widelands-dev team mailing list archive

[GunChleoc <fios@xxxxxxxxxxxxxxxxxxx>]

GunChleoc has proposed merging lp:~widelands-dev/widelands/bug-1818494-workaround-math-clamp-zoom-everywhere into lp:widelands.

Commit message:
Use math::clamp to ensure that zoom will stay within range.

Requested reviews:
  Widelands Developers (widelands-dev)
Related bugs:
  Bug #1818494 in widelands: "Crash on "Reset zoom" bzr9005-201903031251 (Release)"
  https://bugs.launchpad.net/widelands/+bug/1818494

For more details, see:
https://code.launchpad.net/~widelands-dev/widelands/bug-1818494-workaround-math-clamp-zoom-everywhere/+merge/365321

I'm no sure whether this actually fixes or only masks the bug. We might only want this in the Build 20 branch, hoping that it will prevent crashes there.
-- 
Your team Widelands Developers is requested to review the proposed merge of lp:~widelands-dev/widelands/bug-1818494-workaround-math-clamp-zoom-everywhere into lp:widelands.

=== modified file 'src/wui/mapview.cc'
--- src/wui/mapview.cc	2019-03-25 10:46:23 +0000
+++ src/wui/mapview.cc	2019-03-31 15:40:28 +0000
@@ -123,7 +123,8 @@
                             std::deque<MapView::TimestampedView>* plan) {
 	for (int i = 1; i < kNumKeyFrames - 2; i++) {
 		float dt = (duration_ms / kNumKeyFrames) * i;
-		const float zoom = zoom_t.value(dt);
+		// Using math::clamp as a workaround for https://bugs.launchpad.net/widelands/+bug/1818494
+		const float zoom = math::clamp(zoom_t.value(dt), 1.f / kMaxZoom, kMaxZoom);
 		const Vector2f center_point = center_point_t.value(dt);
 		const Vector2f viewpoint = center_point - Vector2f(width * zoom / 2.f, height * zoom / 2.f);
 		plan->push_back(MapView::TimestampedView{
@@ -392,6 +393,8 @@
 			return;
 		}
 		view_ = target_view;
+		// Using math::clamp as a workaround for https://bugs.launchpad.net/widelands/+bug/1818494
+		view_.zoom = math::clamp(view_.zoom, 1.f / kMaxZoom, kMaxZoom);
 		MapviewPixelFunctions::normalize_pix(map_, &view_.viewpoint);
 		changeview();
 		return;