SWORD25: Fix keyboard state handling

Previously, you could get the game into a state where it would think a
key was constantly being pressed. E.g. by pressing 'p' several times
quickly in a row, the game would end in a state where it endlessly
toggled between pause mode and regular mode.

svn-id: r53878

1 files changed, 7 insertions, 0 deletions

diff --git a/engines/sword25/input/inputengine.cpp b/engines/sword25/input/inputengine.cpp
index a85096bc2f..0226458f5f 100644
--- a/engines/sword25/input/inputengine.cpp
+++ b/engines/sword25/input/inputengine.cpp
@@ -87,7 +87,14 @@ bool InputEngine::init() {
 
 void InputEngine::update() {
 	Common::Event event;
+
+	// We keep two sets of keyboard states: The current one, and that of
+	// the previous frame. This allows us to detect which keys changed
+	// state. Also, by keeping a single central keystate array, we
+	// ensure that all script queries for key state during a single
+	// frame get the same consistent replies.
 	_currentState ^= 1;
+	memcpy(_keyboardState[_currentState], _keyboardState[_currentState ^ 1], sizeof(_keyboardState[0]));
 
 	// Loop through processing any pending events
 	bool handleEvents = true;