lib/gamnit/display.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 # Abstract display services
  16 module display
  17
  18 import ::glesv2
  19 import mnit::input
  20
  21 import display_linux is conditional(linux)
  22 import display_android is conditional(android)
  23
  24 # Should Gamnit be more verbose?
  25 fun debug_gamnit: Bool do return false
  26
  27 # General display class, is sized and drawable
  28 class GamnitDisplay
  29
  30         # Width of the display, in pixels
  31         fun width: Int is abstract
  32
  33         # Height of the display, in pixels
  34         fun height: Int is abstract
  35
  36         # Aspect ratio of the screen, `width / height`
  37         var aspect_ratio: Float is lazy do return width.to_f / height.to_f
  38
  39         # Is the cursor locked et the center of the screen?
  40         var lock_cursor = false is writable
  41
  42         # Is the cursor visible?
  43         #
  44         # Only affects the desktop implementations.
  45         var show_cursor: Bool = true is writable
  46
  47         # Number of bits used for the red value in the color buffer
  48         fun red_bits: Int do return 8
  49
  50         # Number of bits used for the green value in the color buffer
  51         fun green_bits: Int do return 8
  52
  53         # Number of bits used for the blue value in the color buffer
  54         fun blue_bits: Int do return 8
  55
  56         # Prepare this display
  57         #
  58         # The implementation varies per platform.
  59         fun setup is abstract
  60
  61         # Close this display and free underlying resources
  62         #
  63         # The implementation varies per platform.
  64         fun close do end
  65
  66         # Flip the display buffers
  67         #
  68         # The implementation varies per platform.
  69         fun flip do end
  70
  71         # Loop on available events and feed them back to the app
  72         #
  73         # The implementation varies per platform.
  74         fun feed_events do end
  75 end