fix snow

core/daynight/grass_leaves.gdshader

@@ -8,10 +8,11 @@ global uniform float global_wind_speed;
 global uniform float global_wind_strength;
 global uniform vec2 global_wind_direction;
 //global uniform sampler2D global_wind_noise : filter_linear_mipmap;
-global uniform float global_snow_start_time;
-global uniform float global_snow_accumulation_speed;
-global uniform float global_snow_melt_time;
-global uniform float global_snow_melt_speed;
+global uniform float global_snow_start_time = -1.0;
+global uniform float global_snow_accumulation_speed = 0.005;
+global uniform float global_snow_melt_time = -1.0;
+global uniform float global_snow_melt_speed = 0.1;
+global uniform float global_snow_amount = 0.0;
 global uniform float global_rain_intensity;
 
 // --- PARAMETRI ESTETICI ---
@@ -32,6 +33,7 @@ uniform vec4 variance_color : source_color = vec4(0.3, 0.5, 0.2, 1.0); // Colore
 uniform float variance_intensity : hint_range(0.0, 1.0) = 0.4; // Quanto si vedono le chiazze
 
 uniform vec4 snow_color : source_color = vec4(0.85, 0.9, 0.95, 1.0);
+uniform float snow_visibility : hint_range(0.0, 1.0) = 1.0;
 
 // --- CONTROLLO GRADIENTE E RANDOM ---
 uniform float height_min = 0.0;
@@ -54,6 +56,21 @@ float hash(vec3 p) {
 	return fract((p.x + p.y) * p.z);
 }
 
+float get_snow_progress() {
+	float snow_progress = clamp(global_snow_amount, 0.0, 1.0);
+
+	if (global_snow_start_time >= 0.0) {
+		float timed_progress = clamp((TIME - global_snow_start_time) * global_snow_accumulation_speed, 0.0, 1.0);
+		snow_progress = max(snow_progress, timed_progress);
+	}
+	if (global_snow_melt_time >= 0.0) {
+		float melt = clamp((TIME - global_snow_melt_time) * global_snow_melt_speed, 0.0, 1.0);
+		snow_progress = min(snow_progress, 1.0 - melt);
+	}
+
+	return snow_progress;
+}
+
 void vertex() {
 	vec3 instance_pos = MODEL_MATRIX[3].xyz;
 	v_world_pos = instance_pos; // Salviamo la posizione dell'istanza
@@ -115,17 +132,10 @@ void fragment() {
 	// Applichiamo la variazione al colore finale dell'erba
 	vec3 varied_grass_color = mix(v_final_color, variance_color.rgb, noise_sample * variance_intensity);
 
-	float snow_amount = 0.0;
-	if (global_snow_start_time >= 0.0) {
-		snow_amount = clamp((TIME - global_snow_start_time) * global_snow_accumulation_speed, 0.0, 1.0);
-	}
-	if (global_snow_melt_time >= 0.0) {
-		float melt = clamp((TIME - global_snow_melt_time) * global_snow_melt_speed, 0.0, 1.0);
-		snow_amount *= (1.0 - melt);
-	}
+	float snow_amount = smoothstep(0.0, 1.0, get_snow_progress());
 	
 	float top_mask = 1.0 - shifted_uv.y; 
-	float snow_mask = smoothstep(1.0 - snow_amount, 1.2 - snow_amount, top_mask);
+	float snow_mask = smoothstep(0.65, 1.0, top_mask) * snow_amount * snow_visibility;
 	snow_mask *= step(0.01, snow_amount);
 	
 	vec3 dark_snow = snow_color.rgb * (1.0 - shadow_intensity);