135 lines
4.1 KiB
TypeScript
135 lines
4.1 KiB
TypeScript
import { describe, expect, it } from "vitest";
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import { rotate90, sampleBilinear } from "./geometry";
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import {
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rotateFreeImage,
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skewImage,
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transformImage,
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zoomImage,
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} from "./affine";
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import { makeImage } from "./test-helpers";
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describe("sampleBilinear", () => {
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it("целые координаты возвращают точный пиксель", () => {
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const img = makeImage(2, 1, [
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[255, 0, 0, 255],
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[0, 0, 255, 255],
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]);
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expect(sampleBilinear(img, 0, 0)).toEqual([255, 0, 0, 255]);
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expect(sampleBilinear(img, 1, 0)).toEqual([0, 0, 255, 255]);
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});
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it("дробная координата интерполирует", () => {
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const img = makeImage(2, 1, [
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[0, 0, 0, 255],
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[200, 200, 200, 255],
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]);
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const [r] = sampleBilinear(img, 0.5, 0);
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expect(r).toBeCloseTo(100, 0);
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});
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it("координаты за краем клампятся", () => {
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const img = makeImage(1, 1, [[7, 7, 7, 255]]);
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expect(sampleBilinear(img, -10, -10)).toEqual([7, 7, 7, 255]);
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});
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});
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describe("rotateFreeImage", () => {
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it("поворот на 180° даёт размеры не меньше исходных и непустой результат", () => {
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const img = makeImage(4, 3, [
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[255, 0, 0, 255],
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[0, 255, 0, 255],
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[0, 0, 255, 255],
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[255, 255, 0, 255],
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[128, 128, 128, 255],
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[64, 64, 64, 255],
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[32, 32, 32, 255],
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[200, 200, 200, 255],
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[10, 20, 30, 255],
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[40, 50, 60, 255],
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[70, 80, 90, 255],
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[100, 100, 100, 255],
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]);
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const out = rotateFreeImage(img, 180);
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expect(out.width).toBeGreaterThanOrEqual(img.width);
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expect(out.height).toBeGreaterThanOrEqual(img.height);
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let opaque = 0;
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const total = out.width * out.height;
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for (let i = 3; i < out.data.length; i += 4) {
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if (out.data[i] > 0) opaque++;
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}
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expect(opaque / total).toBeGreaterThan(0.8);
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});
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it("поворот квадрата на 360° близок к оригиналу", () => {
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const img = makeImage(5, 5, new Array(25).fill([200, 100, 50, 255]));
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const out = rotateFreeImage(img, 360);
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expect(out.width).toBeGreaterThanOrEqual(5);
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expect(out.height).toBeGreaterThanOrEqual(5);
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for (let y = 0; y < 5; y++) {
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for (let x = 0; x < 5; x++) {
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const di = (y * out.width + x) * 4;
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for (let ch = 0; ch < 4; ch++) {
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expect(
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Math.abs(out.data[di + ch] - img.data[(y * 5 + x) * 4 + ch]),
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).toBeLessThanOrEqual(4);
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}
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}
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}
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});
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});
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describe("skewImage", () => {
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it("наклон X=45° расширяет холст до w+h−1 и сдвигает строки вправо", () => {
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const img = makeImage(2, 2, new Array(4).fill([255, 0, 0, 255]));
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const out = skewImage(img, 45, 0);
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expect(out.width).toBe(3);
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expect(out.height).toBe(2);
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let opaque = 0;
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for (let i = 3; i < out.data.length; i += 4) {
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if (out.data[i] === 255) {
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opaque++;
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expect([out.data[i - 3], out.data[i - 2], out.data[i - 1]]).toEqual([
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255, 0, 0,
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]);
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}
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}
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expect(opaque).toBe(4);
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});
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it("углы 0° — тождественное преобразование", () => {
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const img = makeImage(2, 2, [
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[255, 0, 0, 255],
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[0, 255, 0, 255],
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[0, 0, 255, 255],
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[128, 128, 128, 255],
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]);
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const out = skewImage(img, 0, 0);
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expect(out.width).toBe(2);
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expect([...out.data]).toEqual([...img.data]);
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});
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});
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describe("transformImage — заливка фона", () => {
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it("сдвиг с белым фоном заполняет освободившийся край", () => {
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const img = makeImage(2, 2, [
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[255, 0, 0, 255],
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[0, 255, 0, 255],
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[0, 0, 255, 255],
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[128, 128, 128, 255],
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]);
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const out = transformImage(img, [1, 0, 0, 1, -1, 0], 2, 2, "#ffffff");
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expect(out.width).toBe(2);
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expect(out.height).toBe(2);
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for (let y = 0; y < 2; y++) {
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const di = y * 2 * 4;
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expect([...out.data.slice(di, di + 4)]).toEqual([255, 255, 255, 255]);
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}
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});
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it("без фона освободившийся край остаётся прозрачным", () => {
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const img = makeImage(2, 2, new Array(4).fill([10, 20, 30, 255]));
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const out = transformImage(img, [1, 0, 0, 1, -1, 0], 2, 2);
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expect(out.data[3]).toBe(0);
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});
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});
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