enhance(frontend): improve zoomLines image effect

3 files changed, 113 insertions, 9 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index fd64126227..48cd121042 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@
 - Feat: 動画を圧縮してアップロードできるようになりました
 - Enhance: チャットの日本語名称がダイレクトメッセージに戻るとともに、ベータ版機能ではなくなりました
 - Enhance: 画像編集にマスクエフェクト(塗りつぶし、ぼかし、モザイク)を追加
+- Enhance: 画像編集の集中線エフェクトを強化
 - Enhance: ウォーターマークにアカウントのQRコードを追加できるように
 - Enhance: テーマをドラッグ&ドロップできるように
 - Enhance: 絵文字ピッカーのサイズをより大きくできるように
diff --git a/packages/frontend/src/utility/image-effector/fxs/zoomLines.ts b/packages/frontend/src/utility/image-effector/fxs/zoomLines.ts
index 2e16ebea3b..4ea28658dd 100644
--- a/packages/frontend/src/utility/image-effector/fxs/zoomLines.ts
+++ b/packages/frontend/src/utility/image-effector/fxs/zoomLines.ts
@@ -4,11 +4,14 @@
  */
 
 import { defineImageEffectorFx } from '../ImageEffector.js';
+import { GLSL_LIB_SNOISE } from '@/utility/webgl.js';
 import { i18n } from '@/i18n.js';
 
 const shader = `#version 300 es
 precision mediump float;
 
+${GLSL_LIB_SNOISE}
+
 in vec2 in_uv;
 uniform sampler2D in_texture;
 uniform vec2 in_resolution;
@@ -22,10 +25,22 @@ out vec4 out_color;
 
 void main() {
 	vec4 in_color = texture(in_texture, in_uv);
-	float angle = atan(-u_pos.y + (in_uv.y), -u_pos.x + (in_uv.x));
-	float t = (1.0 + sin(angle * u_frequency)) / 2.0;
+	vec2 centeredUv = (in_uv - vec2(0.5, 0.5));
+	vec2 uv = centeredUv;
+
+	float seed = 1.0;
+	float time = 0.0;
+
+	vec2 noiseUV = (uv - u_pos) / distance((uv - u_pos), vec2(0.0));
+	float noiseX = (noiseUV.x + seed) * u_frequency;
+	float noiseY = (noiseUV.y + seed) * u_frequency;
+  float noise = (1.0 + snoise(vec3(noiseX, noiseY, time))) / 2.0;
+
+	float t = noise;
 	if (u_thresholdEnabled) t = t < u_threshold ? 1.0 : 0.0;
-	float d = distance(in_uv * vec2(2.0, 2.0), u_pos * vec2(2.0, 2.0));
+
+	// TODO: マスクの形自体も揺らぎを与える
+	float d = distance(uv * vec2(2.0, 2.0), u_pos * vec2(2.0, 2.0));
 	float mask = d < u_maskSize ? 0.0 : ((d - u_maskSize) * (1.0 + (u_maskSize * 2.0)));
 	out_color = vec4(
 		mix(in_color.r, u_black ? 0.0 : 1.0, t * mask),
@@ -61,9 +76,9 @@ export const FX_zoomLines = defineImageEffectorFx({
 		frequency: {
 			label: i18n.ts._imageEffector._fxProps.frequency,
 			type: 'number',
-			default: 30.0,
-			min: 1.0,
-			max: 200.0,
+			default: 5.0,
+			min: 0.0,
+			max: 15.0,
 			step: 0.1,
 		},
 		smoothing: {
@@ -75,7 +90,7 @@ export const FX_zoomLines = defineImageEffectorFx({
 		threshold: {
 			label: i18n.ts._imageEffector._fxProps.zoomLinesThreshold,
 			type: 'number',
-			default: 0.2,
+			default: 0.5,
 			min: 0.0,
 			max: 1.0,
 			step: 0.01,
@@ -95,8 +110,8 @@ export const FX_zoomLines = defineImageEffectorFx({
 		},
 	},
 	main: ({ gl, u, params }) => {
-		gl.uniform2f(u.pos, (1.0 + params.x) / 2.0, (1.0 + params.y) / 2.0);
-		gl.uniform1f(u.frequency, params.frequency);
+		gl.uniform2f(u.pos, params.x / 2, params.y / 2);
+		gl.uniform1f(u.frequency, params.frequency * params.frequency);
 		// thresholdの調整が有効な間はsmoothingが利用できない
 		gl.uniform1i(u.thresholdEnabled, params.smoothing ? 0 : 1);
 		gl.uniform1f(u.threshold, params.threshold);
diff --git a/packages/frontend/src/utility/webgl.ts b/packages/frontend/src/utility/webgl.ts
index ae595b605c..dee2103ecf 100644
--- a/packages/frontend/src/utility/webgl.ts
+++ b/packages/frontend/src/utility/webgl.ts
@@ -38,3 +38,91 @@ export function initShaderProgram(gl: WebGL2RenderingContext, vsSource: string,
 
 	return shaderProgram;
 }
+
+export const GLSL_LIB_SNOISE = `
+// Description : Array and textureless GLSL 2D/3D/4D simplex
+//               noise functions.
+//      Author : Ian McEwan, Ashima Arts.
+//  Maintainer : stegu
+//     Lastmod : 20201014 (stegu)
+//     License : Copyright (C) 2011 Ashima Arts. All rights reserved.
+//               Distributed under the MIT License. See LICENSE file.
+//               https://github.com/ashima/webgl-noise
+//               https://github.com/stegu/webgl-noise
+
+vec3 mod289(vec3 x) {
+	return x - floor(x * (1.0 / 289.0)) * 289.0;
+}
+
+vec4 mod289(vec4 x) {
+	return x - floor(x * (1.0 / 289.0)) * 289.0;
+}
+
+vec4 permute(vec4 x) {
+	return mod289(((x * 34.0) + 10.0) * x);
+}
+
+vec4 taylorInvSqrt(vec4 r) {
+	return 1.79284291400159 - 0.85373472095314 * r;
+}
+
+float snoise(vec3 v) {
+	const vec2 C = vec2(1.0/6.0, 1.0/3.0);
+	const vec4 D = vec4(0.0, 0.5, 1.0, 2.0);
+
+	vec3 i = floor(v + dot(v, C.yyy));
+	vec3 x0 = v - i + dot(i, C.xxx);
+
+	vec3 g = step(x0.yzx, x0.xyz);
+	vec3 l = 1.0 - g;
+	vec3 i1 = min(g.xyz, l.zxy);
+	vec3 i2 = max(g.xyz, l.zxy);
+
+	vec3 x1 = x0 - i1 + C.xxx;
+	vec3 x2 = x0 - i2 + C.yyy;
+	vec3 x3 = x0 - D.yyy;
+
+	i = mod289(i);
+	vec4 p = permute(permute(permute(
+						i.z + vec4(0.0, i1.z, i2.z, 1.0))
+					+ i.y + vec4(0.0, i1.y, i2.y, 1.0))
+					+ i.x + vec4(0.0, i1.x, i2.x, 1.0));
+
+	float n_ = 0.142857142857;
+	vec3 ns = n_ * D.wyz - D.xzx;
+
+	vec4 j = p - 49.0 * floor(p * ns.z * ns.z);
+
+	vec4 x_ = floor(j * ns.z);
+	vec4 y_ = floor(j - 7.0 * x_);
+
+	vec4 x = x_ * ns.x + ns.yyyy;
+	vec4 y = y_ * ns.x + ns.yyyy;
+	vec4 h = 1.0 - abs(x) - abs(y);
+
+	vec4 b0 = vec4(x.xy, y.xy);
+	vec4 b1 = vec4(x.zw, y.zw);
+
+	vec4 s0 = floor(b0) * 2.0 + 1.0;
+	vec4 s1 = floor(b1) * 2.0 + 1.0;
+	vec4 sh = -step(h, vec4(0.0));
+
+	vec4 a0 = b0.xzyw + s0.xzyw * sh.xxyy;
+	vec4 a1 = b1.xzyw + s1.xzyw * sh.zzww;
+
+	vec3 p0 = vec3(a0.xy, h.x);
+	vec3 p1 = vec3(a0.zw, h.y);
+	vec3 p2 = vec3(a1.xy, h.z);
+	vec3 p3 = vec3(a1.zw, h.w);
+
+	vec4 norm = taylorInvSqrt(vec4(dot(p0, p0), dot(p1, p1), dot(p2, p2), dot(p3, p3)));
+	p0 *= norm.x;
+	p1 *= norm.y;
+	p2 *= norm.z;
+	p3 *= norm.w;
+
+	vec4 m = max(0.5 - vec4(dot(x0, x0), dot(x1, x1), dot(x2, x2), dot(x3, x3)), 0.0);
+	m = m * m;
+	return 105.0 * dot(m * m, vec4(dot(p0, x0), dot(p1, x1), dot(p2, x2), dot(p3, x3)));
+}
+`;