author unc0rr Sat, 08 Mar 2014 22:49:13 +0400 changeset 10185 007a40cfbb3d parent 10184 f87776bd5acd child 10186 3fa109a1ae95
Strip Z axis from calculations
```--- a/hedgewars/uLandGenPerlin.pas	Sat Mar 08 13:50:50 2014 +0400
+++ b/hedgewars/uLandGenPerlin.pas	Sat Mar 08 22:49:13 2014 +0400
@@ -27,49 +27,42 @@
end;

-function grad(hash, x, y, z: LongInt) : LongInt;
+function grad(hash, x, y: LongInt) : LongInt;
var h, v, u: LongInt;
begin
h:= hash and 15;
if h < 8 then u:= x else u:= y;
if h < 4 then v:= y else
-        if (h = 12) or (h = 14) then v:= x else v:= z;
+        if (h = 12) or (h = 14) then v:= x else v:= 0;

-    if odd(h) then u:= -u;
-    if odd(h shr 1) then v:= -v;
+    if (h and 1) <> 0 then u:= -u;
+    if (h and 2) <> 0 then v:= -v;

end;

-function inoise(x, y, z: LongInt) : LongInt;
+function inoise(x, y: LongInt) : LongInt;
const N = \$10000;
-var xx, yy, zz, u, v, w, A, AA, AB, B, BA, BB: LongInt;
+var xx, yy, u, v, A, AA, AB, B, BA, BB: LongInt;
begin
xx:= (x shr 16) and 255;
yy:= (y shr 16) and 255;
-    zz:= (z shr 16) and 255;

x:= x and \$FFFF;
y:= y and \$FFFF;
-    z:= z and \$FFFF;

-    A:= p[xx    ] + yy; AA:= p[A] + zz; AB:= p[A + 1] + zz;
-    B:= p[xx + 1] + yy; BA:= p[B] + zz; BB:= p[B + 1] + zz;
+    A:= p[xx    ] + yy; AA:= p[A]; AB:= p[A + 1];
+    B:= p[xx + 1] + yy; BA:= p[B]; BB:= p[B + 1];

inoise:=
-             lerp(w, lerp(v, lerp(u, grad(p[AA  ], x   , y   , z   ),
-                                     grad(p[BA  ], x-N , y   , z   )),
-                             lerp(u, grad(p[AB  ], x   , y-N , z   ),
-                                     grad(p[BB  ], x-N , y-N , z   ))),
-                     lerp(v, lerp(u, grad(p[AA+1], x   , y   , z-N ),
-                                     grad(p[BA+1], x-N , y   , z-N )),
-                             lerp(u, grad(p[AB+1], x   , y-N , z-N ),
-                                     grad(p[BB+1], x-N , y-N , z-N ))));
+            lerp(v, lerp(u, grad(p[AA  ], x   , y  ),
+                            grad(p[BA  ], x-N , y  )),
+                    lerp(u, grad(p[AB  ], x   , y-N),
+                            grad(p[BB  ], x-N , y-N)));
end;

function f(t: double): double;
@@ -115,7 +108,7 @@
for x:= 0 to pred(width) do
begin
dj:= detail * field * x div width;
-            r:= (abs(inoise(di, dj, detail*field)) + y*4) mod 65536 div 256;
+            r:= (abs(inoise(di, dj)) + y*4) mod 65536 div 256;
r:= r - max(0, abs(x - width div 2) - width * 45 div 100); // fade on edges
//r:= r - max(0, - abs(x - width div 2) + width * 2 div 100); // split vertically in the middle
```