Hi, I have noticed that loading an image into a GLTexture using
Drawable d = getResource().getDrawable(...); Bitmap bitmap = Bitmap.createBitmap(...); Rect rect = new Rect(...) d.setBounds(rect) d.draw(new Canvas(bitmap)); GLUtils.texImage2D(...) Will create a texture with premultiplied alpha. Not a problem, as long as I use glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA) to blend instead of glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA) which will cause dark borders. However, I've found that if I render text onto the Bitmap and convert to glTexture using: Bitmap bitmap = Bitmap.createBitmap(...); Canvas c = new Canvas(bitmap); Paint p = new Paint(); p.setColor/setAntiAlias/setTextSize(...) c.drawText(text, x, y, p) GLUtils.texImage2D(...) ..the resultant texture is NOT premultiplied, and using glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA) will cause ugly over- saturated edges when blended into the 3D world. Blending using glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA) makes it look right again. To confirm this, I saved the bitmap into a PNG file and load it as a resource into a texture, and the resultant texture is premultiplied and renders correctly using glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA) Is there a way to force the text rendering onto the bitmap to be pre- multiplied? -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
