kallaballa
2 years ago
parent
edebe275b8
commit
cf2f777b6f
8 changed files with 254 additions and 14 deletions
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<!doctype html> |
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<html lang="en-us"> |
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<head> |
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<title>Display an Image through NanoVG</title> |
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<style> |
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body { |
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font-family: arial; |
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margin: 0; |
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padding: none; |
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} |
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.emscripten { padding-right: 0; margin-left: auto; margin-right: auto; display: block; } |
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div.emscripten { text-align: center; } |
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div.emscripten_border { border: 1px solid black; } |
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/* the canvas *must not* have any border or padding, or mouse coords will be wrong */ |
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canvas.emscripten { border: 0px none; background-color: black; } |
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.spinner { |
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height: 30px; |
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width: 30px; |
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margin: 0; |
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margin-top: 20px; |
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margin-left: 20px; |
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display: inline-block; |
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vertical-align: top; |
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-webkit-animation: rotation .8s linear infinite; |
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-moz-animation: rotation .8s linear infinite; |
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-o-animation: rotation .8s linear infinite; |
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animation: rotation 0.8s linear infinite; |
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border-left: 5px solid rgb(235, 235, 235); |
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border-right: 5px solid rgb(235, 235, 235); |
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border-bottom: 5px solid rgb(235, 235, 235); |
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border-top: 5px solid rgb(120, 120, 120); |
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border-radius: 100%; |
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background-color: rgb(189, 215, 46); |
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} |
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@-webkit-keyframes rotation { |
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from {-webkit-transform: rotate(0deg);} |
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to {-webkit-transform: rotate(360deg);} |
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} |
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@-moz-keyframes rotation { |
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from {-moz-transform: rotate(0deg);} |
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to {-moz-transform: rotate(360deg);} |
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} |
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@-o-keyframes rotation { |
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from {-o-transform: rotate(0deg);} |
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to {-o-transform: rotate(360deg);} |
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} |
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@keyframes rotation { |
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from {transform: rotate(0deg);} |
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to {transform: rotate(360deg);} |
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} |
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#status { |
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display: inline-block; |
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vertical-align: top; |
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margin-top: 30px; |
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margin-left: 20px; |
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font-weight: bold; |
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color: rgb(120, 120, 120); |
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} |
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#progress { |
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height: 20px; |
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width: 300px; |
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} |
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#output { |
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width: 100%; |
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height: 200px; |
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margin: 0 auto; |
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margin-top: 10px; |
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border-left: 0px; |
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border-right: 0px; |
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padding-left: 0px; |
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padding-right: 0px; |
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display: block; |
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color: white; |
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font-family: 'Lucida Console', Monaco, monospace; |
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outline: none; |
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} |
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</style> |
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</head> |
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<body> |
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<span id='controls'> |
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<span> |
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<button id="fullscreenBtn">Fullscreen</button> |
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</span> |
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</span> |
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<div class="emscripten" id="status">Downloading...</div> |
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<div class="emscripten"> |
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<progress value="0" max="100" id="progress" hidden=1></progress> |
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</div> |
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<canvas id="v4dOffscreenCanvas" style="display:none;"></canvas> |
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<div class="emscripten_border"> |
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<canvas class="emscripten" id="canvas" oncontextmenu="event.preventDefault()" tabindex=-1></canvas> |
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</div> |
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<script type='text/javascript'> |
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var statusElement = document.getElementById('status'); |
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var progressElement = document.getElementById('progress'); |
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var fsButton = document.querySelector("#fullscreenBtn"); |
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var offscreenCanvas = document.querySelector("#v4dOffscreenCanvas"); |
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var width = 960; |
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var height = 960; |
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function fixCanvasSize() { |
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Module.canvas.style.width = (width / window.devicePixelRatio) + "px"; |
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Module.canvas.style.height = (height / window.devicePixelRatio) + "px"; |
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Module.canvas.width = width; |
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Module.canvas.height = height; |
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offscreenCanvas.style.width = (width / window.devicePixelRatio) + "px"; |
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offscreenCanvas.style.height = (height / window.devicePixelRatio) + "px"; |
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offscreenCanvas.width = width; |
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offscreenCanvas.height = height; |
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} |
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var Module = { |
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onRuntimeInitialized: function() { |
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fixCanvasSize(); |
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}, |
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preRun: [], |
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postRun: [], |
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print: (function() { |
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var element = document.getElementById('output'); |
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if (element) element.value = ''; // clear browser cache |
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return function(text) { |
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if (arguments.length > 1) text = Array.prototype.slice.call(arguments).join(' '); |
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// These replacements are necessary if you render to raw HTML |
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//text = text.replace(/&/g, "&"); |
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//text = text.replace(/</g, "<"); |
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//text = text.replace(/>/g, ">"); |
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//text = text.replace('\n', '<br>', 'g'); |
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console.log(text); |
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if (element) { |
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element.value += text + "\n"; |
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element.scrollTop = element.scrollHeight; // focus on bottom |
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} |
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}; |
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})(), |
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printErr: function(text) { |
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if (arguments.length > 1) text = Array.prototype.slice.call(arguments).join(' '); |
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console.error(text); |
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}, |
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canvas: (function() { |
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var canvas = document.getElementById('canvas'); |
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// As a default initial behavior, pop up an alert when webgl context is lost. To make your |
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// application robust, you may want to override this behavior before shipping! |
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// See http://www.khronos.org/registry/webgl/specs/latest/1.0/#5.15.2 |
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canvas.addEventListener("webglcontextlost", function(e) { alert('WebGL context lost. You will need to reload the page.'); e.preventDefault(); }, false); |
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return canvas; |
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})(), |
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setStatus: function(text) { |
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if (!Module.setStatus.last) Module.setStatus.last = { time: Date.now(), text: '' }; |
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if (text === Module.setStatus.last.text) return; |
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var m = text.match(/([^(]+)\((\d+(\.\d+)?)\/(\d+)\)/); |
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var now = Date.now(); |
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if (m && now - Module.setStatus.last.time < 30) return; // if this is a progress update, skip it if too soon |
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Module.setStatus.last.time = now; |
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Module.setStatus.last.text = text; |
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if (m) { |
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text = m[1]; |
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progressElement.value = parseInt(m[2])*100; |
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progressElement.max = parseInt(m[4])*100; |
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progressElement.hidden = false; |
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} else { |
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progressElement.value = null; |
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progressElement.max = null; |
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progressElement.hidden = true; |
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} |
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statusElement.innerHTML = text; |
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}, |
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totalDependencies: 0, |
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monitorRunDependencies: function(left) { |
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this.totalDependencies = Math.max(this.totalDependencies, left); |
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Module.setStatus(left ? 'Preparing... (' + (this.totalDependencies-left) + '/' + this.totalDependencies + ')' : 'All downloads complete.'); |
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} |
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}; |
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Module.setStatus('Downloading...'); |
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window.onerror = function(event) { |
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// TODO: do not warn on ok events like simulating an infinite loop or exitStatus |
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Module.setStatus('Exception thrown, see JavaScript console'); |
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//spinnerElement.style.display = 'none'; |
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Module.setStatus = function(text) { |
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if (text) Module.printErr('[post-exception status] ' + text); |
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}; |
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}; |
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fsButton.addEventListener('click', async function () { |
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Module.requestFullscreen(false, false) |
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}); |
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window.addEventListener('fullscreenchange', function (event) { |
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if (document.fullscreenElement) { |
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console.log("Element: " + document.fullscreenElement.id + " entered fullscreen mode."); |
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} else { |
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console.log('Leaving fullscreen mode.'); |
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} |
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}); |
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</script> |
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<script type="text/javascript" src="example_v4d_display_image_nvg.js" defer></script> |
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</body> |
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</html> |
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@ -0,0 +1,16 @@ |
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# Display an image using NanoVG {#v4d_display_image_nvg} |
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@prev_tutorial{v4d_display_image_fb} |
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@next_tutorial{v4d_vector_graphics} |
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| | | |
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| -: | :- | |
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| Original author | Amir Hassan (kallaballa) <amir@viel-zu.org> | |
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| Compatibility | OpenCV >= 4.7 | |
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## Using NanoVG to display images |
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Instead of feeding to the video pipeline or doing a direct framebuffer access we can use NanoVG to display an image. It is not as convinient as the other methods but it is very fast and flexible. |
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\htmlinclude "../samples/example_v4d_display_image_nvg.html" |
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@include samples/display_image_nvg.cpp |
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