yes

modules/wallpaper-engine/effects/opacity/preview/shaders/effects/opacity.frag

@@ -0,0 +1,13 @@
+
+varying vec4 v_TexCoord;
+
+uniform sampler2D g_Texture0; // {"material":"Framebuffer","hidden":true}
+uniform sampler2D g_Texture1; // {"material":"Mask","mode":"opacitymask","default":"util/white"}
+
+void main() {
+	vec4 albedo = texSample2D(g_Texture0, v_TexCoord.xy);
+	float mask = texSample2D(g_Texture1, v_TexCoord.zw).r;
+	albedo.a *= mask;
+	
+	gl_FragColor = albedo;
+}

modules/wallpaper-engine/effects/opacity/preview/shaders/effects/opacity.vert

@@ -0,0 +1,15 @@
+
+uniform mat4 g_ModelViewProjectionMatrix;
+uniform vec4 g_Texture1Resolution;
+
+attribute vec3 a_Position;
+attribute vec2 a_TexCoord;
+
+varying vec4 v_TexCoord;
+
+void main() {
+	gl_Position = mul(vec4(a_Position, 1.0), g_ModelViewProjectionMatrix);
+	v_TexCoord.xy = a_TexCoord;
+	v_TexCoord.zw = vec2(v_TexCoord.x * g_Texture1Resolution.z / g_Texture1Resolution.x,
+						v_TexCoord.y * g_Texture1Resolution.w / g_Texture1Resolution.y);
+}