// deck.gl
// SPDX-License-Identifier: MIT
// Copyright (c) vis.gl contributors

export default /* wgsl */ `\
struct ConstantAttributes {
  instanceNormals: vec3<f32>,
  instanceColors: vec4<f32>,
  instancePositions: vec3<f32>,
  instancePositions64Low: vec3<f32>,
  instancePickingColors: vec3<f32>
};

const constants = ConstantAttributes(
  vec3<f32>(1.0, 0.0, 0.0),
  vec4<f32>(0.0, 0.0, 0.0, 1.0),
  vec3<f32>(0.0),
  vec3<f32>(0.0),
  vec3<f32>(0.0)
);

struct Attributes {
  @builtin(instance_index) instanceIndex : u32,
  @builtin(vertex_index) vertexIndex : u32,
  @location(0) positions: vec3<f32>,
  @location(1) instancePositions: vec3<f32>,
  @location(2) instancePositions64Low: vec3<f32>,
  @location(3) instanceNormals: vec3<f32>,
  @location(4) instanceColors: vec4<f32>,
  @location(5) instancePickingColors: vec3<f32>
};

struct Varyings {
  @builtin(position) position: vec4<f32>,
  @location(0) vColor: vec4<f32>,
  @location(1) unitPosition: vec2<f32>,
};

@vertex
fn vertexMain(attributes: Attributes) -> Varyings {
  var varyings: Varyings;
  
  // var geometry: Geometry;
  // geometry.worldPosition = instancePositions;
  // geometry.normal = project_normal(instanceNormals);

  // position on the containing square in [-1, 1] space
  varyings.unitPosition = attributes.positions.xy;
  geometry.uv = varyings.unitPosition;
  geometry.pickingColor = attributes.instancePickingColors;

  // Find the center of the point and add the current vertex
  let offset = vec3<f32>(attributes.positions.xy * project_unit_size_to_pixel(pointCloud.radiusPixels, pointCloud.sizeUnits), 0.0);
  // DECKGL_FILTER_SIZE(offset, geometry);

  varyings.position = project_position_to_clipspace(attributes.instancePositions, attributes.instancePositions64Low, vec3<f32>(0.0)); // TODO , geometry.position);
  // DECKGL_FILTER_GL_POSITION(gl_Position, geometry);
  let clipPixels = project_pixel_size_to_clipspace(offset.xy);
  varyings.position.x += clipPixels.x;
  varyings.position.y += clipPixels.y;

  // Apply lighting
  let lightColor = lighting_getLightColor2(attributes.instanceColors.rgb, project.cameraPosition, geometry.position.xyz, geometry.normal);

  // Apply opacity to instance color, or return instance picking color
  varyings.vColor = vec4(lightColor, attributes.instanceColors.a * color.opacity);
  // DECKGL_FILTER_COLOR(vColor, geometry);

  return varyings;
}

@fragment
fn fragmentMain(varyings: Varyings) -> @location(0) vec4<f32> {
  // var geometry: Geometry;
  // geometry.uv = unitPosition.xy;

  let distToCenter = length(varyings.unitPosition);
  if (distToCenter > 1.0) {
    discard;
  }

  var fragColor: vec4<f32>;

  fragColor = varyings.vColor;
  // DECKGL_FILTER_COLOR(fragColor, geometry);

  // Apply premultiplied alpha as required by transparent canvas
  fragColor = deckgl_premultiplied_alpha(fragColor);

  return fragColor;
}
`;