From 4abcce013c9ee3053badf2abda77190233066676 Mon Sep 17 00:00:00 2001 From: Mitja Felicijan Date: Fri, 23 Feb 2024 10:35:22 +0100 Subject: Testing thoughts page --- ...ing-to-build-a-new-kind-of-terminal-emulator.md | 254 --------------------- 1 file changed, 254 deletions(-) delete mode 100644 _posts/2023-01-26-trying-to-build-a-new-kind-of-terminal-emulator.md (limited to '_posts/2023-01-26-trying-to-build-a-new-kind-of-terminal-emulator.md') diff --git a/_posts/2023-01-26-trying-to-build-a-new-kind-of-terminal-emulator.md b/_posts/2023-01-26-trying-to-build-a-new-kind-of-terminal-emulator.md deleted file mode 100644 index ced58bb..0000000 --- a/_posts/2023-01-26-trying-to-build-a-new-kind-of-terminal-emulator.md +++ /dev/null @@ -1,254 +0,0 @@ ---- -title: Trying to build a New kind of terminal emulator for the modern age -permalink: /trying-to-build-a-new-kind-of-terminal-emulator.html -date: 2023-01-26T12:00:00+02:00 -layout: post -type: post -draft: false ---- - -Over the past few weeks, I have been really thinking about terminal emulators, -how we interact with computers, the separation of text-based programs and GUI -ones. To be perfectly honest, I got pissed off one evening when I was cleaning -up files on my computer. Normally, I go into console and do `ncdu` and check -where the junk is. Then I start deleting stuff. Without any discrimination, -usually. But when it comes to screenshots, I have learned that it's good to keep -them somewhere near if I need to refer to something that I was doing. I am an -avid screenshot taker. So at that point I checked Pictures folder and also did a -basic search `find . -type f -name "*.jpg"` for all the JPEG files in my home -directory and immediately got pissed off. Why can’t I see thumbnails in my -terminal? I know why, but why in the year of 2022 this is still a problem. I am -used to traversing my disk via terminal. I am faster, and I am more comfortable -this way. But when it comes to visualization, I then need to revert to GUI -applications and again find the same file to see it. I know that programs like -`feh` and `sxiv` are available, but I would just like to see the preview. Like -[Jupyter notebook](https://jupyter.org/) or something similar. Just having it -inline. Part of a result. - -It also didn’t help that I was spending some time with the [Plan -9](https://plan9.io/plan9/) Operating system. More specifically -[9FRONT](http://9front.org/). The way that [ACME editor](http://acme.cat-v.org/) -handles text editing is just wonderful. Different and fresh somehow, even though -it’s super old. - -So, I went on a lookout for an interesting way of visualizing results of some -query. I found these applications to be outstanding examples of how not to be a -captive of a predetermined way of doing things. - -- [Wolfram Mathematica](https://www.wolfram.com/mathematica/) -- [Jupyter notebooks](https://jupyter.org/) -- [Plan 9 / 9FRONT](http://www.9front.org) -- [Temple OS](https://templeos.org/) -- [Emacs](https://www.gnu.org/software/emacs/) - -My idea is not as out there as ACME is, but it is a spin on the terminal -emulators. I like the modes that Vi/Vim provides you with. I like the way the -Emacs does its own `M-x` `M-c`. Furthermore, I really like how Mathematica and -Jupyter present the data in a free flowing form. And I love how Temple OS is -basically a C interpreter on some level. - -> **Note:** This is part 1 of the journey. Nowhere finished yet. I am just -> tinkering with this at the moment. This whole thing can easily spectacularly -> fail. - -So I started. I knew that I wanted to have the couple of modes, but I didn’t -like the repetition of keystrokes, so the only option was to have some sort of -toggle and indicate to the user that they are in a special mode. Like Vi does -for Normal and Visual mode. - -These modes would for the first version be: - -- *Preview mode* (toggle with Ctrl + P) - - When this mode would be enabled, the `ls` command would try to find images - from the results and display thumbnails from them in the terminal itself. - No ASCII art. Proper images. In a grid! -- *Detach mode* (toggle with Ctrl + D) - - When this mode would be enabled, every command would open a new window - and execute that command in it. This would be useful for starting `htop` - in a separate window. - -The reason for having these modes togglable is to not ask for previews every -time. You enable a mode and until you disable it, it behaves that way. Purely -out of ergonomic reasons. - -I would like to treat every terminal I open as a session mentally. When I start -using the terminal, I start digging deeper into the issue I am trying to -resolve. And while I am doing this, I would like to open detached windows -etc. A lot of these things can be done easily with something like -[i3](https://i3wm.org/), but also that pull you out of the context of what you -were doing. I would like to orchestrate everything from one single point. - -In planning for this project, I knew that I would need to use a language like C -and a library such as [SDL2](https://www.libsdl.org/) in order to achieve the -desired results. I had considered other options, but ultimately determined that -[SDL2](https://www.libsdl.org/) was the best fit based on its capabilities and -reputation in the programming community. - -At first, I thought the idea of a hardware accelerated terminal was a bit of a -joke. It seemed like such a niche and unnecessary feature, especially given the -fact that terminal emulators have been around for decades and have always relied -on software rendering. But to be fair, [Alacritty](https://alacritty.org/) is -doing the same thing. Well, they are doing a remarkable job at it. - -So, I embarked on a journey. Everything has to start somewhere. For me, it -started with creating a window! It has to start somewhere. 🙂 - -```c -// Oh, Hi Mark! -// Create the window, obviously. -SDL_Window *window = SDL_CreateWindow( - WINDOW_TITLE, SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, - WINDOW_WIDTH, WINDOW_HEIGHT, - SDL_WINDOW_RESIZABLE | SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN); -``` - -I continued like this to get some text displayed on the screen. - -I noted that -[`TTF_RenderText_Solid`](https://wiki.libsdl.org/SDL_ttf/TTF_RenderText_Solid) -rendered text really poorly. There were no antialiasing at all. In my wisdom, I -never checked the documentation. Well, that was a fail. To uneducated like me: -`TTF_RenderText_Solid` renders Latin1 text at fast quality to a new 8-bit -surface. So, that's why the texts looked like shit. No wonder. - -Remarks on `TTF_RenderText_Solid`: This function will allocate a new 8-bit, -palettized surface. The surface's 0 pixel will be the colorkey, giving a -transparent background. The 1 pixel will be set to the text color. - -After I replaced it with -[`TTF_RenderText_LCD`](https://wiki.libsdl.org/SDL_ttf/TTF_RenderText_LCD) which -renders Latin1 text at LCD subpixel quality to a new ARGB surface, the text -started looking good. Really make sure you read the documentation. It’s actually -good. As a side note, you can find all the documentation regarding [SDL2 on -their Wiki](https://wiki.libsdl.org/). - -After that was done, I started working on displaying other things like `Preview` -and `Detach` modes. This wasn’t really that hard. In SDL2 you can check all the -available events with `while (SDL_PollEvent(&event) > 0)` and have a bunch of -switch statements to determine which key is currently being pressed. More about -keys, [SDLKey](https://documentation.help/SDL/sdlkey.html) and mroe about -pooling the events on -[SDL_PollEvent](https://documentation.help/SDL/sdlpollevent.html). - -```c -while (SDL_PollEvent(&event) > 0) -{ - switch (event.type) - { - case SDL_QUIT: - running = false; - break; - - case SDL_TEXTINPUT: - if (!meta_key_pressed) - { - strncat(input_prompt_text, event.text.text, 1); - update_input_prompt = true; - } - break; - } -} -``` - -After that was somewhat working correctly, I started creating a struct that -would hold all the commands and results and I call them Cells. Yes, I stole that -naming idea from Jupyter. - -```c -typedef struct -{ - char *command; - char *result; - SDL_Surface *surface; - SDL_Texture *texture; - SDL_Rect rect; -} Cell; -``` - -I am at a place now where I am starting to implement scrolling. This will for -sure be fun to code. Memory management in C is super easy. 😂 - -I have also added a simple [INI file like -configuration](https://en.wikipedia.org/wiki/INI_file) support. It is done in an -[STB style of -header](https://github.com/nothings/stb/blob/master/docs/stb_howto.txt) and maps -to specific options supported by the terminal. It is not universal, and the code -below demonstrates how I will use it in the future. - -```c -#ifndef CONFIG_H -#define CONFIG_H - -/* -# This is a comment - -# This is the first configuration option -dettach=value11111 - -# This is the second configuration option -preview=value22222 - -# This is the third configuration option -debug=value33333 -*/ - -// Define a struct to hold the configuration options -typedef struct -{ - char dettach[256]; - char preview[256]; - char debug[256]; -} Config; - -// Read the configuration file and return the options as a struct -extern Config read_config_file(const char *filename) -{ - // Create a struct to hold the configuration options - Config config = {0}; - - // Open the configuration file - FILE *file = fopen(filename, "r"); - - // Read each line from the file - char line[256]; - while (fgets(line, sizeof(line), file)) - { - // Check if this line is a comment or empty - if (line[0] == '#' || line[0] == '\n') - continue; - - // Parse the line to get the option and value - char option[128], value[128]; - if (sscanf(line, "%[^=]=%s", option, value) != 2) - continue; - - // Set the value of the appropriate option in the config struct - if (strcmp(option, "dettach") == 0) - { - strncpy(config.option1, value, sizeof(config.option1)); - } - else if (strcmp(option, "preview") == 0) - { - strncpy(config.option2, value, sizeof(config.option2)); - } - else if (strcmp(option, "debug") == 0) - { - strncpy(config.option3, value, sizeof(config.option3)); - } - } - - // Close the configuration file - fclose(file); - - // Return the configuration options - return config; -} - -#endif -``` - -This is as far as I managed to get for now. I have a daily job and this -prohibits me to work on these things full time. But I should probably get back -and finish this. At least have a simple version working out, so I can start -testing it on my machines. Fingers crossed. 🕵️‍♂️ - -- cgit v1.2.3