{"id":145,"date":"2007-05-12T16:10:22","date_gmt":"2007-05-12T14:10:22","guid":{"rendered":" http:\/\/www.nsonic.de\/blog\/2007\/05\/fonts-anti-aliasing-text\/"},"modified":"2007-05-12T16:10:24","modified_gmt":"2007-05-12T14:10:24","slug":"fonts-anti-aliasing-text","status":"publish","type":"post","link":"https:\/\/www.nsonic.de\/blog\/2007\/05\/fonts-anti-aliasing-text\/","title":{"rendered":"Fonts: Anti-Aliasing Text"},"content":{"rendered":"

Of course it is slower than non-antialiased text. So it is important to
\noptimize the routine. Here is some part of the routine I use, it’s
\nprobably the part that’s most important to optimize (might be faster
\nwhen precalculating OfsPtr to an array?):
\n<\/em>
\n
\n[code lang=”delphi”]For OuterY := 0 To TextDIB.Height-1 Do Begin
\n TextPtr := ResultBitmap.ScanLine[OuterY];
\n InnerOffset := 0;
\n For OuterX := 0 To TempBitmap.Width-1 Do Begin
\n \/\/ get average color
\n VSum := 0;
\n For InnerY := 0 To Zoom2 Do Begin
\n OfsPtr := TempBitmap.ScanLine[(OuterY SHL FQuality)+InnerY];
\n For InnerX := 0 To Zoom2 Do Begin
\n Inc (VSum,OfsPtr^[InnerOffset+InnerX]);
\n End;
\n End;
\n \/\/ set pixel
\n TextPtr^ := VSum SHR ShiftValue;
\n \/\/ next pixel
\n Inc (TextPtr);
\n Inc (InnerOffset,FZoom);
\n End;
\n End;
\n[\/code]<\/p>\n

I guess I have to explain some variables. The quality is set by
\nFQuality, some variables that are used often are precalculated:
\n[code lang=”delphi”] FZoom := 1 SHL FQuality;
\n Zoom2 := FZoom-1;
\n ShiftValue := FQuality SHL 1;
\nTempBitmap is FZoom times larger than ResultBitmap
\n[\/code]<\/p>\n

As I always draw the text to 8 bit bitmaps, OfsPtr = ^TByteArray where
\nTByteArray = Array[0..65535] of Byte. The result is 8 bit, too (so
\nTextPtr = ^Byte) because I use this result to combine it with the
\noriginal image by some other procedure. This is more flexible, because
\nyou have to calculate the result only once and can use it for colored
\ntext, its shadow and any other effect you can think of. Of course you
\ncan do this in one step, then you have to interpret black (or white) as
\ntransparent and grays as semi-transparent. The code would look like:<\/p>\n

[code lang=”delphi”] VVal := VSum SHR ShiftValue;
\n TextPtr^.Red := TextPtr^.Red+((SomeColor.Red-TextPtr^.Red)*VVal DIV 256);
\n TextPtr^.Green := TextPtr^.Green+((SomeColor.Green-TextPtr^.Green)*VVal DIV 256);
\n TextPtr^.Blue := TextPtr^.Blue+((SomeColor.Blue-TextPtr^.Blue)*VVal DIV 256);
\n[\/code]
\nBut I guess it’s not much slower when doing this in a second step where
\nVVal := TextPtr^ (the difference is that you save all VVals in
\nResultBitmap before you use them) and really much more powerful when
\nadding routines for effects like shadow, glow etc. to your routine.<\/p>\n

[tags]Delphi, Graphic, Fonts[\/tags]<\/p>\n","protected":false},"excerpt":{"rendered":"

Of course it is slower than non-antialiased text. So it is important to optimize the routine. Here is some part of the routine…<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":""},"categories":[11],"tags":[75,103,101],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p71Tml-2l","_links":{"self":[{"href":"https:\/\/www.nsonic.de\/blog\/wp-json\/wp\/v2\/posts\/145"}],"collection":[{"href":"https:\/\/www.nsonic.de\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.nsonic.de\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.nsonic.de\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.nsonic.de\/blog\/wp-json\/wp\/v2\/comments?post=145"}],"version-history":[{"count":0,"href":"https:\/\/www.nsonic.de\/blog\/wp-json\/wp\/v2\/posts\/145\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.nsonic.de\/blog\/wp-json\/wp\/v2\/media?parent=145"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.nsonic.de\/blog\/wp-json\/wp\/v2\/categories?post=145"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.nsonic.de\/blog\/wp-json\/wp\/v2\/tags?post=145"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}