noise, but noghint working

shaders/dissolve.gdshader

@@ -1,20 +1,21 @@
 shader_type canvas_item;
 
-uniform sampler2D sim_texture;
+uniform sampler2D trail_texture;
 
 uniform float decay_factor;
 
 void fragment() {
-	vec3 orig = texture(sim_texture, UV).rgb;
-	float trail = texture(sim_texture, UV).g;
+	vec3 orig = texture(trail_texture, UV).rgb;
+	float trail = orig.r;
 
 	float sum = 0.0;
-	for(int i=-1;i<=1;i++) {
-		for(int j=-1;j<=1;j++) {
-			sum += texture(sim_texture, UV).g;
+	for(float i=-1.0;i<=1.5;i++) {
+		for(float j=-1.0;j<=1.5;j++) {
+			vec2 offset = vec2(i,j);
+			sum += texture(trail_texture, UV + vec2(i,j)).g;
 		}
 	}
 	trail = sum / 9.0;
 	trail = trail * decay_factor;
-	COLOR = vec4(orig.r, trail, orig.b, 1.0);
+	COLOR = vec4(trail, orig.g, orig.b, 1.0);
 }