Add vertical / horizontal mapping for snow, sand, moss, etc (everything going on top of something)

data/shaders/sp_pass.vert

@@ -37,6 +37,7 @@ out vec2 uv;
 out vec2 uv_two;
 out vec4 color;
 out vec4 world_position;
+out vec3 world_normal;
 out float camdist;
 out float hue_change;
 
@@ -52,15 +53,15 @@ void main()
     vec4 quaternion = normalize(vec4(i_rotation.xyz, i_scale.w));
     vec4 v_world_position = getWorldPosition(i_origin, quaternion, i_scale.xyz,
         i_position);
-    vec3 world_normal = rotateVector(quaternion, i_normal.xyz);
+    vec3 v_world_normal = rotateVector(quaternion, i_normal.xyz);
     vec3 world_tangent = rotateVector(quaternion, i_tangent.xyz);
 
     tangent = (u_view_matrix * vec4(world_tangent, 0.0)).xyz;
     bitangent = (u_view_matrix *
        // bitangent sign
-      vec4(cross(world_normal, world_tangent) * i_tangent.w, 0.0)
+      vec4(cross(v_world_normal, world_tangent) * i_tangent.w, 0.0)
       ).xyz;
-    normal = (u_view_matrix * vec4(world_normal, 0.0)).xyz;
+    normal = (u_view_matrix * vec4(v_world_normal, 0.0)).xyz;
 
     uv = vec2(i_uv.x + (i_texture_trans.x * i_normal.w),
         i_uv.y + (i_texture_trans.y * i_normal.w));
@@ -71,4 +72,5 @@ void main()
     hue_change = float(i_misc_data.y) * 0.01;
     gl_Position = u_projection_view_matrix * v_world_position;
     world_position = v_world_position;
+    world_normal = v_world_normal;
 }

data/shaders/sp_vertical_mapping.frag

@@ -0,0 +1,63 @@
+in vec3 bitangent;
+in vec4 color;
+in float hue_change;
+in vec3 normal;
+in vec3 world_normal;
+in vec3 tangent;
+in vec2 uv;
+
+layout(location = 0) out vec4 o_diffuse_color;
+layout(location = 1) out vec4 o_normal_color;
+
+#stk_include "utils/encode_normal.frag"
+#stk_include "utils/rgb_conversion.frag"
+#stk_include "utils/sp_texture_sampling.frag"
+
+void main()
+{
+    vec4 col = sampleTextureLayer4(uv * 2.0);
+    //col = vec4(1.0, 0.0, 0.0, 1.0);
+    vec4 col_2 = sampleTextureLayer5(uv * 2.0);//vec4(0.0, 1.0, 0.0, 1.0);
+
+    float factor = dot(vec3(0.,1.,1.), world_normal);
+    factor = clamp(factor, 0.0, 1.0);
+    col = mix(col_2, col, factor);
+
+    if (hue_change > 0.0)
+    {
+        float mask = col.a;
+        vec3 old_hsv = rgbToHsv(col.rgb);
+        float mask_step = step(mask, 0.5);
+#if !defined(Advanced_Lighting_Enabled)
+        // For similar color
+        float saturation = mask * 1.825; // 2.5 * 0.5 ^ (1. / 2.2)
+#else
+        float saturation = mask * 2.5;
+#endif
+        vec2 new_xy = mix(vec2(old_hsv.x, old_hsv.y), vec2(hue_change,
+            max(old_hsv.y, saturation)), vec2(mask_step, mask_step));
+        vec3 new_color = hsvToRgb(vec3(new_xy.x, new_xy.y, old_hsv.z));
+        col = vec4(new_color.r, new_color.g, new_color.b, 1.0);
+    }
+
+    vec3 final_color = col.xyz * color.xyz;
+
+#if defined(Advanced_Lighting_Enabled)
+    vec4 layer_2 = sampleTextureLayer2(uv);
+    vec4 layer_3 = sampleTextureLayer3(uv);
+    o_diffuse_color = vec4(final_color, layer_2.z);
+
+    vec3 tangent_space_normal = 2.0 * layer_3.xyz - 1.0;
+    vec3 frag_tangent = normalize(tangent);
+    vec3 frag_bitangent = normalize(bitangent);
+    vec3 frag_normal = normalize(normal);
+    mat3 t_b_n = mat3(frag_tangent, frag_bitangent, frag_normal);
+
+    vec3 world_normal = t_b_n * tangent_space_normal;
+
+    o_normal_color.xy = 0.5 * EncodeNormal(normalize(world_normal)) + 0.5;
+    o_normal_color.zw = layer_2.xy;
+#else
+    o_diffuse_color = vec4(final_color, 1.0);
+#endif
+}

data/shaders/sps_11_verticalMapping.xml

@@ -0,0 +1,15 @@
+<spshader>
+    <shader-info name="verticalMapping" fallback-shader="solid" use-tangents="Y"/>
+    <first-pass vertex-shader="sp_pass.vert"
+        fragment-shader="sp_vertical_mapping.frag"
+        skinned-mesh-shader="sp_skinning.vert">
+    </first-pass>
+    <shadow-pass vertex-shader="sp_shadow.vert"
+        fragment-shader="white.frag"
+        skinned-mesh-shader="sp_skinning_shadow.vert">
+    </shadow-pass>
+    <uniform-assigners>
+        <uniform-assigner name="layer"
+        function="shadowCascadeUniformAssigner"/>
+    </uniform-assigners>
+</spshader>