base circular divided panel for gmod

circlepicker.lua

DEFINE_BASECLASS "EditablePanel"

local mat = surface.GetTextureID("vgui/white")

function PANEL:Init()
    self.ObjectCount = 3
    self:InvalidateLayout(true)
end

function PANEL:SetObjectCount(n)
    self.ObjectCount = n
    self:InvalidateLayout(true)
end

function PANEL:PerformLayout(w, h)
    w = math.min(w, h)
    local r = w / 2
    local obj = {}
    for i = 1, w * 2 do
        -- clockwise
        local d = math.rad(-i / w * 180)
        obj[i] = {
            x = math.sin(d) * r + r,
            y = math.cos(d) * r + r,
        }
    end
    self.Poly = obj

    local lines = {}

    for i = 1, self.ObjectCount do

        local pos = Angle(0,360 / self.ObjectCount * i, 0):Forward():GetNormalized() * r
        lines[i] = {
            x = pos.x + r,
            y = pos.y + r
        }

    end

    self.Lines = lines
end

function PANEL:GetLeftRightAt(y)
    local dist = y / (self:GetWide() / 2)

    if (dist < 0) then
        dist = -dist
    end
    dist = 1 - dist

    dist = math.sin(math.acos(dist))

    local left = self:GetWide() * (0.5 - dist / 2)

    return self:GetWide() * (0.5 - dist / 2), self:GetWide() * (0.5 + dist / 2)
end

function PANEL:TestMouseInside()

    if (vgui.GetHoveredPanel() ~= self) then
        return false
    end

    local leftx, rightx = self:GetLeftRightAt(gui.MouseY() - select(2, self:GetPos()))

    local x = gui.MouseX() - self:GetPos()
    return (leftx > x and 1 or 0) + (rightx > x and 1 or 0) == 1

end

function PANEL:GetPointedObject()

    local mouse = Vector(gui.MousePos())
    local w, h = self:GetWide() / 2, self:GetTall() / 2

    w = math.min(w, h)
    local middle = Vector(w, w)

    local ang = (middle - mouse):Angle()

    ang = math.NormalizeAngle(ang.y) + 180

    local r = math.floor(ang / (360 / self.ObjectCount)) + 1

    return r

end

function PANEL:Think()

    self.IsHovered = self:TestMouseInside()
    self.WasReleased = self.IsClicked
    self.IsClicked = self.IsHovered and input.IsMouseDown(MOUSE_LEFT)
    self.WasReleased = self.WasReleased and not self.IsClicked

    if (self.WasReleased) then
        self:OnClick()
    end

end

function PANEL:Paint(w, h)
    local drawc = Color(255,255,255,255)
    if (self.IsHovered) then
        drawc = Color(180,180,180,255)
        surface.SetTextColor(255,128,128,255)
    else
        surface.SetTextColor(255,128,128,255)
    end

    surface.SetDrawColor(drawc)
    surface.SetTexture(mat)

    surface.DrawPoly(self.Poly)

    surface.SetDrawColor(0,0,0,255)

    for i = 1, self.ObjectCount do

        surface.DrawLine(w / 2, h / 2, self.Lines[i].x, self.Lines[i].y)

    end

    surface.SetFont "DermaDefault"

    local text = ("Pointing at %i"):format(self:GetPointedObject())

    local left, right = self:GetLeftRightAt(h / 2)

    local textw, texth = surface.GetTextSize(text)


    surface.SetTextPos((right + left) / 2 - textw / 2, h / 2 - texth / 2)

    surface.DrawText(text)
end

function PANEL:OnClick()
    self:DoClick()
end

function PANEL:DoClick()
end