fix river water direction2

core/daynight/water_river.gdshader

@@ -32,9 +32,6 @@ uniform float foam_roughness : hint_range(0.0, 1.0, 0.01) = 0.05;
 
 group_uniforms Wave;
 uniform sampler2D wave_texture;
-#if !USE_UNSHADED
-	uniform sampler2D wave_normal_texture;
-#endif
 uniform float wave_softness : hint_range(0.0, 10.0, 0.1) = 3.0;
 uniform vec2 wave_scale = vec2(0.2);
 uniform vec2 wave_layer_scale = vec2(1.5);
@@ -42,6 +39,7 @@ uniform float wave_highlight : hint_range(0.0, 1.0, 0.05) = 0.5;
 
 group_uniforms Wave.Motion;
 uniform vec2 wave_velocity = vec2(0.02);
+instance uniform vec2 river_flow_direction = vec2(0.0, 0.0);
 
 group_uniforms Foam;
 uniform sampler2D foam_texture;
@@ -72,6 +70,7 @@ uniform float foam_exponent = 2.0;
 
 uniform sampler2D screen_texture : hint_screen_texture;
 varying vec3 world_pos;
+varying vec2 world_wave_velocity;
 
 #if USE_CAUSTICS
 	vec3 sample_caustics(vec2 uv){
@@ -103,17 +102,47 @@ vec4 sample_wave(sampler2D tex, vec2 uv, vec2 velocity, float lod){
 	return wave2;
 }
 
+vec3 sample_wave_normal(vec2 uv, vec2 velocity, float center_wave) {
+	vec2 normal_offset = vec2(0.25, 0.0);
+	float wave_x = sample_wave(wave_texture, uv + normal_offset.xy, velocity, wave_softness).r;
+	float wave_z = sample_wave(wave_texture, uv + normal_offset.yx, velocity, wave_softness).r;
+	vec2 slope = vec2(center_wave - wave_x, center_wave - wave_z) * 0.35;
+	return normalize(vec3(slope, 1.0)) * 0.5 + 0.5;
+}
+
+vec2 get_world_wave_velocity(mat4 model_matrix) {
+	float velocity_length = length(wave_velocity);
+	if (velocity_length <= 0.0001) {
+		return vec2(0.0);
+	}
+
+	float flow_direction_length = length(river_flow_direction);
+	if (flow_direction_length > 0.0001) {
+		return (river_flow_direction / flow_direction_length) * velocity_length;
+	}
+
+	vec3 world_direction_3d = (model_matrix * vec4(0.0, 1.0, 0.0, 0.0)).xyz;
+	vec2 world_direction = world_direction_3d.xz;
+	float world_direction_length = length(world_direction);
+	if (world_direction_length <= 0.0001) {
+		return wave_velocity;
+	}
+
+	return (world_direction / world_direction_length) * velocity_length;
+}
+
 void vertex(){
 	world_pos = (MODEL_MATRIX * vec4(VERTEX, 1.0)).xyz;
+	world_wave_velocity = get_world_wave_velocity(MODEL_MATRIX);
 	
 	#if USE_DISPLACEMENT
-		float wave = sample_wave(wave_texture, world_pos.xz, wave_velocity, wave_softness).r;
+		float wave = sample_wave(wave_texture, world_pos.xz, world_wave_velocity, wave_softness).r;
 		VERTEX.y += wave*displacement_amount;
 	#endif
 }
 
 void fragment() {
-	float wave = sample_wave(wave_texture, world_pos.xz, wave_velocity, wave_softness).r;
+	float wave = sample_wave(wave_texture, world_pos.xz, world_wave_velocity, wave_softness).r;
 	wave = smoothstep(0.0,1.0,wave);
 	
 	vec2 screen_uv = SCREEN_UV;
@@ -141,8 +170,8 @@ void fragment() {
 	
 	// Caustics
 	#if USE_CAUSTICS
-		vec3 caustics1 = sample_caustics(surface_uv + (TIME * -wave_velocity));
-		vec3 caustics2 = sample_caustics((surface_uv + (caustics1.r*0.05)) + (TIME * (wave_velocity*0.5)));
+		vec3 caustics1 = sample_caustics(surface_uv + (TIME * -world_wave_velocity));
+		vec3 caustics2 = sample_caustics((surface_uv + (caustics1.r*0.05)) + (TIME * (world_wave_velocity*0.5)));
 		vec3 caustics = caustics2 * (1.0 - depth);
 	#endif
 	
@@ -170,7 +199,7 @@ void fragment() {
 	color = mix(color, foam_color.rgb, foam);
 	
 	#if !USE_UNSHADED
-		vec3 wave_normal_map = sample_wave(wave_normal_texture, world_pos.xz, wave_velocity, wave_softness).rgb;
+		vec3 wave_normal_map = sample_wave_normal(world_pos.xz, world_wave_velocity, wave);
 		NORMAL_MAP = wave_normal_map;
 	#endif