lib/gamnit/gamnit.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #     http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 # Unless required by applicable law or agreed to in writing, software
  10 # distributed under the License is distributed on an "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 # See the License for the specific language governing permissions and
  13 # limitations under the License.
  14
  15 # Game and multimedia framework for Nit
  16 module gamnit
  17
  18 import app
  19
  20 import display
  21 import textures
  22 import programs
  23
  24 import gamnit_android is conditional(android)
  25 import gamnit_linux is conditional(linux)
  26
  27 redef class App
  28
  29         # Main `GamnitDisplay` initialized by `on_create`
  30         var display: nullable GamnitDisplay = null
  31
  32         redef fun on_create
  33         do
  34                 super
  35
  36                 var display = new GamnitDisplay
  37                 display.setup
  38                 self.display = display
  39         end
  40
  41         # Core of the frame logic, executed only when the display is visible
  42         #
  43         # This method should be redefined by user modules to customize the behavior of the game.
  44         protected fun frame_core(display: GamnitDisplay) do end
  45
  46         # Full frame logic, executed even if the display is not visible
  47         #
  48         # This method wraps `frame_core` and other services to be executed in the main app loop.
  49         #
  50         # To customize the behavior on each turn, it is preferable to redefined `frame_core`.
  51         # Still, `frame_full` can be redefined with care for more control.
  52         protected fun frame_full
  53         do
  54                 var display = display
  55                 if display != null then frame_core(display)
  56
  57                 feed_events
  58         end
  59
  60         redef fun run
  61         do
  62                 # TODO manage exit condition
  63                 loop frame_full
  64         end
  65
  66         # Loop on available events and feed them back to the app
  67         #
  68         # The implementation varies per platform.
  69         private fun feed_events do end
  70
  71         # Hook to receive and respond to `event` triggered by the user or system
  72         #
  73         # Returns whether or not the event is used or intercepted.
  74         # If `true`, the event will not be processed further by the system.
  75         # Returns `false` to intercepts events like the back key on mobile devices.
  76         #
  77         # The instances passed as `event` may be freed (or overwritten),
  78         # right after this method returns. They should not be preserved.
  79         fun accept_event(event: InputEvent): Bool do return false
  80
  81         # The window has been resized by the user or system
  82         #
  83         # The framework handles resizing the viewport automatically.
  84         fun on_resize(display: GamnitDisplay) do end
  85 end