# This effect blends 4 materials based on a material map
# The textures should be setup like in the 04-Material-Blending sample.

# The last material is the base material and thus has no blending. It will
# be wherever no other material is.

vertex:

fragment:
  inout: |
    uniform sampler2D p3d_Texture0;      // Alpha -  Map

    uniform sampler2D p3d_Texture1;      // M1 - Diffuse
    uniform sampler2D p3d_Texture2;      // M1 - Normal
    uniform sampler2D p3d_Texture3;      // M1 - Specular
    uniform sampler2D p3d_Texture4;      // M1 - Blendmap

    uniform sampler2D p3d_Texture5;      // M2 - Diffuse
    uniform sampler2D p3d_Texture6;      // M2 - Normal
    uniform sampler2D p3d_Texture7;      // M2 - Specular
    uniform sampler2D p3d_Texture8;      // M2 - Blendmap

    uniform sampler2D p3d_Texture9;      // M3 - Diffuse
    uniform sampler2D p3d_Texture10;     // M3 - Normal
    uniform sampler2D p3d_Texture11;     // M3 - Specular
    uniform sampler2D p3d_Texture12;     // M3 - Blendmap

    uniform sampler2D p3d_Texture13;     // M4 - Diffuse
    uniform sampler2D p3d_Texture14;     // M4 - Normal
    uniform sampler2D p3d_Texture15;     // M4 - Specular
    uniform sampler2D p3d_Texture16;     // M4 - Blendmap

    uniform float detail_scale_factor;

    uniform float material_0_pow;
    uniform float material_0_add;
    uniform float material_1_pow;
    uniform float material_1_add;
    uniform float material_2_pow;
    uniform float material_2_add;

  defines: |
    #define DONT_FETCH_DEFAULT_TEXTURES 1
    #define DONT_SET_MATERIAL_PROPERTIES 1

  material: |

    // Get detail coordinate
    vec2 detail_coord = texcoord * detail_scale_factor;
    vec4 layers = texture(p3d_Texture0, texcoord);
    layers.xyz *= layers.w;

    // Blend all materials
    layers.x = blend_material(layers.x, texture(p3d_Texture4,  detail_coord).x, material_0_add, material_0_pow);
    layers.y = blend_material(layers.y, texture(p3d_Texture8,  detail_coord).x, material_1_add, material_1_pow);
    layers.z = blend_material(layers.z, texture(p3d_Texture12, detail_coord).x, material_2_add, material_2_pow);
    layers.w = saturate(1.0 - dot(layers.xyz, vec3(1))); // More inituitive

    // Diffuse
    vec3 m_base = vec3(0);
    m_base  = texture(p3d_Texture1,  detail_coord).xyz * layers.x;
    m_base += texture(p3d_Texture5,  detail_coord).xyz * layers.y;
    m_base += texture(p3d_Texture9,  detail_coord).xyz * layers.z;
    m_base += texture(p3d_Texture13, detail_coord).xyz * layers.w;

    // Normal
    vec3 m_nrm = vec3(0);
    m_nrm += unpack_texture_normal(texture(p3d_Texture2,  detail_coord).xyz) * layers.x;
    m_nrm += unpack_texture_normal(texture(p3d_Texture6,  detail_coord).xyz) * layers.y;
    m_nrm += unpack_texture_normal(texture(p3d_Texture10, detail_coord).xyz) * layers.z;
    m_nrm += unpack_texture_normal(texture(p3d_Texture14, detail_coord).xyz) * layers.w;

    // Specular
    float spec = 0.0;
    spec  = texture(p3d_Texture3,  detail_coord).x * layers.x;
    spec += texture(p3d_Texture7,  detail_coord).x * layers.y;
    spec += texture(p3d_Texture11, detail_coord).x * layers.z;
    spec += texture(p3d_Texture15, detail_coord).x * layers.w;

    // Material properties
    m.shading_model = mInput.shading_model;
    m.basecolor = m_base * mInput.color;
    m.normal = apply_normal_map(vOutput.normal, m_nrm, mInput.normalfactor);
    m.specular_ior = blend_ior(mInput.specular_ior, spec);
    m.roughness = mInput.roughness;
    m.metallic = mInput.metallic;
    m.shading_model_param0 = mInput.arbitrary0;