IssueTracker

Sergio shared a WIP CL to calculate more correct bounds. You can see in the screenshot attached here that it does a better job of tightening the bounds around the object (the yellow box), but that it misses some of the curves which expand beyond these tighter bounds. In particular, note the two triangles and the two blob shapes (rotated round rects).
I've attached another 2 screenshots from the ShapeEditor view of one of the blobs, showing the shape and controls/anchors. You can see that the tighter bounds (yellow rectangle) are constrained to the anchors, but the curves at the end go beyond those points and exceed the bounds.

Part of the problem is that the min/max values are assigned the anchors to begin with. That would cause the problem we're seeing in #2, because these new bounds are constrained to the rectangle created by the anchor points, even if the control points cause curves to go outside of those bounds.
But that's not all of the problem here. When I changed those min/max values to use the control points instead, the bounds expanded to be essentially the same as the estimated bounds from before. So there's more to it.

Some of #3 is incorrect - the bounds can be expanded from the initial min/max values, so it is fine to have them start at the anchor points.

Meanwhile, I thought part of the problem might be calculating derivatives/etc for zero-length curves (of which there are many, given the way our shape rounding works). But adding in a check for this (setting the bounds of a curve to the same point when the anchors are equal within the distance epsilon) did not fix the problem; we still end up with bounds that are inside some of the curves (see attached screenshot)

Project: platform/frameworks/support
Branch: androidx-main

commit 958577b15712233aa487003deb0ab37de3af7ab7
Author: Chet Haase <chet@google.com>
Date:   Wed Dec 20 13:21:53 2023

    Added more bounds calculation utilities
   
    Previously, calculateBounds() returned the estimated bounds
    for a RoundedPolygon. This is reasonable in most cases, but sometimes
    you want the actual/minimal bounds instead. Also, sometimes you want
    the max bounds for an object that might be rotated within its container,
    so you need to size the container appropriately.
   
    This CL introduces options for bounds calculations to handle these
    new cases, along with some minor cleanups along the way.
   
    Bug: 317286450
    Test: Existing tests pass, added new bounds tests
    Relnote: Now more options for retrieving exact and max bounds
   
    Change-Id: I6d49f468a28c1f360000e8370f02a50841f744e4

M       graphics/graphics-shapes/api/current.txt
M       graphics/graphics-shapes/api/restricted_current.txt
M       graphics/graphics-shapes/src/androidInstrumentedTest/kotlin/androidx/graphics/shapes/PolygonTest.kt
M       graphics/graphics-shapes/src/commonMain/kotlin/androidx/graphics/shapes/Cubic.kt
M       graphics/graphics-shapes/src/commonMain/kotlin/androidx/graphics/shapes/RoundedPolygon.kt
M       graphics/graphics-shapes/src/commonMain/kotlin/androidx/graphics/shapes/Utils.kt
M       graphics/integration-tests/testapp-compose/src/main/java/androidx/graphics/shapes/testcompose/DebugDraw.kt
M       graphics/integration-tests/testapp-compose/src/main/java/androidx/graphics/shapes/testcompose/MainActivity.kt

https://android-review.googlesource.com/2889768