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Hi Christoph.<div><br></div><div>> <span style="font-family: Arial, Helvetica, sans-serif;font-size: 13px">For a potentially relevant reference implementtion ...</span></div><div><span style="font-family: Arial, Helvetica, sans-serif;font-size: 13px">And maybe double-check with the specification: </span><span style="font-size: 10pt"><a href="https://www.w3.org/Graphics/GIF/spec-gif89a.txt" style="font-size: 10pt">https://www.w3.org/Graphics/GIF/spec-gif89a.txt</a></span></div><div><br></div><div>Best,</div><div>Marcel</div><div class="mb_sig"></div><blockquote class='history_container' type='cite' style='border-left-style:solid;border-width:1px; margin-top:20px; margin-left:0px;padding-left:10px;'>
<p style='color: #AAAAAA; margin-top: 10px;'>Am 09.10.2020 16:15:36 schrieb commits@source.squeak.org <commits@source.squeak.org>:</p><div style='font-family:Arial,Helvetica,sans-serif'>Christoph Thiede uploaded a new version of Graphics to project The Inbox:<br>http://source.squeak.org/inbox/Graphics-ct.443.mcz<br><br>==================== Summary ====================<br><br>Name: Graphics-ct.443<br>Author: ct<br>Time: 9 October 2020, 4:15:09.97236 pm<br>UUID: 897346b7-ceaa-1a43-874f-3571d893309c<br>Ancestors: Graphics-pre.439<br><br>Adds basic support for storing an animated GIF file via AnimatedGIFReadWriter.<br><br>Note that this implementation indeed is very rudimentary only. I found several GIF files on my computer that cannot be saved as a GIF correctly (something is wrong with the encoding of the background/alpha color). But on the other hand, I also met a number of GIF files that cannot be read by the AnimatedGIFReadWriter ("error: improper store") ...<br>For a potentially relevant reference implementtion, I found this one, but I did not yet find the time apply it: https://gist.github.com/JimBobSquarePants/cac72c4e7d9f05f13ac9<br><br>Following the idea of "baby steps", I'd like to get this into the Trunk at this early state however. The motivation behind this is that I would like to use this concept from another project so establishing the protocol as soon as possible would be helpful for me to write tests.<br><br>=============== Diff against Graphics-pre.439 ===============<br><br>Item was added:<br>+ ----- Method: AnimatedGIFReadWriter class>>exampleAnim (in category 'examples') -----<br>+ exampleAnim<br>+ "AnimatedGIFReadWriter exampleAnim"<br>+ <br>+ | extent center frames |<br>+ extent := 42 @ 42.<br>+ center := extent // 2.<br>+ frames := (2 to: center x - 1 by: 2) collect: [:r |<br>+ "Make a fancy anim without using Canvas - inefficient as hell"<br>+ | image |<br>+ image := ColorForm extent: extent depth: 8.<br>+ 0.0 to: 359.0 do: [:theta |<br>+ image<br>+ colorAt: (center + (Point r: r degrees: theta)) rounded<br>+ put: Color red].<br>+ image].<br>+ <br>+ ^ FileStream newFileNamed: 'anim.gif' do: [:stream |<br>+ self<br>+ putForms: frames<br>+ andDelays: (frames withIndexCollect: [:frame :index |<br>+ 10 + (index / frames size * 100)]) "Start fast, end slow"<br>+ onStream: stream]!<br><br>Item was added:<br>+ ----- Method: AnimatedGIFReadWriter class>>putForms:andDelays:onStream: (in category 'image reading/writing') -----<br>+ putForms: forms andDelays: delays onStream: aWriteStream<br>+ "Store the given form sequence as an animation on the given stream."<br>+ <br>+ | writer canvas |<br>+ self assert: forms size = delays size.<br>+ <br>+ writer := self on: aWriteStream.<br>+ canvas := Form extent: forms first extent depth: 32.<br>+ [Cursor write showWhile: [<br>+ writer loopCount: -1.<br>+ forms with: delays do: [:form :delay |<br>+ writer delay: delay; flag: #todo. "ct: Does not work"<br>+ form displayOn: canvas at: 0 @ 0 rule: Form over.<br>+ writer nextPutImage: canvas]]]<br>+ ensure: [writer close].!<br><br>Item was added:<br>+ ----- Method: AnimatedGIFReadWriter class>>putForms:onFileNamed: (in category 'image reading/writing') -----<br>+ putForms: formSequence onFileNamed: fileName<br>+ "Store the given form sequence as an animation on a file of the given name."<br>+ <br>+ FileStream newFileNamed: fileName do: [:stream |<br>+ self putForms: formSequence onStream: stream].!<br><br>Item was added:<br>+ ----- Method: AnimatedGIFReadWriter class>>putForms:onStream: (in category 'image reading/writing') -----<br>+ putForms: forms onStream: aWriteStream<br>+ "Store the given form sequence as an animation on the given stream."<br>+ <br>+ ^ self<br>+ putForms: forms<br>+ andDelays: ((1 to: forms size) collect: [:i | 20])<br>+ onStream: aWriteStream!<br><br>Item was changed:<br> ----- Method: BMPReadWriter class>>readAllFrom: (in category 'testing') -----<br> readAllFrom: fd<br> "MessageTally spyOn:[BMPReadWriter readAllFrom: FileDirectory default]"<br> fd fileNames do:[:fName|<br> (fName endsWith: '.bmp') ifTrue:[<br>+ [Form fromBinaryStream: (fd readOnlyFileNamed: fName)] ifError: [].<br>- [Form fromBinaryStream: (fd readOnlyFileNamed: fName)] on: Error do:[:nix].<br> ].<br> ].<br> fd directoryNames do:[:fdName|<br> self readAllFrom: (fd directoryNamed: fdName)<br> ].!<br><br>Item was removed:<br>- ----- Method: GIFReadWriter class>>exampleAnim (in category 'examples') -----<br>- exampleAnim<br>- "GIFReadWriter exampleAnim"<br>- <br>- | writer extent center |<br>- writer := GIFReadWriter on: (FileStream newFileNamed: 'anim.gif').<br>- writer loopCount: 20. "Repeat 20 times"<br>- writer delay: 10. "Wait 10/100 seconds"<br>- extent := 42@42.<br>- center := extent / 2.<br>- Cursor write showWhile: [<br>- [2 to: center x - 1 by: 2 do: [:r |<br>- "Make a fancy anim without using Canvas - inefficient as hell"<br>- | image |<br>- image := ColorForm extent: extent depth: 8.<br>- 0.0 to: 359.0 do: [:theta | image colorAt: (center + (Point r: r degrees: theta)) rounded put: Color red].<br>- writer nextPutImage: image]<br>- ] ensure: [writer close]].!<br><br><br></div></blockquote>
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