using Godot;
using System;

using Rokojori.Extensions;
namespace Rokojori
{
  /** The uniform block Shading/Library/ControlMap.gdshaderinc expects a consumer
      to declare, as property names.

      Same role TerrainOffsetShader plays for GeometryTerrainOffset: the names
      live in one place, so ControlMapTerrain.PushToMaterials() feeds any
      material that declares them without either side holding a string literal.

      The include itself declares no uniforms - it takes a ControlMapSetup struct
      the consumer fills. These are the uniforms the consumer needs in order to
      fill it.
  */
  public class ControlMapShader
  {
    /** The packed control map. R32F, read with texelFetch only. */
    public static readonly Sampler2DPropertyName controlMap
      = Sampler2DPropertyName.Create( "control_map" );

    /** Ground albedo, with the texture's height in alpha. */
    public static readonly Sampler2DArrayPropertyName albedoArray
      = Sampler2DArrayPropertyName.Create( "control_albedo_array" );

    /** Ground normal maps, with roughness in alpha. */
    public static readonly Sampler2DArrayPropertyName normalArray
      = Sampler2DArrayPropertyName.Create( "control_normal_array" );

    /** One row of ( metersPerTile, detile, normalStrength, roughness ), one
        texel per texture index.
    */
    public static readonly Sampler2DPropertyName textureParams
      = Sampler2DPropertyName.Create( "control_texture_params" );

    public static readonly BoolPropertyName hasTextureParams
      = BoolPropertyName.Create( "control_has_texture_params" );

    public static readonly Vector4PropertyName defaultParams
      = Vector4PropertyName.Create( "control_default_params" );

    /* Placement - the same convention as TerrainOffsetShader, so a control map
       and a height map over the same rect line up texel for texel.
    */

    public static readonly Vector2PropertyName centerXZ
      = Vector2PropertyName.Create( "control_center_xz" );

    public static readonly Vector2PropertyName sizeXZ
      = Vector2PropertyName.Create( "control_size_xz" );

    /* The bit layout. Each is ( offset, bit count ), pushed from
       ControlMapFormat so the packer and the GPU decoder cannot disagree.

       angleField is fed from ControlMapFormat.rotationField - the shader calls
       it an angle because it decodes radians, the authoring side calls it a
       rotation because that is what the user picks. See
       ControlMapFormat.PushToMaterial, which is the only place the two meet.
    */

    public static readonly Vector2IPropertyName baseField
      = Vector2IPropertyName.Create( "control_base_field" );

    public static readonly Vector2IPropertyName overlayField
      = Vector2IPropertyName.Create( "control_overlay_field" );

    public static readonly Vector2IPropertyName blendField
      = Vector2IPropertyName.Create( "control_blend_field" );

    public static readonly Vector2IPropertyName angleField
      = Vector2IPropertyName.Create( "control_angle_field" );

    public static readonly Vector2IPropertyName scaleField
      = Vector2IPropertyName.Create( "control_scale_field" );

    public static readonly Vector2IPropertyName holeField
      = Vector2IPropertyName.Create( "control_hole_field" );

    public static readonly Vector2IPropertyName navigableField
      = Vector2IPropertyName.Create( "control_navigable_field" );

    /* Value mapping and shading options. */

    public static readonly FloatPropertyName scaleMin
      = FloatPropertyName.Create( "control_scale_min" );

    public static readonly FloatPropertyName scaleStep
      = FloatPropertyName.Create( "control_scale_step" );

    public static readonly FloatPropertyName blendSharpness
      = FloatPropertyName.Create( "control_blend_sharpness" );

    public static readonly BoolPropertyName bilinear
      = BoolPropertyName.Create( "control_bilinear" );
  }
}