third_party/WebKit/public/platform/WebGamepad.h

   1 // Copyright (C) 2011, Google Inc. All rights reserved.
   2 //
   3 // Redistribution and use in source and binary forms, with or without
   4 // modification, are permitted provided that the following conditions are met:
   5 //
   6 // 1. Redistributions of source code must retain the above copyright
   7 //    notice, this list of conditions and the following disclaimer.
   8 // 2. Redistributions in binary form must reproduce the above copyright
   9 //    notice, this list of conditions and the following disclaimer in the
  10 //    documentation and/or other materials provided with the distribution.
  11 //
  12 // THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND
  13 // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  14 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  15 // ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE
  16 // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  17 // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  18 // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  19 // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  20 // LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  21 // OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  22 // DAMAGE.
  23
  24 #ifndef WebGamepad_h
  25 #define WebGamepad_h
  26
  27 #include "WebCommon.h"
  28
  29 #if BLINK_IMPLEMENTATION
  30 #include "wtf/Assertions.h"
  31 #endif
  32
  33 namespace blink {
  34
  35 #pragma pack(push, 1)
  36
  37 class WebGamepadButton {
  38 public:
  39     WebGamepadButton()
  40         : pressed(false)
  41         , value(0.)
  42     {
  43     }
  44     WebGamepadButton(bool pressed, double value)
  45         : pressed(pressed)
  46         , value(value)
  47     {
  48     }
  49     bool pressed;
  50     double value;
  51 };
  52
  53 // This structure is intentionally POD and fixed size so that it can be shared
  54 // memory between hardware polling threads and the rest of the browser. See
  55 // also WebGamepads.h.
  56 class WebGamepad {
  57 public:
  58     static const size_t idLengthCap = 128;
  59     static const size_t mappingLengthCap = 16;
  60     static const size_t axesLengthCap = 16;
  61     static const size_t buttonsLengthCap = 32;
  62
  63     WebGamepad()
  64         : connected(false)
  65         , timestamp(0)
  66         , axesLength(0)
  67         , buttonsLength(0)
  68     {
  69         id[0] = 0;
  70         mapping[0] = 0;
  71     }
  72
  73     // Is there a gamepad connected at this index?
  74     bool connected;
  75
  76     // Device identifier (based on manufacturer, model, etc.).
  77     WebUChar id[idLengthCap];
  78
  79     // Monotonically increasing value referring to when the data were last
  80     // updated.
  81     unsigned long long timestamp;
  82
  83     // Number of valid entries in the axes array.
  84     unsigned axesLength;
  85
  86     // Normalized values representing axes, in the range [-1..1].
  87     double axes[axesLengthCap];
  88
  89     // Number of valid entries in the buttons array.
  90     unsigned buttonsLength;
  91
  92     // Button states
  93     WebGamepadButton buttons[buttonsLengthCap];
  94
  95     // Mapping type (for example "standard")
  96     WebUChar mapping[mappingLengthCap];
  97 };
  98
  99 #if BLINK_IMPLEMENTATION
 100 static_assert(sizeof(WebGamepad) == 721, "WebGamepad has wrong size");
 101 #endif
 102
 103 #pragma pack(pop)
 104
 105 }
 106
 107 #endif // WebGamepad_h