Add randomness
authorunc0rr
Fri, 07 Mar 2014 23:59:04 +0400
changeset 10182 9d34898b22f7
parent 10181 4708343d5963
child 10183 189afaf2d076
Add randomness
hedgewars/uLandGenPerlin.pas
--- a/hedgewars/uLandGenPerlin.pas	Fri Mar 07 23:36:56 2014 +0400
+++ b/hedgewars/uLandGenPerlin.pas	Fri Mar 07 23:59:04 2014 +0400
@@ -6,7 +6,7 @@
 procedure GenPerlin;
 
 implementation
-uses uVariables, uConsts, math; // for min()
+uses uVariables, uConsts, uRandom, math; // for min()
 
 var fadear: array[byte] of LongInt;
     p: array[0..511] of LongInt;
@@ -77,29 +77,23 @@
     f:= t * t * t * (t * (t * 6 - 15) + 10);
 end;
 
-const permutation: array[byte] of LongInt = ( 151,160,137,91,90,15,
-   131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23,
-   190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33,
-   88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166,
-   77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244,
-   102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196,
-   135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123,
-   5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42,
-   223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9,
-   129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228,
-   251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107,
-   49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254,
-   138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180
-   );
+procedure inoise_setup();
+var i, ii, t: LongInt;
+begin
+    for i:= 0 to 254 do
+        p[i]:= i + 1;
+    p[255]:= 0;
 
-procedure inoise_setup();
-var i: LongInt;
-begin
+    for i:= 0 to 254 do
+    begin
+        ii:= GetRandom(256 - i) + i;
+        t:= p[i];
+        p[i]:= p[ii];
+        p[ii]:= t
+    end;
+
     for i:= 0 to 255 do
-        begin
-        p[256 + i]:= permutation[i];
-        p[i]:= permutation[i]
-        end;
+        p[256 + i]:= p[i];
 
     for i:= 0 to 255 do
         fadear[i]:= trunc($1000 * f(i / 256));