pixel-editor/js/_loadPalette.js
2020-04-12 10:58:19 +02:00

51 lines
2.2 KiB
JavaScript

//this is called when a user picks a file after selecting "load palette" from the new pixel dialogue
document.getElementById('load-palette-browse-holder').addEventListener('change', function () {
if (this.files && this.files[0]) {
//make sure file is allowed filetype
var fileContentType = this.files[0].type;
if (fileContentType == 'image/png' || fileContentType == 'image/gif') {
//load file
var fileReader = new FileReader();
fileReader.onload = function(e) {
var img = new Image();
img.onload = function() {
//draw image onto the temporary canvas
var loadPaletteCanvas = document.getElementById('load-palette-canvas-holder');
var loadPaletteContext = loadPaletteCanvas.getContext('2d');
loadPaletteCanvas.width = img.width;
loadPaletteCanvas.height = img.height;
loadPaletteContext.drawImage(img, 0, 0);
//create array to hold found colors
var colorPalette = [];
var imagePixelData = loadPaletteContext.getImageData(0,0,this.width, this.height).data;
console.log(imagePixelData);
//loop through pixels looking for colors to add to palette
for (var i = 0; i < imagePixelData.length; i += 4) {
var color = '#'+rgbToHex(imagePixelData[i],imagePixelData[i + 1],imagePixelData[i + 2]);
if (colorPalette.indexOf(color) == -1) {
colorPalette.push(color);
}
}
//add to palettes so that it can be loaded when they click okay
palettes['Loaded palette'] = {};
palettes['Loaded palette'].colors = colorPalette;
setText('palette-button', 'Loaded palette');
};
img.src = e.target.result;
};
fileReader.readAsDataURL(this.files[0]);
}
else alert('Only PNG and GIF files are supported at this time.');
}
});