Hello,

I would like to draw a text on a transparent image (buffer). I can set the buffer transparent, but when rendering, every letter of my text has no-alpha (i.e. alpha = 1.0) background.

My code is like this:
Code:

PGraphics txtBuff;
PFont font;

void setup() {
  size(400, 200);
  font = loadFont("somefont.vlw");
  txtBuff = createGraphics(width, height, P3D);
}

void draw() {
  background(255, 0, 0); // Red

  txtBuff.beginDraw();
  txtBuff.background(0, 0); // Black background, transparent
  txtBuff.textFont(font, 48);
  txtBuff.fill(0, 255, 0); // Green text
  txtBuff.text("Hello, World!", 100, 100);
  txtBuff.textFont(font, 40);
  txtBuff.fill(0, 0, 255); // Blue text
  txtBuff.text("Hello, World!", 100, 120);
  txtBuff.endDraw();

  image(txtBuff, 0, 0);
}
 

The result is a red background with the two texts over it, but the two text (which are correctly rendered one over the other), have a black background.

How can I preserve background transparency under the letters?

Thanks
~Ale

Yes, thanks. I also "discovered" this:
http://dev.processing.org/bugs/show_bug.cgi?id=641

which I didn't see in the documentation for createGraphics:
http://processing.org/reference/createGraphics_.html

I'm not using 3D now, but I will.

Until now I hacked this issue copy()ing doing the composition of text later, reading the background before rendering. Anyway it's a bit pointless

Thanks!

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