GOB: Add setBPP()

To allow converting the surface's bytes per pixel
without destroying it first.

svn-id: r55260

1 files changed, 17 insertions, 1 deletions

diff --git a/engines/gob/surface.cpp b/engines/gob/surface.cpp
index 554edfc753..fa2d9cf9ab 100644
--- a/engines/gob/surface.cpp
+++ b/engines/gob/surface.cpp
@@ -167,7 +167,7 @@ uint16 Surface::getHeight() const {
 	return _height;
 }
 
-uint16 Surface::getBPP() const {
+uint8 Surface::getBPP() const {
 	return _bpp;
 }
 
@@ -186,6 +186,22 @@ void Surface::resize(uint16 width, uint16 height) {
 	memset(_vidMem, 0, _bpp * _width * _height);
 }
 
+void Surface::setBPP(uint8 bpp) {
+	if (_bpp == bpp)
+		return;
+
+	if (_ownVidMem) {
+		delete[] _vidMem;
+
+		_vidMem = new byte[bpp * _width * _height];
+	} else
+		_width = (_width * _bpp) / bpp;
+
+	_bpp = bpp;
+
+	memset(_vidMem, 0, _bpp * _width * _height);
+}
+
 byte *Surface::getData(uint16 x, uint16 y) {
 	return _vidMem + (y * _width * _bpp) + (x * _bpp);
 }