From cea919a55d61b14b4b408e2886dbfe7a0c2b618b Mon Sep 17 00:00:00 2001
From: -=yb4f310 <theunis.botha1@gmail.com>
Date: Fri, 1 Sep 2017 17:05:29 +0200
Subject: [PATCH] linear interpolation for heightmaps

---
 src/game-lib-a-2-utils.js     | 25 +++++++++++++++++++++++++
 src/game-lib-d3-mesh-plane.js | 13 +++++++------
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/src/game-lib-a-2-utils.js b/src/game-lib-a-2-utils.js
index f77c3c4..6876cf4 100644
--- a/src/game-lib-a-2-utils.js
+++ b/src/game-lib-a-2-utils.js
@@ -123,6 +123,31 @@ GameLib.Utils.LoadIdsFromObjectToIdObject = function(object, idToObject) {
     return idToObject;
 };
 
+GameLib.Utils.InterpolateArray = function(data, fitCount) {
+
+    var linearInterpolate = function (before, after, atPoint) {
+        return before + (after - before) * atPoint;
+    };
+
+    var newData = [];
+
+    var springFactor = Number((data.length - 1) / (fitCount - 1));
+
+    newData[0] = data[0]; // for new allocation
+
+    for ( var i = 1; i < fitCount - 1; i++) {
+        var tmp     = i * springFactor;
+        var before  = Number(Math.floor(tmp)).toFixed();
+        var after   = Number(Math.ceil(tmp)).toFixed();
+        var atPoint = tmp - before;
+        newData[i]  = linearInterpolate(data[before], data[after], atPoint);
+    }
+
+    newData[fitCount - 1] = data[data.length - 1]; // for new allocation
+
+    return newData;
+};
+
 /**
  * Undefined or null check
  * @param variable
diff --git a/src/game-lib-d3-mesh-plane.js b/src/game-lib-d3-mesh-plane.js
index 95e6bee..5ad6e2d 100644
--- a/src/game-lib-d3-mesh-plane.js
+++ b/src/game-lib-d3-mesh-plane.js
@@ -226,20 +226,20 @@ GameLib.D3.Mesh.Plane.prototype.getHeightData = function() {
 	}
 
 	var canvas = document.createElement( 'canvas' );
-	canvas.width = img.width;
-	canvas.height = img.height;
+	canvas.width = this.widthSegments + 1;//img.width;
+	canvas.height = this.heightSegments + 1;//img.height;
 	var context = canvas.getContext( '2d' );
 
-	var size = img.width * img.height;
+	var size = (this.widthSegments + 1) * (this.heightSegments + 1);
 	var data = new Float32Array( size );
 
-	context.drawImage(img,0,0);
+	context.drawImage(img,0,0, canvas.width, canvas.height);
 
 	for (i = 0; i < size; i ++ ) {
 		data[i] = 0
 	}
 
-	var imgd = context.getImageData(0, 0, img.width, img.height);
+	var imgd = context.getImageData(0, 0, (this.widthSegments + 1), (this.heightSegments + 1));
 	var pix = imgd.data;
 
 	var j=0;
@@ -248,8 +248,9 @@ GameLib.D3.Mesh.Plane.prototype.getHeightData = function() {
 		data[j++] = all/(12*this.heightMapScale);
 	}
 
-	return data;
+	// data = GameLib.Utils.InterpolateArray(data, (this.widthSegments + 1) * (this.heightSegments + 1));
 
+	return data;
 };
 
 /**