Bind callback to image instance (#1335)

* Misc doc updates

* Bind scan callbacks

packages/utils/src/index.test.ts

@@ -1,40 +1,41 @@
 import { expect, test, describe } from "vitest";
 
-import { colorDiff } from "./index.js";
+import { colorDiff, scan } from "./index.js";
+import { JimpClass } from "@jimp/types";
 
 // Convert [0..1] float to a percent value with only one decimal.
 const pct = (n: number) => ((n * 1000) << 0) / 10;
 
 describe("colorDiff", () => {
   test("totally opaque (no alpha defined)", () => {
     expect(colorDiff({ r: 255, g: 0, b: 0 }, { r: 255, g: 0, b: 0 })).toEqual(
-      0,
+      0
     );
 
     expect(
-      pct(colorDiff({ r: 255, g: 0, b: 0 }, { r: 0, g: 0, b: 0 })),
+      pct(colorDiff({ r: 255, g: 0, b: 0 }, { r: 0, g: 0, b: 0 }))
     ).toEqual(33.3);
 
     expect(
-      pct(colorDiff({ r: 255, g: 0, b: 0 }, { r: 0, g: 255, b: 0 })),
+      pct(colorDiff({ r: 255, g: 0, b: 0 }, { r: 0, g: 255, b: 0 }))
     ).toEqual(66.6);
 
     expect(colorDiff({ r: 255, g: 0, b: 0 }, { r: 0, g: 255, b: 255 })).toEqual(
-      1,
+      1
     );
 
     expect(colorDiff({ r: 0, g: 0, b: 0 }, { r: 255, g: 255, b: 255 })).toEqual(
-      1,
+      1
     );
   });
 
   test("totally transparent", () => {
     expect(
-      colorDiff({ r: 255, g: 0, b: 0, a: 0 }, { r: 255, g: 0, b: 0, a: 0 }),
+      colorDiff({ r: 255, g: 0, b: 0, a: 0 }, { r: 255, g: 0, b: 0, a: 0 })
     ).toEqual(0);
 
     expect(
-      colorDiff({ r: 0, g: 0, b: 0, a: 0 }, { r: 255, g: 255, b: 255, a: 0 }),
+      colorDiff({ r: 0, g: 0, b: 0, a: 0 }, { r: 255, g: 255, b: 255, a: 0 })
     ).toEqual(1);
   });
 
@@ -43,13 +44,39 @@ describe("colorDiff", () => {
       pct(
         colorDiff(
           { r: 255, g: 0, b: 0, a: 100 },
-          { r: 255, g: 0, b: 0, a: 150 },
-        ),
-      ),
+          { r: 255, g: 0, b: 0, a: 150 }
+        )
+      )
     ).toEqual(3.8);
 
     expect(
-      colorDiff({ r: 0, g: 0, b: 0, a: 0 }, { r: 255, g: 255, b: 255, a: 255 }),
+      colorDiff({ r: 0, g: 0, b: 0, a: 0 }, { r: 255, g: 255, b: 255, a: 255 })
     ).toEqual(1);
   });
 });
+
+describe("scan", () => {
+  class TestImage {
+    public bitmap = {
+      height: 3,
+      width: 3,
+      data: Buffer.from([
+        0xff, 0x00, 0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0xff, 0x00, 0x00, 0x00,
+        0xff, 0x00, 0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0xff, 0x00, 0x00, 0x00,
+      ]),
+    };
+  }
+
+  const img = new TestImage() as JimpClass;
+
+  test("scan", () => {
+    let count = 0;
+
+    scan(img, function (_, __, idx) {
+      count++;
+      expect(img.bitmap.data[idx]).toBe(this.bitmap.data[idx]);
+    });
+
+    expect(count).toBe(img.bitmap.width * img.bitmap.height);
+  });
+});

packages/utils/src/index.ts

@@ -15,7 +15,7 @@ export function clone<I extends JimpClass>(image: I): I {
 export function scan<I extends JimpClass>(
   image: I,
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  f: (this: I, x: number, y: number, idx: number) => any,
+  f: (this: I, x: number, y: number, idx: number) => any
 ): I;
 export function scan<I extends { bitmap: Bitmap }>(
   image: I,
@@ -24,7 +24,7 @@ export function scan<I extends { bitmap: Bitmap }>(
   w: number,
   h: number,
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  cb: (x: number, y: number, idx: number) => any,
+  cb: (x: number, y: number, idx: number) => any
 ): I;
 export function scan<I extends { bitmap: Bitmap }>(
   image: I,
@@ -34,7 +34,7 @@ export function scan<I extends { bitmap: Bitmap }>(
   wArg?: number,
   hArg?: number,
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  cbArg?: (x: number, y: number, idx: number) => any,
+  cbArg?: (x: number, y: number, idx: number) => any
 ): I {
   let x: number;
   let y: number;
@@ -67,10 +67,13 @@ export function scan<I extends { bitmap: Bitmap }>(
   w = Math.round(w);
   h = Math.round(h);
 
+  const bound = cb.bind(image);
+
   for (let _y = y; _y < y + h; _y++) {
     for (let _x = x; _x < x + w; _x++) {
       const idx = (image.bitmap.width * _y + _x) << 2;
-      cb(_x, _y, idx);
+      // Bind the images so this.bitmap works
+      bound(_x, _y, idx);
     }
   }
 
@@ -82,7 +85,7 @@ export function* scanIterator<I extends JimpClass>(
   x: number,
   y: number,
   w: number,
-  h: number,
+  h: number
 ) {
   // round input
   x = Math.round(x);
@@ -125,14 +128,14 @@ export function intToRGBA(i: number) {
   rgba.g = Math.floor((i - rgba.r * Math.pow(256, 3)) / Math.pow(256, 2));
   rgba.b = Math.floor(
     (i - rgba.r * Math.pow(256, 3) - rgba.g * Math.pow(256, 2)) /
-      Math.pow(256, 1),
+      Math.pow(256, 1)
   );
   rgba.a = Math.floor(
     (i -
       rgba.r * Math.pow(256, 3) -
       rgba.g * Math.pow(256, 2) -
       rgba.b * Math.pow(256, 1)) /
-      Math.pow(256, 0),
+      Math.pow(256, 0)
   );
 
   return rgba;
@@ -216,7 +219,7 @@ export function rgbaToInt(r: number, g: number, b: number, a: number) {
  */
 export function colorDiff(
   rgba1: RGBAColor | RGBColor,
-  rgba2: RGBAColor | RGBColor,
+  rgba2: RGBAColor | RGBColor
 ) {
   const sq = (n: number) => Math.pow(n, 2);
   const { max } = Math;

plugins/plugin-print/src/index.ts

@@ -213,7 +213,7 @@ export const methods = {
       y += font.common.lineHeight;
     });
 
-    cb({ x: x + longestLine, y });
+    cb.bind(image)({ x: x + longestLine, y });
 
     return image;
   },