skia2/experimental/canvaskit/interface.js
Kevin Lubick 1a05fceb38 [canvaskit] Expand canvas2d API
Made addPath take one more arg to allow for append/expand
(which makes emulating the HTML canvas easier).

Add Gold test for various lineTo/pathTo, etc.

Make CanvasKit.Color() choose a better value for alpha
when omitted (was 0, should be 1).

Add some parsing logic to deal with colors/font sizes.
Fonts are going to be rather complex it seems.

Moves some arc-related logic to the JS side, (although
this should preserve the behavior of CanvasKit.arc() to
behave like the Canvas implementation)

Make Examples and tests to a side-by-side comparison to
HTML canvas where applicable.

Add a Changelog for PathKit.  There was a bug (I thought), but
turns out I was wrong.  The Changelog will be for future
bug fixes.

Bug: skia:
Change-Id: I1bd603fdb518232604b098e24543e3453015b504
Reviewed-on: https://skia-review.googlesource.com/c/170446
Reviewed-by: Kevin Lubick <kjlubick@google.com>
2018-11-20 18:39:43 +00:00

442 lines
16 KiB
JavaScript

// Adds JS functions to augment the CanvasKit interface.
// For example, if there is a wrapper around the C++ call or logic to allow
// chaining, it should go here.
(function(CanvasKit) {
// CanvasKit.onRuntimeInitialized is called after the WASM library has loaded.
// Anything that modifies an exposed class (e.g. SkPath) should be set
// after onRuntimeInitialized, otherwise, it can happen outside of that scope.
CanvasKit.onRuntimeInitialized = function() {
// All calls to 'this' need to go in externs.js so closure doesn't minify them away.
// Add some helpers for matrices. This is ported from SkMatrix.cpp
// to save complexity and overhead of going back and forth between
// C++ and JS layers.
CanvasKit.SkMatrix = {};
function sdot(a, b, c, d, e, f) {
e = e || 0;
f = f || 0;
return a * b + c * d + e * f;
}
// Return a matrix representing a rotation by n degrees.
// px, py optionally say which point the rotation should be around
// with the default being (0, 0);
CanvasKit.SkMatrix.rotated = function(degrees, px, py) {
px = px || 0;
py = py || 0;
var rad = degreesToRadians(degrees);
var sinV = Math.sin(rad);
var cosV = Math.cos(rad);
return [
cosV, -sinV, sdot( sinV, py, 1 - cosV, px),
sinV, cosV, sdot(-sinV, px, 1 - cosV, py),
0, 0, 1,
];
};
// TODO(kjlubick): translated, scaled
CanvasKit.SkPath.prototype.addArc = function(oval, startAngle, sweepAngle) {
// see arc() for the HTMLCanvas version
// note input angles are degrees.
this._addArc(oval, startAngle, sweepAngle);
return this;
};
CanvasKit.SkPath.prototype.addPath = function() {
// Takes 1, 2, 7, or 10 required args, where the first arg is always the path.
// The last arg is optional and chooses between add or extend mode.
// The options for the remaining args are:
// - an array of 6 or 9 parameters (perspective is optional)
// - the 9 parameters of a full matrix or
// the 6 non-perspective params of a matrix.
var args = Array.prototype.slice.call(arguments);
var path = args[0];
var extend = false;
if (typeof args[args.length-1] === "boolean") {
extend = args.pop();
}
if (args.length === 1) {
// Add path, unchanged. Use identity matrix
this._addPath(path, 1, 0, 0,
0, 1, 0,
0, 0, 1,
extend);
} else if (args.length === 2) {
// User provided the 9 params of a full matrix as an array.
var a = args[1];
this._addPath(path, a[0], a[1], a[2],
a[3], a[4], a[5],
a[6] || 0, a[7] || 0, a[8] || 1,
extend);
} else if (args.length === 7 || args.length === 10) {
// User provided the 9 params of a (full) matrix directly.
// (or just the 6 non perspective ones)
// These are in the same order as what Skia expects.
var a = args;
this._addPath(path, a[1], a[2], a[3],
a[4], a[5], a[6],
a[7] || 0, a[8] || 0, a[9] || 1,
extend);
} else {
console.error('addPath expected to take 1, 2, 7, or 10 required args. Got ' + args.length);
return null;
}
return this;
};
CanvasKit.SkPath.prototype.addRect = function() {
// Takes 1, 2, 4 or 5 args
// - SkRect
// - SkRect, isCCW
// - left, top, right, bottom
// - left, top, right, bottom, isCCW
if (arguments.length === 1 || arguments.length === 2) {
var r = arguments[0];
var ccw = arguments[1] || false;
this._addRect(r.fLeft, r.fTop, r.fRight, r.fBottom, ccw);
} else if (arguments.length === 4 || arguments.length === 5) {
var a = arguments;
this._addRect(a[0], a[1], a[2], a[3], a[4] || false);
} else {
console.error('addRect expected to take 1, 2, 4, or 5 args. Got ' + arguments.length);
return null;
}
return this;
};
CanvasKit.SkPath.prototype.arc = function(x, y, radius, startAngle, endAngle, ccw) {
// emulates the HTMLCanvas behavior. See addArc() for the SkPath version.
// Note input angles are radians.
var bounds = CanvasKit.LTRBRect(x-radius, y-radius, x+radius, y+radius);
var sweep = radiansToDegrees(endAngle - startAngle) - (360 * !!ccw);
var temp = new CanvasKit.SkPath();
temp.addArc(bounds, radiansToDegrees(startAngle), sweep);
this.addPath(temp, true);
temp.delete();
return this;
};
CanvasKit.SkPath.prototype.arcTo = function(x1, y1, x2, y2, radius) {
this._arcTo(x1, y1, x2, y2, radius);
return this;
};
CanvasKit.SkPath.prototype.close = function() {
this._close();
return this;
};
CanvasKit.SkPath.prototype.conicTo = function(x1, y1, x2, y2, w) {
this._conicTo(x1, y1, x2, y2, w);
return this;
};
CanvasKit.SkPath.prototype.cubicTo = function(cp1x, cp1y, cp2x, cp2y, x, y) {
this._cubicTo(cp1x, cp1y, cp2x, cp2y, x, y);
return this;
};
CanvasKit.SkPath.prototype.dash = function(on, off, phase) {
if (this._dash(on, off, phase)) {
return this;
}
return null;
};
CanvasKit.SkPath.prototype.lineTo = function(x, y) {
this._lineTo(x, y);
return this;
};
CanvasKit.SkPath.prototype.moveTo = function(x, y) {
this._moveTo(x, y);
return this;
};
CanvasKit.SkPath.prototype.op = function(otherPath, op) {
if (this._op(otherPath, op)) {
return this;
}
return null;
};
CanvasKit.SkPath.prototype.quadTo = function(cpx, cpy, x, y) {
this._quadTo(cpx, cpy, x, y);
return this;
};
CanvasKit.SkPath.prototype.simplify = function() {
if (this._simplify()) {
return this;
}
return null;
};
CanvasKit.SkPath.prototype.stroke = function(opts) {
// Fill out any missing values with the default values.
/**
* See externs.js for this definition
* @type {StrokeOpts}
*/
opts = opts || {};
opts.width = opts.width || 1;
opts.miter_limit = opts.miter_limit || 4;
opts.cap = opts.cap || CanvasKit.StrokeCap.BUTT;
opts.join = opts.join || CanvasKit.StrokeJoin.MITER;
if (this._stroke(opts)) {
return this;
}
return null;
};
CanvasKit.SkPath.prototype.transform = function() {
// Takes 1 or 9 args
if (arguments.length === 1) {
// argument 1 should be a 6 or 9 element array.
var a = arguments[0];
this._transform(a[0], a[1], a[2],
a[3], a[4], a[5],
a[6] || 0, a[7] || 0, a[8] || 1);
} else if (arguments.length === 6 || arguments.length === 9) {
// these arguments are the 6 or 9 members of the matrix
var a = arguments;
this._transform(a[0], a[1], a[2],
a[3], a[4], a[5],
a[6] || 0, a[7] || 0, a[8] || 1);
} else {
throw 'transform expected to take 1 or 9 arguments. Got ' + arguments.length;
}
return this;
};
// isComplement is optional, defaults to false
CanvasKit.SkPath.prototype.trim = function(startT, stopT, isComplement) {
if (this._trim(startT, stopT, !!isComplement)) {
return this;
}
return null;
};
// bones should be a 3d array.
// Each bone is a 3x2 transformation matrix in column major order:
// | scaleX skewX transX |
// | skewY scaleY transY |
// and bones is an array of those matrices.
// Returns a copy of this (SkVertices) with the bones applied.
CanvasKit.SkVertices.prototype.applyBones = function(bones) {
var bPtr = copy3dArray(bones, CanvasKit.HEAPF32);
var vert = this._applyBones(bPtr, bones.length);
CanvasKit._free(bPtr);
return vert;
}
CanvasKit.SkImage.prototype.encodeToData = function() {
if (arguments.length === 0) {
return this._encodeToData();
}
if (arguments.length === 2) {
var a = arguments;
return this._encodeToDataWithFormat(a[0], a[1]);
}
throw 'encodeToData expected to take 0 or 2 arguments. Got ' + arguments.length;
}
// Run through the JS files that are added at compile time.
if (CanvasKit._extraInitializations) {
CanvasKit._extraInitializations.forEach(function(init) {
init();
});
}
} // end CanvasKit.onRuntimeInitialized, that is, anything changing prototypes or dynamic.
CanvasKit.LTRBRect = function(l, t, r, b) {
return {
fLeft: l,
fTop: t,
fRight: r,
fBottom: b,
};
}
var nullptr = 0; // emscripten doesn't like to take null as uintptr_t
// arr can be a normal JS array or a TypedArray
// dest is something like CanvasKit.HEAPF32
function copy1dArray(arr, dest) {
if (!arr || !arr.length) {
return nullptr;
}
var ptr = CanvasKit._malloc(arr.length * dest.BYTES_PER_ELEMENT);
// 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.
dest.set(arr, ptr / dest.BYTES_PER_ELEMENT);
return ptr;
}
// arr should be a non-jagged 2d JS array (TypeyArrays can't be nested
// inside themselves.)
// dest is something like CanvasKit.HEAPF32
function copy2dArray(arr, dest) {
if (!arr || !arr.length) {
return nullptr;
}
var ptr = CanvasKit._malloc(arr.length * arr[0].length * dest.BYTES_PER_ELEMENT);
var idx = 0;
var adjustedPtr = ptr / dest.BYTES_PER_ELEMENT;
for (var r = 0; r < arr.length; r++) {
for (var c = 0; c < arr[0].length; c++) {
dest[adjustedPtr + idx] = arr[r][c];
idx++;
}
}
return ptr;
}
// arr should be a non-jagged 3d JS array (TypeyArrays can't be nested
// inside themselves.)
// dest is something like CanvasKit.HEAPF32
function copy3dArray(arr, dest) {
if (!arr || !arr.length || !arr[0].length) {
return nullptr;
}
var ptr = CanvasKit._malloc(arr.length * arr[0].length * arr[0][0].length * dest.BYTES_PER_ELEMENT);
var idx = 0;
var adjustedPtr = ptr / dest.BYTES_PER_ELEMENT;
for (var x = 0; x < arr.length; x++) {
for (var y = 0; y < arr[0].length; y++) {
for (var z = 0; z < arr[0][0].length; z++) {
dest[adjustedPtr + idx] = arr[x][y][z];
idx++;
}
}
}
return ptr;
}
CanvasKit.MakeSkDashPathEffect = function(intervals, phase) {
if (!phase) {
phase = 0;
}
if (!intervals.length || intervals.length % 2 === 1) {
throw 'Intervals array must have even length';
}
var ptr = copy1dArray(intervals, CanvasKit.HEAPF32);
var dpe = CanvasKit._MakeSkDashPathEffect(ptr, intervals.length, phase);
CanvasKit._free(ptr);
return dpe;
}
CanvasKit.MakeImageShader = function(imgData, xTileMode, yTileMode) {
var iptr = CanvasKit._malloc(imgData.byteLength);
CanvasKit.HEAPU8.set(new Uint8Array(imgData), iptr);
// No need to _free iptr, ImageShader takes it with SkData::MakeFromMalloc
return CanvasKit._MakeImageShader(iptr, imgData.byteLength, xTileMode, yTileMode);
}
CanvasKit.MakeLinearGradientShader = function(start, end, colors, pos, mode, localMatrix, flags) {
var colorPtr = copy1dArray(colors, CanvasKit.HEAP32);
var posPtr = copy1dArray(pos, CanvasKit.HEAPF32);
flags = flags || 0;
if (localMatrix) {
// Add perspective args if not provided.
if (localMatrix.length === 6) {
localMatrix.push(0, 0, 1);
}
var lgs = CanvasKit._MakeLinearGradientShader(start, end, colorPtr, posPtr,
colors.length, mode, flags, localMatrix);
} else {
var lgs = CanvasKit._MakeLinearGradientShader(start, end, colorPtr, posPtr,
colors.length, mode, flags);
}
CanvasKit._free(colorPtr);
CanvasKit._free(posPtr);
return lgs;
}
CanvasKit.MakeRadialGradientShader = function(center, radius, colors, pos, mode, localMatrix, flags) {
// TODO: matrix and flags
var colorPtr = copy1dArray(colors, CanvasKit.HEAP32);
var posPtr = copy1dArray(pos, CanvasKit.HEAPF32);
flags = flags || 0;
if (localMatrix) {
// Add perspective args if not provided.
if (localMatrix.length === 6) {
localMatrix.push(0, 0, 1);
}
var rgs = CanvasKit._MakeRadialGradientShader(center, radius, colorPtr, posPtr,
colors.length, mode, flags, localMatrix);
} else {
var rgs = CanvasKit._MakeRadialGradientShader(center, radius, colorPtr, posPtr,
colors.length, mode, flags);
}
CanvasKit._free(colorPtr);
CanvasKit._free(posPtr);
return rgs;
}
CanvasKit.MakeSkVertices = function(mode, positions, textureCoordinates, colors,
boneIndices, boneWeights, indices) {
var positionPtr = copy2dArray(positions, CanvasKit.HEAPF32);
var texPtr = copy2dArray(textureCoordinates, CanvasKit.HEAPF32);
// Since we write the colors to memory as signed integers (JSColor), we can
// read them out on the other side as unsigned ints (SkColor) just fine
// - it's effectively casting.
var colorPtr = copy1dArray(colors, CanvasKit.HEAP32);
var boneIdxPtr = copy2dArray(boneIndices, CanvasKit.HEAP32);
var boneWtPtr = copy2dArray(boneWeights, CanvasKit.HEAPF32);
var idxPtr = copy1dArray(indices, CanvasKit.HEAPU16);
var idxCount = (indices && indices.length) || 0;
// _MakeVertices will copy all the values in, so we are free to release
// the memory after.
var vertices = CanvasKit._MakeSkVertices(mode, positions.length, positionPtr,
texPtr, colorPtr, boneIdxPtr, boneWtPtr,
idxCount, idxPtr);
positionPtr && CanvasKit._free(positionPtr);
texPtr && CanvasKit._free(texPtr);
colorPtr && CanvasKit._free(colorPtr);
idxPtr && CanvasKit._free(idxPtr);
boneIdxPtr && CanvasKit._free(boneIdxPtr);
boneWtPtr && CanvasKit._free(boneWtPtr);
return vertices;
}
CanvasKit.MakeNimaActor = function(nimaFile, nimaTexture) {
var nptr = CanvasKit._malloc(nimaFile.byteLength);
CanvasKit.HEAPU8.set(new Uint8Array(nimaFile), nptr);
var tptr = CanvasKit._malloc(nimaTexture.byteLength);
CanvasKit.HEAPU8.set(new Uint8Array(nimaTexture), tptr);
// No need to _free these ptrs, NimaActor takes them with SkData::MakeFromMalloc
return CanvasKit._MakeNimaActor(nptr, nimaFile.byteLength, tptr, nimaTexture.byteLength);
}
}(Module)); // When this file is loaded in, the high level object is "Module";
// Intentionally added outside the scope to allow usage in canvas2d.js and other
// pre-js files. These names are unlikely to cause emscripten collisions.
function radiansToDegrees(rad) {
return (rad / Math.PI) * 180;
}
function degreesToRadians(deg) {
return (deg / 180) * Math.PI;
}