{"id":65,"date":"2007-06-04T12:58:37","date_gmt":"2007-06-04T17:58:37","guid":{"rendered":"http:\/\/www.pixelwit.com\/blog\/2007\/06\/04\/improving-the-limit-function\/"},"modified":"2009-08-13T21:25:13","modified_gmt":"2009-08-14T02:25:13","slug":"improving-the-limit-function","status":"publish","type":"post","link":"https:\/\/www.pixelwit.com\/blog\/2007\/06\/04\/improving-the-limit-function\/","title":{"rendered":"Improving the Limit Function"},"content":{"rendered":"

As a continuation of a previous post “How to Limit a Number Between Two Values<\/a>” I thought I’d make my “limiting” code a little more versatile.<\/p>\n

The previous post used the following code to ‘limit’ or ‘constrain’ a number between a low and high value:<\/p>\n

\/\/<\/span>
\n\/\/ Limit a number between two values.<\/span>
\nfunction<\/span> limit (<\/span>num, lo, hi)<\/span>{<\/span>
\n    if<\/span> (<\/span>num <<\/span> lo)<\/span> return<\/span> lo;
\n    if<\/span> (<\/span>num ><\/span> hi)<\/span> return<\/span> hi;
\n    return<\/span> num;
\n}<\/span>
\n\/\/<\/span><\/div><\/div>\n

But what if you don’t want to, or can’t, control the order of the “lo” and “hi” arguments? Currently, if you try something like “limit(10, 60, 50)” the above limit function incorrectly returns “60”. Wouldn’t it be easier if the function properly limited the first argument regardless of the order of the second and third arguments? In other words, “limit(10, 50, 60)” and “limit(10, 60, 50)” would both produce “50”.<\/p>\n

Implementing this improvement is a simple matter of adding a conditional statement to the beginning of the “limit” function to determine whether the second or third argument is larger and then proceeding accordingly. The new version looks like this:<\/p>\n

\/\/<\/span>
\n\/\/ Limit a number between two values.<\/span>
\nfunction<\/span> limit (<\/span>num, limA, limB)<\/span>{<\/span>
\n    if<\/span> (<\/span>limA <<\/span>= limB)<\/span>{<\/span>
\n        if<\/span> (<\/span>num <<\/span> limA)<\/span> return<\/span> limA;
\n        if<\/span> (<\/span>num ><\/span> limB)<\/span> return<\/span> limB;
\n        return<\/span> num;
\n    }<\/span>else<\/span> {<\/span>
\n        if<\/span> (<\/span>num ><\/span> limA)<\/span> return<\/span> limA;
\n        if<\/span> (<\/span>num <<\/span> limB)<\/span> return<\/span> limB;
\n        return<\/span> num;
\n    }<\/span>
\n}<\/span>
\n\/\/<\/span>
\n\/\/<\/span><\/div><\/div>\n

And when we add this new version to the previous code sample we get this:<\/p>\n

\/\/<\/span>
\n\/\/ Limit a number between two values.<\/span>
\nfunction<\/span> limit (<\/span>num, limA, limB)<\/span>{<\/span>
\n    if<\/span> (<\/span>limA <<\/span>= limB)<\/span>{<\/span>
\n        if<\/span> (<\/span>num <<\/span> limA)<\/span> return<\/span> limA;
\n        if<\/span> (<\/span>num ><\/span> limB)<\/span> return<\/span> limB;
\n        return<\/span> num;
\n    }<\/span>else<\/span> {<\/span>
\n        if<\/span> (<\/span>num ><\/span> limA)<\/span> return<\/span> limA;
\n        if<\/span> (<\/span>num <<\/span> limB)<\/span> return<\/span> limB;
\n        return<\/span> num;
\n    }<\/span>
\n}<\/span>
\n\/\/<\/span>
\n\/\/<\/span>
\n\/\/<\/span>
\n\/\/ Build Description textfields.<\/span>
\ncreateTextField<\/span>(<\/span>"LoDescTF"<\/span>, 10<\/span>, 50<\/span>, 10<\/span>, 100<\/span>, 20<\/span>)<\/span>;
\nLoDescTF.text<\/span> = "Limit A"<\/span>;
\n\/\/<\/span>
\ncreateTextField<\/span>(<\/span>"LimitedDescTF"<\/span>, 20<\/span>, 200<\/span>, 10<\/span>, 100<\/span>, 20<\/span>)<\/span>;
\nLimitedDescTF.text<\/span> = "Limited Value"<\/span>;
\n\/\/<\/span>
\ncreateTextField<\/span>(<\/span>"HiDescTF"<\/span>, 30<\/span>, 350<\/span>, 10<\/span>, 100<\/span>, 20<\/span>)<\/span>;
\nHiDescTF.text<\/span> = "Limit B"<\/span>;
\n\/\/<\/span>
\n\/\/<\/span>
\n\/\/<\/span>
\n\/\/ Build User-input textfields.<\/span>
\ncreateTextField<\/span>(<\/span>"ALimitTF"<\/span>, 11<\/span>, 50<\/span>, 30<\/span>, 100<\/span>, 20<\/span>)<\/span>;
\nALimitTF.type<\/span> = "input"<\/span>;
\nALimitTF.border<\/span> = true<\/span>;
\nALimitTF.restrict<\/span> = "0-9"<\/span>;
\nALimitTF.text<\/span> = "0"<\/span>;
\n\/\/<\/span>
\ncreateTextField<\/span>(<\/span>"LimitedTF"<\/span>, 21<\/span>, 200<\/span>, 30<\/span>, 100<\/span>, 20<\/span>)<\/span>;
\nLimitedTF.type<\/span> = "input"<\/span>;
\nLimitedTF.border<\/span> = true<\/span>;
\nLimitedTF.restrict<\/span> = "0-9"<\/span>;
\nLimitedTF.text<\/span> = "50"<\/span>;
\n\/\/<\/span>
\ncreateTextField<\/span>(<\/span>"BLimitTF"<\/span>, 31<\/span>, 350<\/span>, 30<\/span>, 100<\/span>, 20<\/span>)<\/span>;
\nBLimitTF.type<\/span> = "input"<\/span>;
\nBLimitTF.border<\/span> = true<\/span>;
\nBLimitTF.restrict<\/span> = "0-9"<\/span>;
\nBLimitTF.text<\/span> = "100"<\/span>;
\n\/\/<\/span>
\n\/\/<\/span>
\n\/\/<\/span>
\n\/\/ Build Instructions textfield.<\/span>
\ncreateTextField<\/span>(<\/span>"Instructions"<\/span>, 40<\/span>, 10<\/span>, 60<\/span>, 480<\/span>, 40<\/span>)<\/span>;
\nInstructions.wordWrap<\/span> = true<\/span>;
\nInstructions.multiline<\/span> = true<\/span>;
\nInstructions.text<\/span> = "Type a number in the middle box and press the enter key to constrain the number between the the two limiting values"<\/span>;
\n\/\/<\/span>
\n\/\/<\/span>
\n\/\/<\/span>
\n\/\/ Limit the value in the middle box when the Enter key is pressed.<\/span>
\nLimitedTF.onKeyDown<\/span> = function<\/span>(<\/span>)<\/span>{<\/span>
\n    if<\/span>(<\/span>Key<\/span>.isDown<\/span>(<\/span>Key<\/span>.ENTER<\/span>)<\/span>)<\/span>{<\/span>
\n        var<\/span> aa = ALimitTF.text<\/span> - 0<\/span>;
\n        var<\/span> bb = BLimitTF.text<\/span> - 0<\/span>;
\n        var<\/span> lim = this<\/span>.text<\/span> - 0<\/span>;
\n        this<\/span>.text<\/span> = limit(<\/span>lim, aa, bb)<\/span>;
\n    }<\/span>
\n}<\/span>
\nKey<\/span>.addListener<\/span>(<\/span>LimitedTF)<\/span>;
\n\/\/<\/span>
\n\/\/<\/span><\/div><\/div>\n

And the code above produces the following SWF:<\/p>\n\n\n\t\n\t\n\t\n\t\n\t\t\n\t\n\t<\/object>\n\t\n<\/object>\n

As you can see, the middle number will now be limited (restricted or constrained) between the two outer numbers regardless of their order.<\/p>\n

I hope you find it useful.<\/p>\n","protected":false},"excerpt":{"rendered":"

An ActionScript tutorial examining various techniques used to limit a number between two unknown values.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":""},"categories":[8],"tags":[23,36],"class_list":["post-65","post","type-post","status-publish","format-standard","hentry","category-flash","tag-actionscript","tag-swfs"],"_links":{"self":[{"href":"https:\/\/www.pixelwit.com\/blog\/wp-json\/wp\/v2\/posts\/65","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.pixelwit.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.pixelwit.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.pixelwit.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.pixelwit.com\/blog\/wp-json\/wp\/v2\/comments?post=65"}],"version-history":[{"count":0,"href":"https:\/\/www.pixelwit.com\/blog\/wp-json\/wp\/v2\/posts\/65\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.pixelwit.com\/blog\/wp-json\/wp\/v2\/media?parent=65"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.pixelwit.com\/blog\/wp-json\/wp\/v2\/categories?post=65"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.pixelwit.com\/blog\/wp-json\/wp\/v2\/tags?post=65"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}