So basically i want to draw tree leaves into the shadowmap, to do that i would need to disable depth writes to zbuff and read depth value of current fragment to see if leaf (as its a texture with alpha) is closer to light than actual fragment.
Now i know that i cant write and read to the same fbo texture so i could sample depth (please note i write depth value to rgba tex), now when i try to draw an alpha tex i need to sample this alpha texture to see if it has alpha 1.0 to perform a ch