From f6a86fddad6c7bc532f1f184d186196aa4e7f8b2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cam=20Sa=C3=BCl?= <cammsaul@gmail.com>
Date: Fri, 2 Oct 2015 16:59:19 -0700
Subject: [PATCH] Rewrite Java code for rendering map tiles in Clojure
---
project.clj | 2 -
.../api/tiles/GoogleMapPinsOverlay.java | 109 --------------
.../metabase/corvus/api/tiles/MapPixel.java | 24 ---
.../metabase/corvus/api/tiles/MapPoint.java | 24 ---
src/metabase/api/tiles.clj | 137 ++++++++++++------
5 files changed, 92 insertions(+), 204 deletions(-)
delete mode 100644 src/java/com/metabase/corvus/api/tiles/GoogleMapPinsOverlay.java
delete mode 100644 src/java/com/metabase/corvus/api/tiles/MapPixel.java
delete mode 100644 src/java/com/metabase/corvus/api/tiles/MapPoint.java
diff --git a/project.clj b/project.clj
index 8f7489c12c2..cc8c80303cd 100644
--- a/project.clj
+++ b/project.clj
@@ -52,12 +52,10 @@
[swiss-arrows "1.0.0"]] ; 'Magic wand' macro -<>, etc.
:plugins [[lein-environ "1.0.0"] ; easy access to environment variables
[lein-ring "0.9.3"]] ; start the HTTP server with 'lein ring server'
- :java-source-paths ["src/java"]
:main ^:skip-aot metabase.core
:manifest {"Liquibase-Package" "liquibase.change,liquibase.changelog,liquibase.database,liquibase.parser,liquibase.precondition,liquibase.datatype,liquibase.serializer,liquibase.sqlgenerator,liquibase.executor,liquibase.snapshot,liquibase.logging,liquibase.diff,liquibase.structure,liquibase.structurecompare,liquibase.lockservice,liquibase.sdk,liquibase.ext"}
:target-path "target/%s"
:javac-options ["-target" "1.6" "-source" "1.6"]
- ;; :jar-exclusions [#"\.java"] Circle CI doesn't like regexes because it's using the EDN reader and is retarded
:ring {:handler metabase.core/app
:init metabase.core/init
:destroy metabase.core/destroy}
diff --git a/src/java/com/metabase/corvus/api/tiles/GoogleMapPinsOverlay.java b/src/java/com/metabase/corvus/api/tiles/GoogleMapPinsOverlay.java
deleted file mode 100644
index 9d3ac1783b0..00000000000
--- a/src/java/com/metabase/corvus/api/tiles/GoogleMapPinsOverlay.java
+++ /dev/null
@@ -1,109 +0,0 @@
-package com.metabase.corvus.api.tiles;
-
-import javax.imageio.ImageIO;
-import java.awt.*;
-import java.awt.image.BufferedImage;
-import java.io.ByteArrayOutputStream;
-import java.io.File;
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Vector;
-
-/**
- * Created by agilliland on 3/23/15.
- */
-public class GoogleMapPinsOverlay {
-
- public static final int TILE_SIZE = 256;
- public static final MapPoint PIXEL_ORIGIN = new MapPoint(TILE_SIZE / 2, TILE_SIZE / 2);
- public static final double PIXELS_PER_LON_DEGREE = TILE_SIZE / 360.0;
- public static final double PIXELS_PER_LON_RADIAN = TILE_SIZE / (2 * Math.PI);
-
-
- private final int numTiles;
- private final BufferedImage tile;
-
-
- public GoogleMapPinsOverlay(int zoom, ArrayList<ArrayList> points) {
- // the zoom is an integer which tells us how many tiles (256x256) are in view at the moment
- this.numTiles = 1 << zoom;
-
- // create an empty image to serve as our pins overlay image
- this.tile = new BufferedImage(TILE_SIZE, TILE_SIZE, BufferedImage.TYPE_INT_ARGB);
-
- // do the real work here
- render(points);
- }
-
-
- // given a set of lat/lon points this will update the image and render a "pin" for each point
- private void render(ArrayList<ArrayList> points) {
- Graphics g = this.tile.getGraphics();
- g.setColor(Color.red);
- try {
- for(ArrayList point : points) {
- // add a pin to the image
- double latitude = (Double) point.get(0);
- double longitude = (Double) point.get(1);
-
- // determine map point given our lat/long
- double SinY = this.bound(Math.sin(this.degreesToRadians(latitude)), -0.9999, 0.9999);
- MapPoint mapPoint = new MapPoint(
- PIXEL_ORIGIN.getX() + (longitude * PIXELS_PER_LON_DEGREE),
- PIXEL_ORIGIN.getY() + 0.5 * Math.log((1 + SinY) / (1 - SinY)) * (PIXELS_PER_LON_RADIAN * -1));
-
- // determine pixel location of our map point
- MapPixel mapPixel = new MapPixel(
- (int) Math.floor(mapPoint.getX() * numTiles),
- (int) Math.floor(mapPoint.getY() * numTiles));
-
- // convert map pixel to tile pixel
- MapPixel tilePixel = new MapPixel(
- mapPixel.getX() % TILE_SIZE,
- mapPixel.getY() % TILE_SIZE);
-
- // now draw a "pin" at the given tile pixel location
- g.fillOval(tilePixel.getX(), tilePixel.getY(), 5, 5);
- }
- } catch (Throwable t) {
- t.printStackTrace();
- } finally {
- g.dispose();
- }
- }
-
-
- // return our image as a byte[] array. makes it easy to serialize to any other input stream desired.
- public byte[] toByteArray() {
- ByteArrayOutputStream baos = null;
- try {
- baos = new ByteArrayOutputStream();
- ImageIO.write(this.tile, "png", baos);
- baos.flush();
- return baos.toByteArray();
- } catch(IOException e) {
- return new byte[0];
- } finally {
- if (baos != null) {
- try {
- baos.close();
- } catch (Exception ex) {}
- }
- }
- }
-
-
- // make sure the given value stays within a given min/max range.
- private double bound(double val, double min_val, double max_val) {
- return Math.min(Math.max(val, min_val), max_val);
- }
-
- private double degreesToRadians(double deg) {
- return deg * (Math.PI / 180);
- }
-
- private double radiansToDegrees(double rad) {
- return rad / (Math.PI / 180);
- }
-
-}
diff --git a/src/java/com/metabase/corvus/api/tiles/MapPixel.java b/src/java/com/metabase/corvus/api/tiles/MapPixel.java
deleted file mode 100644
index dff56e0ec31..00000000000
--- a/src/java/com/metabase/corvus/api/tiles/MapPixel.java
+++ /dev/null
@@ -1,24 +0,0 @@
-package com.metabase.corvus.api.tiles;
-
-/**
- * Created by agilliland on 3/23/15.
- */
-public class MapPixel {
-
- private final int x;
- private final int y;
-
- public MapPixel(int x, int y) {
- this.x = x;
- this.y = y;
- }
-
-
- public int getX() {
- return x;
- }
-
- public int getY() {
- return y;
- }
-}
diff --git a/src/java/com/metabase/corvus/api/tiles/MapPoint.java b/src/java/com/metabase/corvus/api/tiles/MapPoint.java
deleted file mode 100644
index 33b1bbd8f33..00000000000
--- a/src/java/com/metabase/corvus/api/tiles/MapPoint.java
+++ /dev/null
@@ -1,24 +0,0 @@
-package com.metabase.corvus.api.tiles;
-
-/**
- * Created by agilliland on 3/23/15.
- */
-public class MapPoint {
-
- private final double x;
- private final double y;
-
- public MapPoint(double x, double y) {
- this.x = x;
- this.y = y;
- }
-
-
- public double getX() {
- return x;
- }
-
- public double getY() {
- return y;
- }
-}
diff --git a/src/metabase/api/tiles.clj b/src/metabase/api/tiles.clj
index c1545a8f78c..f57872df92a 100644
--- a/src/metabase/api/tiles.clj
+++ b/src/metabase/api/tiles.clj
@@ -3,58 +3,104 @@
[compojure.core :refer [GET]]
[metabase.api.common :refer :all]
[metabase.db :refer :all]
- [metabase.driver :as driver])
- (:import (java.util ArrayList
- Collection)))
+ [metabase.driver :as driver]
+ [metabase.util :as u])
+ (:import java.awt.Color
+ java.awt.image.BufferedImage
+ (java.io ByteArrayOutputStream IOException)
+ javax.imageio.ImageIO))
+;;; # ------------------------------------------------------------ CONSTANTS ------------------------------------------------------------
-(def ^:const tile-size 256)
-(def ^:const pixel-origin (float (/ tile-size 2)))
-(def ^:const pixel-per-lon-degree (float (/ tile-size 360.0)))
-(def ^:const pixel-per-lon-radian (float (/ tile-size (* 2 Math/PI))))
+(def ^:private ^:const tile-size 256.0)
+(def ^:private ^:const pixel-origin (float (/ tile-size 2)))
+(def ^:private ^:const pin-size 5)
+(def ^:private ^:const pixels-per-lon-degree (float (/ tile-size 360)))
+(def ^:private ^:const pixels-per-lon-radian (float (/ tile-size (* 2 Math/PI))))
-(defn- radians->degrees [rad]
- (/ rad (float (/ Math/PI 180))))
-(defn- tile-lat-lon
- "Get the Latitude & Longitude of the upper left corner of a given tile"
- [x y zoom]
+;;; # ------------------------------------------------------------ UTIL FNS ------------------------------------------------------------
+
+(defn- degrees->radians ^double [^double degrees]
+ (* degrees (/ Math/PI 180.0)))
+
+(defn- radians->degrees ^double [^double radians]
+ (/ radians (/ Math/PI 180.0)))
+
+
+;;; # ------------------------------------------------------------ QUERY FNS ------------------------------------------------------------
+
+(defn- x+y+zoom->lat-lon
+ "Get the latitude & longitude of the upper left corner of a given tile."
+ [^double x, ^double y, ^long zoom]
(let [num-tiles (bit-shift-left 1 zoom)
- corner-x (float (/ (* x tile-size) num-tiles))
- corner-y (float (/ (* y tile-size) num-tiles))
- lon (float (/ (- corner-x pixel-origin) pixel-per-lon-degree))
- lat-radians (/ (- corner-y pixel-origin) (* pixel-per-lon-radian -1))
+ corner-x (/ (* x tile-size) num-tiles)
+ corner-y (/ (* y tile-size) num-tiles)
+ lon (/ (- corner-x pixel-origin) pixels-per-lon-degree)
+ lat-radians (/ (- corner-y pixel-origin) (* pixels-per-lon-radian -1))
lat (radians->degrees (- (* 2 (Math/atan (Math/exp lat-radians)))
(/ Math/PI 2)))]
- {:lat lat
- :lon lon}))
-
+ {:lat lat, :lon lon}))
(defn- query-with-inside-filter
- "Add an 'Inside' filter to the given query to restrict results to a bounding box"
+ "Add an `INSIDE` filter to the given query to restrict results to a bounding box"
[details lat-field-id lon-field-id x y zoom]
- (let [{top-lt-lat :lat top-lt-lon :lon} (tile-lat-lon x y zoom)
- {bot-rt-lat :lat bot-rt-lon :lon} (tile-lat-lon (+ x 1) (+ y 1) zoom)
- inside-filter ["INSIDE", lat-field-id, lon-field-id, top-lt-lat, top-lt-lon, bot-rt-lat, bot-rt-lon]]
- (update-in details [:filter]
+ (let [top-left (x+y+zoom->lat-lon x y zoom)
+ bottom-right (x+y+zoom->lat-lon (inc x) (inc y) zoom)
+ inside-filter ["INSIDE" lat-field-id lon-field-id (top-left :lat) (top-left :lon) (bottom-right :lat) (bottom-right :lon)]]
+ (update details :filter
#(match %
- ["AND" & _] (conj % inside-filter)
- [(_ :guard string?) & _] (conj ["AND"] % inside-filter)
- :else inside-filter))))
+ ["AND" & _] (conj % inside-filter)
+ [(_ :guard string?) & _] (conj ["AND"] % inside-filter)
+ :else inside-filter))))
+
+
+;;; # ------------------------------------------------------------ RENDERING ------------------------------------------------------------
+
+(defn- ^BufferedImage create-tile [zoom points]
+ (let [num-tiles (bit-shift-left 1 zoom)
+ tile (BufferedImage. tile-size tile-size (BufferedImage/TYPE_INT_ARGB))
+ graphics (.getGraphics tile)]
+ (.setColor graphics Color/red)
+ (try
+ (doseq [[^double lat, ^double lon] points]
+ (let [sin-y (-> (Math/sin (degrees->radians lat))
+ (Math/max -0.9999) ; bound sin-y between -0.9999 and 0.9999 (why ?))
+ (Math/min 0.9999))
+ point {:x (+ pixel-origin
+ (* lon pixels-per-lon-degree))
+ :y (+ pixel-origin
+ (* 0.5
+ (Math/log (/ (+ 1 sin-y)
+ (- 1 sin-y)))
+ (* pixels-per-lon-radian -1.0)))} ; huh?
+ map-pixel {:x (int (Math/floor (* (point :x) num-tiles)))
+ :y (int (Math/floor (* (point :y) num-tiles)))}
+ tile-pixel {:x (mod (map-pixel :x) tile-size)
+ :y (mod (map-pixel :y) tile-size)}]
+ ;; now draw a "pin" at the given tile pixel location
+ (.fillOval graphics (tile-pixel :x) (tile-pixel :y) pin-size pin-size)))
+ (catch Throwable e
+ (.printStackTrace e))
+ (finally
+ (.dispose graphics)))
+ tile))
+(defn- tile->byte-array [^BufferedImage tile]
+ (let [output-stream (ByteArrayOutputStream.)]
+ (try
+ (do (ImageIO/write tile "png" output-stream) ; wrap this in a do or eastwood complains about unused return values
+ (.flush output-stream)
+ (.toByteArray output-stream))
+ (catch IOException e
+ (byte-array 0)) ; return empty byte array if we fail for some reason
+ (finally
+ (try
+ (.close output-stream)
+ (catch Throwable _))))))
-(defn- extract-points
- "Takes in a dataset query result object and pulls out the Latitude/Longitude pairs into nested `java.util.ArrayLists`.
- This is specific to the way we plan to feed data into `com.metabase.corvus.api.tiles.GoogleMapPinsOverlay`."
- [lat-col-idx lon-col-idx {{:keys [rows cols]} :data}]
- (if-not (> (count rows) 0)
- ;; if we have no rows then return an empty list of points
- (ArrayList. (ArrayList.))
- ;; otherwise we go over the data, pull out the lat/lon columns, and convert them to ArrayLists
- (ArrayList. ^Collection (map (fn [row]
- (ArrayList. ^Collection (vector (nth row lat-col-idx) (nth row lon-col-idx))))
- rows))))
+;;; # ------------------------------------------------------------ ENDPOINT ------------------------------------------------------------
(defendpoint GET "/:zoom/:x/:y/:lat-field/:lon-field/:lat-col-idx/:lon-col-idx/"
"This endpoints provides an image with the appropriate pins rendered given a json query.
@@ -69,16 +115,17 @@
lat-col-idx String->Integer
lon-col-idx String->Integer
query String->Dict}
- (let [updated-query (assoc query :query (query-with-inside-filter (:query query) lat-field lon-field x y zoom))
- result (driver/dataset-query updated-query {:executed_by *current-user-id*
- :synchronously true})
- lat-lon-points (extract-points lat-col-idx lon-col-idx result)]
+ (let [updated-query (update query :query #(query-with-inside-filter % lat-field lon-field x y zoom))
+ result (driver/dataset-query updated-query {:executed_by *current-user-id*
+ :synchronously true})
+ points (for [row (-> result :data :rows)]
+ [(nth row lat-col-idx) (nth row lon-col-idx)])]
;; manual ring response here. we simply create an inputstream from the byte[] of our image
{:status 200
:headers {"Content-Type" "image/png"}
- :body (-> (com.metabase.corvus.api.tiles.GoogleMapPinsOverlay. zoom lat-lon-points)
- (.toByteArray)
- (java.io.ByteArrayInputStream.))}))
+ :body (-> (create-tile zoom points)
+ tile->byte-array
+ java.io.ByteArrayInputStream.)}))
(define-routes)
--
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