3 files changed, 88 insertions, 0 deletions
diff --git a/apps/web/src/lib/effects/definitions/blur.frag.glsl b/apps/web/src/lib/effects/definitions/blur.frag.glsl
new file mode 100644
index 00000000..2c015725
--- /dev/null
+++ b/apps/web/src/lib/effects/definitions/blur.frag.glsl
@@ -0,0 +1,25 @@
+precision mediump float;
+
+uniform sampler2D u_texture;
+uniform vec2 u_resolution;
+uniform float u_sigma;
+uniform vec2 u_direction;
+
+varying vec2 v_texCoord;
+
+void main() {
+  vec2 texelSize = 1.0 / u_resolution;
+
+  vec4 color = vec4(0.0);
+  float totalWeight = 0.0;
+
+  // step=1 texel — scaling step size instead causes discrete ghosting artifacts
+  for (int i = -30; i <= 30; i++) {
+    float fi = float(i);
+    float weight = exp(-(fi * fi) / (2.0 * u_sigma * u_sigma));
+    color += texture2D(u_texture, v_texCoord + texelSize * u_direction * fi) * weight;
+    totalWeight += weight;
+  }
+
+  gl_FragColor = color / totalWeight;
+}
diff --git a/apps/web/src/lib/effects/definitions/blur.ts b/apps/web/src/lib/effects/definitions/blur.ts
new file mode 100644
index 00000000..3a8f691a
--- /dev/null
+++ b/apps/web/src/lib/effects/definitions/blur.ts
@@ -0,0 +1,50 @@
+import type { EffectDefinition } from "@/types/effects";
+import blurFragmentShader from "./blur.frag.glsl";
+
+export const blurEffectDefinition: EffectDefinition = {
+	type: "blur",
+	name: "Blur",
+	keywords: ["blur", "soft", "defocus"],
+	params: [
+		{
+			key: "intensity",
+			label: "Intensity",
+			type: "number",
+			default: 15,
+			min: 0,
+			max: 100,
+			step: 1,
+		},
+	],
+	renderer: {
+		type: "webgl",
+		passes: [
+			{
+				fragmentShader: blurFragmentShader,
+				uniforms: ({ effectParams }) => {
+					const intensity =
+						typeof effectParams.intensity === "number"
+							? effectParams.intensity
+							: Number.parseFloat(String(effectParams.intensity));
+					return {
+						u_sigma: Math.max(intensity / 5, 0.001),
+						u_direction: [1, 0],
+					};
+				},
+			},
+			{
+				fragmentShader: blurFragmentShader,
+				uniforms: ({ effectParams }) => {
+					const intensity =
+						typeof effectParams.intensity === "number"
+							? effectParams.intensity
+							: Number.parseFloat(String(effectParams.intensity));
+					return {
+						u_sigma: Math.max(intensity / 5, 0.001),
+						u_direction: [0, 1],
+					};
+				},
+			},
+		],
+	},
+};
diff --git a/apps/web/src/lib/effects/definitions/index.ts b/apps/web/src/lib/effects/definitions/index.ts
new file mode 100644
index 00000000..1742b1d7
--- /dev/null
+++ b/apps/web/src/lib/effects/definitions/index.ts
@@ -0,0 +1,13 @@
+import { hasEffect, registerEffect } from "../registry";
+import { blurEffectDefinition } from "./blur";
+
+const defaultEffects = [blurEffectDefinition];
+
+export function registerDefaultEffects(): void {
+	for (const definition of defaultEffects) {
+		if (hasEffect({ effectType: definition.type })) {
+			continue;
+		}
+		registerEffect({ definition });
+	}
+}