Mercurial > hg > orthanc-stone
diff Platforms/WebAssembly/wasm-viewport.js @ 223:d30a10d574ec am
refactoring continued - not working
author | am@osimis.io |
---|---|
date | Thu, 14 Jun 2018 10:57:02 +0200 |
parents | |
children |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Platforms/WebAssembly/wasm-viewport.js Thu Jun 14 10:57:02 2018 +0200 @@ -0,0 +1,197 @@ +// http://stackoverflow.com/a/28900478/881731 + +function WebAssemblyViewport(module, canvasId) { + this.module = module; + + // Obtain a reference to the canvas element using its id + this.htmlCanvas = document.getElementById(canvasId); + + // Obtain a graphics context on the canvas element for drawing. + this.context = htmlCanvas.getContext('2d'); + + // ImageData structure that can be used to update the content of the canvas + this.imageData = null; + + // Temporary buffer in the WebAssembly heap that is used to render the pixels + this.renderingBuffer = null; + + // Get access to the WebAssembly functions + this.ViewportSetSize = this.module.cwrap('ViewportSetSize', null, [ 'number', 'number' ]); + this.ViewportRender = this.module.cwrap('ViewportRender', 'number', [ 'number', 'number', 'number' ]); + this.ViewportMouseDown = this.module.cwrap('ViewportMouseDown', null, [ 'number', 'number', 'number', 'number' ]); + this.ViewportMouseMove = this.module.cwrap('ViewportMouseMove', null, [ 'number', 'number' ]); + this.ViewportMouseUp = this.module.cwrap('ViewportMouseUp', null, [ ]); + this.ViewportMouseEnter = this.module.cwrap('ViewportMouseEnter', null, []); + this.ViewportMouseLeave = this.module.cwrap('ViewportMouseLeave', null, []); + this.ViewportMouseWheel = this.module.cwrap('ViewportMouseWheel', null, [ 'number', 'number', 'number', 'number' ]); + this.ViewportKeyPressed = this.module.cwrap('ViewportKeyPressed', null, [ 'string', 'number', 'number' ]); + + this.Redraw = function() { + if (this.imageData === null || + this.renderingBuffer === null || + ViewportRender(this.imageData.width, + this.imageData.height, + this.renderingBuffer) == 0) { + console.log('The rendering has failed'); + } else { + // Create an accessor to the rendering buffer (i.e. create a + // "window" above the heap of the WASM module), then copy it to + // the ImageData object + this.imageData.data.set(new Uint8ClampedArray( + this.module.buffer, + this.renderingBuffer, + this.imageData.width * this.imageData.height * 4)); + + this.context.putImageData(imageData, 0, 0); + } + } + + this.Resize = function() { + if (this.imageData != null && + (this.imageData.width != this.window.innerWidth || + this.imageData.height != this.window.innerHeight)) { + this.imageData = null; + } + + this.htmlCanvas.width = window.innerWidth; + this.htmlCanvas.height = window.innerHeight; + + if (this.imageData === null) { + this.imageData = context.getImageData(0, 0, this.htmlCanvas.width, this.htmlCanvas.height); + ViewportSetSize(this.htmlCanvas.width, this.htmlCanvas.height); + + if (this.renderingBuffer != null) { + this.module._free(this.renderingBuffer); + } + + renderingBuffer = this.module._malloc(this.imageData.width * this.imageData.height * 4); + } + + this.Redraw(); + } + + // Force the rendering of the viewport for the first time + this.Resize(); + + // Register an event listener to call the Resize() function + // each time the window is resized. + window.addEventListener('resize', this.Resize, false); + + var that = this; + + this.htmlCanvas.addEventListener('contextmenu', function(event) { + // Prevent right click on the canvas + event.preventDefault(); + }, false); + + this.htmlCanvas.addEventListener('mouseleave', function(event) { + that.ViewportMouseLeave(); + }); + + this.htmlCanvas.addEventListener('mouseenter', function(event) { + that.ViewportMouseEnter(); + }); + + this.htmlCanvas.addEventListener('mousedown', function(event) { + var x = event.pageX - this.offsetLeft; + var y = event.pageY - this.offsetTop; + that.ViewportMouseDown(event.button, x, y, 0 /* TODO */); + }); + + this.htmlCanvas.addEventListener('mousemove', function(event) { + var x = event.pageX - this.offsetLeft; + var y = event.pageY - this.offsetTop; + that.ViewportMouseMove(x, y); + }); + + this.htmlCanvas.addEventListener('mouseup', function(event) { + that.ViewportMouseUp(); + }); + + window.addEventListener('keydown', function(event) { + that.ViewportKeyPressed(event.key, event.shiftKey, event.ctrlKey, event.altKey); + }); + + this.htmlCanvas.addEventListener('wheel', function(event) { + var x = event.pageX - this.offsetLeft; + var y = event.pageY - this.offsetTop; + that.ViewportMouseWheel(event.deltaY, x, y, event.ctrlKey); + event.preventDefault(); + }); + + + // Touch events + this.touchTranslation = false; + this.touchZoom = false; + + this.ResetTouch = function() { + if (this.touchTranslation || + this.touchZoom) { + this.ViewportMouseUp(); + } + + this.touchTranslation = false; + this.touchZoom = false; + } + + this.GetTouchTranslation = function(event) { + var touch = event.targetTouches[0]; + return [ + touch.pageX, + touch.pageY + ]; + } + + this.GetTouchZoom = function(event) { + var touch1 = event.targetTouches[0]; + var touch2 = event.targetTouches[1]; + var dx = (touch1.pageX - touch2.pageX); + var dy = (touch1.pageY - touch2.pageY); + var d = Math.sqrt(dx * dx + dy * dy); + return [ + (touch1.pageX + touch2.pageX) / 2.0, + (touch1.pageY + touch2.pageY) / 2.0, + d + ]; + } + + this.htmlCanvas.addEventListener('touchstart', function(event) { + ResetTouch(); + }); + + this.htmlCanvas.addEventListener('touchend', function(event) { + ResetTouch(); + }); + + this.htmlCanvas.addEventListener('touchmove', function(event) { + if (that.touchTranslation.length == 2) { + var t = GetTouchTranslation(event); + that.ViewportMouseMove(t[0], t[1]); + } + else if (that.touchZoom.length == 3) { + var z0 = that.touchZoom; + var z1 = GetTouchZoom(event); + that.ViewportMouseMove(z0[0], z0[1] - z0[2] + z1[2]); + } + else { + // Realize the gesture event + if (event.targetTouches.length == 1) { + // Exactly one finger inside the canvas => Setup a translation + that.touchTranslation = GetTouchTranslation(event); + that.ViewportMouseDown(1 /* middle button */, + that.touchTranslation[0], + that.touchTranslation[1], 0); + } else if (event.targetTouches.length == 2) { + // Exactly 2 fingers inside the canvas => Setup a pinch/zoom + that.touchZoom = GetTouchZoom(event); + var z0 = that.touchZoom; + that.ViewportMouseDown(2 /* right button */, + z0[0], + z0[1], 0); + } + } + }); + + return this; + } + \ No newline at end of file