LibGDX/OpenGL - glReadPixels Transparency Issue -

i have problem glreadpixels/screenutils.getframebufferpixmap() semi-transparent sprites drawn on top of opaque ones seem "overwrite" transparency, resulting in mess.

black sprites 10% transparency drawn on top of tiles shadows.

original (in-game) image:

image obtained glreadpixels in screenutils.getframebufferpixmap(...):

(the shadows white because they're transparent)

how make alpha blending work in getframebufferpixmap()?

you need use glblendfuncseparate instead of glblendfunc, spritebatch uses. spritebatch provides door (undocumented think reason) using glblendfuncseparate. set it's blend function parameters -1, , can manually set own glblendfuncseparate leaves alpha of frame buffer 1.0:

spritebatch.setblendfunction(-1, -1); gdx.gl.glblendfuncseparate(     gl20.gl_src_alpha, gl20.gl_one_minus_src_alpha, gl20.gl_zero, gl20.gl_one); //... spritebatch.begin(); //... spritebatch.end(); 

also make sure alpha of glclearcolor 1.0f.