pixel-editor/js/_fill.js
2021-06-28 22:03:57 +02:00

108 lines
4.4 KiB
JavaScript

function fill(cursorLocation) {
//changes a pixels color
function colorPixel(tempImage, pixelPos, fillColor) {
//console.log('colorPixel:',pixelPos);
tempImage.data[pixelPos] = fillColor.r;
tempImage.data[pixelPos + 1] = fillColor.g;
tempImage.data[pixelPos + 2] = fillColor.b;
tempImage.data[pixelPos + 3] = 255;
}
//change x y to color value passed from the function and use that as the original color
function matchStartColor(tempImage, pixelPos, color) {
//console.log('matchPixel:',x,y)
var r = tempImage.data[pixelPos];
var g = tempImage.data[pixelPos + 1];
var b = tempImage.data[pixelPos + 2];
var a = tempImage.data[pixelPos + 3];
//console.log(r == color[0] && g == color[1] && b == color[2]);
return (r == color[0] && g == color[1] && b == color[2] && a == color[3]);
}
//save history state
new HistoryStateEditCanvas();
//saveHistoryState({type: 'canvas', canvas: context.getImageData(0, 0, canvasSize[0], canvasSize[1])});
//console.log('filling at '+ Math.floor(cursorLocation[0]/zoom) + ','+ Math.floor(cursorLocation[1]/zoom));
//temporary image holds the data while we change it
var tempImage = currentLayer.context.getImageData(0, 0, canvasSize[0], canvasSize[1]);
//this is an array that holds all of the pixels at the top of the cluster
var topmostPixelsArray = [[Math.floor(cursorLocation[0]/zoom), Math.floor(cursorLocation[1]/zoom)]];
//console.log('topmostPixelsArray:',topmostPixelsArray)
//the offset of the pixel in the temp image data to start with
var startingPosition = (topmostPixelsArray[0][1] * canvasSize[0] + topmostPixelsArray[0][0]) * 4;
//the color of the cluster that is being filled
var clusterColor = [tempImage.data[startingPosition],tempImage.data[startingPosition+1],tempImage.data[startingPosition+2], tempImage.data[startingPosition+3]];
//the new color to fill with
var fillColor = hexToRgb(currentLayer.context.fillStyle);
//if you try to fill with the same color that's already there, exit the function
if (clusterColor[0] == fillColor.r &&
clusterColor[1] == fillColor.g &&
clusterColor[2] == fillColor.b &&
clusterColor[3] == fillColor.a)
return;
//loop until there are no more values left in this array
while (topmostPixelsArray.length) {
var reachLeft, reachRight;
//move the most recent pixel from the array and set it as our current working pixels
var currentPixel = topmostPixelsArray.pop();
//set the values of this pixel to x/y variables just for readability
var x = currentPixel[0];
var y = currentPixel[1];
//this variable holds the index of where the starting values for the current pixel are in the data array
//we multiply the number of rows down (y) times the width of each row, then add x. at the end we multiply by 4 because
//each pixel has 4 values, rgba
var pixelPos = (y * canvasSize[0] + x) * 4;
//move up in the image until you reach the top or the pixel you hit was not the right color
while (y-- >= 0 && matchStartColor(tempImage, pixelPos, clusterColor)) {
pixelPos -= canvasSize[0] * 4;
}
pixelPos += canvasSize[0] * 4;
++y;
reachLeft = false;
reachRight = false;
while (y++ < canvasSize[1] - 1 && matchStartColor(tempImage, pixelPos, clusterColor)) {
colorPixel(tempImage, pixelPos, fillColor);
if (x > 0) {
if (matchStartColor(tempImage, pixelPos - 4, clusterColor)) {
if (!reachLeft) {
topmostPixelsArray.push([x - 1, y]);
reachLeft = true;
}
}
else if (reachLeft) {
reachLeft = false;
}
}
if (x < canvasSize[0] - 1) {
if (matchStartColor(tempImage, pixelPos + 4, clusterColor)) {
if (!reachRight) {
topmostPixelsArray.push([x + 1, y]);
reachRight = true;
}
}
else if (reachRight) {
reachRight = false;
}
}
pixelPos += canvasSize[0] * 4;
}
}
currentLayer.context.putImageData(tempImage, 0, 0);
//console.log('done filling')
}