################################################################################
# Bloom

(fn bloom-init ()
	# Samplers
	(sampler smp-bloom-blur
		(sampling linear)
		(mipmaps linear)
		(lod 0 100)
		(wrapping clamp-edge)
	)
	(sampler smp-bloom-input
		(sampling nearest)
	)

	# First ping/pong texture & targets
	(texture tx-bloom1 rgb-f16 $vp-width $vp-height 6)
	(framebuffer rt-bloom1-lod0 (color tx-bloom1 0))
	(framebuffer rt-bloom1-lod1 (color tx-bloom1 1))
	(framebuffer rt-bloom1-lod2 (color tx-bloom1 2))
	(framebuffer rt-bloom1-lod3 (color tx-bloom1 3))
	(framebuffer rt-bloom1-lod4 (color tx-bloom1 4))
	(framebuffer rt-bloom1-lod5 (color tx-bloom1 5))
	(odbg tx-bloom1 hdr "Bloom")

	# Second ping/pong texture & targets
	(texture tx-bloom2 rgb-f16 $vp-width $vp-height 6)
	(framebuffer rt-bloom2-lod0 (color tx-bloom2 0))
	(framebuffer rt-bloom2-lod1 (color tx-bloom2 1))
	(framebuffer rt-bloom2-lod2 (color tx-bloom2 2))
	(framebuffer rt-bloom2-lod3 (color tx-bloom2 3))
	(framebuffer rt-bloom2-lod4 (color tx-bloom2 4))
	(framebuffer rt-bloom2-lod5 (color tx-bloom2 5))
	(odbg tx-bloom2 hdr "Bloom (partial)")

	# High pass program
	(program prg-bloom-highpass "bloom-highpass.f.glsl")
	(pipeline pl-bloom-highpass prg-fullscreen prg-bloom-highpass)

	# Downsampling program
	(program prg-bloom-downsample "downsample.f.glsl")
	(pipeline pl-bloom-downsample prg-fullscreen prg-bloom-downsample)

	# Blur pass
	(program prg-bloom-blur "blur-pass.f.glsl")
	(pipeline pl-bloom-blur prg-fullscreen prg-bloom-blur)

	# Inputs that control the high pass filter
	(input bloom-power 1.6)
	(input bloom-factor 1.2)
	(input bloom-output-factor 1.05)

	# Inputs that control the blur weights
	(input bloom-bw0 .324)
	(input bloom-bw1 .232)
	(input bloom-bw2 .0855)
	(input bloom-bw3 .0205)

	# Blur size
	(input bloom-blur-size 1.3)

	# Input overrides
	(ui-overrides
		(section "Post-processing"
			(section "Bloom"
				(section "Input filter"
					(float "Input power" bloom-power
						(min .5) (max 4) (slider))
					(float "Input factor" bloom-factor
						(min .5) (max 4) (slider))
					(float "Output factor" bloom-output-factor
						(min .5) (max 4) (slider))
				)
				(section "Blur"
					(float "Size" bloom-blur-size
						(min .5) (max 4) (slider))
					(float4 "Weights"
						bloom-bw0 bloom-bw1 bloom-bw2 bloom-bw3
						(min 0) (max 1) (step .00005))
				)
			)
		)
	)
)

(fn bloom-render (in-scene)
	(profiling "BLOOOOM!"
		(uniforms-i prg-bloom-highpass 0 0)
		(uniforms-i prg-bloom-highpass 1 0)
		(uniforms prg-bloom-highpass 2 $vp-width $vp-height)
		(uniforms-i prg-bloom-downsample 0 0)
		(uniforms-i prg-bloom-blur 0 0)

		# High pass
		(use-texture 0 in-scene smp-bloom-input)
		(uniforms prg-bloom-highpass 3
			(get-input bloom-power)
			(get-input bloom-factor)
			(get-input bloom-output-factor)
		)
		(use-framebuffer rt-bloom1-lod0)
		(use-pipeline pl-bloom-highpass)
		(viewport 0 0 $vp-width $vp-height)
		(fullscreen)

		# Set up blur weights
		(uniforms prg-bloom-blur 4
			(get-input bloom-bw0)
			(get-input bloom-bw1)
			(get-input bloom-bw2)
			(get-input bloom-bw3))

		# Blur & downsample
		(uniforms prg-bloom-blur 1 $vp-width $vp-height)
		(call bloom-blur-pass 0 rt-bloom1-lod0 rt-bloom2-lod0)
		(call bloom-downsample rt-bloom1-lod1 1)
		(call bloom-blur-pass 1 rt-bloom1-lod1 rt-bloom2-lod1)
		(call bloom-downsample rt-bloom1-lod2 2)
		(call bloom-blur-pass 2 rt-bloom1-lod2 rt-bloom2-lod2)
		(call bloom-downsample rt-bloom1-lod3 3)
		(call bloom-blur-pass 3 rt-bloom1-lod3 rt-bloom2-lod3)
		(call bloom-downsample rt-bloom1-lod4 4)
		(call bloom-blur-pass 4 rt-bloom1-lod4 rt-bloom2-lod4)
		(call bloom-downsample rt-bloom1-lod5 5)
		(call bloom-blur-pass 5 rt-bloom1-lod5 rt-bloom2-lod5)
	)
)

(fn bloom-downsample (target level)
	(locals m w h)
	(set m (pow 2 $level))
	(set w (div $vp-width $m))
	(set h (div $vp-height $m))

	(use-pipeline pl-bloom-downsample)
	(use-framebuffer target)
	(use-texture 0 tx-bloom1 smp-bloom-blur)
	(uniforms prg-bloom-downsample 1 $w $h)
	(uniforms-i prg-bloom-downsample 2 (sub $level 1))
	(viewport 0 0 $w $h)
	(fullscreen)

	(uniforms prg-bloom-blur 1 $w $h)
)

(fn bloom-blur-pass (lod fb1 fb2)
	# Common stuff for both passes
	(use-pipeline pl-bloom-blur)
	(uniforms-i prg-bloom-blur 2 $lod)

	# Pass 1
	(use-framebuffer fb2)
	(use-texture 0 tx-bloom1 smp-bloom-blur)
	(uniforms prg-bloom-blur 3
		(get-input bloom-blur-size) 0)
	(fullscreen)

	# Pass 2
	(use-framebuffer fb1)
	(use-texture 0 tx-bloom2 smp-bloom-blur)
	(uniforms prg-bloom-blur 3
		0 (get-input bloom-blur-size))
	(fullscreen)
)


# vim: syntax=demo-srd