blob: fe900b5264fdea06bfd3a7191666d38bb60cb5a3 [file] [log] [blame]
/*
* This file houses utilities for copying blocks of memory to and from
* the WASM heap.
*/
/**
* Malloc returns a TypedArray backed by the C++ memory of the
* given length. It should only be used by advanced users who
* can manage memory and initialize values properly. When used
* correctly, it can save copying of data between JS and C++.
* When used incorrectly, it can lead to memory leaks.
* Any memory allocated by CanvasKit.Malloc needs to be released with CanvasKit.Free.
*
* const mObj = CanvasKit.Malloc(Float32Array, 20);
* Get a TypedArray view around the malloc'd memory (this does not copy anything).
* const ta = mObj.toTypedArray();
* // store data into ta
* const cf = CanvasKit.ColorFilter.MakeMatrix(ta); // mObj could also be used.
*
* // eventually...
* CanvasKit.Free(mObj);
*
* @param {TypedArray} typedArray - constructor for the typedArray.
* @param {number} len - number of *elements* to store.
*/
CanvasKit.Malloc = function(typedArray, len) {
var byteLen = len * typedArray.BYTES_PER_ELEMENT;
var ptr = CanvasKit._malloc(byteLen);
return {
'_ck': true,
'length': len,
'byteOffset': ptr,
typedArray: null,
'subarray': function(start, end) {
var sa = this['toTypedArray']().subarray(start, end);
sa['_ck'] = true;
return sa;
},
'toTypedArray': function() {
// Check if the previously allocated array is still usable.
// If it's falsy, then we haven't created an array yet.
// If it's empty, then WASM resized memory and emptied the array.
if (this.typedArray && this.typedArray.length) {
return this.typedArray;
}
this.typedArray = new typedArray(CanvasKit.HEAPU8.buffer, ptr, len);
// add a marker that this was allocated in C++ land
this.typedArray['_ck'] = true;
return this.typedArray;
},
};
};
/**
* Free frees the memory returned by Malloc.
* Any memory allocated by CanvasKit.Malloc needs to be released with CanvasKit.Free.
*/
CanvasKit.Free = function(mallocObj) {
CanvasKit._free(mallocObj['byteOffset']);
mallocObj['byteOffset'] = nullptr;
// Set these to null to make sure the TypedArrays can be garbage collected.
mallocObj['toTypedArray'] = null;
mallocObj.typedArray = null;
};
// This helper will free the given pointer unless the provided array is one
// that was returned by CanvasKit.Malloc.
function freeArraysThatAreNotMallocedByUsers(ptr, arr) {
if (!wasMalloced(arr)) {
CanvasKit._free(ptr);
}
}
// wasMalloced returns true if the object was created by a call to Malloc. This is determined
// by looking at a property that was added to our Malloc obj and typed arrays.
function wasMalloced(obj) {
return obj && obj['_ck'];
}
// We define some "scratch" variables which will house both the pointer to
// memory we allocate at startup as well as a Malloc object, which we can
// use to get a TypedArray view of that memory.
var _scratch3x3MatrixPtr = nullptr;
var _scratch3x3Matrix; // the result from CanvasKit.Malloc
var _scratch4x4MatrixPtr = nullptr;
var _scratch4x4Matrix;
var _scratchColorPtr = nullptr;
var _scratchColor;
var _scratchFourFloatsA;
var _scratchFourFloatsAPtr = nullptr;
var _scratchFourFloatsB;
var _scratchFourFloatsBPtr = nullptr;
var _scratchThreeFloatsA;
var _scratchThreeFloatsAPtr = nullptr;
var _scratchThreeFloatsB;
var _scratchThreeFloatsBPtr = nullptr;
var _scratchIRect;
var _scratchIRectPtr = nullptr;
var _scratchRRect;
var _scratchRRectPtr = nullptr;
var _scratchRRect2;
var _scratchRRect2Ptr = nullptr;
// arr can be a normal JS array or a TypedArray
// dest is a string like 'HEAPU32' that specifies the type the src array
// should be copied into.
// ptr can be optionally provided if the memory was already allocated.
// Callers should eventually free the data unless the C++ object owns the memory,
// or the provided pointer is a scratch pointer or a user-malloced value.
// see also freeArraysThatAreNotMallocedByUsers().
function copy1dArray(arr, dest, ptr) {
if (!arr || !arr.length) {
return nullptr;
}
// This was created with CanvasKit.Malloc, so it's already been copied.
if (wasMalloced(arr)) {
return arr.byteOffset;
}
var bytesPerElement = CanvasKit[dest].BYTES_PER_ELEMENT;
if (!ptr) {
ptr = CanvasKit._malloc(arr.length * bytesPerElement);
}
// In c++ terms, the WASM heap is a uint8_t*, a long buffer/array of single
// byte elements. When we run _malloc, we always get an offset/pointer into
// that block of memory.
// CanvasKit exposes some different views to make it easier to work with
// different types. HEAPF32 for example, exposes it as a float*
// However, to make the ptr line up, we have to do some pointer arithmetic.
// Concretely, we need to convert ptr to go from an index into a 1-byte-wide
// buffer to an index into a 4-byte-wide buffer (in the case of HEAPF32)
// and thus we divide ptr by 4.
// It is important to make sure we are grabbing the freshest view of the
// memory possible because if we call _malloc and the heap needs to grow,
// the TypedArrayView will no longer be valid.
CanvasKit[dest].set(arr, ptr / bytesPerElement);
return ptr;
}
// Copies an array of colors to wasm, returning an object with the pointer
// and info necessary to use the copied colors.
// Accepts either a flat Float32Array, flat Uint32Array or Array of Float32Arrays.
// If color is an object that was allocated with CanvasKit.Malloc, its pointer is
// returned and no extra copy is performed.
// TODO(nifong): have this accept color builders.
function copyFlexibleColorArray(colors) {
var result = {
colorPtr: nullptr,
count: colors.length,
colorType: CanvasKit.ColorType.RGBA_F32,
};
if (colors instanceof Float32Array) {
result.colorPtr = copy1dArray(colors, 'HEAPF32');
result.count = colors.length / 4;
} else if (colors instanceof Uint32Array) {
result.colorPtr = copy1dArray(colors, 'HEAPU32');
result.colorType = CanvasKit.ColorType.RGBA_8888;
} else if (colors instanceof Array) {
result.colorPtr = copyColorArray(colors);
} else {
throw('Invalid argument to copyFlexibleColorArray, Not a color array '+typeof(colors));
}
return result;
}
function copyColorArray(arr) {
if (!arr || !arr.length) {
return nullptr;
}
// 4 floats per color, 4 bytes per float.
var ptr = CanvasKit._malloc(arr.length * 4 * 4);
var idx = 0;
var adjustedPtr = ptr / 4; // cast the byte pointer into a float pointer.
for (var r = 0; r < arr.length; r++) {
for (var c = 0; c < 4; c++) {
CanvasKit.HEAPF32[adjustedPtr + idx] = arr[r][c];
idx++;
}
}
return ptr;
}
var defaultPerspective = Float32Array.of(0, 0, 1);
// Copies the given DOMMatrix/Array/TypedArray to the CanvasKit heap and
// returns a pointer to the memory. This memory is a float* of length 9.
// If the passed in matrix is null/undefined, we return 0 (nullptr). The
// returned pointer should NOT be freed, as it is either null or a scratch
// pointer.
function copy3x3MatrixToWasm(matr) {
if (!matr) {
return nullptr;
}
var wasm3x3Matrix = _scratch3x3Matrix['toTypedArray']();
if (matr.length) {
if (matr.length === 6 || matr.length === 9) {
// matr should be an array or typed array.
copy1dArray(matr, 'HEAPF32', _scratch3x3MatrixPtr);
if (matr.length === 6) {
// Overwrite the last 3 floats with the default perspective. The divide
// by 4 casts the pointer into a float pointer.
CanvasKit.HEAPF32.set(defaultPerspective, 6 + _scratch3x3MatrixPtr / 4);
}
return _scratch3x3MatrixPtr;
} else if (matr.length === 16) {
// Downsample the 4x4 matrix into a 3x3
wasm3x3Matrix[0] = matr[0];
wasm3x3Matrix[1] = matr[1];
wasm3x3Matrix[2] = matr[3];
wasm3x3Matrix[3] = matr[4];
wasm3x3Matrix[4] = matr[5];
wasm3x3Matrix[5] = matr[7];
wasm3x3Matrix[6] = matr[12];
wasm3x3Matrix[7] = matr[13];
wasm3x3Matrix[8] = matr[15];
return _scratch3x3MatrixPtr;
}
throw 'invalid matrix size';
} else if (matr['m11'] === undefined) {
throw 'invalid matrix argument';
}
// Reminder that DOMMatrix is column-major.
wasm3x3Matrix[0] = matr['m11'];
wasm3x3Matrix[1] = matr['m21'];
wasm3x3Matrix[2] = matr['m41'];
wasm3x3Matrix[3] = matr['m12'];
wasm3x3Matrix[4] = matr['m22'];
wasm3x3Matrix[5] = matr['m42'];
wasm3x3Matrix[6] = matr['m14'];
wasm3x3Matrix[7] = matr['m24'];
wasm3x3Matrix[8] = matr['m44'];
return _scratch3x3MatrixPtr;
}
// Copies the given DOMMatrix/Array/TypedArray to the CanvasKit heap and
// returns a pointer to the memory. This memory is a float* of length 16.
// If the passed in matrix is null/undefined, we return 0 (nullptr). The
// returned pointer should NOT be freed, as it is either null or a scratch
// pointer.
function copy4x4MatrixToWasm(matr) {
if (!matr) {
return nullptr;
}
var wasm4x4Matrix = _scratch4x4Matrix['toTypedArray']();
if (matr.length) {
if (matr.length !== 16 && matr.length !== 6 && matr.length !== 9) {
throw 'invalid matrix size';
}
if (matr.length === 16) {
// matr should be an array or typed array.
return copy1dArray(matr, 'HEAPF32', _scratch4x4MatrixPtr);
}
// Upscale the row-major 3x3 or 3x2 matrix into a 4x4 row-major matrix
// TODO(skbug.com/10108) This will need to change when we convert our
// JS 4x4 to be column-major.
// When upscaling, we need to overwrite the 3rd column and the 3rd row with
// 0s. It's easiest to just do that with a fill command.
wasm4x4Matrix.fill(0);
wasm4x4Matrix[0] = matr[0];
wasm4x4Matrix[1] = matr[1];
// skip col 2
wasm4x4Matrix[3] = matr[2];
wasm4x4Matrix[4] = matr[3];
wasm4x4Matrix[5] = matr[4];
// skip col 2
wasm4x4Matrix[7] = matr[5];
// skip row 2
wasm4x4Matrix[12] = matr[6];
wasm4x4Matrix[13] = matr[7];
// skip col 2
wasm4x4Matrix[15] = matr[8];
if (matr.length === 6) {
// fix perspective for the 3x2 case (from above, they will be undefined).
wasm4x4Matrix[12]=0;
wasm4x4Matrix[13]=0;
wasm4x4Matrix[15]=1;
}
return _scratch4x4MatrixPtr;
} else if (matr['m11'] === undefined) {
throw 'invalid matrix argument';
}
// Reminder that DOMMatrix is column-major.
wasm4x4Matrix[0] = matr['m11'];
wasm4x4Matrix[1] = matr['m21'];
wasm4x4Matrix[2] = matr['m31'];
wasm4x4Matrix[3] = matr['m41'];
wasm4x4Matrix[4] = matr['m12'];
wasm4x4Matrix[5] = matr['m22'];
wasm4x4Matrix[6] = matr['m32'];
wasm4x4Matrix[7] = matr['m42'];
wasm4x4Matrix[8] = matr['m13'];
wasm4x4Matrix[9] = matr['m23'];
wasm4x4Matrix[10] = matr['m33'];
wasm4x4Matrix[11] = matr['m43'];
wasm4x4Matrix[12] = matr['m14'];
wasm4x4Matrix[13] = matr['m24'];
wasm4x4Matrix[14] = matr['m34'];
wasm4x4Matrix[15] = matr['m44'];
return _scratch4x4MatrixPtr;
}
// copies a 4x4 matrix at the given pointer into a JS array.
function copy4x4MatrixFromWasm(matrPtr) {
// read them out into an array. TODO(kjlubick): If we change Matrix to be
// typedArrays, then we should return a typed array here too.
var rv = new Array(16);
for (var i = 0; i < 16; i++) {
rv[i] = CanvasKit.HEAPF32[matrPtr/4 + i]; // divide by 4 to cast to float.
}
return rv;
}
// copies the given floats into the wasm heap as an SkColor4f. Unless a non-scratch pointer is
// passed into ptr, callers do NOT need to free the returned pointer.
function copyColorToWasm(color4f, ptr) {
return copy1dArray(color4f, 'HEAPF32', ptr || _scratchColorPtr);
}
// copies the given color into the wasm heap. Callers do not need to free the returned pointer.
function copyColorComponentsToWasm(r, g, b, a) {
var colors = _scratchColor['toTypedArray']();
colors[0] = r;
colors[1] = g;
colors[2] = b;
colors[3] = a;
return _scratchColorPtr;
}
// copies the given color into the wasm heap. Callers must free the returned pointer.
function copyColorToWasmNoScratch(color4f) {
// TODO(kjlubick): accept 4 floats or int color
return copy1dArray(color4f, 'HEAPF32');
}
// copies the four floats at the given pointer in a js Float32Array
function copyColorFromWasm(colorPtr) {
var rv = new Float32Array(4);
for (var i = 0; i < 4; i++) {
rv[i] = CanvasKit.HEAPF32[colorPtr/4 + i]; // divide by 4 to cast to float.
}
return rv;
}
// copies the given floats into the wasm heap as an SkRect. Unless a non-scratch pointer is
// passed into ptr, callers do NOT need to free the returned pointer.
function copyRectToWasm(fourFloats, ptr) {
return copy1dArray(fourFloats, 'HEAPF32', ptr || _scratchFourFloatsAPtr);
}
// copies the given ints into the wasm heap as an SkIRect. Unless a non-scratch pointer is
// passed into ptr, callers do NOT need to free the returned pointer.
function copyIRectToWasm(fourInts, ptr) {
return copy1dArray(fourInts, 'HEAP32', ptr || _scratchIRectPtr);
}
// copies the given floats into the wasm heap as an SkRRect. Unless a non-scratch pointer is
// passed into ptr, callers do NOT need to free the returned pointer.
function copyRRectToWasm(twelveFloats, ptr) {
return copy1dArray(twelveFloats, 'HEAPF32', ptr || _scratchRRectPtr);
}