Useful rainbow drawing functions

[MysteryPancake]

I just wanted to make a quick post about a [URL="https://github.com/MysteryPancake/GMod-Rainbows"]GitHub thing I just set up[/URL]. It's a bunch of rainbow functions I made for you guys to use in whatever rainbow-related projects you might have lying around. Feel free to contribute your own rainbow-related functions if you have any, and have fun with them!

[bitches]

I wonder if you might further develop this through some optimization. For example, you could optionally render all of this only once into a texture and then only draw that texture in the requested screen space, so that the individual transitioning lines don't need recalculation.

I don't remember if you can render to a rendertarget once and it simply stick with the last seen render or if ceasing rendering to the RT means it goes blank. If it goes blank you could render to a .png file and then draw the png. Or just like, turn this into a function that generates smooth rainbow textures of the requested dimensions.

[MysteryPancake]

Well, optimization like that would be a very good idea, but I don't really know how to do that, I'll try that though, thanks for the idea!

[MysteryPancake]

[URL="https://github.com/MysteryPancake/GMod-Rainbows"]I added a few more functions to the thing[/URL], I'm quite happy that the DrawRainbowText one actually works. Maybe I'll try optimizing it soon, but rendering .png files and drawing them usually takes even longer than drawing a billion colored rects, so I don't really want to do it yet

[bitches]

[QUOTE=MPan1;50324385][URL="https://github.com/Mysterypancake1/GMod-Rainbows/blob/master/rainbow.lua"]I added a few more functions to the thing[/URL], I'm quite happy that the DrawRainbowText one actually works. Maybe I'll try optimizing it soon, but rendering .png files and drawing them usually takes even longer than drawing a billion colored rects, so I don't really want to do it yet[/QUOTE]

it doesn't take longer if you calculate the billion rects only once and thereafter only draw the generated png

[pogh10]

Wow nice job! Thanks for sharing this :D

[Zeh Matt]

Why is everybody talking about generating pngs? You can already create materials, take a look at how I did rain.

	function GM:RenderRain()

		if RAIN_SETUP == false then
			-- Create a new rain texture
			local scaleDown = 1
			local scaleUp = 1

			for i = 0, RAIN_LAYERS do

				local progress = (i / RAIN_LAYERS)
				local inverse = 1 - progress

				local RainRenderTarget = GetRenderTarget("CoopRainLayerN" .. tostring(i), ScrW(), ScrH(), false)

				do -- Create rain texture

					render.PushRenderTarget(RainRenderTarget)
					--render.SuppressEngineLighting(true)
					render.OverrideAlphaWriteEnable( true, true )

					render.Clear(0, 0, 0, 0, true)
					render.ClearDepth()

					cam.Start2D()
					local mat = Matrix()
					mat:Translate(Vector(0,0,0))
					mat:Scale( Vector(1, 1, 1) * scaleDown)

					cam.PushModelMatrix(mat)

					local alpha = ((progress * 70) * 0.4)
					DbgPrint(alpha)

					--for i = 0, (1024 * RAIN_DENSITY) do
					for n = 0, ( (i + 1) * RAIN_DENSITY ) do
						local x = math.random(0, ScrW() * scaleUp )
						local y = math.random(0, ScrH() * scaleUp )
						local z = 0
						local pos = Vector(x, y, z)
						--draw.DrawLine(pos, pos + Vector(1, 1, -2), Color(255, 255, 255), true)
						if math.random(0, 10) == 0 then
							--alpha = alpha + 60
						end

						local rainStep = 2
						for p = 0, 10 do
							local offset = (p * rainStep)
							local mulitplier = 20 + alpha
							surface.SetDrawColor(255, 255, 255, (1 - (p / 10)) * 20 )
							surface.DrawLine( x, y + offset, x , y + offset + rainStep )
						end
					end

					--if i % 2 == 0 then
						-- Turns it black
						--render.BlurRenderTarget(RainRenderTarget, 16, 16, 12)
					--end

					cam.PopModelMatrix()

					--render.BlurRenderTarget(RainRenderTarget, 8, 8, 12)
					cam.End2D()

					render.OverrideAlphaWriteEnable( false )
					--render.SuppressEngineLighting(false)
					render.PopRenderTarget()

					-- Blur the thing.
					local params = {
						--["$basetexture"] = "rain/coop_rain.vtf",
						["$surfaceprop"] = "water",
						["$surfaceprop2"] = "water",
						["$translucent"] = 1,
						["$bumpframe"] = 0,
						["$alpha"] = 1,
						Proxies =
						{
							TextureScroll =
							{
								texturescrollvar = "$basetexturetransform",
								texturescrollrate = RAIN_SPEED, -- Rain mass?
								texturescrollangle = (80 + math.random(1, 5)),
							},
						}
					}

					local mat = CreateMaterial("CoopRain__" .. CurTime(), "UnlitGeneric", params);
					mat:SetTexture("$basetexture", RainRenderTarget)

					table.insert(RAIN_TEXTURES, mat)
				end

			end

			RAIN_SETUP = true

		end

		local ply = LocalPlayer()

		render.UpdateScreenEffectTexture()

		--render.SuppressEngineLighting(true)
		for i, mat in pairs(RAIN_TEXTURES) do
			local spacing = 32
			local delta = 32
			local offset = (delta * (i - 1))

			-- Just return if it hasn't
			--if ( spacing == self.spacing && offset == self.offset ) then return true end

			local pos = ply:EyePos()
			local ang = ply:EyeAngles()
			ang.p = 0
			local fwd = ang:Forward()
			local back = -ang:Forward()

			if ( ply:GetViewEntity() != ply ) then
				pos = ply:GetViewEntity():GetPos()
				fwd = ply:GetViewEntity():GetForward()
			end

			--render.UpdateRefractTexture()
			//render.UpdateScreenEffectTexture()

			render.SetMaterial( mat )
			local shift = math.random(i * 10, 100)
			--render.DrawSprite( pos, 1024 + (i * shift), 1024 + (i * shift), Color( 255, 255, 255 ) )

			do -- Draw infront.

				local pos1 = pos + ( fwd * spacing ) + ( fwd * offset )
				pos1.x = alignCoord(pos1.x, spacing)
				pos1.y = alignCoord(pos1.y, spacing)
				pos1.z = alignCoord(pos1.z, spacing)

				local up = pos1:Angle():Up()
				local traceEnd = pos1 + (up * 1024)
				local traceStart
				local tr = util.TraceLine({
					start = pos1,
					endpos = pos1 + Vector(0, 0, 16384), -- TODO: Optimize me, we can estimate this number upfront by analysis later.
					mask = MASK_SOLID_BRUSHONLY,
				})

				local renderQuad = false

				if tr.Fraction < 1 then
					if tr.HitSky then
						renderQuad = true
					end
				end

				if renderQuad then
					--render.SetMaterial( mat )
					fwd.x = math.Round(fwd.x)
					fwd.y = math.Round(fwd.y)
					fwd.z = 0
					render.DrawQuadEasy(pos1, -fwd, ScrW(), ScrH(), Color(255, 255, 255), 20 )
				end

				--render.SetMaterial(MAT_WHITE)
				--render.DrawQuadEasy(pos1, -fwd, 16, 16)
			end


			do -- Draw behind 

				--render.SetMaterial( mat )
				-- We reduce the spacing here
				local pos2 = pos + ( back * (spacing * 0.5) ) + ( back * offset )
				pos2.x = alignCoord(pos2.x, spacing)
				pos2.y = alignCoord(pos2.y, spacing)

				fwd.x = math.Round(fwd.x)
				fwd.y = math.Round(fwd.y)
				fwd.z = 0

				render.DrawQuadEasy(pos2, -back, ScrW(), ScrH(), Color(200, 200, 200), 20)

			end
		end
		
		--render.SuppressEngineLighting(false)

	end

Its not perfect but it did the job.

[MysteryPancake]

[URL="https://github.com/MysteryPancake/GMod-Rainbows"]I added a new function to my rainbow-drawing thing.[/URL] It looks like this:
[IMG]http://i.imgur.com/J8JbKGL.png[/IMG]
It's incredibly slow to run, but was fun to find out the code that made it work. [URL="https://github.com/MysteryPancake/GMod-Rainbows/blob/master/README.md"]I also added pictures to my readme[/URL] so you can tell the functions apart (it'd be good if someone could help me with naming things, since I can't seem to do it very well myself).

[Zeh Matt]

[QUOTE=MPan1;50463586][URL="https://github.com/Mysterypancake1/GMod-Rainbows/blob/master/rainbow.lua#L144-L153"]I added a new function to my rainbow-drawing thing.[/URL] It looks like this:
[IMG]http://i.imgur.com/J8JbKGL.png[/IMG]
It's incredibly slow to run, but was fun to find out. [URL="https://github.com/Mysterypancake1/GMod-Rainbows/blob/master/README.md"]I also added pictures to my readme[/URL] so you can tell the functions apart (it'd be good if someone could help me with naming things, since I can't seem to do it very well myself).[/QUOTE]

You could just render them onto a render target and create a new material and render a Sprite/Quad with the given material, your function seem to be perfectly suitable to do that as they already use the surface library which is all 2d.

However I wouldn't change the code instead I would just utilize them as they are and they look perfectly fine.