thanks for the explanations
i'm a bit confused about transparency. here is a shot:
for both text and bubbles, upper lines are blitted by old method and lower lines are with new one. source texture is same for both lines. for bubbles transparency increases from left to right: -200, 0, 200, 400.. for text similar, -100, 0, 100, 200..
text transparency is alright, it cannot be seen in the shot but lower line of letters are completely opaque starting from 'c' as expected. the right most bubble has a transparency value of 800 but it's still transparent ?
i guess, the term 'sharp' was incorrect but you may see lower line of text is jagged. those letters are rendered to texture by using antialiasing. i thought antialiasing wont help much and even will look worse in this case, as we dont know the background color when we are creating the texture, but surprisingly it works quite fine for upper line. it may be because they're rendered to a transparent background (BufferedImage.TYPE_INT_ARGB) but not sure ?