unmaintained/4DNav/camera/camera-docs.factor

   1 ! Copyright (C) 2008 Jean-François Bigot.
   2 ! See http://factorcode.org/license.txt for BSD license.
   3 USING: help.markup help.syntax kernel ;
   4 IN: 4DNav.camera
   5
   6 HELP: camera-eye
   7 { $values
   8
   9      { "point" "position" }
  10 }
  11 { $description "return the position of the camera" } ;
  12
  13 HELP: camera-focus
  14 { $values
  15
  16      { "point" "position" }
  17 }
  18 { $description "return the point the camera looks at" } ;
  19
  20 HELP: camera-up
  21 { $values
  22
  23      { "dirvec" "upside direction" }
  24 }
  25 { $description "In order to precise the roling position of camera give an upward vector" } ;
  26
  27 HELP: do-look-at
  28 { $values
  29      { "camera" "direction" }
  30 }
  31 { $description "Word to use in replacement of gl-look-at when using a camera" } ;
  32
  33 ARTICLE: "4DNav.camera" "Camera"
  34 { $vocab-link "4DNav.camera" }
  35 $nl
  36 "A camera is defined by:"
  37 { $list
  38 { "a position (" { $link camera-eye } ")" }
  39 { "a focus direction (" { $link camera-focus } ")" }
  40 { "an attitude information (" { $link camera-up } ")" }
  41 }
  42 "Use " { $link do-look-at } " in opengl statement in placement of gl-look-at"
  43 $nl
  44 "A camera is a " { $vocab-link "4DNav.turtle" } " object. Its a special vocab to handle mouvements of a 3D object:"
  45 { $list
  46 { "To define a camera"
  47 {
  48     $unchecked-example
  49
  50 "VAR: my-camera"
  51 ": init-my-camera ( -- )"
  52 "    <turtle> >my-camera"
  53 "    [ my-camera> >self"
  54 "      reset-turtle "
  55 "    ] with-scope ;"
  56 } }
  57 { "To move it"
  58 {
  59     $unchecked-example
  60
  61 "    [ my-camera> >self"
  62 "      45 pitch-up "
  63 "      5 step-turtle"
  64 "    ] with-scope "
  65 } }
  66 { "or"
  67 {
  68     $unchecked-example
  69
  70 "    [ my-camera> >self"
  71 "      5 strafe-left"
  72 "    ] with-scope "
  73 }
  74 }
  75 {
  76 "to use it in an opengl statement"
  77 {
  78     $unchecked-example
  79   "my-camera> do-look-at"
  80
  81 }
  82 }
  83 }
  84
  85
  86 ;
  87
  88 ABOUT: "4DNav.camera"