Add gertsner wave shader

1 files changed, 102 insertions, 0 deletions

diff --git a/Wave.gdshader b/Wave.gdshader
new file mode 100644
index 0000000..ff04afd
--- /dev/null
+++ b/Wave.gdshader
@@ -0,0 +1,102 @@
+shader_type spatial;
+render_mode cull_disabled, depth_draw_always;
+
+uniform vec4 wave1 = vec4(0.5,0.5,0.5,1.0);
+uniform vec2 wave1_dir = vec2(1.0,0.0);
+
+uniform vec4 wave2 = vec4(0.5,0.5,0.5,1.0);
+uniform vec2 wave2_dir = vec2(1.0,0.0);
+
+uniform vec4 wave3 = vec4(0.5,0.5,0.5,1.0);
+uniform vec2 wave3_dir = vec2(1.0,0.0);
+
+uniform vec4 water_colour: hint_color;
+uniform vec4 deep_water_colour : hint_color;
+uniform sampler2D noise;
+
+uniform float foam_amount = 0.6;
+uniform float murkiness = 4.0;
+
+varying float vertex_y;
+
+vec3 gerstner_wave(vec4 wave, vec2 wave_dir, vec3 pos, inout vec3 tangent, inout vec3 binormal)
+{
+    float steepness = wave.x;
+    float k = wave.y;
+    float a = wave.z;
+    float t = wave.w;
+
+    vec2 d = normalize(wave_dir);
+    float f = k * (dot(d,pos.xz) - t);
+
+    float tmp1 = steepness * sin(f);
+    float tmp2 = steepness * cos(f);
+
+    tangent += vec3(
+        -d.x * d.x * tmp1,
+        d.x * tmp2,
+        -d.x * d.y * tmp1
+       );
+
+    binormal += vec3(
+        -d.x * d.y * tmp1,
+        d.y * tmp2,
+        -d.y * d.y * tmp1
+       );
+
+    float tmp3 = a * cos(f);
+    vec3 new_pos = vec3(
+        d.x * tmp3,
+        a * sin(f),
+        d.y * tmp3
+       );
+
+    return new_pos;
+}
+
+void vertex()
+{
+    vec3 global_vertex = (WORLD_MATRIX * vec4(VERTEX,1.0)).xyz;
+    VERTEX = global_vertex;
+    TANGENT = vec3(1.0,0.0,0.0);
+    BINORMAL = vec3(0.0,0.0,1.0);
+    VERTEX += gerstner_wave(wave1,wave1_dir,global_vertex,TANGENT,BINORMAL);
+    VERTEX += gerstner_wave(wave2,wave2_dir,global_vertex,TANGENT,BINORMAL);
+    VERTEX += gerstner_wave(wave3,wave3_dir,global_vertex,TANGENT,BINORMAL);
+    vertex_y = VERTEX.y;
+    NORMAL = normalize(cross(BINORMAL,TANGENT));
+}
+
+void fragment()
+{
+    ALPHA = 1.0;
+    SPECULAR = 0.4;
+    ROUGHNESS = 0.05;
+
+    NORMALMAP = texture(noise, UV + (TIME * vec2(-1.0,0.0) * 0.05)).xyz;
+    NORMALMAP_DEPTH = 0.3;
+
+    float depth = texture(DEPTH_TEXTURE, SCREEN_UV).r;
+    vec3 depth_coords_clip = vec3(SCREEN_UV, depth);
+    depth_coords_clip = depth_coords_clip * 2.0 - 1.0;
+    vec4 depth_coords_view = INV_PROJECTION_MATRIX * vec4(depth_coords_clip,1.0);
+    depth_coords_view.xyz /= depth_coords_view.w;
+    depth = -depth_coords_view.z;
+    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;
+
+    vec3 oriented_normalmap = vec3(TANGENT*NORMALMAP.x + NORMAL*NORMALMAP.y + BINORMAL*NORMALMAP.z);
+    vec3 normal = normalize(mix(NORMAL,oriented_normalmap,NORMALMAP_DEPTH));
+    vec2 refraction_uv = SCREEN_UV + (normal.xz * 0.005);
+    float murky = murkiness * ROUGHNESS;
+    murky *= submersion;
+    float depth_scatter = exp(murky);
+    float depth_visibility = exp(-murky);
+    depth_visibility = clamp(depth_visibility,0.0,1.0);
+    vec4 bg_color = textureLod(SCREEN_TEXTURE, refraction_uv, depth_scatter);
+    EMISSION = mix(water_color, bg_color, depth_visibility).rgb * (1.0 - water_color.a);
+}