Add merge! for animation types, insert! for AnimationTrack.

src/MeshCat.jl

@@ -72,6 +72,7 @@ export ArrowVisualizer
 abstract type AbstractObject end
 abstract type AbstractMaterial end
 
+include("util.jl")
 include("trees.jl")
 using .SceneTrees
 include("mesh_files.jl")

src/animations.jl

@@ -2,8 +2,37 @@
 struct AnimationTrack{T}
     name::String
     jstype::String
-    frames::Vector{Int}
-    values::Vector{T}
+    events::Vector{Pair{Int, T}} # frame => value
+end
+
+AnimationTrack{T}(name::String, jstype::String) where {T} = AnimationTrack(name, jstype, Pair{Int, T}[])
+
+wider_js_type(::Type{<:Integer}) = Float64  # Javascript thinks everything is a `double`
+wider_js_type(::Type{Float64}) = Float64
+wider_js_type(x) = x
+
+function Base.insert!(track::AnimationTrack, frame::Integer, value)
+    i = searchsortedfirst(track.events, frame; by=first)
+    if i <= length(track.events) && first(track.events[i]) == frame
+        track.events[i] = frame => value
+    else
+        insert!(track.events, i, frame => value)
+    end
+    return track
+end
+
+function Base.merge!(a::AnimationTrack{T}, others::AnimationTrack{T}...) where T
+    l = length(a)
+    events = copy(a.events)
+    for other in others
+        @assert other.name == a.name
+        @assert other.jstype == a.jstype
+        events_temp = similar(events, length(events) + length(other.events))
+        mergesorted!(events_temp, events, other.events; by=first)
+        events = events_temp
+    end
+    a.events = unique(first, a.events) # TODO: use unique! in ≥ 1.1
+    return a
 end
 
 @with_kw struct AnimationClip
@@ -12,13 +41,31 @@ end
     name::String = "default"
 end
 
+function Base.merge!(a::AnimationClip, others::AnimationClip...)
+    for other in others
+        @assert other.fps == a.fps
+        merge!(merge!, a.tracks, other.tracks) # merge tracks recursively
+    end
+    return a
+end
+
 struct Animation
     clips::Dict{Path, AnimationClip}
     default_framerate::Int
 end
 
 Animation(fps::Int=30) = Animation(Dict{Path, AnimationClip}(), fps)
 
+function Base.merge!(a::Animation, others::Animation...)
+    for other in others
+        @assert a.default_framerate == other.default_framerate
+        merge!(merge!, a.clips, other.clips) # merge clips recursively
+    end
+    return a
+end
+
+Base.merge(a::Animation, others::Animation...) = merge!(Animation(a.default_framerate), a, others...)
+
 function convert_frames_to_video(tar_file_path::AbstractString, output_path::AbstractString="output.mp4"; framerate=60, overwrite=false)
     output_path = abspath(output_path)
     if !isfile(tar_file_path)

src/atframe.jl

@@ -1,18 +1,10 @@
-function _setprop!(track::AnimationTrack, frame::Integer, value)
-    i = searchsortedfirst(track.frames, frame)
-    insert!(track.frames, i, frame)
-    insert!(track.values, i, value)
-end
-
-wider_js_type(::Type{<:Integer}) = Float64  # Javascript thinks everything is a `double`
-wider_js_type(::Type{Float64}) = Float64
-wider_js_type(x) = x
-
 function _setprop!(clip::AnimationClip, frame::Integer, prop::AbstractString, jstype::AbstractString, value)
+    T = wider_js_type(typeof(value))
     track = get!(clip.tracks, prop) do
-        AnimationTrack(prop, jstype, Int[], wider_js_type(typeof(value))[])
+        AnimationTrack{T}(prop, jstype)
     end
-    _setprop!(track, frame, value)
+    insert!(track, frame, value)
+    return nothing
 end
 
 function getclip!(animation::Animation, path::Path)

src/lowering.jl

@@ -323,9 +323,9 @@ function lower(track::AnimationTrack)
         "name" => string(".", track.name),
         "type" => track.jstype,
         "keys" => [Dict{String, Any}(
-            "time" => track.frames[i],
-            "value" => lower(track.values[i])
-        ) for i in eachindex(track.frames)]
+            "time" => frame,
+            "value" => lower(value)
+        ) for (frame, value) in track.events]
     )
 end
 

src/util.jl

@@ -0,0 +1,33 @@
+# Port of possible implementation of std::merge (second version),
+# https://en.cppreference.com/w/cpp/algorithm/merge
+# TODO: contribute to base.
+@inline function mergesorted!(dest::AbstractVector, a, b; by=identity, lt=isless)
+    i = 1
+    it_a = iterate(a)
+    it_b = iterate(b)
+    while it_a !== nothing
+        val_a, state_a = it_a
+        if it_b === nothing
+            dest[i] = val_a
+            i += 1
+            copyto!(dest, i, Iterators.rest(a, state_a))
+            return dest
+        end
+        val_b, state_b = it_b
+        if lt(by(val_b), by(val_a))
+            dest[i] = val_b
+            it_b = iterate(b, state_b)
+        else
+            dest[i] = val_a
+            it_a = iterate(a, state_a)
+        end
+        i += 1
+    end
+    if it_b !== nothing
+        val_b, state_b = it_b
+        dest[i] = val_b
+        i += 1
+        copyto!(dest, i, Iterators.rest(b, state_b))
+    end
+    return dest
+end

test/runtests.jl

@@ -6,6 +6,8 @@ using CoordinateTransformations
 using Colors
 using MeshIO, FileIO
 
+include("util.jl")
+
 @testset "MeshCat" begin
     include("video_rendering.jl")
     include("paths.jl")

test/util.jl

@@ -0,0 +1,35 @@
+module UtilTest
+
+using Test
+using Random
+using MeshCat: mergesorted!
+
+@testset "mergesorted!" begin
+    @testset "basic" begin
+        rng = MersenneTwister(1)
+        for i = 1 : 1000
+            a = sort(rand(1 : 100, rand(0 : 20)))
+            b = sort(rand(1 : 100, rand(0 : 20)))
+            result = similar(a, length(a) + length(b))
+            mergesorted!(result, a, b)
+            @test issorted(result)
+            @test a ⊆ result
+            @test b ⊆ result
+        end
+    end
+
+    @testset "by" begin
+        rng = MersenneTwister(1)
+        for i = 1 : 1000
+            a = sort([rand(1 : 100) => rand(1 : 100) for _ in rand(0 : 20)]; dims=1, by=first)
+            b = sort([rand(1 : 100) => rand(1 : 100) for _ in rand(0 : 20)]; dims=1, by=first)
+            result = similar(a, length(a) + length(b))
+            mergesorted!(result, a, b; by=first)
+            @test issorted(result; by=first)
+            @test a ⊆ result
+            @test b ⊆ result
+        end
+    end
+end
+
+end

test/visualizer.jl

@@ -248,20 +248,25 @@ end
     end
 
     @testset "Animation (new style)" begin
-        anim = Animation()
-        atframe(anim, 0) do
+        anim1 = Animation()
+        atframe(anim1, 0) do
             settransform!(vis[:shapes][:box], Translation(0., 0, 0))
         end
-        atframe(anim, 30) do
+        atframe(anim1, 30) do
             settransform!(vis[:shapes][:box], Translation(2., 0, 0) ∘ LinearMap(RotZ(π/2)))
         end
-        atframe(anim, 0) do
+        setanimation!(vis, anim1)
+        anim2 = Animation()
+        atframe(anim2, 0) do
             setprop!(vis["/Cameras/default/rotated/<object>"], "zoom", 1)
         end
-        atframe(anim, 30) do
+        atframe(anim2, 30) do
             setprop!(vis["/Cameras/default/rotated/<object>"], "zoom", 0.5)
         end
-        setanimation!(vis, anim)
+        setanimation!(vis, anim2)
+        anim_combined = merge(anim1, anim2)
+        @test Set(Iterators.flatten((keys(anim1.clips), keys(anim2.clips)))) == Set(keys(anim_combined.clips))
+        setanimation!(vis, anim_combined)
     end
 end