blob: b6e3ace9422e0a4bc380e969fab66d15d05011fb [file] [log] [blame]
/*
* Copyright 2019 Google LLC
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef WasmCommon_DEFINED
#define WasmCommon_DEFINED
#include <emscripten.h>
#include <emscripten/bind.h>
#include "include/core/SkColor.h"
using namespace emscripten;
// Self-documenting types
using JSArray = emscripten::val;
using JSObject = emscripten::val;
using JSString = emscripten::val;
using SkPathOrNull = emscripten::val;
using TypedArray = emscripten::val;
using Uint8Array = emscripten::val;
using Uint16Array = emscripten::val;
using Uint32Array = emscripten::val;
using Float32Array = emscripten::val;
/**
* Create a typed-array (in the JS heap) and initialize it with the provided
* data (from the wasm heap). The caller is responsible for matching the type of data
* with the specified arrayType.
*
* TODO: can we specialize this on T and provide the correct string?
* e.g. T==uint8_t --> "Uint8Array"
*/
template <typename T>
TypedArray MakeTypedArray(int count, const T src[], const char arrayType[]) {
emscripten::val length = emscripten::val(count);
emscripten::val jarray = emscripten::val::global(arrayType).new_(count);
jarray.call<void>("set", val(typed_memory_view(count, src)));
return jarray;
}
/**
* Reads a JS array, and returns a copy of it in the std::vector.
*
* It is up to the caller to ensure the T and arrayType-string match
* e.g. T == uint16_t, arrayType == "Uint16Array"
*
* Note, this checks the JS type, and if it does not match, it will still attempt
* to return a copy, just by performing a 1-element-at-a-time copy
* via emscripten::vecFromJSArray().
*/
template <typename T>
std::vector<T> CopyTypedArray(JSArray src, const char arrayType[]) {
if (src.instanceof(emscripten::val::global(arrayType))) {
const size_t len = src["length"].as<size_t>();
std::vector<T> dst;
dst.resize(len);
auto dst_view = emscripten::val(typed_memory_view(len, dst.data()));
dst_view.call<void>("set", src);
return dst;
} else {
// copies one at a time
return emscripten::vecFromJSArray<T>(src);
}
}
#endif