Byte Battle - Revision history

Pestis: Add raytraced tunnel to the examples.

2022-12-19T09:46:40Z

Add raytraced tunnel to the examples.

2022-12-19T09:12:16Z

‎Dithering

2022-12-19T09:06:48Z

2022-12-19T09:06:11Z

Add 4x4 dithering with expression defined dithering matrix.

2022-12-19T08:52:53Z

2022-12-19T08:48:42Z

Add 4x4 dithering

2022-12-18T17:29:01Z

Clarify the use of ellipsis in loaded functions

2022-12-18T17:15:31Z

add i^2.5%1 dithering

2022-12-18T17:12:37Z

Add modulo dithering

2022-08-11T05:39:42Z

‎Basic optimizations

@@ Line 211: / Line 211: @@
    v=99/(x*x+y*y)^.5+t
    poke4(i,u//1~v//1)
   end
 end

@@ Line 77: / Line 77: @@
 | <code>(i*2-i//80%2)%4/4</code> || 17     || [[File:Block dithering from i.png]] ||  2x2 block dithering (almost), from i only
 |-
-| <code>(x*2-y%2)%4/4+((x&2)-y//2%2)%4/16</code> || 33   || [[File:Block4 dithering exp.png]] ||  4x4 with expression defined dithering matrix defined by an expression
+| <code>(x*2-y%2)%4/4+((x&2)-y//2%2)%4/16</code> || 33   || [[File:Block4 dithering exp.png]] ||  4x4 with dithering matrix defined by an expression
 |-
 | <code>('0415627326158473'):sub(p,p)/8</code> || 44   || [[File:Block4 dithering.png]] ||  4x4 with data-defined dithering matrix, <code>p</code> defined as <code>p=y%4*4+x%4+1</code>

@@ Line 77: / Line 77: @@
 | <code>(i*2-i//80%2)%4/4</code> || 17     || [[File:Block dithering from i.png]] ||  2x2 block dithering (almost), from i only
 |-
-| <code>(x*2-y%2)%4/4+((x&2)-y//2%2)%4/16</code> || 33   || [[File:Block4 dithering exp.png|thumb]] ||  4x4 with expression defined dithering matrix defined by an expression
+| <code>(x*2-y%2)%4/4+((x&2)-y//2%2)%4/16</code> || 33   || [[File:Block4 dithering exp.png]] ||  4x4 with expression defined dithering matrix defined by an expression
 |-
 | <code>('0415627326158473'):sub(p,p)/8</code> || 44   || [[File:Block4 dithering.png]] ||  4x4 with data-defined dithering matrix, <code>p</code> defined as <code>p=y%4*4+x%4+1</code>

@@ Line 76: / Line 76: @@
 |-
 | <code>(i*2-i//80%2)%4/4</code> || 17     || [[File:Block dithering from i.png]] ||  2x2 block dithering (almost), from i only
 |-
 | <code>('0415627326158473'):sub(p,p)/8</code> || 44   || [[File:Block4 dithering.png]] ||  4x4 with data-defined dithering matrix, <code>p</code> defined as <code>p=y%4*4+x%4+1</code>

@@ Line 77: / Line 77: @@
 | <code>(i*2-i//80%2)%4/4</code> || 17     || [[File:Block dithering from i.png]] ||  2x2 block dithering (almost), from i only
 |-
-| <code>('0415627326158473'):sub(p,p)/8</code> || 42   || [[File:Block4 dithering.png]] ||  4x4 with data-defined dithering matrix, <code>p</code> defined as <code>p=y%4*4+x%4</code>
+| <code>('0415627326158473'):sub(p,p)/8</code> || 44   || [[File:Block4 dithering.png]] ||  4x4 with data-defined dithering matrix, <code>p</code> defined as <code>p=y%4*4+x%4+1</code>
 |}

@@ Line 46: / Line 46: @@
 As a rule of thumb, one-lining and using the load trick can bring a ~ 275 character code down to 256.
-<code>load</code> can be even used to minimize a function with parameters: <code>...</code> returns the parameters. For example, the following example saves 3 bytes:
+Any arguments passes to a function defined with <code>load</code> can be fetched with the ellipsis (<code>...</code>). For example, <code>SCN=function(x)poke(16320,x)end</code> can be implemented as:
 <syntaxhighlight lang="lua">
-SCN=load'r=...poke(16320,r)'
+SCN=load'poke(16320,...)'
 </syntaxhighlight>
-Multiple parameters can be fetched with <code>x,y=...</code>.
+This saves 6 characters. Multiple arguments can be fetched with <code>x,y=...</code>.
 '''Warning: The backslash causes problems when using the load trick.''' In particular, if you have a string with escaped characters in the original code e.g. <code>print("foo\nbar")</code>, then this needs to be double-escaped: <code>load'print("foo\\nbar")'</code>

@@ Line 67: / Line 67: @@
 | <code>i%.7</code>              || 4      || [[File:Modulo dithering.png]]       ||
 |-
-| <code>s(i)*i%1</code>          || 8      || [[File:Random dithering.png]]       || "random" dithering
+| <code>i^2.5%1</code>           || 7      || [[File:Power dithering.png]]        || "random" dithering
 |-
 | <code>i*481/960%1</code>       || 11     || [[File:Chess dithering.png]]        ||  <code>(x/2+y/4)%1</code> if you have x&y. <code>i*25/96%1</code> or <code>i*97/192</code> if desperate.

@@ Line 64: / Line 64: @@
 |-
 |                                ||        || [[File:No dithering.png]]           || No dithering
 |-
 | <code>s(i)*i%1</code>          || 8      || [[File:Random dithering.png]]       || "random" dithering

@@ Line 20: / Line 20: @@
 * Functions, that are called three or more times should be aliased. For example, <code>e=elli</code> with <code>e()e()e()</code> is 3 characters shorter than <code>elli()elli()elli()</code>. Functions with 5-character-long names may already benefit from aliasing with two calls: <code>r=rectb</code> with <code>r()r()</code> is 1 character shorter than <code>rectb()rectb()</code>.
-* <code>t=0</code> with <code>t=t+.1</code> is 3 characters shorter than <code>t=time()/399</code>.
+* <code>t=0</code> with <code>t=t+.01</code> is 1 character shorter than <code>t=time()*.6</code>.
 * <code>for i=0,32639 do x=i%240y=i/240 end</code> is 2-3 characters shorter than <code>for y=0,135 do for x=0,239 do end end</code>.
 * <code>(x*x+y*y)^.5</code> is 6 characters shorter than <code>math.sqrt(x*x+y*y)</code>.