From 50e433afca801b5a8250e9067216f004a9859243 Mon Sep 17 00:00:00 2001
From: samuncle <samuncle06@gmail.com>
Date: Sun, 15 Apr 2018 09:37:55 +0200
Subject: [PATCH] Add shader specialized for roads, still some stuff to be
 tuned

---
 data/shaders/sp_road_blending.frag   | 90 ++++++++++++++++++++++++++++
 data/shaders/sps_12_roadBlending.xml | 17 ++++++
 2 files changed, 107 insertions(+)
 create mode 100644 data/shaders/sp_road_blending.frag
 create mode 100644 data/shaders/sps_12_roadBlending.xml

diff --git a/data/shaders/sp_road_blending.frag b/data/shaders/sp_road_blending.frag
new file mode 100644
index 000000000..d6715dde6
--- /dev/null
+++ b/data/shaders/sp_road_blending.frag
@@ -0,0 +1,90 @@
+in vec3 bitangent;
+in vec4 color;
+in float hue_change;
+in vec3 normal;
+in vec3 tangent;
+in vec2 uv;
+in vec4 world_position;
+in float camdist;
+
+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()
+{
+    vec2 uuv = vec2(world_position.x, world_position.z);
+    uuv *= 0.2;
+    vec4 col = multi_sampleTextureLayer0(uv, camdist);
+
+    float mask = sampleTextureLayer4(uuv * 2.0).r;
+
+    //* (1.0 - color.g)
+    mask = mix(1.0, mask, color.r);
+    mask = mix(0.0, mask, 1.0 - color.g);
+    if(mask < 0.5)
+    {
+        discard;
+    }
+
+    // Adding some skidding marks to the road
+    float mask_2 = sampleTextureLayer4(uuv * 0.1).r;
+    float mask_3 = sampleTextureLayer4(uuv * 3.5).r;
+    mask_2 = pow(mask_2, 1.5);
+    mask_2 *= pow(mask_3, 0.5);
+
+    float skidding_marks = sampleTextureLayer5(uv * 10).g;
+    skidding_marks *= mask_2;
+    col = mix(col, vec4(0.0, 0.0, 0.0, 1.0), skidding_marks);
+
+    float skidding_marks_2 = sampleTextureLayer5(uv * 15).g;
+    skidding_marks_2 *= mask_2;
+    col = mix(col, vec4(0.0, 0.0, 0.0, 1.0), skidding_marks_2);
+
+    // Add some cracks
+    float cracks_marks = sampleTextureLayer5(uv * 11).b;
+    float crack_mask = sampleTextureLayer4(uuv * 0.5).r;
+    cracks_marks *= crack_mask;
+    col = mix(col, vec4(0.0, 0.0, 0.0, 1.0), cracks_marks);
+
+    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 = multi_sampleTextureLayer2(uv, camdist);
+    vec4 layer_3 = multi_sampleTextureLayer3(uv, camdist);
+    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
+}
diff --git a/data/shaders/sps_12_roadBlending.xml b/data/shaders/sps_12_roadBlending.xml
new file mode 100644
index 000000000..9bb29db6d
--- /dev/null
+++ b/data/shaders/sps_12_roadBlending.xml
@@ -0,0 +1,17 @@
+<spshader>
+    <shader-info name="roadBlending" fallback-shader="solid" use-tangents="Y"/>
+    <first-pass vertex-shader="sp_pass.vert"
+        fragment-shader="sp_road_blending.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>