The scene is rendered once into an HDR buffer, then each pass reads that image and writes another. Toggle passes, reorder them, and watch the cost in full-screen passes rather than triangles.
Click a pass chip to enable or disable it. Tone map and gamma encode are pinned to the end of the chain — that is where they belong.
What to notice. Nothing here touches geometry; every effect is a function of the image. Turn gamma encode off and the whole frame goes dark and muddy — that single pow(x, 1/2.2) at the very end is doing more for the picture than any of the fancy passes. And bloom only looks like light when it runs before tone mapping, on values that were still above 1.0.