From 2bddccaaf08af2807803fc751b155fe745d6ea6f Mon Sep 17 00:00:00 2001
From: Evert Timberg <evert.timberg@gmail.com>
Date: Mon, 8 Jun 2015 19:03:47 -0400
Subject: [PATCH] Use the correct base for linear scales. This gives the
 correct fill for lines and animations start at the correct point

---
 src/Chart.Line.js    | 11 ++++++++++-
 src/Chart.Radar.js   | 12 +++++++++++-
 src/Chart.Scatter.js | 11 ++++++++++-
 3 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/src/Chart.Line.js b/src/Chart.Line.js
index 6598d8d13..c715855ed 100644
--- a/src/Chart.Line.js
+++ b/src/Chart.Line.js
@@ -232,6 +232,15 @@
             // Update the lines
             this.eachDataset(function(dataset, datasetIndex) {
                 var yScale = this.scales[dataset.yAxisID];
+                var scaleBase;
+
+                if (yScale.min < 0 && yScale.max < 0) {
+                    scaleBase = yScale.getPixelForValue(yScale.max);
+                } else if (yScale.min > 0 && yScale.max > 0) {
+                    scaleBase = yScale.getPixelForValue(yScale.min);
+                } else {
+                    scaleBase = yScale.getPixelForValue(0);
+                }
 
                 helpers.extend(dataset.metaDataset, {
                     // Utility
@@ -252,7 +261,7 @@
                         // Scale
                         scaleTop: yScale.top,
                         scaleBottom: yScale.bottom,
-                        scaleZero: yScale.getPixelForValue(0),
+                        scaleZero: scaleBase,
                     },
                 });
 
diff --git a/src/Chart.Radar.js b/src/Chart.Radar.js
index 5f58cce7e..cb2d81991 100644
--- a/src/Chart.Radar.js
+++ b/src/Chart.Radar.js
@@ -192,6 +192,16 @@
 
             // Update the lines
             this.eachDataset(function(dataset, datasetIndex) {
+                var scaleBase;
+
+                if (this.scale.min < 0 && this.scale.max < 0) {
+                    scaleBase = this.scale.getPointPosition(0, this.scale.max);
+                } else if (this.scale.min > 0 && this.scale.max > 0) {
+                    scaleBase = this.scale.getPointPosition(0, this.scale.min);
+                } else {
+                    scaleBase = this.scale.getPointPosition(0, 0);
+                }
+
                 helpers.extend(dataset.metaDataset, {
                     // Utility
                     _datasetIndex: datasetIndex,
@@ -213,7 +223,7 @@
                         // Scale
                         scaleTop: this.scale.top,
                         scaleBottom: this.scale.bottom,
-                        scaleZero: this.scale.getPointPosition(0),
+                        scaleZero: scaleBase,
                     },
                 });
 
diff --git a/src/Chart.Scatter.js b/src/Chart.Scatter.js
index 09f2b643f..c32b876a4 100644
--- a/src/Chart.Scatter.js
+++ b/src/Chart.Scatter.js
@@ -241,6 +241,15 @@
             // Update the lines
             this.eachDataset(function(dataset, datasetIndex) {
                 var yScale = this.scales[dataset.yAxisID];
+                var scaleBase;
+
+                if (yScale.min < 0 && yScale.max < 0) {
+                    scaleBase = yScale.getPixelForValue(yScale.max);
+                } else if (yScale.min > 0 && yScale.max > 0) {
+                    scaleBase = yScale.getPixelForValue(yScale.min);
+                } else {
+                    scaleBase = yScale.getPixelForValue(0);
+                }
 
                 helpers.extend(dataset.metaDataset, {
                     // Utility
@@ -261,7 +270,7 @@
                         // Scale
                         scaleTop: yScale.top,
                         scaleBottom: yScale.bottom,
-                        scaleZero: yScale.getPixelForValue(0),
+                        scaleZero: scaleBase,
                     },
                 });
 
-- 
2.47.3