diff --git a/Recursive/FloodFill.js b/Recursive/FloodFill.js index 33ea6025ad..5143b8f4ff 100644 --- a/Recursive/FloodFill.js +++ b/Recursive/FloodFill.js @@ -9,7 +9,7 @@ * @see https://www.techiedelight.com/flood-fill-algorithm/ */ -const neighbors = [ +const neighborOffsets = [ [-1, -1], [-1, 0], [-1, 1], @@ -20,6 +20,27 @@ const neighbors = [ [1, 1] ] +function isInside(rgbData, location) { + const x = location[0] + const y = location[1] + return x >= 0 && x < rgbData.length && y >= 0 && y < rgbData[0].length +} + +function checkLocation(rgbData, location) { + if (!isInside(rgbData, location)) { + throw new Error('location should point to a pixel within the rgbData') + } +} + +function* neighbors(rgbData, location) { + for (const offset of neighborOffsets) { + const neighborLocation = [location[0] + offset[0], location[1] + offset[1]] + if (isInside(rgbData, neighborLocation)) { + yield neighborLocation + } + } +} + /** * Implements the flood fill algorithm through a breadth-first approach using a queue. * @@ -34,14 +55,7 @@ export function breadthFirstSearch( targetColor, replacementColor ) { - if ( - location[0] < 0 || - location[0] >= rgbData.length || - location[1] < 0 || - location[1] >= rgbData[0].length - ) { - throw new Error('location should point to a pixel within the rgbData') - } + checkLocation(rgbData, location) const queue = [] queue.push(location) @@ -65,14 +79,7 @@ export function depthFirstSearch( targetColor, replacementColor ) { - if ( - location[0] < 0 || - location[0] >= rgbData.length || - location[1] < 0 || - location[1] >= rgbData[0].length - ) { - throw new Error('location should point to a pixel within the rgbData') - } + checkLocation(rgbData, location) depthFirstFill(rgbData, location, targetColor, replacementColor) } @@ -98,13 +105,8 @@ function breadthFirstFill( if (rgbData[currentLocation[0]][currentLocation[1]] === targetColor) { rgbData[currentLocation[0]][currentLocation[1]] = replacementColor - - for (let i = 0; i < neighbors.length; i++) { - const x = currentLocation[0] + neighbors[i][0] - const y = currentLocation[1] + neighbors[i][1] - if (x >= 0 && x < rgbData.length && y >= 0 && y < rgbData[0].length) { - queue.push([x, y]) - } + for (const neighborLocation of neighbors(rgbData, currentLocation)) { + queue.push(neighborLocation) } } } @@ -120,13 +122,8 @@ function breadthFirstFill( function depthFirstFill(rgbData, location, targetColor, replacementColor) { if (rgbData[location[0]][location[1]] === targetColor) { rgbData[location[0]][location[1]] = replacementColor - - for (let i = 0; i < neighbors.length; i++) { - const x = location[0] + neighbors[i][0] - const y = location[1] + neighbors[i][1] - if (x >= 0 && x < rgbData.length && y >= 0 && y < rgbData[0].length) { - depthFirstFill(rgbData, [x, y], targetColor, replacementColor) - } + for (const neighborLocation of neighbors(rgbData, location)) { + depthFirstFill(rgbData, neighborLocation, targetColor, replacementColor) } } } diff --git a/Recursive/test/FloodFill.test.js b/Recursive/test/FloodFill.test.js index 291788addd..618692dd97 100644 --- a/Recursive/test/FloodFill.test.js +++ b/Recursive/test/FloodFill.test.js @@ -21,6 +21,19 @@ describe('FloodFill', () => { }) }) +describe.each([breadthFirstSearch, depthFirstSearch])('%o', (floodFillFun) => { + it.each([ + [1, -1], + [-1, 1], + [0, 7], + [7, 0] + ])('throws for start position [%i, %i]', (location) => { + expect(() => + floodFillFun(generateTestRgbData(), location, green, orange) + ).toThrowError() + }) +}) + /** * Utility-function to test the function "breadthFirstSearch". *