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| author | Mitja Felicijan <mitja.felicijan@gmail.com> | 2023-06-27 14:50:20 +0200 |
|---|---|---|
| committer | Mitja Felicijan <mitja.felicijan@gmail.com> | 2023-06-27 14:50:20 +0200 |
| commit | 8697555125c57ae64a0c9b78514b4aac4fd523de (patch) | |
| tree | a699df53a7c35a4425f30bca86982c4341f6de40 /content/posts/2023-01-26-trying-to-build-a-new-kind-of-terminal-emulator.md | |
| parent | 33b2615a5038bc85036081e8b5e0da8584d88097 (diff) | |
| download | mitjafelicijan.com-8697555125c57ae64a0c9b78514b4aac4fd523de.tar.gz | |
Massive formatting and added figcaption
Diffstat (limited to 'content/posts/2023-01-26-trying-to-build-a-new-kind-of-terminal-emulator.md')
| -rw-r--r-- | content/posts/2023-01-26-trying-to-build-a-new-kind-of-terminal-emulator.md | 184 |
1 files changed, 95 insertions, 89 deletions
diff --git a/content/posts/2023-01-26-trying-to-build-a-new-kind-of-terminal-emulator.md b/content/posts/2023-01-26-trying-to-build-a-new-kind-of-terminal-emulator.md index 4ec307f..a03a2a4 100644 --- a/content/posts/2023-01-26-trying-to-build-a-new-kind-of-terminal-emulator.md +++ b/content/posts/2023-01-26-trying-to-build-a-new-kind-of-terminal-emulator.md | |||
| @@ -5,32 +5,33 @@ date: 2023-01-26T12:00:00+02:00 | |||
| 5 | draft: false | 5 | draft: false |
| 6 | --- | 6 | --- |
| 7 | 7 | ||
| 8 | Over the past few weeks, I have been really thinking about terminal emulators, | 8 | Over the past few weeks, I have been really thinking about terminal emulators, |
| 9 | how we interact with computers, the separation of text-based programs and GUI | 9 | how we interact with computers, the separation of text-based programs and GUI |
| 10 | ones. To be perfectly honest, I got pissed off one evening when I was cleaning | 10 | ones. To be perfectly honest, I got pissed off one evening when I was cleaning |
| 11 | up files on my computer. Normally, I go into console and do `ncdu` and check | 11 | up files on my computer. Normally, I go into console and do `ncdu` and check |
| 12 | where the junk is. Then I start deleting stuff. Without any discrimination, | 12 | where the junk is. Then I start deleting stuff. Without any discrimination, |
| 13 | usually. But when it comes to screenshots, I have learned that it's good to | 13 | usually. But when it comes to screenshots, I have learned that it's good to keep |
| 14 | keep them somewhere near if I need to refer to something that I was doing. I | 14 | them somewhere near if I need to refer to something that I was doing. I am an |
| 15 | am an avid screenshot taker. So at that point I checked Pictures folder and | 15 | avid screenshot taker. So at that point I checked Pictures folder and also did a |
| 16 | also did a basic search `find . -type f -name "*.jpg"` for all the JPEG files | 16 | basic search `find . -type f -name "*.jpg"` for all the JPEG files in my home |
| 17 | in my home directory and immediately got pissed off. Why can’t I see thumbnails | 17 | directory and immediately got pissed off. Why can’t I see thumbnails in my |
| 18 | in my terminal? I know why, but why in the year of 2022 this is still a | 18 | terminal? I know why, but why in the year of 2022 this is still a problem. I am |
| 19 | problem. I am used to traversing my disk via terminal. I am faster, and I am | 19 | used to traversing my disk via terminal. I am faster, and I am more comfortable |
| 20 | more comfortable this way. But when it comes to visualization, I then need to | 20 | this way. But when it comes to visualization, I then need to revert to GUI |
| 21 | revert to GUI applications and again find the same file to see it. I know that | 21 | applications and again find the same file to see it. I know that programs like |
| 22 | programs like `feh` and `sxiv` are available, but I would just like to see the | 22 | `feh` and `sxiv` are available, but I would just like to see the preview. Like |
| 23 | preview. Like [Jupyter notebook](https://jupyter.org/) or something similar. | 23 | [Jupyter notebook](https://jupyter.org/) or something similar. Just having it |
| 24 | Just having it inline. Part of a result. | 24 | inline. Part of a result. |
| 25 | 25 | ||
| 26 | It also didn’t help that I was spending some time with the [Plan 9](https://plan9.io/plan9/) | 26 | It also didn’t help that I was spending some time with the [Plan |
| 27 | Operating system. More specifically [9FRONT](http://9front.org/). The way | 27 | 9](https://plan9.io/plan9/) Operating system. More specifically |
| 28 | that [ACME editor](http://acme.cat-v.org/) handles text editing is just | 28 | [9FRONT](http://9front.org/). The way that [ACME editor](http://acme.cat-v.org/) |
| 29 | wonderful. Different and fresh somehow, even though it’s super old. | 29 | handles text editing is just wonderful. Different and fresh somehow, even though |
| 30 | 30 | it’s super old. | |
| 31 | So, I went on a lookout for an interesting way of visualizing results of some | 31 | |
| 32 | query. I found these applications to be outstanding examples of how not to be | 32 | So, I went on a lookout for an interesting way of visualizing results of some |
| 33 | a captive of a predetermined way of doing things. | 33 | query. I found these applications to be outstanding examples of how not to be a |
| 34 | captive of a predetermined way of doing things. | ||
| 34 | 35 | ||
| 35 | - [Wolfram Mathematica](https://www.wolfram.com/mathematica/) | 36 | - [Wolfram Mathematica](https://www.wolfram.com/mathematica/) |
| 36 | - [Jupyter notebooks](https://jupyter.org/) | 37 | - [Jupyter notebooks](https://jupyter.org/) |
| @@ -38,56 +39,56 @@ a captive of a predetermined way of doing things. | |||
| 38 | - [Temple OS](https://templeos.org/) | 39 | - [Temple OS](https://templeos.org/) |
| 39 | - [Emacs](https://www.gnu.org/software/emacs/) | 40 | - [Emacs](https://www.gnu.org/software/emacs/) |
| 40 | 41 | ||
| 41 | My idea is not as out there as ACME is, but it is a spin on the terminal | 42 | My idea is not as out there as ACME is, but it is a spin on the terminal |
| 42 | emulators. I like the modes that Vi/Vim provides you with. I like the way | 43 | emulators. I like the modes that Vi/Vim provides you with. I like the way the |
| 43 | the Emacs does its own `M-x` `M-c`. Furthermore, I really like how Mathematica | 44 | Emacs does its own `M-x` `M-c`. Furthermore, I really like how Mathematica and |
| 44 | and Jupyter present the data in a free flowing form. And I love how Temple OS | 45 | Jupyter present the data in a free flowing form. And I love how Temple OS is |
| 45 | is basically a C interpreter on some level. | 46 | basically a C interpreter on some level. |
| 46 | 47 | ||
| 47 | > **Note:** This is part 1 of the journey. Nowhere finished yet. I am just | 48 | > **Note:** This is part 1 of the journey. Nowhere finished yet. I am just |
| 48 | > tinkering with this at the moment. This whole thing can easily spectacularly | 49 | > tinkering with this at the moment. This whole thing can easily spectacularly |
| 49 | > fail. | 50 | > fail. |
| 50 | 51 | ||
| 51 | So I started. I knew that I wanted to have the couple of modes, but I didn’t | 52 | So I started. I knew that I wanted to have the couple of modes, but I didn’t |
| 52 | like the repetition of keystrokes, so the only option was to have some sort of | 53 | like the repetition of keystrokes, so the only option was to have some sort of |
| 53 | toggle and indicate to the user that they are in a special mode. Like Vi does | 54 | toggle and indicate to the user that they are in a special mode. Like Vi does |
| 54 | for Normal and Visual mode. | 55 | for Normal and Visual mode. |
| 55 | 56 | ||
| 56 | These modes would for the first version be: | 57 | These modes would for the first version be: |
| 57 | 58 | ||
| 58 | - *Preview mode* (toggle with Ctrl + P) | 59 | - *Preview mode* (toggle with Ctrl + P) |
| 59 | - When this mode would be enabled, the `ls` command would try to find images | 60 | - When this mode would be enabled, the `ls` command would try to find images |
| 60 | from the results and display thumbnails from them in the terminal itself. | 61 | from the results and display thumbnails from them in the terminal itself. |
| 61 | No ASCII art. Proper images. In a grid! | 62 | No ASCII art. Proper images. In a grid! |
| 62 | - *Detach mode* (toggle with Ctrl + D) | 63 | - *Detach mode* (toggle with Ctrl + D) |
| 63 | - When this mode would be enabled, every command would open a new window | 64 | - When this mode would be enabled, every command would open a new window |
| 64 | and execute that command in it. This would be useful for starting `htop` | 65 | and execute that command in it. This would be useful for starting `htop` |
| 65 | in a separate window. | 66 | in a separate window. |
| 66 | 67 | ||
| 67 | The reason for having these modes togglable is to not ask for previews every | 68 | The reason for having these modes togglable is to not ask for previews every |
| 68 | time. You enable a mode and until you disable it, it behaves that way. | 69 | time. You enable a mode and until you disable it, it behaves that way. Purely |
| 69 | Purely out of ergonomic reasons. | 70 | out of ergonomic reasons. |
| 70 | 71 | ||
| 71 | I would like to treat every terminal I open as a session mentally. When I start | 72 | I would like to treat every terminal I open as a session mentally. When I start |
| 72 | using the terminal, I start digging deeper into the issue I am trying to resolve. | 73 | using the terminal, I start digging deeper into the issue I am trying to |
| 73 | And while I am doing this, I would like to open detached windows etc. A lot of | 74 | resolve. And while I am doing this, I would like to open detached windows |
| 74 | these things can be done easily with something like [i3](https://i3wm.org/), | 75 | etc. A lot of these things can be done easily with something like |
| 75 | but also that pull you out of the context of what you were doing. I would | 76 | [i3](https://i3wm.org/), but also that pull you out of the context of what you |
| 76 | like to orchestrate everything from one single point. | 77 | were doing. I would like to orchestrate everything from one single point. |
| 77 | 78 | ||
| 78 | In planning for this project, I knew that I would need to use a language like | 79 | In planning for this project, I knew that I would need to use a language like C |
| 79 | C and a library such as [SDL2](https://www.libsdl.org/) in order to achieve | 80 | and a library such as [SDL2](https://www.libsdl.org/) in order to achieve the |
| 80 | the desired results. I had considered other options, but ultimately determined | 81 | desired results. I had considered other options, but ultimately determined that |
| 81 | that [SDL2](https://www.libsdl.org/) was the best fit based on its capabilities | 82 | [SDL2](https://www.libsdl.org/) was the best fit based on its capabilities and |
| 82 | and reputation in the programming community. | 83 | reputation in the programming community. |
| 83 | 84 | ||
| 84 | At first, I thought the idea of a hardware accelerated terminal was a bit of | 85 | At first, I thought the idea of a hardware accelerated terminal was a bit of a |
| 85 | a joke. It seemed like such a niche and unnecessary feature, especially given | 86 | joke. It seemed like such a niche and unnecessary feature, especially given the |
| 86 | the fact that terminal emulators have been around for decades and have always | 87 | fact that terminal emulators have been around for decades and have always relied |
| 87 | relied on software rendering. But to be fair, [Alacritty](https://alacritty.org/) | 88 | on software rendering. But to be fair, [Alacritty](https://alacritty.org/) is |
| 88 | is doing the same thing. Well, they are doing a remarkable job at it. | 89 | doing the same thing. Well, they are doing a remarkable job at it. |
| 89 | 90 | ||
| 90 | So, I embarked on a journey. Everything has to start somewhere. For me, it | 91 | So, I embarked on a journey. Everything has to start somewhere. For me, it |
| 91 | started with creating a window! It has to start somewhere. 🙂 | 92 | started with creating a window! It has to start somewhere. 🙂 |
| 92 | 93 | ||
| 93 | ```c | 94 | ```c |
| @@ -101,28 +102,31 @@ SDL_Window *window = SDL_CreateWindow( | |||
| 101 | 102 | ||
| 102 | I continued like this to get some text displayed on the screen. | 103 | I continued like this to get some text displayed on the screen. |
| 103 | 104 | ||
| 104 | I noted that [`TTF_RenderText_Solid`](https://wiki.libsdl.org/SDL_ttf/TTF_RenderText_Solid) | 105 | I noted that |
| 105 | rendered text really poorly. There were no antialiasing at all. In my wisdom, | 106 | [`TTF_RenderText_Solid`](https://wiki.libsdl.org/SDL_ttf/TTF_RenderText_Solid) |
| 106 | I never checked the documentation. Well, that was a fail. To uneducated like | 107 | rendered text really poorly. There were no antialiasing at all. In my wisdom, I |
| 107 | me: `TTF_RenderText_Solid` renders Latin1 text at fast quality to a new 8-bit | 108 | never checked the documentation. Well, that was a fail. To uneducated like me: |
| 109 | `TTF_RenderText_Solid` renders Latin1 text at fast quality to a new 8-bit | ||
| 108 | surface. So, that's why the texts looked like shit. No wonder. | 110 | surface. So, that's why the texts looked like shit. No wonder. |
| 109 | 111 | ||
| 110 | Remarks on `TTF_RenderText_Solid`: This function will allocate a new 8-bit, | 112 | Remarks on `TTF_RenderText_Solid`: This function will allocate a new 8-bit, |
| 111 | palettized surface. The surface's 0 pixel will be the colorkey, giving a | 113 | palettized surface. The surface's 0 pixel will be the colorkey, giving a |
| 112 | transparent background. The 1 pixel will be set to the text color. | 114 | transparent background. The 1 pixel will be set to the text color. |
| 113 | 115 | ||
| 114 | After I replaced it with [`TTF_RenderText_LCD`](https://wiki.libsdl.org/SDL_ttf/TTF_RenderText_LCD) | 116 | After I replaced it with |
| 115 | which renders Latin1 text at LCD subpixel quality to a new ARGB surface, the | 117 | [`TTF_RenderText_LCD`](https://wiki.libsdl.org/SDL_ttf/TTF_RenderText_LCD) which |
| 116 | text started looking good. Really make sure you read the documentation. It’s | 118 | renders Latin1 text at LCD subpixel quality to a new ARGB surface, the text |
| 117 | actually good. As a side note, you can find all the documentation regarding | 119 | started looking good. Really make sure you read the documentation. It’s actually |
| 118 | [SDL2 on their Wiki](https://wiki.libsdl.org/). | 120 | good. As a side note, you can find all the documentation regarding [SDL2 on |
| 119 | 121 | their Wiki](https://wiki.libsdl.org/). | |
| 120 | After that was done, I started working on displaying other things like | 122 | |
| 121 | `Preview` and `Detach` modes. This wasn’t really that hard. In SDL2 you can | 123 | After that was done, I started working on displaying other things like `Preview` |
| 122 | check all the available events with `while (SDL_PollEvent(&event) > 0)` and | 124 | and `Detach` modes. This wasn’t really that hard. In SDL2 you can check all the |
| 123 | have a bunch of switch statements to determine which key is currently being | 125 | available events with `while (SDL_PollEvent(&event) > 0)` and have a bunch of |
| 124 | pressed. More about keys, [SDLKey](https://documentation.help/SDL/sdlkey.html) | 126 | switch statements to determine which key is currently being pressed. More about |
| 125 | and mroe about pooling the events on [SDL_PollEvent](https://documentation.help/SDL/sdlpollevent.html). | 127 | keys, [SDLKey](https://documentation.help/SDL/sdlkey.html) and mroe about |
| 128 | pooling the events on | ||
| 129 | [SDL_PollEvent](https://documentation.help/SDL/sdlpollevent.html). | ||
| 126 | 130 | ||
| 127 | ```c | 131 | ```c |
| 128 | while (SDL_PollEvent(&event) > 0) | 132 | while (SDL_PollEvent(&event) > 0) |
| @@ -144,9 +148,9 @@ while (SDL_PollEvent(&event) > 0) | |||
| 144 | } | 148 | } |
| 145 | ``` | 149 | ``` |
| 146 | 150 | ||
| 147 | After that was somewhat working correctly, I started creating a struct that | 151 | After that was somewhat working correctly, I started creating a struct that |
| 148 | would hold all the commands and results and I call them Cells. Yes, I stole | 152 | would hold all the commands and results and I call them Cells. Yes, I stole that |
| 149 | that naming idea from Jupyter. | 153 | naming idea from Jupyter. |
| 150 | 154 | ||
| 151 | ```c | 155 | ```c |
| 152 | typedef struct | 156 | typedef struct |
| @@ -159,13 +163,15 @@ typedef struct | |||
| 159 | } Cell; | 163 | } Cell; |
| 160 | ``` | 164 | ``` |
| 161 | 165 | ||
| 162 | I am at a place now where I am starting to implement scrolling. This will for | 166 | I am at a place now where I am starting to implement scrolling. This will for |
| 163 | sure be fun to code. Memory management in C is super easy. 😂 | 167 | sure be fun to code. Memory management in C is super easy. 😂 |
| 164 | 168 | ||
| 165 | I have also added a simple [INI file like configuration](https://en.wikipedia.org/wiki/INI_file) | 169 | I have also added a simple [INI file like |
| 166 | support. It is done in an [STB style of header](https://github.com/nothings/stb/blob/master/docs/stb_howto.txt) | 170 | configuration](https://en.wikipedia.org/wiki/INI_file) support. It is done in an |
| 167 | and maps to specific options supported by the terminal. It is not universal, | 171 | [STB style of |
| 168 | and the code below demonstrates how I will use it in the future. | 172 | header](https://github.com/nothings/stb/blob/master/docs/stb_howto.txt) and maps |
| 173 | to specific options supported by the terminal. It is not universal, and the code | ||
| 174 | below demonstrates how I will use it in the future. | ||
| 169 | 175 | ||
| 170 | ```c | 176 | ```c |
| 171 | #ifndef CONFIG_H | 177 | #ifndef CONFIG_H |
| @@ -239,8 +245,8 @@ extern Config read_config_file(const char *filename) | |||
| 239 | #endif | 245 | #endif |
| 240 | ``` | 246 | ``` |
| 241 | 247 | ||
| 242 | This is as far as I managed to get for now. I have a daily job and this | 248 | This is as far as I managed to get for now. I have a daily job and this |
| 243 | prohibits me to work on these things full time. But I should probably get | 249 | prohibits me to work on these things full time. But I should probably get back |
| 244 | back and finish this. At least have a simple version working out, so I can | 250 | and finish this. At least have a simple version working out, so I can start |
| 245 | start testing it on my machines. Fingers crossed. 🕵️♂️ | 251 | testing it on my machines. Fingers crossed. 🕵️♂️ |
| 246 | 252 | ||
