<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br></div><div>Nice! Keep pushing this project -- Matthias</div><div><br></div><div><br></div><br><div><div>On Feb 22, 2013, at 3:30 PM, Daniel Prager wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div dir="ltr">Thanks Sam and Matthias for the tips: I've been able to clean up the directory structure and<div>add a (save-movie) command that writes out an animated gif. </div><div><br></div><div>Example: <a href="https://github.com/danprager/turtlegraphics/blob/master/docs/animated-circle.gif">https://github.com/danprager/turtlegraphics/blob/master/docs/animated-circle.gif</a><div>
<br><div class="gmail_extra"><div class="gmail_quote"><div class="im" style="font-family:arial,sans-serif;font-size:12.499999046325684px"><div style="">Matthias wrote:</div><div>> Thanks, that's great. In what way did you find the existing one lacking?</div>
<div><br></div></div><div style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12.499999046325684px">I did start with that existing package, but initially wanted to simplify the process of drawing pictures interactively, and boost the immediate appeal for my kids. Specifically, I wanted:</div>
<div style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12.499999046325684px">* input and output directly in Dr Racket's REPL window, rather than an an "edit definitions-run-close graphics window" cycle.</div>
<div style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12.499999046325684px">* a realistic image of a turtle, rather than a triangle.</div><div style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12.499999046325684px">
<br></div><div style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12.499999046325684px">Based on observation of my kids I made improvements to enhance usability and appeal. Main additions:</div><div style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12.499999046325684px">
* (undo) and (redo) to improve interactivity</div><div style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12.499999046325684px">* facility to change the turtle's image into e.g. a pink girl</div><div style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12.499999046325684px">
* replay all the turtle's steps as an animation: (movie) </div><div style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12.499999046325684px">* (show-program) to recap the interactive commands used so far for copying into the definitions window</div>
<div style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12.499999046325684px"><br></div><div style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12.499999046325684px">Of these (movie) is definitely the "wow" feature. </div>
<div style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12.499999046325684px"><br></div><div style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12.499999046325684px">BTW: If someone would like to contribute, a bit-blt-based "color-in" operation, that would be great.</div>
<div style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12.499999046325684px"><br></div><div style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12.499999046325684px">I should add that after taking Shriram's recent online PLAI course I restructured the whole thing around a sugared and desugared language. This approach allowed me -- amongst other simplifications -- to cleanly separate out the chopping-out-into-frames needed for animation from the rest of the code. Previously both modes of movement were smooshed together.</div>
<div style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12.499999046325684px"><br></div><div><span style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12.499999046325684px">Dan</span></div></div></div>
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