From dc167d06568dae4d64243bcdf88570111fcbf219 Mon Sep 17 00:00:00 2001
From: Stuart Buchanan <stuart_d_buchanan@yahoo.co.uk>
Date: Sat, 28 May 2022 20:44:25 +0100
Subject: [PATCH] WS30: Improved coastlines

Modify the ws30 shader to build a coastline using
a high resolution overlay texture mixed with the
landclass texture.
---
 Effects/ws30.eff            | 28 +++++++++++++++++++++++++++-
 Shaders/ws30-ALS-ultra.frag | 34 +++++++++++++++++++++++++---------
 defaults.xml                |  3 ++-
 3 files changed, 54 insertions(+), 11 deletions(-)

diff --git a/Effects/ws30.eff b/Effects/ws30.eff
index e4b8829b8..de9b76af4 100644
--- a/Effects/ws30.eff
+++ b/Effects/ws30.eff
@@ -27,7 +27,14 @@
       <wrap-t>repeat</wrap-t>
       <internal-format>normalized</internal-format>
     </texture>
-
+    <texture n="8">
+      <image>Textures/Terrain/sand6.png</image>
+      <type>2d</type>
+      <filter>nearest</filter>
+      <wrap-s>repeat</wrap-s>
+      <wrap-t>repeat</wrap-t>
+      <internal-format>normalized</internal-format>
+    </texture>
     <texture n="10">
       <image>Textures/Terrain/snow3.png</image>
       <type>2d</type>
@@ -292,6 +299,15 @@
         <internal-format><use>texture[6]/internal-format</use></internal-format>
       </texture-unit>
 
+      <texture-unit>
+        <unit>8</unit>
+        <image><use>texture[8]/image</use></image>
+        <filter><use>texture[8]/filter</use></filter>
+        <wrap-s><use>texture[8]/wrap-s</use></wrap-s>
+        <wrap-t><use>texture[8]/wrap-t</use></wrap-t>
+        <internal-format><use>texture[8]/internal-format</use></internal-format>
+      </texture-unit>
+
       <program>
         <vertex-shader>Shaders/ws30-ALS-ultra.vert</vertex-shader>
         <vertex-shader>Shaders/filters-ALS.vert</vertex-shader>
@@ -828,6 +844,16 @@
         <name>perlin</name>
         <type>sampler-2d</type>
         <value type="int">6</value>
+      </uniform>
+      <uniform>
+        <name>coastline</name>
+        <type>sampler-2d</type>
+        <value type="int">7</value>
+      </uniform>
+      <uniform>
+        <name>sand</name>
+        <type>sampler-2d</type>
+        <value type="int">8</value>
       </uniform>
           <uniform>
             <name>swatch_size</name>
diff --git a/Shaders/ws30-ALS-ultra.frag b/Shaders/ws30-ALS-ultra.frag
index 35e6ec53f..00be5345e 100644
--- a/Shaders/ws30-ALS-ultra.frag
+++ b/Shaders/ws30-ALS-ultra.frag
@@ -103,6 +103,12 @@ uniform vec4 fg_materialParams1[128];
 uniform vec4 fg_materialParams2[128];
 uniform vec4 fg_materialParams3[128];
 
+// Coastline texture - generated from VPBTechnique
+uniform sampler2D coastline;
+
+// Sand texture
+uniform sampler2D sand;
+
 uniform mat4 fg_zUpTransform;
 uniform vec3 fg_modelOffset;
 
@@ -440,22 +446,32 @@ void main()
   // Testing code: mix with green to show values of variables at each point
   //vec4 green = vec4(0.0, 0.5, 0.0, 0.0);
   //texel = mix(texel, green, (mfact[2]));
-
-  if ((water_shader == 1) && (fg_photoScenery == false) && fg_materialParams3[lc].x > 0.5) { 
-    // This is a water fragment, so calculate the fragment color procedurally
-    // and mix with some sand and cliff colour depending on steepness
-    vec4 steep_texel = lookup_ground_texture_array(2, ground_tex_coord, lc, dxdy_gc);  // Uses the same index as the gradient texture, which it is
-    vec4 beach_texel = lookup_ground_texture_array(3, ground_tex_coord, lc, dxdy_gc);  // Use the dot texture, which is overloaded to be the beach texture
+  vec4 coast = texture2D(coastline, tile_coord);
+  if (coast.b > 0.01) { 
     float waterline_min_steepness = fg_materialParams3[lc].y;
     float waterline_max_steepness = fg_materialParams3[lc].z;
+    vec4 steep_texel = lookup_ground_texture_array(2, ground_tex_coord, lc, dxdy_gc);  // Uses the same index as the gradient texture, which it is
+    vec4 beach_texel = texture2D(sand, ground_tex_coord);  // Use the dot texture, which is overloaded to be the beach texture
+    texel = mix(steep_texel, beach_texel, smoothstep(waterline_max_steepness - 0.1, waterline_max_steepness - 0.03, steepness));
+    
+
+    // G channel used to force a beach texel and reduce artifacts between the beach and the land.
+    fragColor = mix(generateWaterTexel(), texel, smoothstep(0.1,0.9,(coast.b + coast.g - noise_500m) / steepness));    
+    //fragColor = mix(texel, generateWaterTexel(), smoothstep(waterline_min_steepness,waterline_max_steepness,steepness));    
+    fragColor.rgb += getClusteredLightsContribution(ecPosition.xyz, n, fragColor.rgb);    
+  } else if ((water_shader == 1) && (fg_photoScenery == false) && (fg_materialParams3[lc].x > 0.5)) { 
+    // This is a water fragment, so calculate the fragment color procedurally
+    // and mix with some sand and cliff colour depending on steepness
+    //vec4 steep_texel = lookup_ground_texture_array(2, ground_tex_coord, lc, dxdy_gc);  // Uses the same index as the gradient texture, which it is
+    //vec4 beach_texel = lookup_ground_texture_array(3, ground_tex_coord, lc, dxdy_gc);  // Use the dot texture, which is overloaded to be the beach texture
 
     // Mix from a rocky texture to beach for steep slopes, which invariably represent the elevation mesh not being perfectly
     // aligned with the landclass mesh.
-    texel = mix(steep_texel, beach_texel, smoothstep(waterline_max_steepness - 0.1, waterline_max_steepness - 0.03, steepness));
+    // texel = mix(steep_texel, beach_texel, smoothstep(waterline_max_steepness - 0.1, waterline_max_steepness - 0.03, steepness));
 
     // Mix from the beach into the water, which produces a pleasing translucent shallow water effect.
-    texel = mix(texel, generateWaterTexel(), smoothstep(waterline_min_steepness,waterline_max_steepness,steepness));    
-    fragColor = texel;
+    //fragColor = mix(texel, generateWaterTexel(), smoothstep(waterline_min_steepness,waterline_max_steepness,steepness));    
+    fragColor = generateWaterTexel();
     fragColor.rgb += getClusteredLightsContribution(ecPosition.xyz, n, fragColor.rgb);    
   } else {
     // Lookup material parameters for the landclass at this fragment.
diff --git a/defaults.xml b/defaults.xml
index cbbb93105..afdcd3418 100644
--- a/defaults.xml
+++ b/defaults.xml
@@ -269,8 +269,9 @@ Started September 2000 by David Megginson, david@megginson.com
         <line-features-lod-level type="int" userarchive="y">5</line-features-lod-level>
         <area-features-lod-level type="int" userarchive="y">5</area-features-lod-level>
         <vegetation-lod-level type="int" userarchive="y">6</vegetation-lod-level>
+        <water-texture-size type="int" userarchive="y">2048</water-texture-size>
         <coastline-lod-level type="int" userarchive="y">3</coastline-lod-level>
-        <coastline-width type="float" userarchive="y">80.0</coastline-width>
+        <coastline-width type="float" userarchive="y">150.0</coastline-width>
         <lod-level n="0">
           <area-features-min-width>10000</area-features-min-width>
           <line-features-min-width>9999.9</line-features-min-width>