-- namespace Fusion::OverlayVS {

--[[	 Overlay/underlay fuse, to illustrate image uploading		]]--

-- params for the shader:
params =
[[
mat4 transform			// image transform matrices
mat4 utransform
vec2 offset				// offset
vec2 uoffset
float blend				// blend

sampler2D overlaytex	// image samplers, indexed separately with SetImage()
sampler2D underlaytex
]]

-- Here's the GLSL shader itself:
shader =
[[
void ShadePixel(inout FuPixel f)
{
	EvalShadePixel(f);											// get source pixel

	// calculate sample offset
	vec2 coord = f.TexCoord0 - uoffset;
	vec4 uv = vec4(coord.xy, 0, 1) * utransform;				// underlay pixel coords
	vec4 underpix = texture2D(underlaytex, uv.xy + 0.5f);		// fetch underlay pixel
	f.Color.rgb = f.Color.rgb + underpix.rgb * (1.0f-f.Color.a);// additive merge source over underlay

	coord = f.TexCoord0 - offset;
	uv = vec4(coord.xy, 0, 1) * transform;						// overlay pixel coords
	vec4 overpix = texture2D(overlaytex, uv.xy + 0.5f) * blend;	// fetch overlay pixel
	f.Color.rgb = overpix.rgb + f.Color.rgb * (1.0f-overpix.a);	// additive merge overlay over the others

	f.Color.a = clamp(underpix.a + f.Color.a + overpix.a, 0.0, 1.0);
}
]]


-- regnode
FuRegisterClass("OverlayFuse", CT_ViewLUTPlugin, {		-- ID must be unique
	REGS_Name = "Overlay Fuse",
	REGS_Context = "Fusion::OverlayVS",
	})

-- Called on creation. Add any controls here.
-- Note use of Control Pages
function Create()
	self:AddControlPage("Overlay");

	InCenter = self:AddInput(tr("Center"), "Center", {
		LINKID_DataType = "Point",
		INPID_InputControl = "OffsetControl",
		INP_DefaultX  = 0.5,
		INP_DefaultY  = 0.5,
		})

	InSize = self:AddInput(tr("Size"), "Size", {
		LINKID_DataType = "Number",
		INPID_InputControl = "SliderControl",
		INP_MinScale = 0.0,
		INP_MaxScale = 5.0,
		INP_Default  = 1.0,
		})
	InAngle = self:AddInput(tr("Angle"), "Angle", {
		LINKID_DataType = "Number",
		INPID_InputControl = "ScrewControl",
		INP_MinScale = 0.0,
		INP_MaxScale = 360.0,
		INP_Default  = 0.0,
		})
	InBlend = self:AddInput(tr("Blend"), "Blend", {
		LINKID_DataType = "Number",
		INPID_InputControl = "SliderControl",
		INP_Default  = 1.0,
		})

	InFilename = self:AddInput(tr("Overlay Image"), "OverlayImage", {
		LINKID_DataType = "Text",
		INPID_InputControl = "FileControl",
		INP_DefaultText  = "",
		INP_DoNotifyChanged = true,
		})

	self:AddControlPage("Underlay");

	InUnderlayCenter = self:AddInput(tr("Center"), "UnderlayCenter", {
		LINKID_DataType = "Point",
		INPID_InputControl = "OffsetControl",
		INP_DefaultX  = 0.5,
		INP_DefaultY  = 0.5,
		})

	InUnderlaySize = self:AddInput(tr("Size"), "UnderlaySize", {
		LINKID_DataType = "Number",
		INPID_InputControl = "SliderControl",
		INP_MinScale = 0.0,
		INP_MaxScale = 5.0,
		INP_Default  = 1.0,
		})
	InUnderlayAngle = self:AddInput(tr("Angle"), "UnderlayAngle", {
		LINKID_DataType = "Number",
		INPID_InputControl = "ScrewControl",
		INP_MinScale = 0.0,
		INP_MaxScale = 360.0,
		INP_Default  = 0.0,
		})

	InUnderlayFilename = self:AddInput(tr("Underlay Image"), "UnderlayImage", {
		LINKID_DataType = "Text",
		INPID_InputControl = "FileControl",
		INP_DefaultText  = "",
		INP_DoNotifyChanged = true,
		})

	EmptyImage = Image({
		IMG_Width = 1,
		IMG_Height = 1,
		});
	EmptyImage:Fill(Pixel());		-- Pixel defaults to black/clear

	OverlayImage = EmptyImage;
	UnderlayImage = EmptyImage;
end

-- This is called whenever the value of a control changes,
-- for any Input with INP_DoNotifyChanged = true
function NotifyChanged(inp, param, time)
	if param then
		if inp == InFilename then
			local filename = tostring(param.Value)		-- get filename as a string
			local clip = Clip(filename, false)			-- make a Clip out of it (read-only)
			local img = clip:GetFrame(0)				-- exercise: allow other frames in clip (if any)

			if img then
				OverlayImage = img
			else
				OverlayImage = EmptyImage
			end
		elseif inp == InUnderlayFilename then
			local filename = tostring(param.Value)
			local clip = Clip(filename, false)
			local img = clip:GetFrame(0)

			if img then
				UnderlayImage = img
			else
				UnderlayImage = EmptyImage
			end
		end
	end
end

-- This is called when the shader is created
-- img may be nil
function SetupShadeNode(group, req, img)
	return ViewShadeNode(group, "OverlayFuse", params, shader)	-- pass struct name, params, and shader string
end

-- This is called every display refresh
-- img may be nil
function SetupParams(req, vs, img)
	-- Setup overlay params
	local centerx = InCenter:GetValue(req).X	-- retrieve control values
	local centery = InCenter:GetValue(req).Y
	local size  = InSize:GetValue(req).Value
	local angle = InAngle:GetValue(req).Value
	local blend  = InBlend:GetValue(req).Value
	local imgw  = img and img.Width or 1
	local imgh  = img and img.Height or 1
	local uploadw = OverlayImage.Width
	local uploadh = OverlayImage.Height
	local uploadimg = OverlayImage

	if size > 0.0 then
		size = 1.0 / size
	else
		uploadimg = EmptyImage
	end

	local transform = Matrix4()
	transform:Identity()
	transform:Scale(size / uploadw, size / uploadh, 1.0)
	transform:RotZ(angle)
--	transform:Move(overw * 0.5, overh * 0.5, 0)

	vs:Set(1, transform)						-- and setup the shader's parameter values
	vs:Set(3, centerx * imgw, centery * imgh)	-- offset
	vs:Set(5, blend)

	-- upload the image (table args are optional). This Set()s overlaytex (index 1)
	vs:SetImage(1, uploadimg, {"Color"}, {		-- {"Color"}, {"R","G","B","A"}, {"Z","Z","Z","A"} etc
		TR_GLTexTarget = "2D",				-- RECT (default, pixel coords), 2D (normalized coords)
		TR_F3DTexDataType = "int8",			-- int8, int16, float16, float32, ChooseSmallest (default)
		TR_WrapModeS = "Black",				-- Clamp (default), Black, and (not for RECTs) Wrap, Mirror
		TR_WrapModeT = "Black",
		TR_GLMinFilter = "Linear",			-- Linear (default), Nearest
		TR_GLMagFilter = "Linear",
		})

	-- Setup underlay params
	centerx = InUnderlayCenter:GetValue(req).X
	centery = InUnderlayCenter:GetValue(req).Y
	size    = InUnderlaySize:GetValue(req).Value
	angle   = InUnderlayAngle:GetValue(req).Value
	uploadw = UnderlayImage.Width
	uploadh = UnderlayImage.Height
	uploadimg = UnderlayImage

	if size > 0.0 then
		size = 1.0 / size
	else
		uploadimg = EmptyImage
	end

	transform:Identity()
	transform:Scale(size / uploadw, size / uploadh, 1.0)
	transform:RotZ(angle)

	vs:Set(2, transform)						-- utransform
	vs:Set(4, centerx * imgw, centery * imgh)	-- uoffset
	vs:SetImage(2, uploadimg, {"Color"}, {		-- underlaytex (index 2)
		TR_GLTexTarget = "2D",
		TR_WrapModeS = "Black",
		TR_WrapModeT = "Black",
		})

	return true
end

-- };