SCI: added additional comment for setOrigin() commit (from waltervn), after doing some test with sierra interpreter

svn-id: r48775

1 files changed, 2 insertions, 0 deletions

diff --git a/engines/sci/graphics/ports.cpp b/engines/sci/graphics/ports.cpp
index 8802d1ccb2..f3f834e0d8 100644
--- a/engines/sci/graphics/ports.cpp
+++ b/engines/sci/graphics/ports.cpp
@@ -389,6 +389,8 @@ Port *GfxPorts::getPort() {
 
 void GfxPorts::setOrigin(int16 left, int16 top) {
 	// This looks fishy, but it's exactly what sierra did. They removed last bit of left in their interpreter
+	//  It seems sierra did it for EGA byte alignment (EGA uses 1 byte for 2 pixels) and left it in their interpreter even
+	//  when going VGA.
 	_curPort->left = left & 0x7FFE;
 	_curPort->top = top;
 }