straightforward hp/mana bars implementation

lib/simple_ui/level/layout.lua

@@ -4,6 +4,96 @@ local Element = require "lib.simple_ui.element"
 local Rect = require "lib.simple_ui.rect"
 local SkillRow = require "lib.simple_ui.level.skill_row"
 
+--- @class BarElement : UIElement
+--- @field getter fun() : number
+--- @field value number
+--- @field maxValue number
+local barElement = setmetatable({}, Element)
+barElement.__index = barElement
+
+function barElement:update(dt)
+    local val = self.getter()
+    self.value = val < 0 and 0 or val > self.maxValue and self.maxValue or val
+end
+
+function barElement:draw()
+    love.graphics.push()
+    love.graphics.applyTransform(self.transform)
+
+    love.graphics.setColor(1, 1, 1)
+
+    love.graphics.rectangle("fill", self.bounds.x, self.bounds.y, self.bounds.width * self.value / self.maxValue,
+        self.bounds.height)
+
+    love.graphics.setColor(1, 1, 1)
+    love.graphics.pop()
+end
+
+--- @class BottomBars : UIElement
+--- @field children BarElement[]
+local bottomBars = setmetatable({}, Element)
+bottomBars.__index = bottomBars;
+
+--- @param cid Id
+function bottomBars.new(cid)
+    local t = setmetatable({}, bottomBars)
+
+    t.children = {
+        barElement:new {
+            getter = function()
+                local char = Tree.level.characters[cid]
+                return char:try(Tree.behaviors.stats, function(stats)
+                    return stats.hp or 0
+                end)
+            end,
+            maxValue = 20
+        },
+
+        barElement:new {
+            getter = function()
+                local char = Tree.level.characters[cid]
+                return char:try(Tree.behaviors.stats, function(stats)
+                    return stats.mana or 0
+                end)
+            end,
+            maxValue = 10
+        }
+    }
+
+    return t
+end
+
+function bottomBars:update(dt)
+    local padding = 16
+    local screenW, screenH = love.graphics.getDimensions()
+    self.bounds = Rect {
+        height = 10,
+        width = 200 + 200 + padding,
+        y = screenH - 96 - padding
+    }
+
+    self.transform = love.math.newTransform():translate(-self.bounds.width / 2 + screenW / 2, self.bounds.y)
+
+    for i = 1, #self.children do
+        self.children[i].bounds = Rect {
+            width = 200,
+            height = 20
+        }
+        self.children[i].transform = self.transform:clone():translate(padding * (i - 1) + (i - 1) * 200, 0)
+    end
+
+
+
+    for _, el in ipairs(self.children) do
+        el:update(dt)
+    end
+end
+
+function bottomBars:draw()
+    for _, el in ipairs(self.children) do
+        el:draw()
+    end
+end
 
 local layout = {}
 function layout:update(dt)
@@ -11,14 +101,18 @@ function layout:update(dt)
     if cid then
         self.skillRow = SkillRow(cid)
         self.skillRow:show()
+        self.bottomBars = bottomBars.new(cid)
     elseif Tree.level.selector:deselected() then
         self.skillRow:hide()
+        self.bottomBars = nil
     end
     if self.skillRow then self.skillRow:update(dt) end
+    if self.bottomBars then self.bottomBars:update(dt) end
 end
 
 function layout:draw()
     if self.skillRow then self.skillRow:draw() end
+    if self.bottomBars then self.bottomBars:draw() end
 end
 
 return layout