TSAGE: Bugfix for credits animations in Scene 1000

3 files changed, 4 insertions, 2 deletions

diff --git a/engines/tsage/core.cpp b/engines/tsage/core.cpp
index 96723570fc..49ff32e35c 100644
--- a/engines/tsage/core.cpp
+++ b/engines/tsage/core.cpp
@@ -1662,6 +1662,7 @@ void SceneObject::setPosition(const Common::Point &p, int yDiff) {
 }
 
 void SceneObject::setZoom(int percent) {
+	assert(_percent >= 0);
 	if (percent != _percent) {
 		_percent = percent;
 		_flags |= OBJFLAG_PANES;
diff --git a/engines/tsage/graphics.cpp b/engines/tsage/graphics.cpp
index f55605fbac..93bb7ea63f 100644
--- a/engines/tsage/graphics.cpp
+++ b/engines/tsage/graphics.cpp
@@ -277,6 +277,7 @@ void GfxSurface::setSurface(Graphics::Surface *s) {
  * Specifies that the surface should maintain it's own internal surface
  */
 void GfxSurface::create(int width, int height) {
+	assert((width >= 0) && (height >= 0));
 	_screenSurface = false;
 	_customSurface = new Graphics::Surface();
 	_customSurface->create(width, height, 1);
diff --git a/engines/tsage/ringworld_scenes1.cpp b/engines/tsage/ringworld_scenes1.cpp
index 9c81c1a1a4..30ef599269 100644
--- a/engines/tsage/ringworld_scenes1.cpp
+++ b/engines/tsage/ringworld_scenes1.cpp
@@ -3002,13 +3002,13 @@ void Scene1000::Action3::zoom(bool up) {
 
 	if (up) {
 		while ((scene->_object3._percent < 100) && !_vm->shouldQuit()) {
-			scene->_object3.changeZoom(scene->_object3._percent + 5);
+			scene->_object3.changeZoom(MIN(scene->_object3._percent + 5, 100));
 			_globals->_sceneObjects->draw();
 			_globals->_events.delay(1);
 		}
 	} else {
 		while ((scene->_object3._percent > 0) && !_vm->shouldQuit()) {
-			scene->_object3.changeZoom(scene->_object3._percent - 5);
+			scene->_object3.changeZoom(MAX(scene->_object3._percent - 5, 0));
 			_globals->_sceneObjects->draw();
 			_globals->_events.delay(1);
 		}