mth/ebiten
1
0
Fork 0
mirror of https://github.com/hajimehoshi/ebiten.git synced 2024-12-24 18:58:54 +01:00
Code Issues Packages Projects Releases Wiki Activity

jsutil: Avoid allocating ArrayBuffer unnecessarily

Browse Source
This commit is contained in:
Hajime Hoshi 2019-09-26 23:59:00 +09:00
parent 9a42b264fd
commit 59333ba1ad
1 changed files with 20 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
internal/jsutil/go113_js.go
View File

@ -96,44 +96,56 @@ func sliceToByteSlice(s interface{}) (bs []byte) {
return
}
var temporaryBuffer = js.Global().Get("ArrayBuffer").New(16)
func getTemporaryUint8Array(size int) js.Value {
if l := temporaryBuffer.Get("byteLength").Int(); l < size {
for l < size {
l *= 2
}
temporaryBuffer = js.Global().Get("ArrayBuffer").New(l)
}
return js.Global().Get("Uint8Array").New(temporaryBuffer, 0, size)
}
func SliceToTypedArray(s interface{}) (js.Value, func()) {
switch s := s.(type) {
case []int8:
a := js.Global().Get("Uint8Array").New(len(s))
a := getTemporaryUint8Array(len(s))
js.CopyBytesToJS(a, sliceToByteSlice(s))
buf := a.Get("buffer")
return js.Global().Get("Int8Array").New(buf, a.Get("byteOffset"), a.Get("byteLength")), func() {}
case []int16:
a := js.Global().Get("Uint8Array").New(len(s) * 2)
a := getTemporaryUint8Array(len(s) * 2)
js.CopyBytesToJS(a, sliceToByteSlice(s))
buf := a.Get("buffer")
return js.Global().Get("Int16Array").New(buf, a.Get("byteOffset"), a.Get("byteLength").Int()/2), func() {}
case []int32:
a := js.Global().Get("Uint8Array").New(len(s) * 4)
a := getTemporaryUint8Array(len(s) * 4)
js.CopyBytesToJS(a, sliceToByteSlice(s))
buf := a.Get("buffer")
return js.Global().Get("Int32Array").New(buf, a.Get("byteOffset"), a.Get("byteLength").Int()/4), func() {}
case []uint8:
a := js.Global().Get("Uint8Array").New(len(s))
a := getTemporaryUint8Array(len(s))
js.CopyBytesToJS(a, s)
return a, func() {}
case []uint16:
a := js.Global().Get("Uint8Array").New(len(s) * 2)
a := getTemporaryUint8Array(len(s) * 2)
js.CopyBytesToJS(a, sliceToByteSlice(s))
buf := a.Get("buffer")
return js.Global().Get("Uint16Array").New(buf, a.Get("byteOffset"), a.Get("byteLength").Int()/2), func() {}
case []uint32:
a := js.Global().Get("Uint8Array").New(len(s) * 4)
a := getTemporaryUint8Array(len(s) * 4)
js.CopyBytesToJS(a, sliceToByteSlice(s))
buf := a.Get("buffer")
return js.Global().Get("Uint32Array").New(buf, a.Get("byteOffset"), a.Get("byteLength").Int()/4), func() {}
case []float32:
a := js.Global().Get("Uint8Array").New(len(s) * 4)
a := getTemporaryUint8Array(len(s) * 4)
js.CopyBytesToJS(a, sliceToByteSlice(s))
buf := a.Get("buffer")
return js.Global().Get("Float32Array").New(buf, a.Get("byteOffset"), a.Get("byteLength").Int()/4), func() {}
case []float64:
a := js.Global().Get("Uint8Array").New(len(s) * 8)
a := getTemporaryUint8Array(len(s) * 8)
js.CopyBytesToJS(a, sliceToByteSlice(s))
buf := a.Get("buffer")
return js.Global().Get("Float64Array").New(buf, a.Get("byteOffset"), a.Get("byteLength").Int()/8), func() {}