### Install Python Dependencies

Source: https://github.com/matherunner/hldoc/blob/master/README.md

Install the required Python packages listed in 'requirements.txt' after activating the virtual environment.

```bash
pip install -r requirements.txt
```

--------------------------------

### Install Node.js Dependencies

Source: https://github.com/matherunner/hldoc/blob/master/README.md

Install Node.js packages required for the MathJax rendering script.

```bash
npm install
```

--------------------------------

### Build HLPR Documentation

Source: https://context7.com/matherunner/hldoc/llms.txt

Commands to set up a Python virtual environment, install dependencies, and build the HTML documentation with MathJax pre-rendering. Includes commands for cleaning build artifacts.

```bash
# Create and activate Python virtual environment
python -m venv venv
. ./venv/bin/activate

# Install Python dependencies (Sphinx, themes, extensions)
pip install -r requirements.txt

# Install Node.js dependencies for MathJax rendering
npm install

# Build the HTML documentation with MathJax pre-rendering
python build.py build

# Clean build artifacts
python build.py clean
```

--------------------------------

### TikZ Animation Loop Example

Source: https://github.com/matherunner/hldoc/blob/master/STYLEGUIDE.md

Generates multiple TikZ frames for animation by iterating within a \foreach loop. Each \tikzpicture environment creates a new frame. Ensure \pgffor is installed.

```tex
\foreach \i in {1,...,5} {
  \begin{tikzpicture}
    % TikZ drawing commands here
  \end{tikzpicture}
}
```

--------------------------------

### Game Frame Timing Discrepancy Example

Source: https://github.com/matherunner/hldoc/blob/master/source/basicphy.md

Illustrates the observed timing differences between StartFrame and PlayerPreThink calls, highlighting potential issues with gpGlobals->time updates.

```none
startframe, g_ulFrameCount = 3, gpGlobals->time = 1.001
prethink, g_ulFrameCount = 3, gpGlobals->time = 1.003
startframe, g_ulFrameCount = 4, gpGlobals->time = 1.002
prethink, g_ulFrameCount = 4, gpGlobals->time = 1.004
...
```

--------------------------------

### Create Python Virtual Environment

Source: https://github.com/matherunner/hldoc/blob/master/README.md

Use this command to create a Python virtual environment named 'venv'. Ensure Python is installed.

```bash
python -m venv venv
```

--------------------------------

### TikZ Document Class Setup

Source: https://github.com/matherunner/hldoc/blob/master/STYLEGUIDE.md

This is the standard document class for TikZ graphics. Ensure Baskerville 10 Pro and Dark Modern typefaces are installed before use.

```tex
\documentclass{hlprtikz}
\usepackage{tikz}
\begin{document}
\end{document}
```

--------------------------------

### Player Velocity Delta Definition Example

Source: https://github.com/matherunner/hldoc/blob/master/source/basicphy.md

Shows how player velocity components are defined for network transmission, indicating limited precision and rounding.

```none
DEFINE_DELTA( velocity[0], DT_SIGNED | DT_FLOAT, 16, 8.0 ),
DEFINE_DELTA( velocity[1], DT_SIGNED | DT_FLOAT, 16, 8.0 ),
...
...
DEFINE_DELTA( velocity[2], DT_SIGNED | DT_FLOAT, 16, 8.0 ),
```

--------------------------------

### Build HTML Documentation

Source: https://github.com/matherunner/hldoc/blob/master/README.md

Execute the build script to generate the HTML files for the documentation.

```bash
python build.py build
```

--------------------------------

### List all commands

Source: https://github.com/matherunner/hldoc/blob/master/source/player.md

Use the 'cmdlist' command in the game console to generate a list of all available console commands. This is useful for understanding the full range of player and game controls.

```console
cmdlist
```

--------------------------------

### Maximum Groundstrafe Speed

Source: https://context7.com/matherunner/hldoc/llms.txt

Calculates the maximum groundstrafe speed achievable in a steady state, considering friction and acceleration parameters. Provides an example value at 1000fps with default settings.

```mathematica
Maximum groundstrafe speed (steady state):
v_max = M * √(k_e * A * (2 - τ * k_e * A) / (k * (2 - τ * k)))

At 1000fps with defaults: v_max ≈ 505.2 ups
```

--------------------------------

### Maximum Acceleration Strafing - Speed After n Frames

Source: https://context7.com/matherunner/hldoc/llms.txt

Formula to calculate the player's speed after 'n' frames of airstrafing, assuming no friction. Includes an example calculation for frames needed to reach a target speed.

```mathematica
Speed after n frames of airstrafing (no friction):
||v_n|| = √(||v_0||² + n * k_e * τ * M * A * (2L - k_e * τ * M * A))

Example: Frames to airstrafe from 320 to 1000 ups at 1000fps, default settings:
1000² = 320² + n * 0.001 * 320 * 10 * (60 - 0.001 * 320 * 10)
n ≈ 4938 frames
```

--------------------------------

### Activate Python Virtual Environment

Source: https://github.com/matherunner/hldoc/blob/master/README.md

Activate the created Python virtual environment. This command is for Unix-like systems.

```bash
. ./venv/bin/activate
```

--------------------------------

### Set pitch speed for precise viewangle control

Source: https://github.com/matherunner/hldoc/blob/master/source/player.md

To achieve precise viewangle control in TAS, 'cl_pitchspeed' can be set to a calculated value. This example demonstrates calculating 'cl_pitchspeed' to achieve a specific pitch change within a frame, accounting for game physics and potential floating-point inaccuracies by targeting a slightly higher value.

```console
cl_pitchspeed = 9.5 * (360 / 65536) / 0.001
```

--------------------------------

### Bind a key to a command

Source: https://github.com/matherunner/hldoc/blob/master/source/player.md

The 'bind' command is used to associate a keyboard key with a specific game command. This is typically done in 'config.cfg' for default controls, such as binding the 'W' key to '+forward'.

```console
bind "W" "+forward"
```

--------------------------------

### Set Player Random Seed in CmdStart

Source: https://github.com/matherunner/hldoc/blob/master/source/game.md

This C++ function demonstrates how the player's `random_seed` is set within the `CmdStart` function, receiving the seed value from the engine. This is a key part of the shared RNG's seeding process.

```cpp
void CmdStart( const edict_t *player, const struct usercmd_s *cmd, unsigned int random_seed )
{
  entvars_t *pev = (entvars_t *)&player->v;
  CBasePlayer *pl = dynamic_cast< CBasePlayer *>( CBasePlayer::Instance( pev ) );

  [...omitted...]

  pl->random_seed = random_seed;
}
```

--------------------------------

### Optimize SVG with SVGO

Source: https://github.com/matherunner/hldoc/blob/master/STYLEGUIDE.md

Use the `svgo` program to optimize SVG files. The `--multipass` and `-p 2` flags can be used for more thorough optimization with Inkscape-generated SVGs.

```bash
svgo
```

```bash
svgo --multipass -p 2
```

--------------------------------

### Set Document Theme

Source: https://github.com/matherunner/hldoc/blob/master/source/_templates/base.html

Sets the 'theme' data attribute on the document body to 'light'. This is typically used for client-side theme management.

```javascript
document.body.dataset.theme = 'light'
```

--------------------------------

### Enable Fullbright for Map Illumination

Source: https://github.com/matherunner/hldoc/blob/master/source/practical.md

Use `r_fullbright 1` to illuminate the entire map, essential for clear visibility during TAS development. This command requires `sv_cheats` to be enabled.

```console
r_fullbright 1
```

--------------------------------

### Gravity Calculation (Leapfrog Integration)

Source: https://context7.com/matherunner/hldoc/llms.txt

Details Half-Life's split gravity calculation using leapfrog integration for vertical motion. Shows how velocity and position are updated before and after the position update step.

```mathematica
Gravity calculation (leapfrog integration):

Before position update (PM_AddCorrectGravity):
v_z ← v_z - (1/2)*g*τ + b_z*τ
b_z ← 0

Position update:
r_z' = r_z + v_z * τ

After position update (PM_FixupGravityVelocity):
v_z ← v_z - (1/2)*g*τ

Result matches classical mechanics:
v_z' = v_z - g*τ
r_z' = r_z + v_z*τ - (1/2)*g*τ²

Where:
- g = sv_gravity * g_e (entity gravity multiplier)
- b_z: vertical basevelocity
- τ: player frame time (τ_p)
```

--------------------------------

### Reset m_flNextAttack on Restore

Source: https://github.com/matherunner/hldoc/blob/master/source/weapons.md

In CBasePlayer::Restore, m_flNextAttack is reset to UTIL_WeaponTimeBase() when CLIENT_WEAPONS is defined, effectively bypassing the switching delay after a saveload.

```c++
#if defined( CLIENT_WEAPONS )
  // HACK:  This variable is saved/restored in CBaseMonster as a time variable, but we're using it
  //        as just a counter.  Ideally, this needs its own variable that's saved as a plain float.
  //        Barring that, we clear it out here instead of using the incorrect restored time value.
  m_flNextAttack = UTIL_WeaponTimeBase();
#endif
```