/ld26

-- Class: App 

-- An app is where all the magic happens. :) It contains a 

-- view, the group where all major action happens, as well as the

-- meta view, which persists across views. Only one app may run at

-- a time.

--

-- An app's job is to get things up and running -- most of its logic

-- lives in its onRun handler, but for a simple app, you can also

-- use the onUpdate handler instead of writing a custom <View>.

-- 

-- Once an app has begun running, it may be accessed globally via

-- <the>.app.

--

-- Extends:

--  	<Class>

--

-- Event: onRun

-- 		Called once, when the app begins running.

--

-- Event: onEnterFullscreen

--		Called after entering fullscreen successfully.

--

-- Event: onExitFullscreen

--		Called after exiting fullscreen successfully.

App = Class:extend

{

	-- Property: name

	-- This is shown in the window title bar.

	name = 'Zoetrope',

	-- Property: icon

	-- A path to an image to use as the window icon (a 32x32 PNG is recommended).

	-- This doesn't affect the actual executable's icon in the taskbar or dock. 

	-- Property: fps

	-- Maximum frames per second requested. In practice, your

	-- FPS may vary from frame to frame. Every event handler (e.g. onUpdate)

	-- is passed the exact elapsed time in seconds.

	fps = 60,

	-- Property: timeScale

	-- Multiplier for elapsed time; 1.0 is normal, 0 is completely frozen.

	timeScale = 1,

	-- Property: active

	-- If false, nothing receives update-related events, including the meta view.

	-- These events specifically are onStartFrame, onUpdate, and onEndFrame.

	active = true,

	-- Property: deactivateOnBlur

	-- Should the app automatically set its active property to false when its

	-- window loses focus?

	deactivateOnBlur = true,

	-- Property: view

	-- The current <View>. When the app is running, this is also accessible

	-- globally via <the>.view. In order to switch views, you must set this

	-- property, *not* <the>.view.

	-- Property: meta

	-- A <Group> that persists across all views during the app's lifespan.

	-- Property: keys

	-- A <Keys> object that listens to the keyboard. When the app is running, this

	-- is also accessible globally via <the>.keys.

	-- Property: width

	-- The width of the app's canvas in pixels. Changing this value has no effect. To

	-- set this for real, edit conf.lua. This may *not* correspond to the overall

	-- resolution of the window when in fullscreen mode.

	-- Property: height

	-- The height of the window in pixels. Changing this value has no effect. To

	-- set this for real, edit conf.lua. This may *not* correspond to the overall

	-- resolution of the window when in fullscreen mode.

	-- Property: fullscreen

	-- Whether the app is currently running in fullscreen mode. Changing this value

	-- has no effect. To change this, use the enterFullscreen(), exitFullscreen(), or

	-- toggleFullscreen() methods.

	-- Property: inset

	-- The screen coordinates where the app's (0, 0) origin should lie. This is only

	-- used by Zoetrope to either letterbox or pillar fullscreen apps, but there may

	-- be other uses for it.

	inset = { x = 0, y = 0},

	-- internal property: _sleepTime

	-- The amount of time the app intentionally slept for, and should not

	-- be counted against elapsed time.

	-- internal property: _nextFrameTime

	-- Set at the start of a frame to be the next time a frame should be rendered,

	-- in timestamp format. This is used to properly maintain FPS -- see the example

	-- in https://love2d.org/wiki/love.timer.sleep for how this works.

	new = function (self, obj)

		obj = self:extend(obj)

		-- set icon if possible

		if self.icon then

			love.graphics.setIcon(Cached:image(self.icon))

		end

		-- view containers

		obj.meta = obj.meta or Group:new()

		obj.view = obj.view or View:new()		

		-- input

		if love.keyboard then

			obj.keys = obj.keys or Keys:new()

			love.keyboard.setKeyRepeat(0.4, 0.04)

			obj.meta:add(obj.keys)

		end

		if love.mouse then

			obj.mouse = obj.mouse or Mouse:new()

			obj.meta:add(obj.mouse)

		end

		if love.joystick then

			obj.gamepads = {}

			the.gamepads = obj.gamepads

		end

		if obj.numGamepads and obj.numGamepads > 0 then

			for i = 1, obj.numGamepads do

				obj.gamepads[i] = Gamepad:new{ number = i }

				obj.meta:add(obj.gamepads[i])

			end

		end

		-- screen dimensions and state

		obj.width, obj.height, obj.fullscreen = love.graphics.getMode()

		-- housekeeping

		the.app = obj

		if obj.onNew then obj:onNew() end

		return obj

	end,

	-- Method: run

	-- Starts the app running. Nothing will occur until this call.

	--

	-- Arguments:

	-- 		none

	-- 

	-- Returns:

	--		nothing

	run = function (self)

		math.randomseed(os.time())

		-- sync the.view

		the.view = self.view

		-- attach debug console

		if DEBUG then

			self.console = DebugConsole:new()

			self.meta:add(self.console)

		end

		-- set up callbacks

		love.graphics.setCaption(self.name)

		love.update = function (elapsed) self:update(elapsed) end

		love.draw = function() self:draw() end

		love.focus = function (value) self:onFocus(value) end	

		if self.onRun then self:onRun() end

		self._nextFrameTime = love.timer.getMicroTime()

	end,

	-- Method: quit

	-- Quits the application immediately.

	--

	-- Arguments:

	--		none

	--

	-- Returns:

	--		nothing

	quit = function (self)

		love.event.quit()

	end,

	-- Method: useSysCursor

	-- Shows or hides the system mouse cursor.

	--

	-- Arguments:

	--		value - show the cursor?

	--

	-- Returns:

	--		nothing

	useSysCursor = function (self, value)

		if STRICT then

			assert(value == true or value == false,

				   'tried to set system cursor visibility to ' .. type(value))

		end

		love.mouse.setVisible(value)

	end,

	-- Method: enterFullscreen

	-- Enters fullscreen mode. If the app is already in fullscreen, this has no effect.

	-- This tries to use the highest resolution that will not result in distortion, and

	-- adjust the app's offset property to accomodate this.

	--

	-- Arguments:

	--		hint - whether to try to letterbox (vertical black bars) or pillar the app

	--			   (horizontal black bars). You don't need to specify this; the method

	--			   will try to infer based on the aspect ratio of your app.

	--

	-- Returns:

	--		boolean whether this succeeded

	enterFullscreen = function (self, hint)

		if STRICT then

			assert(not self.fullscreen, 'asked to enter fullscreen when already in fullscreen')

		end

		local modes = love.graphics.getModes()

		if not hint then

			if self.width * 9 == self.height * 16 then

				hint = 'letterbox'

			elseif self.width * 3 == self.height * 4 then

				hint = 'pillar'

			end

		end

		-- find the mode with the highest screen area that

		-- matches either width or height, according to our hint

		local bestMode = { area = 0 }

		for _, mode in pairs(modes) do

			mode.area = mode.width * mode.height

			if (mode.area > bestMode.area) and 

			   ((hint == 'letterbox' and mode.width == self.width) or

			    (hint == 'pillar' and mode.height == self.height)) then

					bestMode = mode

			end

		end

		-- if we found a match, switch to it

		if bestMode.width then

			love.graphics.setMode(bestMode.width, bestMode.height, true)

			self.fullscreen = true

			-- and adjust inset and scissor

			self.inset.x = math.floor((bestMode.width - self.width) / 2)

			self.inset.y = math.floor((bestMode.height - self.height) / 2)

			love.graphics.setScissor(self.inset.x, self.inset.y, self.width, self.height)

			if self.onEnterFullscreen then self:onEnterFullscreen() end

		end

		return self.fullscreen

	end,

	-- Method: exitFullscreen

	-- Exits fullscreen mode. If the app is already windowed, this has no effect.

	--

	-- Arguments:

	--		none

	--

	-- Returns:

	--		nothing

	exitFullscreen = function (self)

		if STRICT then

			assert(self.fullscreen, 'asked to exit fullscreen when already out of fullscreen')

		end

		love.graphics.setMode(self.width, self.height, false)

		love.graphics.setScissor(0, 0, self.width, self.height)

		self.fullscreen = false

		self.inset.x = 0

		self.inset.y = 0

		if self.onExitFullscreen then self:onExitFullscreen() end

	end,

	-- Method: toggleFullscreen

	-- Toggles between windowed and fullscreen mode.

	--

	-- Arguments:

	--		none

	--

	-- Returns:

	--		nothing

	toggleFullscreen = function (self)

		if self.fullscreen then

			self:exitFullscreen()

		else

			self:enterFullscreen()

		end

	end,

	-- Method: saveScreenshot

	-- Saves a snapshot of the current frame to disk.

	--

	-- Arguments:

	--		filename - filename to save as, image format is implied by suffix.

	--				   This is forced inside the app's data directory,

	--				   see https://love2d.org/wiki/love.filesystem for details.

	--

	-- Returns:

	--		nothing

	saveScreenshot = function (self, filename)

		if not filename then

			error('asked to save screenshot to a nil filename')

		end

		local screenshot = love.graphics.newScreenshot()

		screenshot:encode(filename)

	end,

	-- Method: add

	-- A shortcut for adding a sprite to the app's view.

	--

	-- Arguments:

	--		sprite - sprite to add

	-- 

	-- Returns:

	--		nothing

	add = function (self, sprite)

		self.view:add(sprite)

	end,

	-- Method: remove

	-- A shortcut for removing a sprite from the app's view.

	--

	-- Arguments:

	--		sprite - sprite to remove

	--

	-- Returns: nothing

	remove = function (self, sprite)

		self.view:remove(sprite)

	end,

	update = function (self, elapsed)

		-- set the next frame time right at the start

		self._nextFrameTime = self._nextFrameTime + 1 / self.fps

		elapsed = elapsed - (self._sleepTime or 0)

		local realElapsed = elapsed

		elapsed = elapsed * self.timeScale

		-- sync the.view with our current view

		local view = self.view

		if the.view ~= view then the.view = view end

		-- if we are not active at all, sleep for a half-second

		if not self.active then

			love.timer.sleep(0.5)

			self._sleepTime = 0.5

			return

		end

		self._sleepTime = 0

		-- update everyone

		-- all update events bubble up from child to parent

		-- (we consider the meta view a little 

		view:startFrame(elapsed)

		self.meta:startFrame(elapsed)

		if self.onStartFrame then self:onStartFrame(elapsed) end

		view:update(elapsed)	

		self.meta:update(elapsed)

		if self.onUpdate then self:onUpdate(elapsed) end

		view:endFrame(elapsed)

		self.meta:endFrame(elapsed)

		if self.onEndFrame then self:onEndFrame(elapsed) end

	end,

	draw = function (self)

		local inset = self.inset.x ~= 0 or self.inset.y ~= 0

		if inset then love.graphics.translate(self.inset.x, self.inset.y) end

		self.view:draw()

		self.meta:draw()

		if inset then love.graphics.translate(0, 0) end

		-- sleep off any unneeded time to keep up at our FPS

		local now = love.timer.getMicroTime()

		if self._nextFrameTime < now then

			self._nextFrameTime = now

		else

			love.timer.sleep(self._nextFrameTime - now)

		end

	end,

	onFocus = function (self, value)

		if self.deactivateOnBlur then

			self.active = value

			if value then

				love.audio.resume()

			else

				love.audio.pause()

			end

		end

	end,

	__tostring = function (self)

		local result = 'App ('

		if self.active then

			result = result .. 'active'

		else

			result = result .. 'inactive'

		end

		return result .. ', ' .. self.fps .. ' fps, ' .. self.view:count(true) .. ' sprites)'

	end

}