added dropplet water, grenade, states, animation, YAYAY

Scripts/Fluid.gdshader

@@ -0,0 +1,22 @@
+shader_type canvas_item;
+
+// Use the captured screen texture from the BackBufferCopy
+uniform sampler2D screen_texture : hint_screen_texture, filter_linear_mipmap;
+
+uniform float threshold : hint_range(0.0, 2.0) = 0.5;
+uniform float smoothness : hint_range(0.0, 1.0) = 0.02;
+uniform vec4 fluid_color : source_color = vec4(0.2, 0.5, 1.0, 1.0);
+
+void fragment() {
+    // 1. Grab the pixel from the 'screen' behind this ColorRect
+    vec4 screen_color = texture(screen_texture, SCREEN_UV);
+    
+    // 2. Read the brightness (density)
+    float density = screen_color.r;
+    
+    // 3. Apply the threshold/cutoff
+    float alpha = smoothstep(threshold, threshold + smoothness, density);
+    
+    // 4. Output the fluid
+    COLOR = vec4(fluid_color.rgb, alpha * fluid_color.a);
+}