Rework sea foam

4 files changed, 82 insertions, 18 deletions

diff --git a/water/Water.tscn b/water/Water.tscn
index 6b4c72b..b37340b 100644
--- a/water/Water.tscn
+++ b/water/Water.tscn
@@ -1,7 +1,8 @@
-[gd_scene load_steps=7 format=2]
+[gd_scene load_steps=8 format=2]
 
 [ext_resource path="res://water/Wave.gdshader" type="Shader" id=1]
 [ext_resource path="res://water/Water.gd" type="Script" id=2]
+[ext_resource path="res://water/foam_map.png" type="Texture" id=3]
 
 [sub_resource type="PlaneMesh" id=9]
 size = Vector2( 2000, 2000 )
@@ -26,11 +27,13 @@ shader_param/wave2_t = 0.0
 shader_param/wave3 = Vector3( 0.25, 0.349066, 0.716197 )
 shader_param/wave3_dir = Vector2( 1, 1.3 )
 shader_param/wave3_t = 0.0
-shader_param/water_colour = Color( 0.694118, 0.945098, 0.941176, 0.368627 )
-shader_param/deep_water_colour = Color( 0.25098, 0.623529, 0.788235, 0.54902 )
-shader_param/foam_amount = 0.6
+shader_param/water_color = Color( 0.25098, 0.623529, 0.788235, 0.54902 )
+shader_param/foam_color = Color( 0.694118, 0.945098, 0.941176, 0.368627 )
+shader_param/foam_amount_edge = 2.0
+shader_param/foam_amount_crest = 4.0
 shader_param/murkiness = 4.0
 shader_param/refraction_amount = 0.01
+shader_param/foam_map = ExtResource( 3 )
 shader_param/noise = SubResource( 21 )
 
 [node name="Water" type="Spatial"]
diff --git a/water/Wave.gdshader b/water/Wave.gdshader
index 95d064e..06c5327 100644
--- a/water/Wave.gdshader
+++ b/water/Wave.gdshader
@@ -13,15 +13,20 @@ uniform vec3 wave3 = vec3(0.5,0.5,0.5);
 uniform vec2 wave3_dir = vec2(1.0,0.0);
 uniform float wave3_t = 0.0;
 
-uniform vec4 water_colour: hint_color;
-uniform vec4 deep_water_colour : hint_color;
-uniform sampler2D noise;
+uniform vec4 water_color : hint_color;
+
+uniform vec4 foam_color: hint_color;
+uniform sampler2D foam_map;
+uniform float foam_amount_edge = 2.0;
+uniform float foam_amount_crest = 4.0;
 
-uniform float foam_amount = 0.6;
 uniform float murkiness = 4.0;
 uniform float refraction_amount = 0.01;
 
-varying float vertex_y;
+uniform sampler2D noise;
+
+varying vec3 global_vertex;
+varying vec3 displacement;
 
 vec3 gerstner_wave(vec3 wave, vec2 wave_dir, float t, vec3 pos, inout vec3 tangent, inout vec3 binormal)
 {
@@ -59,13 +64,14 @@ vec3 gerstner_wave(vec3 wave, vec2 wave_dir, float t, vec3 pos, inout vec3 tange
 
 void vertex()
 {
-    vec3 global_vertex = (WORLD_MATRIX * vec4(VERTEX,1.0)).xyz;
+    global_vertex = (WORLD_MATRIX * vec4(VERTEX,1.0)).xyz;
     TANGENT = vec3(1.0,0.0,0.0);
     BINORMAL = vec3(0.0,0.0,1.0);
-    VERTEX += gerstner_wave(wave1,wave1_dir,wave1_t,global_vertex,TANGENT,BINORMAL);
-    VERTEX += gerstner_wave(wave2,wave2_dir,wave2_t,global_vertex,TANGENT,BINORMAL);
-    VERTEX += gerstner_wave(wave3,wave3_dir,wave3_t,global_vertex,TANGENT,BINORMAL);
-    vertex_y = VERTEX.y;
+    displacement = vec3(0.0,0.0,0.0);
+    displacement += gerstner_wave(wave1,wave1_dir,wave1_t,global_vertex,TANGENT,BINORMAL);
+    displacement += gerstner_wave(wave2,wave2_dir,wave2_t,global_vertex,TANGENT,BINORMAL);
+    displacement += gerstner_wave(wave3,wave3_dir,wave3_t,global_vertex,TANGENT,BINORMAL);
+    VERTEX += displacement;
     NORMAL = normalize(cross(BINORMAL,TANGENT));
 }
 
@@ -80,6 +86,18 @@ float get_depth(vec2 coords, sampler2D tex, mat4 proj)
     return depth;
 }
 
+const float pi = 3.1415;
+const float tau = pi * 2.0;
+
+float wave_position(float k,vec2 dir,float t)
+{
+    float pos = k * (dot(normalize(dir),global_vertex.xz)-t);
+    pos = mod(pos-pi,tau);
+    pos = clamp(pos,0.0,tau);
+    pos = 1.0 - (0.5*cos(0.159*pow(pos,2.0))+0.5);
+    return pos;
+}
+
 void fragment()
 {
     ALPHA = 1.0;
@@ -92,9 +110,15 @@ void fragment()
     float depth = get_depth(SCREEN_UV, DEPTH_TEXTURE, INV_PROJECTION_MATRIX);
     float water_depth = -VERTEX.z;
     float submersion = depth - water_depth;
-    vec4 water_color = mix(deep_water_colour, water_colour, clamp(vertex_y,0.0,1.0));
-    float foam = clamp((foam_amount - submersion) / foam_amount, 0.0, 1.0);
-    ALBEDO = mix(water_color, vec4(1.0), foam).rgb;
+    float wave_pos = wave_position(wave1.y,wave1_dir,wave1_t);
+    wave_pos *= wave_position(wave2.y,wave2_dir,wave2_t);
+    wave_pos *= wave_position(wave3.y,wave3_dir,wave3_t);
+    wave_pos = 1.0 - (pow(1.0 - wave_pos, foam_amount_crest));
+    vec4 foam = texture(foam_map, UV + (-displacement.xz * 0.001));
+    vec4 mapped_foam_color = mix(water_color,foam_color,foam.b);
+    vec4 color = mix(water_color, mapped_foam_color, wave_pos);
+    float object_foam = clamp((foam_amount_edge - submersion) / foam_amount_edge, 0.0, 1.0);
+    ALBEDO = mix(color, vec4(1.0), object_foam).rgb;
 
     vec3 oriented_normalmap = vec3(TANGENT*NORMALMAP.x + NORMAL*NORMALMAP.y + BINORMAL*NORMALMAP.z);
     vec3 normal = normalize(mix(NORMAL,oriented_normalmap,NORMALMAP_DEPTH));
@@ -111,5 +135,5 @@ void fragment()
     }
     float depth_scatter = exp(murky);
     vec4 bg_color = textureLod(SCREEN_TEXTURE, refraction_uv, depth_scatter);
-    EMISSION = mix(water_color, bg_color, depth_visibility).rgb * (1.0 - water_color.a);
+    EMISSION = mix(color, bg_color, depth_visibility).rgb * (1.0 - color.a);
 }
diff --git a/water/foam_map.png b/water/foam_map.png
new file mode 100644
index 0000000..6560cdf
--- /dev/null
+++ b/water/foam_map.png
diff --git a/water/foam_map.png.import b/water/foam_map.png.import
new file mode 100644
index 0000000..d79f7e9
--- /dev/null
+++ b/water/foam_map.png.import
@@ -0,0 +1,37 @@
+[remap]
+
+importer="texture"
+type="StreamTexture"
+path.s3tc="res://.import/foam_map.png-8391a4e69d9c8dcac9b9d144ef3261b8.s3tc.stex"
+path.etc2="res://.import/foam_map.png-8391a4e69d9c8dcac9b9d144ef3261b8.etc2.stex"
+metadata={
+"imported_formats": [ "s3tc", "etc2" ],
+"vram_texture": true
+}
+
+[deps]
+
+source_file="res://water/foam_map.png"
+dest_files=[ "res://.import/foam_map.png-8391a4e69d9c8dcac9b9d144ef3261b8.s3tc.stex", "res://.import/foam_map.png-8391a4e69d9c8dcac9b9d144ef3261b8.etc2.stex" ]
+
+[params]
+
+compress/mode=2
+compress/lossy_quality=0.7
+compress/hdr_mode=0
+compress/bptc_ldr=0
+compress/normal_map=0
+flags/repeat=true
+flags/filter=true
+flags/mipmaps=true
+flags/anisotropic=false
+flags/srgb=2
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/HDR_as_SRGB=false
+process/invert_color=false
+process/normal_map_invert_y=false
+stream=false
+size_limit=0
+detect_3d=false
+svg/scale=1.0