Ticket #4218: interpolationSplit2016_9_16.diff

binaries/data/mods/public/globalscripts/BicubicInterpolation.js

@@ -1 +1 @@
 /**
- * From https://github.com/hughsk/bicubic licensed under MIT 2013 Hugh Kennedy - see /license_mit.txt
+ * Two dimensional interpolation within four equidistant points using polynomials of 3rd degree.
+ * @param {float} xf - Float value between the points to interpolate the property for
+ * @param {float} p0 - Value of the property to calculate at the origin of four point scale
+ * @param {float} px - Value at the property on the points
+ * @return {float} - Value at the given float position in the 4-point scale interpolated from it's property values
+ */
+function cubicInterpolation(xf, p0, p1, p2, p3)
+{
+    return p1
+        + (-0.5 * p0 + 0.5 * p2) * xf
+        + (p0 - 2.5 * p1 + 2.0 * p2 - 0.5 * p3) * xf * xf
+        + (-0.5 * p0 + 1.5 * p1 - 1.5 * p2 + 0.5 * p3) * xf * xf * xf;
+}
+
+/**
  * Two dimensional interpolation within a square grid using polynomials of 3rd degree.
  * @param {float} xf - X coordinate within the subgrid (see below) of the point to interpolate the value for
  * @param {float} yf - y coordinate within the subgrid (see below) of the point to interpolate the value for
  * @param {float} p00 - Value of the property to calculate at the origin of the naighbor grid
  * @param {float} pxy - Value at naighbor grid coordinates x/y, x/y in {0, 1, 2, 3}
  * @return {float} - Value at the given float coordinates in the small grid interpolated from it's values
-  */
+ */
 function bicubicInterpolation(
     xf, yf,
     p00, p01, p02, p03,
@@ -15 +29 @@
     p30, p31, p32, p33
 )
 {
-    var yf2 = yf * yf;
-    var xf2 = xf * xf;
-    var xf3 = xf * xf2;
-
-    var x00 = p03 - p02 - p00 + p01;
-    var x01 = p00 - p01 - x00;
-    var x02 = p02 - p00;
-    var x0 = x00*xf3 + x01*xf2 + x02*xf + p01;
-
-    var x10 = p13 - p12 - p10 + p11;
-    var x11 = p10 - p11 - x10;
-    var x12 = p12 - p10;
-    var x1 = x10*xf3 + x11*xf2 + x12*xf + p11;
-
-    var x20 = p23 - p22 - p20 + p21;
-    var x21 = p20 - p21 - x20;
-    var x22 = p22 - p20;
-    var x2 = x20*xf3 + x21*xf2 + x22*xf + p21;
-
-    var x30 = p33 - p32 - p30 + p31;
-    var x31 = p30 - p31 - x30;
-    var x32 = p32 - p30;
-    var x3 = x30*xf3 + x31*xf2 + x32*xf + p31;
-
-    var y0 = x3 - x2 - x0 + x1;
-    var y1 = x0 - x1 - y0;
-    var y2 = x2 - x0;
-
-    return y0*yf*yf2 + y1*yf2 + y2*yf + x1;
+    let x0 = cubicInterpolation(yf, p00, p01, p02, p03);
+    let x1 = cubicInterpolation(yf, p10, p11, p12, p13);
+    let x2 = cubicInterpolation(yf, p20, p21, p22, p23);
+    let x3 = cubicInterpolation(yf, p30, p31, p32, p33);
+    return cubicInterpolation(xf, x0, x1, x2, x3);
 }

binaries/data/mods/public/maps/random/rmgen2/gaia.js

@@ -1304 +1304 @@
                 shift.y = - 1;
 
             let neighbors = [];
-            for (let localYi = 0; localYi < 4; ++localYi)
-                for (let localXi = 0; localXi < 4; ++localXi)
+            for (let localXi = 0; localXi < 4; ++localXi)
+                for (let localYi = 0; localYi < 4; ++localYi)
                     neighbors.push(heightmap[(hmTile.x + localXi + shift.x - 1) * hmSize + (hmTile.y + localYi + shift.y - 1)]);
 
             setHeight(x, y, bicubicInterpolation(hmPoint.x - hmTile.x - shift.x, hmPoint.y - hmTile.y - shift.y, ...neighbors) / scale);