guichk.lua

-- Various ways of testing a screen point against a GuiBase2d
-- Note: Rounded rect corner radius is inferred from SliceCenter.Min.X

local cos = math.cos
local min = math.min
local rad = math.rad
local sin = math.sin

return {
	-- Axis-aligned rectangle
	aaRect = function(gui, x, y)
		x, y = x + 0.5, y + 0.5
		
		local position = gui.AbsolutePosition
		local p0x, p0y = position.x, position.y
		
		if x >= p0x and y >= p0y then
			local s = gui.AbsoluteSize
			return x < p0x + s.x and y < p0y + s.y
		end
		
		return false
	end,

	-- Rectangle, accounting for rotation
	rect = function(gui, x, y)
		x, y = x + 0.5, y + 0.5
		
		local position = gui.AbsolutePosition
		local size = gui.AbsoluteSize

		local p0x, p0y = position.x, position.y
		local sx, sy = size.x*0.5, size.y*0.5
		local cx, cy = p0x + sx, p0y + sy

		if (x - cx)*(x - cx) + (y - cy)*(y - cy) > sx*sx + sy*sy then
			return false
		end

		local rotationDeg = gui.AbsoluteRotation
		if rotationDeg%180 ~= 0 then
			if rotationDeg%90 ~= 0 then
				local rotationRad = rad(rotationDeg)
				local c = cos(rotationRad)
				local s = sin(rotationRad)

				x, y =
					cx + c*(x - cx) + s*(y - cy),
					cy - s*(x - cx) + c*(y - cy)
			else
				x, y =
					cx - cy + y,
					cx + cy - x
			end
		end

		return x >= p0x and y >= p0y and x < cx + sx and y < cy + sy
	end,

	-- Axis-aligned rounded rectangle
	aaRoundedRect = function(gui, x, y)
		x, y = x + 0.5, y + 0.5
		
		local position = gui.AbsolutePosition
		local p0x, p0y = position.x, position.y

		if x >= p0x and y >= p0y then
			local size = gui.AbsoluteSize
			local sx, sy = size.x, size.y

			local p1x = p0x + sx
			local p1y = p0y + sy

			if x < p1x and y < p1y then
				loca l r = min(gui.SliceCenter.Min.x, sx*0.5, sy*0.5)

				if (x >= p0x + r and x + r < p1x) or (y >= p0y + r and y + r < p1y) then
					return true
				end

				local cx = x - (x > p0x + sx*0.5 and p1x - r or p0x + r)
				local cy = y - (y > p0y + sy*0.5 and p1y - r or p0y + r)

				return cx*cx + cy*cy < r*r
			end
		end

		return false
	end,

	-- Rounded rectangle, accounting for rotation
	roundedRect = function(gui, x, y)
		x, y = x + 0.5, y + 0.5
		
		local position = gui.AbsolutePosition
		local size = gui.AbsoluteSize

		local p0x, p0y = position.x, position.y
		local sx, sy = size.x*0.5, size.y*0.5
		local cx, cy = p0x + sx, p0y + sy

		if (x - cx)*(x - cx) + (y - cy)*(y - cy) > sx*sx + sy*sy then
			return false
		end

		local rotationDeg = gui.AbsoluteRotation
		if rotationDeg%180 ~= 0 then
			if rotationDeg%90 ~= 0 then
				local rotationRad = rad(rotationDeg)
				local c = cos(rotationRad)
				local s = sin(rotationRad)

				x, y =
					cx + c*(x - cx) + s*(y - cy),
					cy - s*(x - cx) + c*(y - cy)
			else
				x, y =
					cx - cy + y,
					cx + cy - x
			end
		end

		local p1x = cx + sx
		local p1y = cy + sy

		if x >= p0x and y >= p0y and x < p1x and y < p1y then
			local r = min(gui.SliceCenter.Min.x, sx, sy)

			if (x >= p0x + r and x + r < p1x) or (y >= p0y + r and y + r < p1y) then
				return true
			end

			cx = x - (x > cx and p1x - r or p0x + r)
			cy = y - (y > cy and p1y - r or p0y + r)

			return cx*cx + cy*cy < r*r
		end

		return false
	end,
}