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

export default /* glsl */ `\
#version 300 es
#define SHADER_NAME scatterplot-layer-vertex-shader

in vec3 positions;

in vec3 instancePositions;
in vec3 instancePositions64Low;
in float instanceRadius;
in float instanceLineWidths;
in vec4 instanceFillColors;
in vec4 instanceLineColors;
in vec3 instancePickingColors;

out vec4 vFillColor;
out vec4 vLineColor;
out vec2 unitPosition;
out float innerUnitRadius;
out float outerRadiusPixels;


void main(void) {
  geometry.worldPosition = instancePositions;

  // Multiply out radius and clamp to limits
  outerRadiusPixels = clamp(
    project_size_to_pixel(scatterplot.radiusScale * instanceRadius, scatterplot.radiusUnits),
    scatterplot.radiusMinPixels, scatterplot.radiusMaxPixels
  );
  
  // Multiply out line width and clamp to limits
  float lineWidthPixels = clamp(
    project_size_to_pixel(scatterplot.lineWidthScale * instanceLineWidths, scatterplot.lineWidthUnits),
    scatterplot.lineWidthMinPixels, scatterplot.lineWidthMaxPixels
  );

  // outer radius needs to offset by half stroke width
  outerRadiusPixels += scatterplot.stroked * lineWidthPixels / 2.0;
  // Expand geometry to accomodate edge smoothing
  float edgePadding = scatterplot.antialiasing ? (outerRadiusPixels + SMOOTH_EDGE_RADIUS) / outerRadiusPixels : 1.0;

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

  innerUnitRadius = 1.0 - scatterplot.stroked * lineWidthPixels / outerRadiusPixels;
  
  if (scatterplot.billboard) {
    gl_Position = project_position_to_clipspace(instancePositions, instancePositions64Low, vec3(0.0), geometry.position);
    DECKGL_FILTER_GL_POSITION(gl_Position, geometry);
    vec3 offset = edgePadding * positions * outerRadiusPixels;
    DECKGL_FILTER_SIZE(offset, geometry);
    gl_Position.xy += project_pixel_size_to_clipspace(offset.xy);
  } else {
    vec3 offset = edgePadding * positions * project_pixel_size(outerRadiusPixels);
    DECKGL_FILTER_SIZE(offset, geometry);
    gl_Position = project_position_to_clipspace(instancePositions, instancePositions64Low, offset, geometry.position);
    DECKGL_FILTER_GL_POSITION(gl_Position, geometry);
  }

  // Apply opacity to instance color, or return instance picking color
  vFillColor = vec4(instanceFillColors.rgb, instanceFillColors.a * layer.opacity);
  DECKGL_FILTER_COLOR(vFillColor, geometry);
  vLineColor = vec4(instanceLineColors.rgb, instanceLineColors.a * layer.opacity);
  DECKGL_FILTER_COLOR(vLineColor, geometry);
}
`;