Curved Health Bar

Hey, I’m curious to learn how to make a curved health bar similar to in GTA IV. What would I use to produce this, DrawPoly?

[lua]local cos, sin, floor, clamp, deg2rad, insert = math.cos, math.sin, math.floor, math.Clamp, math.rad, table.insert
function GeneratePartialPie(x, y, ang1, ang2, rad, thick, prec)
prec = clamp(prec or 256, 6, 256)

local vertices = {}
local ang, dist
local quality = floor(prec / 2)

dist = rad
for i = 1, quality do
	ang = deg2rad(ang1 + (ang2 - ang1) * i / quality)
	insert(vertices, {x = cos(ang) * dist + x, y = sin(ang) * dist + y})
end

dist = rad + thick
for i = 0, quality - 1 do
	ang = deg2rad(ang1 + (ang2 - ang1) * (quality - i) / quality)
	insert(vertices, {x = cos(ang) * dist + x, y = sin(ang) * dist + y})
end

return vertices

end
function GeneratePieSlice(x, y, ang1, ang2, rad, prec)
prec = clamp(prec or 256, 4, 256)

local vertices = {}
local ang
local quality = prec - 1

insert(vertices, {x = x, y = y})

for i = 1, quality do
	ang = deg2rad(ang1 + (ang2 - ang1) * i / quality)
	insert(vertices, {x = cos(ang) * rad + x, y = sin(ang) * rad + y})
end

return vertices

end

hook.Add(“HUDPaint”, “PartialPieTest”, function()
surface.SetDrawColor(50, 155, 50, 255) --Drawin’ green.

--surface.DrawPoly(GeneratePartialPie(ScrW() / 2, ScrH() / 2, -90, 90, 100, 10))
--Won't work... :-C

surface.DrawPoly(GeneratePieSlice(ScrW() / 2, ScrH() / 2, -90, 90, 105))			--Draw a filled pie.

surface.SetDrawColor(0, 0, 0, 255)													--Drawin' black.

local t = GeneratePartialPie(ScrW() / 2, ScrH() / 2, -90, 90, 100, 10)				--Build our polygon.

insert(t, t[1])																		--To ease computation, re-add the first vertex.

local oldshiz																		--This will be the vertex before the currently iterated one.
for _i, shiz in pairs(t) do 														--Iterate through each vertex.
	if _i > 1 then																	--If it is NOT the first one.
		surface.DrawLine(oldshiz.x, oldshiz.y, shiz.x, shiz.y)						--Draw a line from it to the old one.
	end
	oldshiz = shiz																	--This becomes the old one.
end

end)[/lua]

Um, this is as far as I can help.
There sure are better, easier ways, if the interior of our pie is going to be filled with something. (So you can draw an arch.)

Edit:
A little recommendation.
Cache the polygon table if it doesn’t need to be changed. It will save millions of operations per second.

Edit #2:
I added the function for drawing arches.

That’s great for the outline, however how would i make a filled version that would correspond to my health?

Um. You have two options:

  1. Draw more outlines inside each-other, making them thinner every time. (I would definitely not recommend this.)
  2. Draw filled pie slices. Imma come up with the code soon.

Edit:
I replaced the code on the other post. Check it out.