From 5d77d3309df9dccf4d152e38b46d3e23883582ea Mon Sep 17 00:00:00 2001
From: Mattia Basaglia <glax@dragon.best>
Date: Thu, 20 Jun 2024 10:02:49 +0200
Subject: [PATCH 1/3] Old bodymovin compat

---
 docs/compat.md | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++
 mkdocs.yml     |  1 +
 2 files changed, 66 insertions(+)
 create mode 100644 docs/compat.md

diff --git a/docs/compat.md b/docs/compat.md
new file mode 100644
index 00000000..00cd6f70
--- /dev/null
+++ b/docs/compat.md
@@ -0,0 +1,65 @@
+# Compatibility with older versions
+
+This page describes breaking changes that have been introduced over time.
+
+You'd need to check `v` from {ref-link:animation/animation} to see the
+the lottie is so old to need to worry about these.
+
+## [0,255] Colors
+
+Until `v` 4.1.9.
+
+Modern Lotties have [color](concepts.md#colors) components in the [0, 1] range.
+Older ones have components in the [0, 255] range.
+
+Fix: Divide all color components by 255.
+
+## Static text document
+
+Until `v` 4.4.14.
+
+In {ref-link:text/text-data}, `d` was not animated.
+
+Fix: Wrap into an animated property
+
+`text_layer.t.d = {"a": 0, "k": text_layer.t.d}`
+
+## Shape closing
+
+Until `v` 4.4.18.
+
+{ref-link:shapes/path} objects had a `closed` property and `c` was not
+present in the bezier data.
+
+Similarly, {ref-link:helpers/mask} had `cl` that worked the same way.
+
+Fix: For each {ref-link:shapes/path}, update all the keyframes
+(or the non-animated value) of `ks`.
+Do the same to fix `pt` in each {ref-link:helpers/mask}.
+
+## Old keyframe style
+
+Until `v` 5.0.0 (?).
+
+[Keyframes](concepts.md#keyframe) had an `e` property that specified
+the end value for that keyframe (`s` marking the start value),
+and the last keyframe would not have `s`.
+
+Fix: Ignore all the `e` in keyframes, but copy the `e` from the keyframe
+before last into the last keyframe.
+
+`keyframes[keyframes.length - 1].s = keyframes[keyframes.length - 2].e`
+
+
+
+## Static text layer properties
+
+Until `v` 5.7.15.
+
+In {ref-link:text/text-follow-path} properties `r`, `a`, and `p` were
+plain numbers instead of animated properties.
+
+Fix: Wrap all of those into animated properties
+
+`text_layer.t.p.a + {"a": 0, "k": text_layer.t.p.a}`
+
diff --git a/mkdocs.yml b/mkdocs.yml
index 6a088466..8a4edf07 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -42,6 +42,7 @@ nav:
         - constants.md
         - text.md
         - expressions.md
+        - compat.md
     - "Playground":
         - "Builder": playground/builder.md
         - "JSON Editor": playground/json_editor.md

From 5c8c74edcb071c286cf91077704ad3c55ff0fb46 Mon Sep 17 00:00:00 2001
From: Mattia Basaglia <glax@dragon.best>
Date: Thu, 20 Jun 2024 12:12:52 +0200
Subject: [PATCH 2/3] Specify closed was a bool

---
 docs/compat.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/compat.md b/docs/compat.md
index 00cd6f70..d75e3288 100644
--- a/docs/compat.md
+++ b/docs/compat.md
@@ -28,7 +28,7 @@ Fix: Wrap into an animated property
 
 Until `v` 4.4.18.
 
-{ref-link:shapes/path} objects had a `closed` property and `c` was not
+{ref-link:shapes/path} objects had a boolean `closed` property and `c` was not
 present in the bezier data.
 
 Similarly, {ref-link:helpers/mask} had `cl` that worked the same way.

From 5e5bfc3bd5cb24480f314f74c3994cbd2c7139c4 Mon Sep 17 00:00:00 2001
From: Mattia Basaglia <glax@dragon.best>
Date: Thu, 20 Jun 2024 12:15:23 +0200
Subject: [PATCH 3/3] Clarify conversion code

---
 docs/compat.md | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/docs/compat.md b/docs/compat.md
index d75e3288..0f45e6d2 100644
--- a/docs/compat.md
+++ b/docs/compat.md
@@ -5,6 +5,9 @@ This page describes breaking changes that have been introduced over time.
 You'd need to check `v` from {ref-link:animation/animation} to see the
 the lottie is so old to need to worry about these.
 
+The code examples are just for illustrative purposes and are not to be
+taken as a complete conversion code.
+
 ## [0,255] Colors
 
 Until `v` 4.1.9.
@@ -37,6 +40,8 @@ Fix: For each {ref-link:shapes/path}, update all the keyframes
 (or the non-animated value) of `ks`.
 Do the same to fix `pt` in each {ref-link:helpers/mask}.
 
+`shape.ks.k.c = shape.closed ? 1 : 0`
+
 ## Old keyframe style
 
 Until `v` 5.0.0 (?).