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rgba2rgb
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| <!DOCTYPE html> | |
| <html> | |
| <head> | |
| <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> | |
| <title>Convert RGBA to RGB</title> | |
| <style> | |
| #divrgba, #divresult { | |
| width: 120%; | |
| padding: 8px; | |
| } | |
| keyword { | |
| color: rgb(255, 0, 200); | |
| } | |
| literal { | |
| color: rgb(42, 42, 200); | |
| } | |
| </style> | |
| </head> | |
| <body> | |
| <div id="divbg" style="padding: 10px; width: 80%"> | |
| RGB_background | |
| <input id='hex_bg' value="#af9" oninput="recalculate()"/> | |
| <input id='rgb_bg' oninput="hex_bg.value = '#' + this.value.split(',').map(x => (+x).toString(16).padStart(2,0)).join(''); recalculate()"/> | |
| <div id="divrgba"> | |
| RGBA_color | |
| <input id='hex_rgba' oninput="recalculate()" value="#4446"/> | |
| <input id='rgb_rgba' onchange="[r, g, b, a] = rgb_rgba.value.split(','); hex_rgba.value = '#' + [r, g, b, Math.round(a*255)].map(x => (+x).toString(16).padStart(2,0)).join(''); recalculate()"/> | |
| </div> | |
| <div id="divresult"> | |
| RGB_result | |
| <input id="hex_result" readonly=""> | |
| <input id="rgb_result" readonly=""> | |
| </div> | |
| </div> | |
| <h3>Source code</h3> | |
| <pre><keyword>function</keyword> rgba2rgb(RGB_background, RGBA_color) { | |
| <keyword>var</keyword> alpha = RGBA_color.a; | |
| <keyword>return new</keyword> Color( | |
| (<literal>1</literal> - alpha) * RGB_background.r + alpha * RGBA_color.r, | |
| (<literal>1</literal> - alpha) * RGB_background.g + alpha * RGBA_color.g, | |
| (<literal>1</literal> - alpha) * RGB_background.b + alpha * RGBA_color.b | |
| ); | |
| }</pre> | |
| </body> | |
| <script> | |
| function Color(r, g, b, a) { | |
| col = {} | |
| col.r = r; | |
| col.g = g; | |
| col.b = b; | |
| col.a = typeof +a == "number" ? a : 1; | |
| return col; | |
| } | |
| rgba2rgb = function (background, rgba) { | |
| var alpha = rgba.a; | |
| return [(1-alpha) * background.r + alpha * rgba.r, | |
| (1-alpha) * background.g + alpha * rgba.g, | |
| (1-alpha) * background.b + alpha * rgba.b] | |
| }; | |
| function recalculate() { | |
| divbg.style.backgroundColor = hex_bg.value; | |
| rgb_bg.value = divbg.style.backgroundColor.split(/[()]/)[1] | |
| divrgba.style.backgroundColor = hex_rgba.value; | |
| rgb_rgba.value = divrgba.style.backgroundColor.split(/[()]/)[1] | |
| rgb = Color(...rgb_bg.value.split(",")); | |
| rgba = Color(...rgb_rgba.value.split(",")); | |
| divresult.style.backgroundColor = hex_result.value = "#"+rgba2rgb(rgb, rgba).map(x => Math.round(x).toString(16).padStart(2,0)).join('') | |
| rgb_result.value = divresult.style.backgroundColor.split(/[()]/)[1] | |
| } | |
| recalculate(); | |
| </script> | |
| </html> |
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Preview: https://gistpreview.github.io/?943ce68c9c84d662cea1ecd42bc3064b
Original: https://marcodiiga.github.io/rgba2rgb/rgba2rgb.html