From 283c245a88ef8f540f4c2fc119466fc514b49312 Mon Sep 17 00:00:00 2001
From: Christian Paul <info@jaller.de>
Date: Fri, 22 Dec 2017 21:33:10 -0800
Subject: [PATCH] Non-perfect translation of Renderer.js

---
 src/Renderer.js | 342 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 342 insertions(+)
 create mode 100644 src/Renderer.js

diff --git a/src/Renderer.js b/src/Renderer.js
new file mode 100644
index 0000000..e505155
--- /dev/null
+++ b/src/Renderer.js
@@ -0,0 +1,342 @@
+/*
+  termap - Terminal Map Viewer
+  by Michael Strassburger <codepoet@cpan.org>
+
+  The Console Vector Tile renderer - bäm!
+*/
+'use strict';
+const Promise = require('bluebird');
+const x256 = require('x256');
+const simplify = require('simplify-js');
+
+const Canvas = require('./Canvas');
+const LabelBuffer = require('./LabelBuffer');
+const Styler = require('./Styler');
+const Tile = require('./Tile');
+const utils = require('./utils');
+const config = require('./config');
+
+class Renderer {
+  constructor(output, tileSource) {
+    this.output = output;
+    this.tileSource = tileSource;
+    this.labelBuffer = new LabelBuffer();
+  }
+
+  loadStyleFile(file) {
+    this.styler = new Styler(file);
+    this.tileSource.useStyler(this.styler);
+  }
+
+  setSize(width, height) {
+    this.width = width;
+    this.height = height;
+    this.canvas = new Canvas(width, height);
+  }
+
+  draw(center, zoom) {
+    if (this.isDrawing) return Promise.reject();
+    this.isDrawing = true;
+
+    this.labelBuffer.clear();
+    this._seen = {};
+
+    let ref;
+    const color = ((ref = this.styler.styleById['background']) !== null ?
+      ref.paint['background-color']
+    :
+      void 0
+    );
+    if (color) {
+      this.canvas.setBackground(x256(utils.hex2rgb(color)));
+    }
+
+    this.canvas.clear();
+
+    return Promise.resolve(this._visibleTiles(center, zoom)).map((tile) => {
+      return this._getTile(tile);
+    }).map((tile) => {
+      return this._getTileFeatures(tile, zoom);
+    }).then((tiles) => {
+      return this._renderTiles(tiles);
+    }).then(() => {
+      return this._getFrame();
+    }).catch(function(e) {
+      return console.log(e);
+    }).finally((frame) => {
+      this.isDrawing = false;
+      this.lastDrawAt = Date.now();
+      return frame;
+    });
+  }
+
+  _visibleTiles(center, zoom) {
+    const z = utils.baseZoom(zoom);
+    center = utils.ll2tile(center.lon, center.lat, z);
+    
+    const tiles = [];
+    const tileSize = utils.tilesizeAtZoom(zoom);
+    
+    for (let y = Math.floor(center.y) - 1; y <= Math.floor(center.y) + 1; y++) {
+      for (let x = Math.floor(center.x) - 1; x <= Math.floor(center.x) + 1; x++) {
+        const tile = {x, y, z};
+        const position = {
+          x: this.width / 2 - (center.x - tile.x) * tileSize,
+          y: this.height / 2 - (center.y - tile.y) * tileSize,
+        };
+        
+        const gridSize = Math.pow(2, z);
+        
+        tile.x %= gridSize;
+        
+        if (tile.x < 0) {
+          tile.x = z === 0 ? 0 : tile.x + gridSize;
+        }
+        
+        if (tile.y < 0 || tile.y >= gridSize || position.x + tileSize < 0 || position.y + tileSize < 0 || position.x > this.width || position.y > this.height) {
+          continue;
+        }
+        
+        tiles.push({
+          xyz: tile,
+          zoom: zoom,
+          position: position,
+          size: tileSize,
+        });
+      }
+    }
+    return tiles;
+  }
+
+  _getTile(tile) {
+    return this.tileSource
+    .getTile(tile.xyz.z, tile.xyz.x, tile.xyz.y)
+    .then((data) => {
+      tile.data = data;
+      return tile;
+    });
+  }
+
+  _getTileFeatures(tile, zoom) {
+    const position = tile.position;
+    const layers = {};
+    const drawOrder = this._generateDrawOrder(zoom);
+    for (const layerId of drawOrder) {
+      const layer = (tile.data.layers || {})[layerId];
+      if (!layer) {
+        continue;
+      }
+      
+      const scale = layer.extent / utils.tilesizeAtZoom(zoom);
+      layers[layerId] = {
+        scale: scale,
+        features: layer.tree.search({
+          minX: -position.x * scale,
+          minY: -position.y * scale,
+          maxX: (this.width - position.x) * scale,
+          maxY: (this.height - position.y) * scale
+        }),
+      };
+    }
+    tile.layers = layers;
+    return tile;
+  }
+
+  _renderTiles(tiles) {
+    var drawn, feature, i, j, k, l, label, labels, layer, layerId, len, len1, len2, len3, ref, ref1, tile;
+    drawn = {};
+    labels = [];
+    ref = this._generateDrawOrder(tiles[0].xyz.z);
+    for (i = 0, len = ref.length; i < len; i++) {
+      layerId = ref[i];
+      for (j = 0, len1 = tiles.length; j < len1; j++) {
+        tile = tiles[j];
+        if (!(layer = tile.layers[layerId])) {
+          continue;
+        }
+        ref1 = layer.features;
+        for (k = 0, len2 = ref1.length; k < len2; k++) {
+          feature = ref1[k];
+          // continue if feature.id and drawn[feature.id]
+          // drawn[feature.id] = true
+          if (layerId.match(/label/)) {
+            labels.push({
+              tile: tile,
+              feature: feature,
+              scale: layer.scale
+            });
+          } else {
+            this._drawFeature(tile, feature, layer.scale);
+          }
+        }
+      }
+    }
+    labels.sort(function(a, b) {
+      return a.feature.sorty - b.feature.sort;
+    });
+    const results = [];
+    for (const label of labels) {
+      results.push(this._drawFeature(label.tile, label.feature, label.scale));
+    }
+    return results;
+  }
+
+  _getFrame() {
+    let frame = '';
+    if (!this.lastDrawAt) {
+      frame += this.terminal.CLEAR;
+    }
+    frame += this.terminal.MOVE;
+    frame += this.canvas.frame();
+    return frame;
+  }
+
+  featuresAt(x, y) {
+    return this.labelBuffer.featuresAt(x, y);
+  }
+
+  _drawFeature(tile, feature, scale) {
+    let points, placed, genericSymbol;
+    if (feature.style.minzoom && tile.zoom < feature.style.minzoom) {
+      return false;
+    } else if (feature.style.maxzoom && tile.zoom > feature.style.maxzoom) {
+      return false;
+    }
+    
+    switch (feature.style.type) {
+      case 'line':
+        let width = feature.style.paint['line-width'];
+        if (width instanceof Object) {
+          // TODO: apply the correct zoom based value
+          width = width.stops[0][1];
+        }
+        points = this._scaleAndReduce(tile, feature, feature.points, scale);
+        if (points.length) {
+          this.canvas.polyline(points, feature.color, width);
+        }
+        break;
+      case 'fill':
+        points = feature.points.map((p) => {
+          return this._scaleAndReduce(tile, feature, p, scale, false);
+        });
+        this.canvas.polygon(points, feature.color);
+        break;
+      case 'symbol':
+        const text = feature.label || (genericSymbol = config.poiMarker);
+        
+        if (this._seen[text] && !genericSymbol) {
+          return false;
+        }
+        
+        placed = false;
+        const points2 = this._scaleAndReduce(tile, feature, feature.points, scale);
+        for (const point of points2) {
+          let ref1, ref2;
+          const x = point.x - text.length;
+          const margin = ((ref1 = config.layers[feature.layer]) != null ? ref1.margin : void 0) || config.labelMargin;
+          if (this.labelBuffer.writeIfPossible(text, x, point.y, feature, margin)) {
+            this.canvas.text(text, x, point.y, feature.color);
+            placed = true;
+            break;
+          } else if (((ref2 = config.layers[feature.layer]) != null ? ref2.cluster : void 0) && this.labelBuffer.writeIfPossible(config.poiMarker, point.x, point.y, feature, 3)) {
+            this.canvas.text(config.poiMarker, point.x, point.y, feature.color);
+            placed = true;
+            break;
+          }
+        }
+        if (placed) {
+          this._seen[text] = true;
+        }
+    }
+    return true;
+  }
+
+  _scaleAndReduce(tile, feature, points, scale, filter = true) {
+    let lastX;
+    let lastY;
+    let outside;
+    const scaled = [];
+    
+    const minX = -this.tilePadding;
+    const minY = -this.tilePadding;
+    const maxX = this.width + this.tilePadding;
+    const maxY = this.height + this.tilePadding;
+    
+    for (const point of points) {
+      const x = Math.floor(tile.position.x + (point.x / scale));
+      const y = Math.floor(tile.position.y + (point.y / scale));
+      if (lastX === x && lastY === y) {
+        continue;
+      }
+      lastY = y;
+      lastX = x;
+      if (filter) {
+        if (x < minX || x > maxX || y < minY || y > maxY) {
+          if (outside) {
+            continue;
+          }
+          outside = true;
+        } else {
+          if (outside) {
+            outside = null;
+            scaled.push({x: lastX, y: lastY});
+          }
+        }
+      }
+      scaled.push({x, y});
+    }
+    if (feature.style.type !== 'symbol') {
+      if (scaled.length < 2) {
+        return [];
+      }
+      if (config.simplifyPolylines) {
+        return simplify(scaled, .5, true);
+      } else {
+        return scaled;
+      }
+    } else {
+      return scaled;
+    }
+  }
+
+  _generateDrawOrder(zoom) {
+    if (zoom < 2) {
+      return [
+        'admin',
+        'water',
+        'country_label',
+        'marine_label',
+      ];
+    } else {
+      return [
+        'landuse',
+        'water',
+        'marine_label',
+        'building',
+        'road',
+        'admin',
+        'country_label',
+        'state_label',
+        'water_label',
+        'place_label',
+        'rail_station_label',
+        'poi_label',
+        'road_label',
+        'housenum_label',
+      ];
+   }
+  }
+}
+
+Renderer.prototype.terminal = {
+  CLEAR: '\x1B[2J',
+  MOVE: '\x1B[?6h',
+};
+
+Renderer.prototype.isDrawing = false;
+Renderer.prototype.lastDrawAt = 0;
+Renderer.prototype.labelBuffer = null;
+Renderer.prototype.tileSource = null;
+Renderer.prototype.tilePadding = 64;
+
+module.exports = Renderer;