Opentk/Source/OpenTK/Input/KeyboardState.cs
2010-10-28 08:41:48 +00:00

248 lines
7.5 KiB
C#

#region License
//
// The Open Toolkit Library License
//
// Copyright (c) 2006 - 2009 the Open Toolkit library.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights to
// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
// the Software, and to permit persons to whom the Software is furnished to do
// so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
//
#endregion
using System;
using System.Collections.Specialized;
using System.Text;
namespace OpenTK.Input
{
/// <summary>
/// Encapsulates the state of a Keyboard device.
/// </summary>
public struct KeyboardState : IEquatable<KeyboardState>
{
#region Fields
// Allocate enough ints to store all keyboard keys
const int IntSize = sizeof(int);
const int NumInts = ((int)Key.LastKey + IntSize - 1) / IntSize;
// The following line triggers bogus CS0214 in gmcs 2.0.1, sigh...
unsafe fixed int Keys[NumInts];
#endregion
#region Public Members
/// <summary>
/// Gets a <see cref="System.Boolean"/> indicating whether the specified
/// <see cref="OpenTK.Input.Key"/> is pressed.
/// </summary>
/// <param name="key">The <see cref="OpenTK.Input.Key"/> to check.</param>
/// <returns>True if key is pressed; false otherwise.</returns>
public bool this[Key key]
{
get { return IsKeyDown(key); }
internal set
{
if (value)
EnableBit((int)key);
else
DisableBit((int)key);
}
}
/// <summary>
/// Gets a <see cref="System.Boolean"/> indicating whether this key is down.
/// </summary>
/// <param name="key">The <see cref="OpenTK.Input.Key"/> to check.</param>
public bool IsKeyDown(Key key)
{
return ReadBit((int)key);
}
/// <summary>
/// Gets a <see cref="System.Boolean"/> indicating whether this key is up.
/// </summary>
/// <param name="key">The <see cref="OpenTK.Input.Key"/> to check.</param>
public bool IsKeyUp(Key key)
{
return !ReadBit((int)key);
}
/// <summary>
/// Checks whether two <see cref="KeyboardState" /> instances are equal.
/// </summary>
/// <param name="left">
/// A <see cref="KeyboardState"/> instance.
/// </param>
/// <param name="right">
/// A <see cref="KeyboardState"/> instance.
/// </param>
/// <returns>
/// True if both left is equal to right; false otherwise.
/// </returns>
public static bool operator ==(KeyboardState left, KeyboardState right)
{
return left.Equals(right);
}
/// <summary>
/// Checks whether two <see cref="KeyboardState" /> instances are not equal.
/// </summary>
/// <param name="left">
/// A <see cref="KeyboardState"/> instance.
/// </param>
/// <param name="right">
/// A <see cref="KeyboardState"/> instance.
/// </param>
/// <returns>
/// True if both left is not equal to right; false otherwise.
/// </returns>
public static bool operator !=(KeyboardState left, KeyboardState right)
{
return !left.Equals(right);
}
/// <summary>
/// Compares to an object instance for equality.
/// </summary>
/// <param name="obj">
/// The <see cref="System.Object"/> to compare to.
/// </param>
/// <returns>
/// True if this instance is equal to obj; false otherwise.
/// </returns>
public override bool Equals(object obj)
{
if (obj is KeyboardState)
{
return this == (KeyboardState)obj;
}
else
{
return false;
}
}
/// <summary>
/// Generates a hashcode for the current instance.
/// </summary>
/// <returns>
/// A <see cref="System.Int32"/> represting the hashcode for this instance.
/// </returns>
public override int GetHashCode()
{
unsafe
{
fixed (int* k = Keys)
{
int hashcode = 0;
for (int i = 0; i < NumInts; i++)
hashcode ^= (k + i)->GetHashCode();
return hashcode;
}
}
}
#endregion
#region Internal Members
internal bool ReadBit(int offset)
{
ValidateOffset(offset);
int int_offset = offset / 32;
int bit_offset = offset % 32;
unsafe
{
fixed (int* k = Keys)
{
return (*(k + int_offset) & (1 << bit_offset)) != 0u;
}
}
}
internal void EnableBit(int offset)
{
ValidateOffset(offset);
int int_offset = offset / 32;
int bit_offset = offset % 32;
unsafe
{
fixed (int* k = Keys)
{
*(k + int_offset) |= 1 << bit_offset;
}
}
}
internal void DisableBit(int offset)
{
ValidateOffset(offset);
int int_offset = offset / 32;
int bit_offset = offset % 32;
unsafe
{
fixed (int* k = Keys)
{
*(k + int_offset) &= ~(1 << bit_offset);
}
}
}
#endregion
#region Private Members
static void ValidateOffset(int offset)
{
if (offset < 0 || offset >= NumInts * IntSize)
throw new ArgumentOutOfRangeException("offset");
}
#endregion
#region IEquatable<KeyboardState> Members
/// <summary>
/// Compares two KeyboardState instances.
/// </summary>
/// <param name="other">The instance to compare two.</param>
/// <returns>True, if both instances are equal; false otherwise.</returns>
public bool Equals(KeyboardState other)
{
bool equal = true;
unsafe
{
int* k2 = other.Keys;
fixed (int* k1 = Keys)
{
for (int i = 0; equal && i < NumInts; i++)
equal &= *(k1 + i) == *(k2 + i);
}
}
return equal;
}
#endregion
}
}