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 import display_ios is conditional(ios)
  24
  25 # Should Gamnit be more verbose?
  26 fun debug_gamnit: Bool do return false
  27
  28 # General display class, is sized and drawable
  29 class GamnitDisplay
  30
  31         # Width of the display, in pixels
  32         fun width: Int is abstract
  33
  34         # Height of the display, in pixels
  35         fun height: Int is abstract
  36
  37         # Aspect ratio of the screen, `width / height`
  38         fun aspect_ratio: Float do return width.to_f / height.to_f
  39
  40         # Is the cursor locked et the center of the screen?
  41         var lock_cursor = false is writable
  42
  43         # Is the cursor visible?
  44         #
  45         # Only affects the desktop implementations.
  46         var show_cursor: Bool = true is writable
  47
  48         # Number of bits used for the red value in the color buffer
  49         fun red_bits: Int do return 8
  50
  51         # Number of bits used for the green value in the color buffer
  52         fun green_bits: Int do return 8
  53
  54         # Number of bits used for the blue value in the color buffer
  55         fun blue_bits: Int do return 8
  56
  57         # Prepare this display
  58         #
  59         # The implementation varies per platform.
  60         fun setup is abstract
  61
  62         # Close this display and free underlying resources
  63         #
  64         # The implementation varies per platform.
  65         fun close do end
  66
  67         # Flip the display buffers
  68         #
  69         # The implementation varies per platform.
  70         fun flip do end
  71
  72         # Loop on available events and feed them back to the app
  73         #
  74         # The implementation varies per platform.
  75         fun feed_events do end
  76
  77         # Extensions to OpenGL ES 2.0 supported by the current configuration
  78         var gl_extensions: Array[String] is lazy do return glGetString(gl_EXTENSIONS).split(' ')
  79 end