yes

modules/wallpaper-engine/shaders/effectcomposebackground.frag

@@ -0,0 +1,16 @@
+
+varying vec2 v_TexCoord;
+varying vec3 v_ScreenCoord;
+
+uniform sampler2D g_Texture0; // {"hidden":true}
+uniform sampler2D g_Texture1; // {"hidden":true,"default":"_rt_FullFrameBuffer"}
+
+void main() {
+	vec4 result = texSample2D(g_Texture0, v_TexCoord);
+
+	vec2 screenCoord = v_ScreenCoord.xy / v_ScreenCoord.z * CAST2(0.5) + 0.5;
+	vec4 bg = texSample2D(g_Texture1, screenCoord.xy);
+
+	gl_FragColor.rgb = mix(bg.rgb, result.rgb, result.a);
+	gl_FragColor.a = 1.0;
+}