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@mourner mourner/shadows.html
Created Aug 17, 2018

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Experimental Mapbox GL shadows (for custom-layers branch)
<!DOCTYPE html>
<html>
<head>
<title>Mapbox GL JS debug page</title>
<meta charset='utf-8'>
<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no">
<link rel='stylesheet' href='/dist/mapbox-gl.css' />
<style>
body { margin: 0; padding: 0; }
html, body, #map { height: 100%; }
#time { position: absolute; width: 90%; top: 10px; left: 10px; }
</style>
</head>
<body>
<div id='map'></div>
<input id='time' type='range' min="0" max="86400" />
<script src='/dist/mapbox-gl-dev.js'></script>
<script src='https://unpkg.com/suncalc@1.8.0/suncalc.js'></script>
<!-- <script src='/debug/access_token_generated.js'></script> -->
<script>
mapboxgl.accessToken = 'pk.eyJ1IjoibW91cm5lciIsImEiOiJWWnRiWG1VIn0.j6eccFHpE3Q04XPLI7JxbA';
var map = window.map = new mapboxgl.Map({
container: 'map',
zoom: 15,
center: [-74.0059, 40.7064],
style: 'mapbox://styles/mapbox/cjf4m44iw0uza2spb3q0a7s41',
hash: true
});
var date = new Date();
var time = date.getHours() * 60 * 60 + date.getMinutes() * 60 + date.getSeconds();
var timeInput = document.getElementById('time');
timeInput.value = time;
timeInput.oninput = () => {
time = +timeInput.value;
date.setHours(Math.floor(time / 60 / 60));
date.setMinutes(Math.floor(time / 60) % 60);
date.setSeconds(time % 60);
map.triggerRepaint();
};
map.addControl(new mapboxgl.NavigationControl());
class BuildingShadows {
constructor() {
this.id = 'building-shadows';
this.type = 'custom';
this.renderingMode = '3d';
this.opacity = 0.5;
}
onAdd(map, gl) {
this.map = map;
const vertexSource = `
uniform mat4 u_matrix;
uniform float u_height_factor;
uniform float u_altitude;
uniform float u_azimuth;
attribute vec2 a_pos;
attribute vec4 a_normal_ed;
attribute lowp vec2 a_base;
attribute lowp vec2 a_height;
void main() {
float base = max(0.0, a_base.x);
float height = max(0.0, a_height.x);
float t = mod(a_normal_ed.x, 2.0);
vec4 pos = vec4(a_pos, t > 0.0 ? height : base, 1);
float len = pos.z * u_height_factor / tan(u_altitude);
pos.x += cos(u_azimuth) * len;
pos.y += sin(u_azimuth) * len;
pos.z = 0.0;
gl_Position = u_matrix * pos;
}
`;
const fragmentSource = `
void main() {
gl_FragColor = vec4(0.0, 0.0, 0.0, 1.0);
}
`;
const vertexShader = gl.createShader(gl.VERTEX_SHADER);
gl.shaderSource(vertexShader, vertexSource);
gl.compileShader(vertexShader);
const fragmentShader = gl.createShader(gl.FRAGMENT_SHADER);
gl.shaderSource(fragmentShader, fragmentSource);
gl.compileShader(fragmentShader);
this.program = gl.createProgram();
gl.attachShader(this.program, vertexShader);
gl.attachShader(this.program, fragmentShader);
gl.linkProgram(this.program);
gl.validateProgram(this.program);
this.uMatrix = gl.getUniformLocation(this.program, "u_matrix");
this.uHeightFactor = gl.getUniformLocation(this.program, "u_height_factor");
this.uAltitude = gl.getUniformLocation(this.program, "u_altitude");
this.uAzimuth = gl.getUniformLocation(this.program, "u_azimuth");
this.aPos = gl.getAttribLocation(this.program, "a_pos");
this.aNormal = gl.getAttribLocation(this.program, "a_normal_ed");
this.aBase = gl.getAttribLocation(this.program, "a_base");
this.aHeight = gl.getAttribLocation(this.program, "a_height");
}
render(gl, matrix) {
gl.useProgram(this.program);
const source = this.map.style.sourceCaches['mapbox-streets'];
const coords = source.getVisibleCoordinates().reverse();
const buildingsLayer = map.getLayer('3d-buildings');
const context = this.map.painter.context;
const {lng, lat} = this.map.getCenter();
const pos = SunCalc.getPosition(date, lat, lng);
gl.uniform1f(this.uAltitude, pos.altitude);
gl.uniform1f(this.uAzimuth, pos.azimuth + 3 * Math.PI / 2);
map.setLight({
anchor: 'map',
position: [1.5, 180 + pos.azimuth * 180 / Math.PI, 90 - pos.altitude * 180 / Math.PI],
'position-transition': {duration: 0},
color: '#fdb'
// color: `hsl(20, ${50 * Math.cos(pos.altitude)}%, ${ 200 * Math.sin(pos.altitude) }%)`
}, {duration: 0});
this.opacity = Math.sin(Math.max(pos.altitude, 0)) * 0.9;
for (const coord of coords) {
const tile = source.getTile(coord);
const bucket = tile.getBucket(buildingsLayer);
if (!bucket) continue;
const [heightBuffer, baseBuffer] = bucket.programConfigurations.programConfigurations['3d-buildings']._buffers;
gl.uniformMatrix4fv(this.uMatrix, false, coord.posMatrix);
gl.uniform1f(this.uHeightFactor, Math.pow(2, coord.overscaledZ) / tile.tileSize / 8);
for (const segment of bucket.segments.get()) {
const numPrevAttrib = context.currentNumAttributes || 0;
const numNextAttrib = 2;
for (let i = numNextAttrib; i < numPrevAttrib; i++) gl.disableVertexAttribArray(i);
const vertexOffset = segment.vertexOffset || 0;
gl.enableVertexAttribArray(this.aPos);
gl.enableVertexAttribArray(this.aNormal);
gl.enableVertexAttribArray(this.aHeight);
gl.enableVertexAttribArray(this.aBase);
bucket.layoutVertexBuffer.bind();
gl.vertexAttribPointer(this.aPos, 2, gl.SHORT, false, 12, 12 * vertexOffset);
gl.vertexAttribPointer(this.aNormal, 4, gl.SHORT, false, 12, 4 + 12 * vertexOffset);
heightBuffer.bind();
gl.vertexAttribPointer(this.aHeight, 1, gl.FLOAT, false, 4, 4 * vertexOffset);
baseBuffer.bind();
gl.vertexAttribPointer(this.aBase, 1, gl.FLOAT, false, 4, 4 * vertexOffset);
bucket.indexBuffer.bind();
context.currentNumAttributes = numNextAttrib;
gl.drawElements(gl.TRIANGLES, segment.primitiveLength * 3, gl.UNSIGNED_SHORT, segment.primitiveOffset * 3 * 2);
}
}
}
}
map.on('load', () => {
map.removeLayer('building');
map.addLayer({
'id': '3d-buildings',
'source': 'mapbox-streets',
'source-layer': 'building',
'type': 'fill-extrusion',
'minzoom': 14,
'paint': {
'fill-extrusion-color': '#ddd',
'fill-extrusion-height': ["number", ["get", "height"], 5],
'fill-extrusion-base': ["number", ["get", "min_height"], 0],
'fill-extrusion-opacity': 1
}
}, 'road-label');
map.addLayer(new BuildingShadows(), '3d-buildings');
});
</script>
</body>
</html>
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