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tiennm99
fc0121fd48
Pure-function transformRgba in src/lib/image-transform.js supports flip H, flip V, and rotation in 90° steps (fixed application order: rotate → flipH → flipV). Wired into the importer pipeline before resize with buttons for each op; ±90° rotations auto-swap the resize dims so output aspect tracks the rotation. CLI gains --flip-h, --flip-v, --rotate flags using the same shared module. 8 new unit tests cover identity, each flip, 90/180/270 rotation, the flipH+flipV ≡ 180° identity, and invalid rotation rejection.
97 lines
3.5 KiB
JavaScript
97 lines
3.5 KiB
JavaScript
import { describe, it, expect } from 'vitest';
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import { transformRgba } from '../../src/lib/image-transform.js';
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/** Build an RGBA buffer where pixel (x, y) has red = (y*w+x+1)*10, green = y, blue = x.
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* Unique per-pixel so we can assert exact placement after transforms. */
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function build(w, h) {
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const out = new Uint8ClampedArray(w * h * 4);
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for (let y = 0; y < h; y++) {
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for (let x = 0; x < w; x++) {
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const i = (y * w + x) * 4;
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out[i] = (y * w + x + 1) * 10;
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out[i + 1] = y;
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out[i + 2] = x;
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out[i + 3] = 255;
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}
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}
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return out;
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}
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function pixel(rgba, w, x, y) {
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const i = (y * w + x) * 4;
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return [rgba[i], rgba[i + 1], rgba[i + 2], rgba[i + 3]];
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}
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describe('transformRgba', () => {
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it('identity (no flips, rotation=0) returns input copy', () => {
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const src = build(2, 3);
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const { rgba, width, height } = transformRgba(src, 2, 3);
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expect(width).toBe(2);
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expect(height).toBe(3);
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expect(rgba).toEqual(src);
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expect(rgba).not.toBe(src);
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});
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it('flipH mirrors columns', () => {
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const src = build(3, 2);
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const { rgba, width, height } = transformRgba(src, 3, 2, { flipH: true });
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expect(width).toBe(3);
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expect(height).toBe(2);
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// Row 0: src cols 0,1,2 → dst cols 2,1,0
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expect(pixel(rgba, 3, 0, 0)).toEqual(pixel(src, 3, 2, 0));
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expect(pixel(rgba, 3, 2, 0)).toEqual(pixel(src, 3, 0, 0));
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});
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it('flipV mirrors rows', () => {
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const src = build(2, 3);
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const { rgba } = transformRgba(src, 2, 3, { flipV: true });
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expect(pixel(rgba, 2, 0, 0)).toEqual(pixel(src, 2, 0, 2));
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expect(pixel(rgba, 2, 0, 2)).toEqual(pixel(src, 2, 0, 0));
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});
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it('rotate 90° CW swaps dims and maps top-left → top-right', () => {
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const src = build(2, 3); // 2 wide, 3 tall
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const { rgba, width, height } = transformRgba(src, 2, 3, { rotation: 90 });
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expect(width).toBe(3); // h
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expect(height).toBe(2); // w
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// src (0,0) is top-left → dst top-right, i.e. (width-1, 0) = (2, 0)
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expect(pixel(rgba, 3, 2, 0)).toEqual(pixel(src, 2, 0, 0));
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// src (1, 0) top-right → dst bottom-right (2, 1)
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expect(pixel(rgba, 3, 2, 1)).toEqual(pixel(src, 2, 1, 0));
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// src (0, 2) bottom-left → dst top-left (0, 0)
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expect(pixel(rgba, 3, 0, 0)).toEqual(pixel(src, 2, 0, 2));
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});
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it('rotate 180° flips both axes', () => {
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const src = build(2, 3);
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const { rgba, width, height } = transformRgba(src, 2, 3, { rotation: 180 });
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expect(width).toBe(2);
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expect(height).toBe(3);
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expect(pixel(rgba, 2, 0, 0)).toEqual(pixel(src, 2, 1, 2));
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expect(pixel(rgba, 2, 1, 2)).toEqual(pixel(src, 2, 0, 0));
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});
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it('rotate 270° CW is inverse of 90° CW', () => {
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const src = build(2, 3);
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const r90 = transformRgba(src, 2, 3, { rotation: 90 });
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const back = transformRgba(r90.rgba, r90.width, r90.height, { rotation: 270 });
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expect(back.width).toBe(2);
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expect(back.height).toBe(3);
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expect(back.rgba).toEqual(new Uint8ClampedArray(src));
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});
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it('flipH + flipV equals 180° rotation (for square or rectangular)', () => {
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const src = build(3, 2);
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const flipped = transformRgba(src, 3, 2, { flipH: true, flipV: true });
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const rotated = transformRgba(src, 3, 2, { rotation: 180 });
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expect(flipped.rgba).toEqual(rotated.rgba);
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expect(flipped.width).toBe(rotated.width);
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expect(flipped.height).toBe(rotated.height);
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});
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it('throws on unsupported rotation', () => {
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const src = build(2, 2);
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expect(() => transformRgba(src, 2, 2, { rotation: 45 })).toThrow();
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});
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});
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