TK (LTK) Paint Program (Raster) - graphics

I really want to make a raster paint program while keeping the pixel model CPU side.
I want to expose the underlying data structure to users of the program so they can extend it with their own functionality. (Think how Emacs provides a few primitives yet users extend the program indefinitely with Emacs Lisp)
Now, from what I can tell Tk (and LTK by extension) mostly favors a Canvas which deals with pinning premade objects to it acting as a growing queue. My need is going to be having functionality of simply editing smallish bitmaps. Is it even feasible to build a program as simple as Microsoft Paint in Tk? Keep in mind, I do NOT want vector shapes-I want a real time raster editor. The whole model of editing raster objects in real time seems to fight the way computer graphics are done today and I'm simply trying to find a system that allows me to edit an array of "pixels" and display them with sufficient "human speed".
I'm not bound to Ltk but it's one of the most complete toolkits we have in Common Lisp it can also send messages directly to Tk so we get new features as they roll out. I'm just kind of fighting a modern graphics model to maintain a clean API for users' scripting.

Related

Using Haskell Gtk widgets with Graphics.SOE package

I have been working through the book The Haskell School of Expression by Paul Hudak and using its associated gtk based graphics library Graphics.SOE.Gtk (link to documentation) for small 2D drawing experiments.
This library is very basic however, and only really has the ability to draw shapes. At the moment I am writing some programs which require particular GUI widgets such as buttons and text boxes. My question is: Is it possible to use the drawing capabilities of the SOE library alongside the GUI widgets found in gtk2hs? E.g be able to write a program where I can click a button which causes the program to draw a triangle shape in another container in the same window.
I have searched online for a way to do this, but most tutorials suggest using cairo to do any graphics drawing with Gtk ; SOE graphic's API has the appearance of being a relatively self contained thing.
No, there's not a really meaningful way for soegtk and regular gtk to interact. The reason is that soegtk keeps all its data types abstract; this is good practice from a "makes it easy for the implementor to change the implementation without changing the interface" point of view but it can be a bit limiting from a "I'm just a user that wants to munge things in ways the interface don't promise to allow" point of view.
You could:
make a copy of the text of the single module in the soegtk package, and adjust the export line to export more things and happily break any abstraction boundaries you dislike
interact non-meaningfully; e.g. have your gtk button open an soegtk window with the graphics of interest
learn a different drawing library, say, cairo or diagrams

Is a drag-and-drop interface simply infeasible in Pygame?

I'm building a simple RPG using Pygame and would like to implement a drag-and-drop inventory. However, even with the consideration of blitting a separate surface, it seems that the entire screen will need to be recalculated every single time the user drags an item around. Would it be best to allow a limited range of motion, or is it simply not feasible to implement such an interface?
redrawing most or all of the screen is a very normal thing, across all windowing systems. this is rarely an issue, since most objects on screen can be drawn quickly.
To make this practical, it's necessary to organize all of the game objects that have to be drawn in such a way that they can be quickly found and drawn in the right order. This often means that objects of a particular type are grouped into some sort of layer. The drawing code can go through each layer, and for each object in each layer, ask the object to draw itself. If a particular layer is costly to draw, because it's got a lot of objects, can store a prerendered surface and blit that instead.
A really simple hack to get a similar effect is to capture the screen at the start of a drag to a surface, and then blit that every frame instead of the whole game. This obviously only makes sense in a game where dragging also means that the rest of the game is effectively paused.
There are many GUI examples on pygame.org, as well as libraries for GUIs.

How to present to a different window using IDXGISwapChain and ID3D11Device/ID3D11DeviceContext?

Previously, when I've built tools, I've used D3D version 9, where the call to Present() can take a target window and rectangle, and you can thus draw from a single device into many different windows. This is great when using D3D to accelerate desktop applications, and/or building tools rather than games!
I've also built a game renderer with D3D11 before, which is also great, because the state management and threading interfaces are well designed, and you can even target D3D 9 level hardware that's still pretty common in the wild (as opposed to D3D 10, which can only target 10-and-better).
However, now I want to build a tool with D3D11. Unfortunately, the IDXGISwapChain that comes back from D3D11CreateDeviceAndSwapChain() seems to "remember" its HWND, and only wants to present to that window. This is highly inconvenient, because I may have a large number of windows that each need fairly simple graphics drawn to them, and only in response to a WM_PAINT (again, this is for a tool, not a game).
What I want to do is to save back buffer RAM. Specifically, I used to be able to create a single back buffer, the size of the desktop, that I knew could cover all rendering needs, and then that would be the single copy allocated. Even if there are 10 overlapping windows, they all render through the same back buffer, so there's no waste of memory beyond the initial allocation. I can create textures that are not swap chains, and use them as "render targets," but I can't find a good way of presenting to an arbitrary rectangle of an arbitrary client window, without reading back the bitmap and copying it into a DIBSection, which would be really inefficient. Also, there is no way to create many swap chains, and having them share the same back buffer.
The best I can do is to create one swap chain per window, and resize the back buffer of each swap chain to be really small, except when I render to the swap chain, at which point I resize it to match the window. However, this seems inefficient, because resizing the targets is not a "free" operation AFAICT. So, is there a better way?
The answer I ended up with was to create one back buffer per separate display area, and not size it to the back buffer. I imagine that, in a world where desktop composition and transparency can happy to "anything" behind my back, that's probably helpful to the system.
Learn to love the VVM system, I guess :-) (VVM for Virtual Video Memory)

Is there a visual two-dimensional code editor?

Let me explain what I mean by "two-dimensional code editor": imagine of using Inkscape or Gimp in a big canvas (say infinite). The "T - add text" tool is used to write the code. Additionally, all function definitions will be framed and links will connect the called functions.
In other words: you have a very large sheet of (virtual) paper where you can write.
It would be really useful. I don't want to write code as a long list of lines, especially now that big monitors are cheaper.
Is such a code editor out there?
What's your opinion? Would you use a 2d code editor?
I've written 3 or 4 visual editors and my second one worked like this, that was for java and c++ (never published, though I did use it for some published research work)
I still don't like much to write my code 'as a long list of lines'. My point is, after trying a system like this, I tried a windowed system (class outlines in windows, right click to open code editors), then a tree based system...
in the long run (I wrote several apps using all of those), the tree based system with non overlapping windows felt at once most scalable (to different monitor sizes) and foremost, most productive, because dragging the text boxes and links and/or windows in the first version was necessary, without adding much to the programming experience, so it felt wasteful.
If you want to try some of this stuff out, you can google antegram for java (java only) antegram for web (javascript/php/actionscript) and ee-ide (on oogtech.org). I'm not sure if I could dig up the original c++/java textbox + links editor (which could collapse graphs as well, and had an infinite canvas, so pretty close to what you describe).
I'm not working on this as much as I used to as few programmers ever seemed to like it except me, but if you like working the tree way, or feel like adding stuff for your own purposes, ee-ide would be the way to go, as it's nicely modular and easy to extend compared to the rest.
On the commercial side, you can configure visual studio to work with UML-like diagrams. I have a feel it might be a little too heavy (although it's definitely more coding than UML oriented), but I'm not sure, I haven't really tried yet.
This probably doesn't answer your question exactly, but anyway.
Have a look at the NodeBox beta . It is a visual programming environment mostly for creating generative graphics. You can program and edit the nodes with python code, connect and reuse them in multiple ways. (Windows and Mac OS)
Also worth mentioning (in terms of concept) is Field . It is for programming performances and arranges bits of code on a stage/timeline. Very interesting but also very confusing. (Mac OS only)
Third one is vvvv. It is used a lot by graphical artists to create realtime 3d visuals. Node based. (Windows only)
NodeBox and Field are open-source, so if you are looking to create something yourself you can see how it's done there.
Check this out. I came across it today and remembered this question.
Code Bubbles
Developers spend significant time
reading and navigating code fragments
spread across multiple locations. The
file-based nature of contemporary IDEs
makes it prohibitively difficult to
create and maintain a simultaneous
view of such fragments. We propose a
novel user interface metaphor for code
understanding and maintanence based on
collections of lightweight, editable
fragments called bubbles, which form
concurrently visible working sets.
The essential goal of this project is
to make it easier for developers to
see many fragments of code (or other
information) at once without having to
navigate back and forth. Each of these
fragments is shown in a bubble.
A bubble is a fully editable and
interactive view of a fragment such as
a method or collection of member
variables. Bubbles, in contrast to
windows, have minimal border
decoration, avoid clipping their
contents by using automatic code
reflow and elision, and do not overlap
but instead push each other out of the
way. Bubbles exist in a large,
pannable 2-D virtual space where a
cluster of bubbles comprises a
concurrently visible working set.
Bubbles support a lightweight grouping
mechanism, and further support
connections between them.
A quantiative user study indicates
that Code Bubbles increased
performance significantly for two
controlled code understanding tasks. A
qualitative user study with 23
professional developers indicates
substantial interest and enthusiasm
for the approach, despite the radical
departure from what developers are
used to.
http://www.cs.brown.edu/people/acb/codebubbles_site.htm
At one point, LabView had a programming mode like this. You connected program blocks together in a graphical way.
It's been so long since I've used LabView that I don't know if it is still the same.
For me, the MVVM pattern means that there's no code behind the UI controls anyway. The logic is all in a class with properties.
The properties use WPF databinding to update the UI controls. For example, on the form or window, page, whatever, MySearchButton.IsEnabled is bound to ViewModel.MySearchButtonIsEnabled property. So the app logic runs in the ViewModel class and just sets its own properties and the UI updates automatically.
Although this is specific to MS WPF the pattern actually stems from SmallTalk and is found across the development field as MVP. Without WPF one would need to write the databinding or 'presenter' logic, which is common.
This means the UI can be torn off and a new one pasted-in really quickly and with little code knowledge from the UI guy - who, in an ideal world, is a crack creative guy that drives a 70s Citroen.
So my point is that, although it sounds like a neat innovation, a 2D editor like this would be assisting a coding style that is no longer considered optimal.

Fast, Pixel Precision 2D Drawing API for Graphics App?

I woud like to create a cross-platform drawing program. The one requirement for writing my app is that I have pixel level precision over the canvas. For instance, I want to write my own line drawing algorithm rather than rely on someone elses. I do not want any form of anti-aliasing (again, pixel level control is required.) I would like the users interactions on the screen to be quick and responsive (pending my ability to write fast algorithms.)
Ideally, I would like to write this in Python, or perhaps Java as a second choice. The ability to easily make the final app cross-platform is a must. I will submit to different API's on different OS'es if necessary as long as I can write an abstraction layer around them. Any ideas?
addendum: I need the ability to draw on-screen. Drawing out to a file I've got figured out.
I just this week put together some slides and demo code for doing 2d graphics using OpenGL from python using the library pyglet. Here's a representative post: Pyglet week 2, better vertex throughput (or 3D stuff using the same basic ideas)
It is very fast (relatively speaking, for python) I have managed to get around 1,000 independently positioned and oriented objects moving around the screen, each with about 50 vertices.
It is very portable, all the code I have written in this environment works on windows and Linux and mac (and even obscure environments like Pypy) without me ever having to think about it.
Some of these posts are very old, with broken links between them. You should be able to find all the relevant posts using the 'graphics' tag.
The Pyglet library for Python might suit your needs. It lets you use OpenGL, a cross-platform graphics API. You can disable anti-aliasing and capture regions of the screen to a buffer or a file. In addition, you can use its event handling, resource loading, and image manipulation systems. You can probably also tie it into PIL (Python Image Library), and definitely Cairo, a popular cross-platform vector graphics library.
I mention Pyglet instead of pure PyOpenGL because Pyglet handles a lot of ugly OpenGL stuff transparently with no effort on your part.
A friend and I are currently working on a drawing program using Pyglet. There are a few quirks - for example, OpenGL is always double buffered on OS X, so we have to draw everything twice, once for the current frame and again for the other frame, since they are flipped whenever the display refreshes. You can look at our current progress in this subversion repository. (Splatterboard.py in trunk is the file you'll want to run.) If you're not up on using svn, I would be happy to email you a .zip of the latest source. Feel free to steal code if you look into it.
If language choice is open, a Flash file created with Haxe might have a place. Haxe is free, and a full, dynamic programming language. Then there's the related Neko, a virtual machine (like Java's, Ruby's, Parrot...) to run on Mac, Windows and Linux. Being in some ways a new improved form of Flash, naturally it can draw stuff. http://haxe.org/
QT's Canvas an QPainter are very good for this job if you'd like to use C++. and it is cross platform.
There is a python binding for QT but I've never used it.
As for Java, using SWT, pixel level manipulation of a canvas is somewhat difficult and slow so I would not recommend it. On the other hand Swing's Canvas is pretty good and responsive. I've never used the AWT option but you probably don't want to go there.
I would recommend wxPython
It's beautifully cross platform and you can get per pixel control and if you change your mind about that you can use it with libraries such as pyglet or agg.
You can find some useful examples for just what you are trying to do in the docs and demos download.

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