Я обнаружил, что при рендеринге непрозрачного текста в Java (последняя версия 6u23) используется субпиксель AA просто отлично, при этом полупрозрачный текст не делает.
Субпиксельный АА:
Тот же текст, для которого только цвет был изменен с 0xFFFFFFFF на 0xBFFFFFFF:
Как вы можете видеть, полупрозрачный текст явно является стандартным АА, а не чистым полупрозрачным рендерингом, он имеет этот ужасный внешний вид "90-х".
Это связано с техническим ограничением для субпикселя AA в целом или ошибкой на Java или просто потому, что Java даже не пытается получить полупрозрачный текст, или я что-то пропустил?
Инициализация графики
dbGraphics=(Graphics2D)dbImage.getGraphics();
if(dctRoot.properties.getBoolean("Antialias",true)) {
try {
Map hnts=(Map)(dctRoot.awtComponent.getToolkit().getDesktopProperty("awt.font.desktophints"));
// SET AA ON OVERALL (NOTE: GENERAL AA MUST BE OFF FOR SUBPIXEL AA TO BE HONORED - TEXT WIDGETS MUST DO THIS THEMSELVES)
dbGraphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
if(hnts!=null) {
// SET FONT RENDERING HINTS FROM DESKTOP
dbGraphics.addRenderingHints(hnts);
}
else {
try {
// SET TEXT AA TO FONT-SPECIFIED GASP AA (JAVA 6+)
dbGraphics.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,RenderingHints.class.getField("VALUE_TEXT_ANTIALIAS_GASP").get(null));
}
catch(Throwable thr3) {
// SET TEXT AA TO DEFAULT
dbGraphics.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
}
}
}
catch(Throwable thr) {
dctRoot.log.println("Antialiasing not supported on this JVM ("+thr+").");
dctRoot.setProperty("Antialias","False"); // turn off AA for subsequent painting
}
}
else {
try {
dbGraphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_OFF);
dbGraphics.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,RenderingHints.VALUE_TEXT_ANTIALIAS_OFF);
}
catch(Throwable thr) {;} // ignore exception
}
Текстовое рендеринг
Object oaa=disableGeneralAA(gc);
...
gc.drawString(tl,xx,(ty+(xa*met.getHeight())));
restoreGeneralAA(gc,oaa);
...
static private volatile boolean hasRenderingHints=true;
// *****************************************************************************
// STATIC INIT & MAIN
// *****************************************************************************
// *****************************************************************************
// STATIC METHODS
// *****************************************************************************
/**
* Disable the general anti-aliasing rendering hint, returning whether the old value was RenderingHints.VALUE_ANTIALIAS_ON.
* <p>
* This method is needed for text rendering due to a bug in AWT; as of Java 6_20 when general AA is on text is not rendered using subpixel
* AA, so general AA has to be turned off before rendering text and turned back on when done. This method abstracts that work and deals
* with the possibility that the JVM does not support rendering hints, such as is the case with JME JVMs.
*/
static public Object disableGeneralAA(Graphics2D gc) {
Object old=null;
if(hasRenderingHints) {
try {
old=gc.getRenderingHint(RenderingHints.KEY_ANTIALIASING);
gc.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_OFF);
}
catch(NoClassDefFoundError thr) { hasRenderingHints=false; }
catch(NoSuchFieldError thr) { hasRenderingHints=false; }
catch(NoSuchMethodError thr) { hasRenderingHints=false; }
}
return old;
}
/**
* Disable the general anti-aliasing rendering hint, returning whether the old value was RenderingHints.VALUE_ANTIALIAS_ON.
* <p>
* This method is needed for text rendering due to a bug in AWT; as of Java 6_20 when general AA is on text is not rendered using subpixel
* AA, so general AA has to be turned off before rendering text and turned back on when done. This method abstracts that work and deals
* with the possibility that the JVM does not support rendering hints, such as is the case with JME JVMs.
*/
static public void restoreGeneralAA(Graphics2D gc, Object val) {
Object old=null;
if(hasRenderingHints && val!=null) {
try { gc.setRenderingHint(RenderingHints.KEY_ANTIALIASING,val); }
catch(NoClassDefFoundError thr) { hasRenderingHints=false; }
catch(NoSuchFieldError thr) { hasRenderingHints=false; }
catch(NoSuchMethodError thr) { hasRenderingHints=false; }
}
}