#+SETUPFILE: ~/.emacs.d/org-styles/html/darksun.theme
#+TITLE:  BASIC applications collection
#+LANGUAGE: en
#+LATEX_HEADER: \usepackage[margin=1.0in]{geometry}
#+LATEX_HEADER: \usepackage{parskip}
#+LATEX_HEADER: \usepackage[none]{hyphenat}

#+OPTIONS: H:20 num:20
#+OPTIONS: author:nil

#+begin_export html
<style>
  .flex-center {
    display: flex;            /* activate flexbox */
    justify-content: center;  /* horizontally center anything inside   */
  }

  .flex-center video {
    width: min(90%, 1000px); /* whichever is smaller wins */
    height: auto;            /* preserve aspect ratio */
  }

  .responsive-img {
    width: min(100%, 1000px);
    height: auto;
  }
</style>
#+end_export


* Overview
This collection contains lots of applications:

- [[id:3587240c-1d50-478d-b850-04ebc8dc63c7][Miscellaneous]]
- [[id:ebafd8a3-54d4-4834-a03d-a942b535a82f][2D Graphics]]
- [[id:63fd5d58-9bce-4c0a-99d4-ed2d025258f0][3D Graphics]]
- [[id:aa195f33-6d69-48ff-9af5-3f761a51dcb2][Games]]

I wrote them at around year 2000, mostly in QBasic.

* 2D GFX
:PROPERTIES:
:ID:       ebafd8a3-54d4-4834-a03d-a942b535a82f
:END:
** Fractals

*Fractal of circles*

#+attr_html: :class responsive-img
#+attr_latex: :width 1000px
[[file:2D GFX/Fractals/fractal circles.bas][file:2D%20GFX/Fractals/fractal%20circles.png]]

[[file:2D%20GFX/Fractals/fractal%20circles.bas][Source code]]

*Fractal of squares*

#+begin_export html
<div class="flex-center">
  <video controls loop autoplay>
    <source src="2D GFX/Fractals/fractal squares.webm" type="video/webm">
    Your browser does not support the video tag.
  </video>
</div>
#+end_export

[[file:2D%20GFX/Fractals/fractal%20squares.bas][Source code]]

*Fractal of trees*

#+begin_export html
<div class="flex-center">
  <video controls loop autoplay class="flex-center">
    <source src="2D GFX/Fractals/fractal trees.webm" type="video/webm">
    Your browser does not support the video tag.
  </video>
</div>
#+end_export

[[file:2D%20GFX/Fractals/fractal%20trees.bas][Source code]]

** Spiral series

Small collection of programs that are result of exploratory
programming, for fun. It started out from drawing spiral on the
screen. Every iteration built upon previous result.


#+attr_html: :class responsive-img
#+attr_latex: :width 1000px
[[file:2D%20GFX/Spirals/index.html][file:2D%20GFX/Spirals/logo.png]]

[[file:2D%20GFX/Spirals/index.html][Read more]]

** Animations

Collection of various 2D animations. Good for demonstrating various
algorithms and getting fun looking results quite easily.

#+begin_export html
<a href="2D%20GFX/Animations/index.html" class="flex-center">
  <video controls loop autoplay>
    <source src="2D GFX/Animations/text mode animation.webm" type="video/webm">
    Your browser does not support the video tag.
  </video>
</a>
#+end_export

[[file:2D%20GFX/Animations/index.html][Read more]]

* 3D GFX
:PROPERTIES:
:ID:       63fd5d58-9bce-4c0a-99d4-ed2d025258f0
:END:
** 3D Synthezier

Parses scene definition language and creates 3D world based on
it. Result will be in a [[https://en.wikipedia.org/wiki/Wavefront_.obj_file][wavefront obj file]], witch can be then
visualized using external renderer.

See directory:
: 3D GFX/3D Synthetizer/


#+attr_html: :class responsive-img
#+attr_latex: :width 1000px
[[file:3D%20GFX/3D%20Synthezier/doc/index.html][file:3D%20GFX/3D%20Synthezier/doc/hexagonal%20city,%202.jpeg]]

[[file:3D%20GFX/3D%20Synthezier/doc/index.html][Read more]]

** Miscellaneous

*Rotating exclamation mark*

Wireframe 3D model of a rotating exclamation mark.

#+begin_export html
<div class="flex-center">
  <video controls loop autoplay>
    <source src="3D GFX/!.webm" type="video/webm">
    Your browser does not support the video tag.
  </video>
</div>
#+end_export

[[file:3D%20GFX/!.bas][Source code]]

*Pointcloud 3D bouncing ball*

Calculates the pointcloud sphere and bounces it on screen.

#+begin_export html
<div class="flex-center">
  <video controls loop autoplay>
    <source src="3D GFX/3D ball.webm" type="video/webm">
    Your browser does not support the video tag.
  </video>
</div>
#+end_export

[[file:3D%20GFX/3D%20ball.bas][Source code]]

*3D curved surface*

3D model of a curved and shaded surface.

#+begin_export html
<div class="flex-center">
  <video controls loop autoplay>
    <source src="3D GFX/3D land.webm" type="video/webm">
    Your browser does not support the video tag.
  </video>
</div>
#+end_export

[[file:3D%20GFX/3D%20land.bas][Source code]]

*3D game of life animation*

Animation that displays game of life on dynamically deformed 2D
surface placed in 3D world.

#+begin_export html
<div class="flex-center">
  <video controls loop autoplay>
    <source src="3D GFX/3D life.webm" type="video/webm">
    Your browser does not support the video tag.
  </video>
</div>
#+end_export

[[file:3D%20GFX/3D%20life.bas][Source code]]

*3D text in a room*

Wireframe 3D text hanging in a wireframe 3D room. User can look and
fly around in all directions.

#+begin_export html
<div class="flex-center">
  <video controls loop autoplay>
    <source src="3D GFX/3D text.webm" type="video/webm">
    Your browser does not support the video tag.
  </video>
</div>
#+end_export

[[file:3D%20GFX/3D%20text.bas][Source code]]

*3D bouncing cubes on grid floor*

3D wireframe cubes bouncing on a grid floor, creating an immersive and
dynamic visual effect.

#+begin_export html
<div class="flex-center">
  <video controls loop autoplay>
    <source src="3D GFX/bouncing cubes.webm" type="video/webm">
    Your browser does not support the video tag.
  </video>
</div>
#+end_export

[[file:3D%20GFX/bouncing%20cubes.bas][Source code]]

*Attracted particles*

3D simulation of particles attracted to each other. When particles get
too close, stronger repulsive force takes over. There is also
friction. Eventually after some bouncing, particles settle in
equilibrium state.

#+begin_export html
<div class="flex-center">
  <video controls loop autoplay>
    <source src="3D GFX/gravity particles.webm" type="video/webm">
    Your browser does not support the video tag.
  </video>
</div>
#+end_export

[[file:3D%20GFX/gravity%20particles.bas][Source code]]

*Matrix math for rotation in 3D space*

Instead of combining simple 2D rotors, pixels in this 3D space are
rotated by using matrix multiplications.

#+begin_export html
<div class="flex-center">
  <video controls loop autoplay>
    <source src="3D GFX/matrix math.webm" type="video/webm">
    Your browser does not support the video tag.
  </video>
</div>
#+end_export

[[file:3D%20GFX/matrix%20math.bas][Source code]]


*Rocket simulator*

Attempt to simulate rocket taking off from the surface of the earth
and flying into space.

#+begin_export html
<div class="flex-center">
  <video controls loop autoplay>
    <source src="3D GFX/rocket simulator.webm" type="video/webm">
    Your browser does not support the video tag.
  </video>
</div>
#+end_export

[[file:3D%20GFX/rocket%20simulator.bas][Source code]]

*Screensaver to display animation of flying through the star field*

#+begin_export html
<div class="flex-center">
  <video controls loop autoplay>
    <source src="3D GFX/stars.webm" type="video/webm">
    Your browser does not support the video tag.
  </video>
</div>
#+end_export

[[file:3D%20GFX/stars.bas][Source code]]

*Tank animation*

Animated tank driving through the bridge back and forward. User can
look and fly around in all directions.

#+begin_export html
<div class="flex-center">
  <video controls loop autoplay>
    <source src="3D GFX/tank.webm" type="video/webm">
    Your browser does not support the video tag.
  </video>
</div>
#+end_export

[[file:3D%20GFX/tank.bas][Source code]]

*tiled room*

Room with some tiles on the wall and on the floor. User can freely fly
around.

#+begin_export html
<div class="flex-center">
  <video controls loop autoplay>
    <source src="3D GFX/tiled room.webm" type="video/webm">
    Your browser does not support the video tag.
  </video>
</div>
#+end_export

[[file:3D%20GFX/tiled%20room.bas][Source code]]


* Misc
:PROPERTIES:
:ID:       3587240c-1d50-478d-b850-04ebc8dc63c7
:END:
* Games
:PROPERTIES:
:ID:       aa195f33-6d69-48ff-9af5-3f761a51dcb2
:END:
** Multiplayer game of worms

Game supports up to 5 players. Any amount of those players can be AI
controlled. Game has multiple levels. After worms have eaten certain
amount of fruits, game advances to the next level. Each worm has
limited amount of lives. When worm runs into the wall or another worm,
it loses one life.

#+begin_export html
<div class="flex-center">
  <video controls loop autoplay>
    <source src="Games/Worm/screencast.webm" type="video/webm">
    Your browser does not support the video tag.
  </video>
</div>
#+end_export

[[file:Games/Worm/worm.bas][Source code]]

Levels are stored in [[https://www2.svjatoslav.eu/gitweb/?p=qbasicapps.git;a=tree;f=Games/Worm;h=644d30adafb2621f34f6d2f3e43e026084092f60;hb=HEAD]['lvl' files]] that are directly editable using text
editor.

** Checkers

Play checkers against the computer with any board size and any amount
of caps. Does thinking by recursively testing many possible scenarios
with any depth.

Since it is slow QBasic implementation, it isn't practical to play
with many caps or big thinking depth, for reasonable responce time.

[[file:Games/Checkers 2/checkers2.bas][Source code]]

#+attr_html: :class responsive-img
#+attr_latex: :width 1000px
[[file:Games/Checkers 2/checkers2.bas][file:Games/Checkers%202/screenshot.png]]

* Download
** Getting the source code

Programs author is Svjatoslav Agejenko
- Homepage: https://svjatoslav.eu (See also [[https://www.svjatoslav.eu/projects/][other software projects]].)
- Email: mailto://svjatoslav@svjatoslav.eu

*These programs are free software: released under Creative Commons
Zero (CC0) license.*

- [[https://www2.svjatoslav.eu/gitweb/?p=qbasicapps.git;a=summary][Browse Git repository online]].
- [[https://www2.svjatoslav.eu/gitweb/?p=qbasicapps.git;a=snapshot;h=HEAD;sf=tgz][Download latest snapshot in TAR GZ format]].
- You can clone Git repository using git:
  : git clone https://www3.svjatoslav.eu/git/qbasicapps.git

** Installation and Usage

There are various ways to run legacy QBasic applications under Debian
GNU/Linux:

+ Full system virtualization :: One way would be to use full system
virtualization with [[https://www.qemu.org/][QEMU]], [[https://www.virtualbox.org/][VirtualBox]] or [[https://www.vmware.com/products/desktop-hypervisor.html][VMware Workstation or
Player]]. After creating virtual machine, you need to obtain and
install some distribution of DOS like [[https://en.wikipedia.org/wiki/MS-DOS][MS-DOS]] or [[https://www.freedos.org/][FreeDOS]]. Within DOS
you can then use either Microsoft *QBasic* or Microsoft
*QuickBasic*. QBasic is already included in Microsoft DOS by
default. QuickBasic is more capable but must be obtained separately.

- QB64 :: [[https://qb64.com][QB64]] is mostly compatible with Microsoft BASIC variants and
 can be used too.

- [[id:97ea6094-ade6-4c7d-aea9-9874acf9dc86][DOSBox + MS BASIC]] :: Easy to install and good compatibility.

*** DOSBox + MS BASIC
:PROPERTIES:
:ID:       97ea6094-ade6-4c7d-aea9-9874acf9dc86
:END:

Following tutorial focuses on using DOSBox with original Microsoft
QBasic or QuickBasic.

DOSBox is trivial to install and BASIC programs do not need to be
copied to virtual drive or operating system to run them. Using
original BASIC binaries ensures good compatibility.


Here is suggested installation and usage procedure:

1. Install DOSBox by running the following command in your terminal:
   : sudo apt-get install dosbox

2. Obtain and place a copy of QuickBasic *QB.EXE* executable binary
   into directory */QB45/* within project root directory.

   Optionally obtain [[https://en.wikipedia.org/wiki/Volkov_Commander][Volkov Commander]] executable VC.COM and place it
   under project root directory. Volkov Commander simplifies
   filesystem navigation and running arbitrary BASIC program by
   selecting it and pressing ENTER key. For this to work, BAS file
   extension is mapped to BASIC executable within VC.EXT file (already
   available in the project root directory). In case you are using
   QBasic instead, feel free to fix VC.EXT to point to appropriate
   BASIC executable.

3. Optionally check and apply [[id:13c7d873-f1aa-4061-88ac-dc9e43c6303d][DOSBox usage tips]].

4. Execute script that is located in the root directory of the
   repository:
   : ./run_dosbox.sh

5. Now project root directory appears as root directory of virtual
   *C:* drive. You can navigate around and start programs.


Here is suggested project directory layout with QuickBasic and Volkov
Commander installed:
#+begin_example
  ├── COPYING
  ├── index.org
  ├── QB45
  │   ├── QB.EXE
  │   └── QB.INI
  ├── run_dosbox.sh
  ├── (... other repository files and directories)
  ├── VC.COM
  ├── VC.EXT
  └── VC.INI
#+end_example

*** DOSBox usage tips
:PROPERTIES:
:ID:       13c7d873-f1aa-4061-88ac-dc9e43c6303d
:END:
**** How to change keyboard layout to Dvorak

In case you want to use Dvorak keyboard layout and DOSBox fails to
auto-apply it, here is how you can set it manually:

1. Edit file:
  : ~/.dosbox/dosbox-<version>.conf

2. Disable scancodes usage:
   : usescancodes=false

3. Save the changes and restart DOSBox for the configuration to take
   effect.

**** Increase window size

If you have big high-resolution screen, by default DOSBox window could
appear small. To make it bigger:

1. Edit file:
  : ~/.dosbox/dosbox-<version>.conf

2. Set windowresolution to either of those values:
   : windowresolution=1366x768
   : windowresolution=1600x900

3. Save the changes and restart DOSBox for the configuration to take
   effect.

4. If scaling did not work, set output to opengl:
   : output=opengl

**** Exit mouse capture

DOSBox detects when a game uses mouse control. When you click on the
screen, it should get locked (confined to the DOSBox window) and work.

To release mouse lock, press:
: CTRL-F10
**** Increase CPU speed for better animation smoothness

Many applications benefit from as fast CPU as possible. Games and
animations that require limited frames per second always have their
own CPU independent mechanisms for limiting animation speed. So
setting CPU as fast as possible within emulator is beneficial.

This is how I accomplished it in DOSBox:


1. Edit file:
  : ~/.dosbox/dosbox-<version>.conf

2. Edit [cpu] section accordingly:
  #+begin_src conf
    [cpu]
    core=normal
    cputype=auto
    cycles=fixed 100000
  #+end_src

3. Save the changes and restart DOSBox for the configuration to take
   effect.
** See also

- Programs found in the March 1975 3rd printing of David Ahl's 101
  BASIC Computer Games, published by Digital Equipment Corp:
  https://github.com/maurymarkowitz/101-BASIC-Computer-Games

- QB64 is a modern extended BASIC programming language that retains
  QBasic/QuickBASIC 4.5 compatibility and compiles native binaries for
  Windows, Linux, and macOS: https://qb64.com/