From 471cd3ec195051e54e71b4f61a9e64ed5abe5280 Mon Sep 17 00:00:00 2001
From: Francisco Dans <fdansv@gmail.com>
Date: Thu, 13 Aug 2015 22:19:33 +0200
Subject: [PATCH] adds isoline rendering in point renderer

---
 lib/torque/renderer/point.js | 94 +++++++++++++++++++++++++++---------
 1 file changed, 71 insertions(+), 23 deletions(-)

diff --git a/lib/torque/renderer/point.js b/lib/torque/renderer/point.js
index 0354239..3ce0c7b 100644
--- a/lib/torque/renderer/point.js
+++ b/lib/torque/renderer/point.js
@@ -275,22 +275,43 @@ var contour = require('./contour');
       var activePixels = tile.timeCount[key];
       var anchor = this.options.resolution/2;
 
-      // var isolines = true;
-      // if (isolines){
-      //   var tileContour = this._contour(tile);
-      //   ctx.beginPath();
-      //   ctx.strokeStyle = 'blue';
-      //   var initialX = tileContour[0][0] * this.options.resolution + anchor;
-      //   var initialY = tileContour[0][1] * this.options.resolution + anchor;
-      //   ctx.moveTo(initialX, initialY);
-      //   for (var i = 1; i < tileContour.length; i++){
-      //     var x = tileContour[i][0] * this.options.resolution + anchor;
-      //     var y = tileContour[i][1] * this.options.resolution + anchor;
-      //     ctx.lineTo(x, y);
-      //     ctx.stroke();
-      //   }
-      // }
-      // if (activePixels) {
+      
+      if (activePixels) {
+
+        /*
+          Torque Isolines
+          To be moved somewhere else (ideally something link isolines.js within /renderer/)
+        */
+        var isolines = true;
+        if (isolines) {
+          var grid = this._gridData(tile);
+          var cellsX = grid[0].length-1;
+          var cellsY = grid.length-1;
+          var contourValues = [0, 2, 4, 8, 16];
+          var res = this.options.resolution;
+          for(var c = 0; c < contourValues.length; c++){
+            for (var y = 0;  y < cellsY; y++){
+              for (var x = 0;  x < cellsX; x++){
+                var currentCell = [grid[y][x], grid[y][x+1], grid[y+1][x+1], grid[y+1][x]];
+                var pipe = this._getPipe(currentCell, contourValues[c]);
+                if (pipe){
+                  ctx.strokeStyle = "#ffffff"
+                  ctx.beginPath();
+                  ctx.moveTo(x * res + anchor + res * pipe[0][0], pos.y + y * res + anchor + res * pipe[0][1]);
+                  ctx.lineTo(x * res + anchor + res * pipe[1][0], pos.y + y * res + anchor + res * pipe[1][1]);
+                  ctx.stroke();
+                  if (pipe.length === 4){
+                    ctx.beginPath();
+                    ctx.moveTo(x * res + anchor + res * pipe[2][0], pos.y + y * res + anchor + res * pipe[2][1]);
+                    ctx.lineTo(x * res + anchor + res * pipe[3][0], pos.y + y * res + anchor + res * pipe[3][1]);
+                    ctx.stroke();
+                  }
+                }
+              }
+            }
+          }
+        }
+
       //   var pixelIndex = tile.timeIndex[key];
       //   for(var p = 0; p < activePixels; ++p) {
       //     var posIdx = tile.renderDataPos[pixelIndex + p];
@@ -307,16 +328,43 @@ var contour = require('./contour');
       //      }
       //     }
       //   }
-      // }
+      }
       prof.end(true);
     },
+    _getPipe: function(cell, contour){
+      var parsedCell = cell.map(function(cornerValue){
+          if (cornerValue >= contour){
+            return "1";
+          }
+          return "0";
+        }).join("");
+      var type = parseInt(parsedCell, 2);
+      var N = [this._lerp(cell[1], cell[0], contour), 0], 
+          S = [this._lerp(cell[2], cell[3], contour), 1], 
+          E = [1, this._lerp(cell[2], cell[1], contour)], 
+          W = [0, this._lerp(cell[3], cell[0], contour)]
+      // Blank
+      if (type === 0 || type === 15) return null;
+      // W - S
+      if (type === 1 || type === 14) return [W, S]  
+      // S - E
+      if (type === 2 || type === 13) return [S, E]
+      // W - E  
+      if (type === 3 || type === 12) return [W, E]  
+      // N - E
+      if (type === 4 || type === 11) return [N, E]  
+      // N - S
+      if (type === 6 || type === 9) return [N, S]
+      // W - N
+      if (type === 7 || type === 8) return [W, N] 
+      // W - N / S - E
+      if (type === 5) return [W, N, S, E]
+      // W - S / N - E
+      if (type === 10) return [W, S, N, E]
+    },
 
-    _contour: function(tile, x, y){
-      var tileGrid = this._gridData(tile);
-      tileGrid = tileGrid.reverse();
-      // return d3.geom.contour(function(x, y) {
-      //   return x >= 0 && y >= 0 && x < tileGrid[0].length && y < tileGrid.length && tileGrid[y][x] === 0;
-      // })
+    _lerp: function(valueA, valueB, contourValue){
+      return Math.max(Math.min(1 + (-0.5) * (contourValue - valueA) / (valueB - valueA), 0.8), 0.2);
     },
 
     setBlendMode: function(b) {