如何翻转一个字母？

Question

Here I'm trying to flip an English letter upside down for my mail template.

Well I can get it manually. What I'm doing is now manually

just like

 content.append("ɥ"); //actual h letter.
 content.append("ǝ")// actual e letter.

So my question is that , is there any trick/method/any clue to do it in programmatic way ?

What I'm doing now is

switch(letter) {

case 'e':
   return 'ǝ';
}

That looks odd and looking for hints. Thanks for any help.

Answer 1

The fastest way to do character replacement is an array.

create an array of upside down letters. Then, do a check of the value coming in and find it's match.

Java allows you to get the integer representation of a character by simply casting int x = char a; So, it stands to reason that your upsidedown a would be at the index of your char minus the lowest char you are mapping (usually lowercase a).

char[] updown = {'ɐ','q','ɔ','p','ə','ɟ','ƃ','ɥ','ı','ɾ','ʞ','l','ɯ','u','o','d','b','ɹ','s','ʇ','n','ʌ','ʍ','x','ʎ','z'};
//this example uses 26 chars, all lower case;
int a = 'a';
int z = 'z';

String newString = "";
for(int i=0; i<string.length; i++){
    int ch = string.charAt(i);
    if(ch>= a && ch <=z){
        newString = (updown[ch-a]) + newString;
    }
}

Here's a link to IDEONE where you can compile and test for yourself. http://ideone.com/LombFE

Answer 2

I'm not sure of a java-specific solution, but seeing as Strings in java use unicode, I checked out the unicode characters for their upside down counterparts here: http://www.fileformat.info/convert/text/upside-down-map.htm

It doesn't look there's a good programmatic method for finding these. However, there are a variety of converters, like this one http://www.fileformat.info/convert/text/upside-down.htm You could generate config files based on input and output of one of these types of converters and use those config files to drive your upside-down letter selection

Answer 3

If you are looking for a generic way to create upside-down plain text, there is no way.

All the sites that do that, simply substitute adequate unicode characters that do not have anything in common with the original ones, and for some they don't find anything. There is no way to have anything that looks like upside-down j , so as you can see in other answers, the supposed "upside-down j " looks ugly. Were you looking for upside-down ß or @ or 5 , you wouldn't find anything either. The sites that do upside-down text either ignore such symbols, use something really dissimilar, or simply fail to do anything.

Unicode deals with contents of the text, not its orientation.

You mention mail templates. If you are using HTML, you can use this bit of CSS:

.upsidedown {
    -moz-transform: rotate(180deg);
    -webkit-transform: rotate(180deg);
    -ms-transform: rotate(180deg);
    -o-transform: rotate(180deg);
    transform: rotate(180deg);
}

Not all mail clients will display it correctly though.

Answer 4

Try this script, here : http://ideone.com/szPg6V

Input :

• 'So my question is that , is there any trick/method/any clue to do it in programmatic way ?'

Ouput :

• ,¿ ʎɐʍ ɔıʇɐɯɯɐɹboɹd uı ʇı op oʇ ǝnןɔ ʎuɐ/poɥʇǝɯ/ʞɔıɹʇ ʎuɐ ǝɹǝɥʇ sı 'ʇɐɥʇ sı uoıʇsǝnb ʎɯ oS,

Java code :

String normal = "abcdefghijklmnopqrstuvwxyz_,;.?!/\\'";
String split  = "ɐqɔpǝɟbɥıظʞןɯuodbɹsʇnʌʍxʎz‾'؛˙¿¡/\\,";
//maj
normal += "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
split  += "∀qϽᗡƎℲƃHIſʞ˥WNOԀὉᴚS⊥∩ΛMXʎZ";
//number
normal += "0123456789";
split  += "0ƖᄅƐㄣϛ9ㄥ86";

String str = "So my question is that , is there any trick/method/any clue to do it in programmatic way ?";
String newstr = ""; 
char letter;
for (int i=0; i< str.length(); i++) {
    letter = str.charAt(i);

    int a = normal.indexOf(letter);
    newstr += (a != -1) ? split.charAt(a) : letter;
}
System.out.println(new StringBuilder(newstr).reverse().toString());

I use this tools : http://www.upsidedowntext.com/

Answer 5

If you don't like any of the examples above, you can always use an enum. This way you can add other characters you may want with their respective upside down equivalent.

Example :

//only lower case in this example, but new values can be added
enum upsideDown{
    a('ɐ'),
    b('q'),
    c('ɔ'),
    d('p'),
    e('ə'),
    f('ɟ'),
    g('ƃ'),
    h('ɥ'),
    i('ı'),
    j('ɾ'),
    k('ʞ'),
    l('l'),
    m('ɯ'),
    n('u'),
    o('o'),
    p('d'),
    q('b'),
    r('ɹ'),
    s('s'),
    t('ʇ'),
    u('n'),
    v('ʌ'),
    w('ʍ'),
    x('x'),
    y('ʎ'),
    z('z');
    private char value;

    private upsideDown(char value) {
        this.value = value;
    }
    private char getValue(){
        return value;
    }
};


public static void main(String[] args) {

    String hello = "helloworld";
    StringBuilder str = new StringBuilder(hello.length());
    for (int i = hello.length()-1; i >= 0; i--) {
        str.append(upsideDown.valueOf(String.valueOf(hello.charAt(i))).getValue());
    }
    System.out.println(str.toString());

}

Answer 6

I wrote a code to do it in programmatic way, but the code is very slow.

The code computes the differences between the shapes of all letters and the flipped character's shape and choose the one with minimal area.

Example:

a ɐ
e ǝ
i ı
o o
u n

Code:

import java.awt.Font;
import java.awt.Shape;
import java.awt.font.FontRenderContext;
import java.awt.font.GlyphVector;
import java.awt.geom.AffineTransform;
import java.awt.geom.Area;
import java.awt.geom.PathIterator;
import java.awt.geom.Rectangle2D;

class Main {
    private static final Font FONT = new Font(Font.MONOSPACED, Font.PLAIN, 24);

    private static Shape moveToOrigin(Shape s) {
        Rectangle2D r = s.getBounds2D();
        return AffineTransform.getTranslateInstance(-r.getX(), -r.getY())
                .createTransformedShape(s);
    }

    private static Shape flip(Shape s) {
        Rectangle2D r = s.getBounds2D();
        return AffineTransform.getRotateInstance(Math.PI, r.getCenterX(),
                r.getCenterY()).createTransformedShape(s);
    }

    private static double getArea(Shape s) {
        PathIterator path = s.getPathIterator(new AffineTransform());
        double area0 = 0;
        while (!path.isDone()) {
            double area = 0;
            double[] darray = new double[6];
            path.currentSegment(darray);
            double x0 = darray[0], y0 = darray[1];
            double x1 = x0, y1 = y0;
            path.next();
            while (path.currentSegment(darray) != PathIterator.SEG_CLOSE) {
                double x2 = darray[0], y2 = darray[1];
                area += x1 * y2 - y1 * x2;
                x1 = x2;
                y1 = y2;
                path.next();
            }
            path.next();
            area0 += Math.abs((area + x1 * y0 - y1 * x0) / 2);
        }
        return area0;
    }

    public static char findOpposite(char c) {
        FontRenderContext frc = new FontRenderContext(new AffineTransform(),
                true, false);
        GlyphVector gv1 = FONT.createGlyphVector(frc, String.valueOf(c));
        Area area1 = new Area(flip(moveToOrigin(gv1.getOutline())));

        double minDiff = 1.0 / 0.0;
        char bestChar = ' ';
        for (int i = 0; i <= Character.MAX_VALUE; i++) {
            GlyphVector gv2 = FONT.createGlyphVector(frc,
                    String.valueOf((char) i));
            Area area2 = new Area(moveToOrigin(gv2.getOutline()));
            area2.exclusiveOr(area1);

            double diff = getArea(area2);

            if (diff < minDiff) {
                minDiff = diff;
                bestChar = (char) i;
                System.err.println(bestChar + " : " + minDiff);
            }
            if (i % (Character.MAX_VALUE / 100) == 0) {
                System.err.println(i / (Character.MAX_VALUE / 100) + "%");
            }
        }
        return bestChar;
    }

    public static void main(String[] args) {
        System.out.println('a' + " " + findOpposite('a'));
        System.out.println('e' + " " + findOpposite('e'));
        System.out.println('i' + " " + findOpposite('i'));
        System.out.println('o' + " " + findOpposite('o'));
        System.out.println('u' + " " + findOpposite('u'));
    }
}