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      1 // Adds compile-time JS functions to augment the CanvasKit interface.
      2 // Specifically, anything that should only be on the CPU version of canvaskit.
      3 (function(CanvasKit){
      4   CanvasKit._extraInitializations = CanvasKit._extraInitializations || [];
      5   CanvasKit._extraInitializations.push(function() {
      6     // Takes in an html id or a canvas element
      7     CanvasKit.MakeSWCanvasSurface = function(idOrElement) {
      8         var canvas = idOrElement;
      9         if (canvas.tagName !== 'CANVAS') {
     10           canvas = document.getElementById(idOrElement);
     11           if (!canvas) {
     12             throw 'Canvas with id ' + idOrElement + ' was not found';
     13           }
     14         }
     15       // Maybe better to use clientWidth/height.  See:
     16       // https://webglfundamentals.org/webgl/lessons/webgl-anti-patterns.html
     17       var surface = CanvasKit.MakeSurface(canvas.width, canvas.height);
     18       if (surface) {
     19         surface._canvas = canvas;
     20       }
     21       return surface;
     22     };
     23 
     24     // Don't over-write the MakeCanvasSurface set by gpu.js if it exists.
     25     if (!CanvasKit.MakeCanvasSurface) {
     26       CanvasKit.MakeCanvasSurface = CanvasKit.MakeSWCanvasSurface;
     27     }
     28 
     29     CanvasKit.MakeSurface = function(width, height) {
     30       /* @dict */
     31       var imageInfo = {
     32         'width':  width,
     33         'height': height,
     34         'colorType': CanvasKit.ColorType.RGBA_8888,
     35         // Since we are sending these pixels directly into the HTML canvas,
     36         // (and those pixels are un-premultiplied, i.e. straight r,g,b,a)
     37         'alphaType': CanvasKit.AlphaType.Unpremul,
     38       }
     39       var pixelLen = width * height * 4; // it's 8888, so 4 bytes per pixel
     40       // Allocate the buffer of pixels to be drawn into.
     41       var pixelPtr = CanvasKit._malloc(pixelLen);
     42 
     43       var surface = this._getRasterDirectSurface(imageInfo, pixelPtr, width*4);
     44       if (surface) {
     45         surface._canvas = null;
     46         surface._width = width;
     47         surface._height = height;
     48         surface._pixelLen = pixelLen;
     49 
     50         surface._pixelPtr = pixelPtr;
     51         // rasterDirectSurface does not initialize the pixels, so we clear them
     52         // to transparent black.
     53         surface.getCanvas().clear(CanvasKit.TRANSPARENT);
     54       }
     55       return surface;
     56     };
     57 
     58     CanvasKit.SkSurface.prototype.flush = function() {
     59       this._flush();
     60       // Do we have an HTML canvas to write the pixels to?
     61       // We will not if this a GPU build or a raster surface, for example.
     62       if (this._canvas) {
     63         var pixels = new Uint8ClampedArray(CanvasKit.buffer, this._pixelPtr, this._pixelLen);
     64         var imageData = new ImageData(pixels, this._width, this._height);
     65 
     66         this._canvas.getContext('2d').putImageData(imageData, 0, 0);
     67       }
     68     };
     69 
     70     // Call dispose() instead of delete to clean up the underlying memory
     71     CanvasKit.SkSurface.prototype.dispose = function() {
     72       if (this._pixelPtr) {
     73         CanvasKit._free(this._pixelPtr);
     74       }
     75       this.delete();
     76     }
     77 
     78     CanvasKit.currentContext = CanvasKit.currentContext || function() {
     79       // no op if this is a cpu-only build.
     80     };
     81 
     82     CanvasKit.setCurrentContext = CanvasKit.setCurrentContext || function() {
     83        // no op if this is a cpu-only build.
     84     };
     85   });
     86 }(Module)); // When this file is loaded in, the high level object is "Module";
     87