Added Fader class.

main.lua

@@ -4,6 +4,7 @@
 
 local love = require 'love'
 local game_states = require 'src.states'
+local Fader = require 'src.fader'
 
 
 ------------------------------------------------------------------------------
@@ -11,27 +12,17 @@ local game_states = require 'src.states'
 ------------------------------------------------------------------------------
 
 Current_state = 1
-Fade_in = 0.0
+Fade = Fader()
-Fade_out = 1.0
 Change_state = false
 
 
-------------------------------------------------------------------------------
--- Game methods
-------------------------------------------------------------------------------
-
-local function lerp(a, b, t)
-    -- Linear interpolation between two values a and b, by a t between 0.0 and 1.0
-    return (a * t) + (b * (1.0 - t))
-end
-
-
 ------------------------------------------------------------------------------
 -- Game methods
 ------------------------------------------------------------------------------
 
 function love.load()
     game_states[Current_state]:load()
+    Fade:fade_in()
 end
 
 
@@ -39,66 +30,43 @@ function love.update(dt)
     local new_state = game_states[Current_state]:update(dt)
 
     -- If the game state changed then trigger a fade out.
-    if new_state ~= Current_state and Fade_out >= 1.0 then
+    if new_state ~= Current_state and Fade.done then
-        Fade_out = 0.0
+        Fade:fade_out()
         Change_state = true
     end
 
-    -- If there is a fade in going then update it.
+    Fade:update(dt)
-    if Fade_in < 1.0 then
-        Fade_in = Fade_in + (dt / 2)
-    end
-
-    -- If there is a fade out going then update it.
-    if Fade_out < 1.0 then
-        Fade_out = Fade_out + (dt / 2)
-    end
 
     -- Update the game state.
     if game_states[new_state] == nil then
         -- If the new state doesn't exist then wait for the fade out to end and quit.
-        if Fade_out >= 1.0 then
+        if Fade.done then
             game_states[Current_state]:unload(dt)
             love.event.quit()
         end
     else
         -- If the new state exists then unload it's data and set the new state.
-        if Change_state and Fade_out >= 1.0 then
+        if Change_state and Fade.done then
             game_states[Current_state]:unload(dt)
             Current_state = new_state
             game_states[Current_state]:load()
             Change_state = false
+            Fade:fade_in()
         end
     end
 end
 
 
 function love.draw()
-    -- Reset the drawing color and clear the screen.
     love.graphics.clear()
-
-    -- Render the current game state.
     game_states[Current_state]:draw()
-
+    Fade:draw()
-    -- If there is a fade in going then render it.
-    if Fade_in < 1.0 then
-        love.graphics.setColor(0, 0, 0)
-        love.graphics.circle('fill', -320, love.graphics.getHeight() / 2, lerp(0, 400 * 2, Fade_in))
-        love.graphics.setColor()
-    end
-
-    -- If there is a fade out going then render it.
-    if Fade_out < 1.0 then
-        love.graphics.setColor(0, 0, 0)
-        love.graphics.circle('fill', -320, love.graphics.getHeight() / 2, lerp(400 * 2, 0, Fade_out))
-        love.graphics.setColor()
-    end
 end
 
 
 function love.keypressed(key)
     -- Send events to the active game state if there is no fade active.
-    if Fade_in >= 1.0 and Fade_out >= 1.0 then
+    if Fade.done then
         game_states[Current_state]:keypressed(key)
     end
 end
@@ -106,7 +74,7 @@ end
 
 function love.mousemoved(x, y)
     -- Send events to the active game state if there is no fade active.
-    if Fade_in >= 1.0 and Fade_out >= 1.0 then
+    if Fade.done then
         game_states[Current_state]:mousemoved(x, y)
     end
 end
@@ -114,7 +82,7 @@ end
 
 function love.mousepressed(x, y, btn)
     -- Send events to the active game state if there is no fade active.
-    if Fade_in >= 1.0 and Fade_out >= 1.0 then
+    if Fade.done then
         game_states[Current_state]:mousemoved(x, y, btn)
     end
 end

src/fader.lua

@@ -0,0 +1,92 @@
+------------------------------------------------------------------------------
+-- Imports
+------------------------------------------------------------------------------
+
+local love = require 'love'
+local make_class = require 'src.classes'
+
+
+------------------------------------------------------------------------------
+-- Class definitions
+------------------------------------------------------------------------------
+
+local Fader = make_class()
+
+
+------------------------------------------------------------------------------
+-- Class methods
+------------------------------------------------------------------------------
+
+function Fader:_init()
+    self.t = 0.0
+    self.step = 0
+    self.done = true
+    self.reverse = false
+end
+
+
+function Fader:_reset()
+    self.t = 0
+    self.step = 0
+    self.done = false
+end
+
+
+function Fader:fade_in()
+    self:_reset()
+    self.reverse = true
+end
+
+
+function Fader:fade_out()
+    self:_reset()
+    self.reverse = false
+end
+
+
+function Fader:update(dt)
+    if not self.done then
+        self.t = self.t + dt
+
+        if self.t >= 0.009 then
+            self.step = self.step + 1
+            self.t = 0.0
+        end
+
+        if self.step > 175 then self.done = true end
+    end
+end
+
+
+function Fader:draw()
+    local c = 0
+    love.graphics.setColor(0, 0, 0)
+
+    for i = 0, 16 do
+        for j = 0, 10 do
+            if not self.reverse then
+                if c <= self.step then
+                    love.graphics.rectangle('fill', 20 * i, 20 * j, 20, 20)
+                end
+            else
+                if c <= self.step then else
+                    love.graphics.rectangle('fill', 20 * i, 20 * j, 20, 20)
+                end
+            end
+            c = c + 1
+        end
+    end
+
+    love.graphics.setColor()
+--     love.graphics.print(string.format('t: %s', self.t), 5, 35)
+--     love.graphics.print(string.format('step: %s', self.step), 5, 45)
+--     love.graphics.print(string.format('W: %s', love.graphics.getWidth()), 5, 55)
+--     love.graphics.print(string.format('H: %s', love.graphics.getHeight()), 5, 65)
+end
+
+
+------------------------------------------------------------------------------
+-- Module return
+------------------------------------------------------------------------------
+
+return Fader