Pygrr PolyArt (part 2)

Here we are, part two out of three! In this episode, we'll tackle the shape editing and drawing!

First of all, let's add some "nodes" onto each vertex, to allow the user to interact with the shape. If the user right clicks on a node, then it deletes that vertex. Note that it's impossible to delete any node if there are only 3, as then it wouldn't be a polygon anymore!

Now, if the user left clicks on one of the lines (not the smoothed lines, just the rigid ones), it should create a point at their mouse click. We can do this by doing some maths, the wedge product and the dot product. We simply iterate through each line on the shape, checking if the mouse position plugged into the wedge and dot gives us the right output. If they do, then it's on the line! Here's it working:

Now all we need is if the user left clicks and drags a point, then it'll move the point. Note also, in both creating points and moving points, turning the snap grid on and off does indeed have an impact! Here we go:

Let's show off and draw a rubber duck...

Now all we need is to be able to use the arrow keys to re-centre the drawing by moving it around.

Tada! That's all for this, next up, saving and importing. Note that in this art program, you're limited to only 1 polygon, as it's a "pygrr.Polygon" object... In further updates, I'll make another program which supports multiple polygons, so you can create proper detailed things, with multiple colours and everything...

Isaac, over and out...

Popular posts from this blog

Messing around with procedural art - Turtle graphics

Let's take a short break from Pygrr to delve back into the world of Turtle graphics. Turtle graphics: an introduction Well, what are they? Turtle graphics are a simple vector graphic system in programming that uses a relative cursor known as a Turtle to plot data onto a Cartesian plane. Nice, that didn't clear it up at all! To put it simply, Turtle graphics are a type of programming concept where an object (consider it a "pen") is moved around a 2D canvas, drawing wherever it goes! Most people who know Python will be aware of the Turtle module - this is a Pythonic implementation of Turtle graphics (fun fact: it uses Tkinter too, like Pygrr!). Turtle graphics are a key feature of the programming language "Logo". Uses of Turtle graphics Turtle graphics are a popular way to introduce programming to kids, and are often used for this! They are also used as a quick way to implement graphic representation of data when debugging or writing code, as they are super ea
Read more

The fossils of Morocco | Mosasaurus beaugei

Finally, another post! Life has been quite difficult recently, and I've had a lot of appointments in the hospital, and, combined with a much higher workload, I haven't had too much free time. Anyways, enough of that! A couple of weeks ago, I acquired a gorgeous fish and mosasaur association, from a seller on the web. It hails from the Cretaceous of Khouribga, Morocco, unprepped, just split out of the rock! Here's the fossil in question! Ignore the mess in the background... Can you believe this thing is 70.6 - 66 million years old!? Look at the sheer awesome preservation on that fish spine; absolutely stunning! So, story time. The tooth is from the species "Mosasaurus beaugei" , a pretty large mosasaurine. Pictures from www.prehistoric-wildlife.com Here's a nice image (or, 2 images...) of the size of Mosasaurus (silhouette 16) against other mosasaurines, and a human. As yo
Read more

Blog post #0 - Hello, world!

From humble beginnings... Hi, I'm Isaac. I've been in the programming world for almost 7 years now! I started this blog to share my love of fossils and coding with you guys, the world. I'm obsessed with palaeontology, and I have a real passion for teaching others what I love, be it programming, game development, or fossil things. What am I up to? Well, you'll have to wait and see... Just kidding, I'm currently working on: A voxel (3D cube, game) engine as a basis for many other games I have planned A free Python (programming language) library for game development, called "Pygrr"... You'll see more on this very soon! Nice to meet you all, if you feel the sudden urge to send me an email, head over to my "about me" page! Isaac, over and out...
Read more