mapbox-gl/src/data/bucket/symbol_attributes.js

A WebGL interactive maps library

// @flow

import { createLayout } from '../../util/struct_array';

export const symbolLayoutAttributes = createLayout([
    {name: 'a_pos_offset',  components: 4, type: 'Int16'},
    {name: 'a_data',        components: 4, type: 'Uint16'}
]);

export const dynamicLayoutAttributes = createLayout([
    { name: 'a_projected_pos', components: 3, type: 'Float32' }
], 4);

export const placementOpacityAttributes = createLayout([
    { name: 'a_fade_opacity', components: 1, type: 'Uint32' }
], 4);

export const collisionVertexAttributes = createLayout([
    { name: 'a_placed', components: 2, type: 'Uint8' },
    { name: 'a_shift', components: 2, type: 'Float32'}
]);

export const collisionBox = createLayout([
    // the box is centered around the anchor point
    { type: 'Int16', name: 'anchorPointX' },
    { type: 'Int16', name: 'anchorPointY' },

    // distances to the edges from the anchor
    { type: 'Int16', name: 'x1' },
    { type: 'Int16', name: 'y1' },
    { type: 'Int16', name: 'x2' },
    { type: 'Int16', name: 'y2' },

    // the index of the feature in the original vectortile
    { type: 'Uint32', name: 'featureIndex' },
    // the source layer the feature appears in
    { type: 'Uint16', name: 'sourceLayerIndex' },
    // the bucket the feature appears in
    { type: 'Uint16', name: 'bucketIndex' },

    // collision circles for lines store their distance to the anchor in tile units
    // so that they can be ignored if the projected label doesn't extend into
    // the box area
    { type: 'Int16', name: 'radius' },
    { type: 'Int16', name: 'signedDistanceFromAnchor' }
]);

export const collisionBoxLayout = createLayout([ // used to render collision boxes for debugging purposes
    {name: 'a_pos',        components: 2, type: 'Int16'},
    {name: 'a_anchor_pos', components: 2, type: 'Int16'},
    {name: 'a_extrude',    components: 2, type: 'Int16'}
], 4);

export const collisionCircleLayout = createLayout([ // used to render collision circles for debugging purposes
    {name: 'a_pos',        components: 2, type: 'Int16'},
    {name: 'a_anchor_pos', components: 2, type: 'Int16'},
    {name: 'a_extrude',    components: 2, type: 'Int16'}
], 4);

export const placement = createLayout([
    { type: 'Int16', name: 'anchorX' },
    { type: 'Int16', name: 'anchorY' },
    { type: 'Uint16', name: 'glyphStartIndex' },
    { type: 'Uint16', name: 'numGlyphs' },
    { type: 'Uint32', name: 'vertexStartIndex' },
    { type: 'Uint32', name: 'lineStartIndex' },
    { type: 'Uint32', name: 'lineLength' },
    { type: 'Uint16', name: 'segment' },
    { type: 'Uint16', name: 'lowerSize' },
    { type: 'Uint16', name: 'upperSize' },
    { type: 'Float32', name: 'lineOffsetX' },
    { type: 'Float32', name: 'lineOffsetY' },
    { type: 'Uint8', name: 'writingMode' },
    { type: 'Uint8', name: 'hidden' },
    { type: 'Uint32', name: 'crossTileID'}
]);

export const symbolInstance = createLayout([
    { type: 'Int16', name: 'anchorX' },
    { type: 'Int16', name: 'anchorY' },
    { type: 'Int16', name: 'rightJustifiedTextSymbolIndex' },
    { type: 'Int16', name: 'centerJustifiedTextSymbolIndex' },
    { type: 'Int16', name: 'leftJustifiedTextSymbolIndex' },
    { type: 'Int16', name: 'verticalPlacedTextSymbolIndex' },
    { type: 'Uint16', name: 'key' },
    { type: 'Uint16', name: 'textBoxStartIndex' },
    { type: 'Uint16', name: 'textBoxEndIndex' },
    { type: 'Uint16', name: 'iconBoxStartIndex' },
    { type: 'Uint16', name: 'iconBoxEndIndex' },
    { type: 'Uint16', name: 'featureIndex' },
    { type: 'Uint16', name: 'numHorizontalGlyphVertices' },
    { type: 'Uint16', name: 'numVerticalGlyphVertices' },
    { type: 'Uint16', name: 'numIconVertices' },
    { type: 'Uint32', name: 'crossTileID' },
    { type: 'Float32', name: 'textBoxScale'},
    { type: 'Float32', name: 'radialTextOffset'}
]);

export const glyphOffset = createLayout([
    { type: 'Float32', name: 'offsetX' }
]);

export const lineVertex = createLayout([
    { type: 'Int16', name: 'x' },
    { type: 'Int16', name: 'y' },
    { type: 'Int16', name: 'tileUnitDistanceFromAnchor' }
]);