maplibre-gl
Version:
BSD licensed community fork of mapbox-gl, a WebGL interactive maps library
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text/typescript
import StencilMode from '../gl/stencil_mode';
import DepthMode from '../gl/depth_mode';
import CullFaceMode from '../gl/cull_face_mode';
import {
backgroundUniformValues,
backgroundPatternUniformValues
} from './program/background_program';
import type Painter from './painter';
import type SourceCache from '../source/source_cache';
import type BackgroundStyleLayer from '../style/style_layer/background_style_layer';
import {OverscaledTileID} from '../source/tile_id';
export default drawBackground;
function drawBackground(painter: Painter, sourceCache: SourceCache, layer: BackgroundStyleLayer, coords?: Array<OverscaledTileID>) {
const color = layer.paint.get('background-color');
const opacity = layer.paint.get('background-opacity');
if (opacity === 0) return;
const context = painter.context;
const gl = context.gl;
const transform = painter.transform;
const tileSize = transform.tileSize;
const image = layer.paint.get('background-pattern');
if (painter.isPatternMissing(image)) return;
const pass = (!image && color.a === 1 && opacity === 1 && painter.opaquePassEnabledForLayer()) ? 'opaque' : 'translucent';
if (painter.renderPass !== pass) return;
const stencilMode = StencilMode.disabled;
const depthMode = painter.depthModeForSublayer(0, pass === 'opaque' ? DepthMode.ReadWrite : DepthMode.ReadOnly);
const colorMode = painter.colorModeForRenderPass();
const program = painter.useProgram(image ? 'backgroundPattern' : 'background');
const tileIDs = coords ? coords : transform.coveringTiles({tileSize, terrain: painter.style.terrain});
if (image) {
context.activeTexture.set(gl.TEXTURE0);
painter.imageManager.bind(painter.context);
}
const crossfade = layer.getCrossfadeParameters();
for (const tileID of tileIDs) {
const matrix = coords ? tileID.posMatrix : painter.transform.calculatePosMatrix(tileID.toUnwrapped());
const uniformValues = image ?
backgroundPatternUniformValues(matrix, opacity, painter, image, {tileID, tileSize}, crossfade) :
backgroundUniformValues(matrix, opacity, color);
const terrainData = painter.style.terrain && painter.style.terrain.getTerrainData(tileID);
program.draw(context, gl.TRIANGLES, depthMode, stencilMode, colorMode, CullFaceMode.disabled,
uniformValues, terrainData, layer.id, painter.tileExtentBuffer,
painter.quadTriangleIndexBuffer, painter.tileExtentSegments);
}
}