vide.tween added

test/tween-test.luau

@@ -0,0 +1,77 @@
+local vide = require "../../vide"
+local easings = require "../src/easings"
+
+local function system(): (number) -> number
+    local MAX = 40
+    local MIN = 10
+
+    local _, input, output = vide.root(function()
+        local input = vide.source(MAX)
+        local output = vide.tween(input, { time = 2, style = easings.quad_ease_inout })
+        return input, output
+    end)
+
+    local T = 3
+    local t = 0
+    return function(dt)
+        t += dt
+        if t >= T then
+            t -= T
+            input(input() == MAX and MIN or MAX)
+        end
+
+        vide.step(dt)
+
+        return output()
+    end
+end
+
+--------------------------------------------------------------------------------
+
+local function redraw_block(h: number)
+    local OFFSET = 70
+
+    local BLOCK = "█"
+
+    local function remainder_to_block(x)
+        return
+            if x > 7/8 then "█"
+            elseif x > 6/8 then "▇"
+            elseif x > 5/8 then "▆"
+            elseif x > 4/8 then "▅"
+            elseif x > 3/8 then "▄"
+            elseif x > 2/8 then "▃"
+            elseif x > 1/8 then "▂"
+            else "▁"
+    end
+
+    -- math.clamp added just in case an Elastic/Back easing style overshoots below 0
+    local h_f = math.max(0, math.floor(h))
+    local reset = "\27[H\27[2J" -- ANSI clear terminal
+    local offset = string.rep("\n", math.max(0, OFFSET - h_f))
+    local bar = remainder_to_block(h - h_f) .. "\n" .. string.rep(BLOCK .. "\n", h_f)
+    print(reset .. offset .. bar .. "\n" .. h)
+end
+
+local program_time = os.clock()
+
+local function step(): number
+    local FPS = 30
+    local DT = 1/FPS
+
+    repeat until os.clock() - program_time >= DT
+    program_time += DT
+    return DT
+end
+
+local function loop()
+    local callback = system()
+
+    while true do
+        local dt = step()
+        local x = callback(dt)
+        redraw_block(x)
+    end
+end
+
+loop()