need some simplifications. I’m handling orthogonal maps only. I’m not supporting tile properties as well. I also don’t want to handle base64 and zlib encoding in this version, so in the Tiled editor, go at the menu Edit → Preferences and in the Saving tab unmark the options “Use binary encoding” and “Compress Layer Data (gzip)”, like this:
When saving a map it will produce a TMX file like this:
<?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>
For processing it on Python I’m using the event oriented SAX approach for XML. So I create a ContentHandler that handles events the start and end of XML elements. In the first element, map, I know enough to create a Pygame surface with the correct size. I’m also storing the map properties so I can use it later for add some logics or effects on the map. After that we create a instance of the Tileset class from where we will get the each tile by an gid number. Each layer has it’s a bunch of gids in the correct order. So it’s enough information to mount and draw a 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()
Here is the result for opening a four layers map file:
That’s it. You can get this code and adapt for your game because next versions will be a lot more coupled for my own purposes and not so general.
Download:
maploader.tar.bz2 It’s the Netbeans 6.7 (Python EA 2) project file but that can be opened or used with another IDE or without one. Also contains the village.tmx map and the tileset.
Java: Accessing Private Members
Nov 14th
Using reflection to change the accessibility of a private object field and access it at runtime.
import java.lang.reflect.Field; class Life { private int meaning = 42; } class Hack { public static void main(String args[]){ Life life = new Life(); try { Field field = life.getClass().getDeclaredField("meaning"); field.setAccessible(true); System.out.println(field.get(life)); } catch (NoSuchFieldException e) { e.printStackTrace(); } catch (IllegalAccessException e){ e.printStackTrace(); } } }
Output:
42
Jedi Name
Nov 8th
A simple Java class that calculates your Jedi name based on your first, last name, mother’s maiden name and the city you grew up.
/* Jedi first name: 1st 3 letters of last name + 1st 2 letters of first name Jedi last name: 1st 2 letters of mother's maiden name + 1st 3 letters of city you were raised in */ public class JediName { private static String capitalize(String s){ return s.substring(0,1).toUpperCase() + s.substring(1,s.length()).toLowerCase(); } private static String sub(String s, int begin, int end){ return s.substring(begin, (s.length()>=end)?end:s.length()); } public static String generate(String firstName, String lastName, String city, String mother ){ String jediFirstName = capitalize(sub(lastName, 0, 3) + sub(firstName, 0,2)); String jediLastName = capitalize(sub(mother,0,2)+ sub(city,0,3)); return jediFirstName + " " + jediLastName; } }
I used inline conditional expression ()?: to avoid raise a IndexOutOfBoundsException when the string is to small to cut the proper size we want.
And a example of how to use it:
public class JediNameTester { public static void main(String args[]){ String myJediName = JediName.generate("Pedro", "Madeira", "Fortaleza", "Maria"); System.out.println(myJediName); } }
My jedi name is Siljo Iruba. 
7 anos de CEJUG
Sep 16th
fontes: cct-set-2009.zip
- Quando: esse sábado agora, 19 de Setembro de 2009.
- Onde: na Faculdade 7 de Setembro (Rua Alm. Maximiniano da Fonseca, 1395).
- Preço: Gratuito.
O CEJUG está comemorando seu sétimo aniversário com um Café com Tapioca especial e imperdível com diversos palestrantes nacionais e muitos sorteios de brindes. A programação completa e as incrições podem ser feitas atráves do site cafecomtapioca.com! Não percam por nada.
