| // Adds compile-time JS functions to augment the CanvasKit interface. |
| // Specifically, anything that should only be on the GPU version of canvaskit. |
| // Functions in this file are supplemented by cpu.js. |
| (function(CanvasKit){ |
| CanvasKit._extraInitializations = CanvasKit._extraInitializations || []; |
| CanvasKit._extraInitializations.push(function() { |
| function get(obj, attr, defaultValue) { |
| if (obj && obj.hasOwnProperty(attr)) { |
| return obj[attr]; |
| } |
| return defaultValue; |
| } |
| |
| CanvasKit.GetWebGLContext = function(canvas, attrs) { |
| if (!canvas) { |
| throw 'null canvas passed into makeWebGLContext'; |
| } |
| var contextAttributes = { |
| 'alpha': get(attrs, 'alpha', 1), |
| 'depth': get(attrs, 'depth', 1), |
| 'stencil': get(attrs, 'stencil', 8), |
| 'antialias': get(attrs, 'antialias', 0), |
| 'premultipliedAlpha': get(attrs, 'premultipliedAlpha', 1), |
| 'preserveDrawingBuffer': get(attrs, 'preserveDrawingBuffer', 0), |
| 'preferLowPowerToHighPerformance': get(attrs, 'preferLowPowerToHighPerformance', 0), |
| 'failIfMajorPerformanceCaveat': get(attrs, 'failIfMajorPerformanceCaveat', 0), |
| 'enableExtensionsByDefault': get(attrs, 'enableExtensionsByDefault', 1), |
| 'explicitSwapControl': get(attrs, 'explicitSwapControl', 0), |
| 'renderViaOffscreenBackBuffer': get(attrs, 'renderViaOffscreenBackBuffer', 0), |
| }; |
| |
| if (attrs && attrs['majorVersion']) { |
| contextAttributes['majorVersion'] = attrs['majorVersion'] |
| } else { |
| // Default to WebGL 2 if available and not specified. |
| contextAttributes['majorVersion'] = (typeof WebGL2RenderingContext !== 'undefined') ? 2 : 1; |
| } |
| |
| // This check is from the emscripten version |
| if (contextAttributes['explicitSwapControl']) { |
| throw 'explicitSwapControl is not supported'; |
| } |
| // Creates a WebGL context and sets it to be the current context. |
| // These functions are defined in emscripten's library_webgl.js |
| var handle = GL.createContext(canvas, contextAttributes); |
| if (!handle) { |
| return 0; |
| } |
| GL.makeContextCurrent(handle); |
| return handle; |
| }; |
| |
| CanvasKit.deleteContext = function(handle) { |
| GL.deleteContext(handle); |
| }; |
| |
| // idOrElement can be of types: |
| // - String - in which case it is interpreted as an id of a |
| // canvas element. |
| // - HTMLCanvasElement - in which the provided canvas element will |
| // be used directly. |
| // colorSpace - sk_sp<ColorSpace> - one of the supported color spaces: |
| // CanvasKit.ColorSpace.SRGB |
| // CanvasKit.ColorSpace.DISPLAY_P3 |
| // CanvasKit.ColorSpace.ADOBE_RGB |
| CanvasKit.MakeWebGLCanvasSurface = function(idOrElement, colorSpace, attrs) { |
| colorSpace = colorSpace || null; |
| var canvas = idOrElement; |
| var isHTMLCanvas = typeof HTMLCanvasElement !== 'undefined' && canvas instanceof HTMLCanvasElement; |
| var isOffscreenCanvas = typeof OffscreenCanvas !== 'undefined' && canvas instanceof OffscreenCanvas; |
| if (!isHTMLCanvas && !isOffscreenCanvas) { |
| canvas = document.getElementById(idOrElement); |
| if (!canvas) { |
| throw 'Canvas with id ' + idOrElement + ' was not found'; |
| } |
| } |
| |
| var ctx = this.GetWebGLContext(canvas, attrs); |
| if (!ctx || ctx < 0) { |
| throw 'failed to create webgl context: err ' + ctx; |
| } |
| |
| var grcontext = this.MakeGrContext(ctx); |
| |
| // Note that canvas.width/height here is used because it gives the size of the buffer we're |
| // rendering into. This may not be the same size the element is displayed on the page, which |
| // constrolled by css, and available in canvas.clientWidth/height. |
| var surface = this.MakeOnScreenGLSurface(grcontext, canvas.width, canvas.height, colorSpace); |
| if (!surface) { |
| Debug('falling back from GPU implementation to a SW based one'); |
| // we need to throw away the old canvas (which was locked to |
| // a webGL context) and create a new one so we can |
| var newCanvas = canvas.cloneNode(true); |
| var parent = canvas.parentNode; |
| parent.replaceChild(newCanvas, canvas); |
| // add a class so the user can detect that it was replaced. |
| newCanvas.classList.add('ck-replaced'); |
| |
| return CanvasKit.MakeSWCanvasSurface(newCanvas); |
| } |
| surface._context = ctx; |
| surface.grContext = grcontext; |
| surface.openGLversion = canvas.GLctxObject.version; |
| return surface; |
| }; |
| // Default to trying WebGL first. |
| CanvasKit.MakeCanvasSurface = CanvasKit.MakeWebGLCanvasSurface; |
| }); |
| }(Module)); // When this file is loaded in, the high level object is "Module"; |