C# roguelike, devlog 7: Raylib and ImGui
Introduction
It’s time to bring the project into the third dimension by using the raylib library.
Raylib is written in C, but has bindings for a whole bunch of programming languages. The bindings for C# is Raylib-cs. For documentation on how to use the library we can check the C# usage examples, the Raylib Cheatsheet and the Raymath Cheatsheet.
In addition to raylib I’ll add Dear ImGui and use it first and foremost for debugging but perhaps also to build some tools later on. ImGui.NET is the C# wrapper for ImGui and to get ImGui to use raylib for rendering I’ll also add the rlImGui-cs library.
Implementation
Here I’ll setup a basic raylib game loop and render the map and player using some simple geometric shapes. I’ll also add a little minimap and a debug mode that can be accessed by pressing Tab. When the debug mode is active ImGui is visible.
Folder structure:
Roguelike
├── + Makefile
├── Roguelike.csproj
└── src
├── BspNode.cs
├── BspTree.cs
├── Corridor.cs
├── Game.cs
├── + LogEntry.cs
├── + Logger.cs
├── Map.cs
├── PathGraph.cs
├── Rand.cs
├── Room.cs
└── Vec2.cs
├── + Makefile
├── Roguelike.csproj
└── src
├── BspNode.cs
├── BspTree.cs
├── Corridor.cs
├── Game.cs
├── + LogEntry.cs
├── + Logger.cs
├── Map.cs
├── PathGraph.cs
├── Rand.cs
├── Room.cs
└── Vec2.cs
Adding Raylib and ImGui to the project is very easy by using the NuGet package manager:
laser-wolf@arch:~/Roguelike $ dotnet add package Raylib-cslaser-wolf@arch:~/Roguelike $ dotnet add package ImGui.NETlaser-wolf@arch:~/Roguelike $ dotnet add package rlImgui-csWhen working with Raylib we’ll use pointers when reading stuff like texture data from memory. To allow the use of pointers in C# AllowUnsafeBlocks needs to be set to true in the .csproj file, additionally any method using pointers needs to include the unsafe keyword.
Roguelike.csproj:
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net8.0</TargetFramework>
<ImplicitUsings>enable</ImplicitUsings>
+ <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
<Nullable>enable</Nullable>
</PropertyGroup>
+ <ItemGroup>
+ <PackageReference Include="ImGui.NET" Version="1.90.8.1" />
+ <PackageReference Include="Raylib-cs" Version="6.0.0" />
+ <PackageReference Include="rlImgui-cs" Version="2.0.3" />
+ </ItemGroup>
</Project>
It’s probably a good time now to add a Makefile to the project. Even though the command for running a dotnet project is very short I prefer to have a makefile and use the command make run instead.
Makefile:
build:
dotnet publish -o builds/ -r linux-x64 -p:PublishSingleFile=true --self-contained true
rm builds/*.pdb
build-win:
dotnet publish -o builds/ -r win-x64 -p:PublishSingleFile=true --self-contained true
rm builds/*.pdb
run:
dotnet run
clean:
dotnet clean
Logger.cs:
namespace Roguelike;
/// <summary>
/// Logs messages and errors for debugging.
/// </summary>
static class Logger
{
public static List<LogEntry> log { get; private set; } = new List<LogEntry>();
// Add message to the log
public static void Log(string message)
{
log.Add(new LogEntry(message));
}
// Add error message to the log
public static void Err(string message)
{
log.Add(new LogEntry(message, error: true));
}
}
LogEntry.cs:
namespace Roguelike;
/// <summary>
/// A entry in the Logger.
/// </summary>
public class LogEntry
{
public readonly string message;
public readonly bool error;
public LogEntry(string message, bool error = false)
{
this.message = message;
this.error = error;
}
}
BspTree.cs:
// Print info for a given node
private void NodeInfo(BspNode node)
{
- Console.WriteLine("Node (" + node.id.ToString() + "), parent: " + (node.parent != null ? node.parent.id : "null") + ", sibling: " + (node.GetSibling() != null ? node.GetSibling().id : "null") + ", children[0]: " + (node.children[0] != null ? node.children[0].id : "null") + ", children[1]: " + (node.children[1] != null ? node.children[1].id : "null"));
+ Logger.Log("Node (" + node.id.ToString() + "), parent: " + (node.parent != null ? node.parent.id : "null") + ", sibling: " + (node.GetSibling() != null ? node.GetSibling().id : "null") + ", children[0]: " + (node.children[0] != null ? node.children[0].id : "null") + ", children[1]: " + (node.children[1] != null ? node.children[1].id : "null"));
}
Player.cs:
+ using Raylib_cs;
+ using System.Numerics;
...
- private int visionRange = 16;
+ private int visionRange = 48;
public Player()
{
Spawn();
Fov();
}
+ public void Render3D()
+ {
+ Raylib.DrawSphereWires(new Vector3((float)x + 0.5f, 0.5f, (float)y + 0.5f), 0.5f, 4, 4, Color.Pink);
+ }
...
Map.cs:
+ using Raylib_cs;
+ using System.Numerics;
...
// Map data
public BspTree tree { get; private set; }
private bool?[,] map;
private List<int> mapSeen = new List<int>();
private List<int> mapVisible = new List<int>();
public readonly PathGraph pathGraph;
+ private List<int> doors = new List<int>();
...
// Add a door to the map
public void AddDoor(int x, int y)
{
int coord = MapCoord(x, y);
if (map[x, y] == true)
{
+ doors.Add(coord);
blocksLight[coord] = 12;
}
}
+ // Returns true if a given location contains a door
+ public bool GetDoor(int coord)
+ {
+ return doors.Contains(coord);
+ }
...
- // Render map as ascii characters
- public void Render() {
- for (int y = 0; y < height; y++)
- {
- for (int x = 0; x < width; x++)
- {
- int coord = MapCoord(x, y);
- char tileChar = '.';
- Console.ForegroundColor = ConsoleColor.White;
- // Render player
- if (Game.player.x == x && Game.player.y == y) { tileChar = '@'; }
- // Check if location has been seen
- else if (GetSeen(coord))
- {
- if (map[x, y] == true)
- {
- tileChar = ' ';
- }
- else if (map[x, y] == false)
- {
- tileChar = '#';
- }
-
- // Visualize light intensity
- if (GetVisible(coord))
- {
- int lightIntensity = GetLightIntensity(x, y);
- if (lightIntensity > 16) { Console.BackgroundColor = ConsoleColor.Yellow; }
- else if (lightIntensity > 8) { Console.BackgroundColor = ConsoleColor.Gray; }
- else if (lightIntensity > 0) { Console.BackgroundColor = ConsoleColor.DarkGray; }
- else { Console.BackgroundColor = ConsoleColor.Black; }
- }
- }
- // Fade out non-visible locations
- if (!GetVisible(coord)) { Console.ForegroundColor = ConsoleColor.DarkGray; }
- // Write char to console
- Console.Write(tileChar);
- Console.ResetColor();
- }
-
- // Go to next line
- Console.Write(Environment.NewLine);
- }
- }
+ // Render map
+ public void Render3D()
+ {
+ for (int y = 0; y < height; y++)
+ {
+ for (int x = 0; x < width; x++)
+ {
+ if (map[x, y] != null)
+ {
+ // Get the coord for the current location
+ int coord = MapCoord(x, y);
+
+ // Check if location has been seen
+ if (GetSeen(coord) || Game.debugMode)
+ {
+ Color color = Color.LightGray;
+
+ // Check if location is visible
+ if (GetVisible(coord)) {
+
+ // Check if the current location is open space
+ if (map[x, y] == true) {
+
+ // Set floor color
+ color = Color.Green;
+
+ // Visualize light intensity
+ int lightIntensity = GetLightIntensity(x, y);
+ Color lightColor = Color.Gray;
+ if (lightIntensity > 16) { lightColor = Color.Yellow; }
+ else if (lightIntensity > 8) { lightColor = new Color(200, 200, 0, 255);; }
+ else if (lightIntensity > 0) { lightColor = new Color(150, 150, 0, 255);; }
+ Raylib.DrawSphereEx(new Vector3(x + 0.5f, 0.5f, y + 0.5f), 0.15f, 4, 4, lightColor);
+
+ // Check if the current location contains a door
+ if (GetDoor(coord))
+ {
+ // Set door color
+ color = Color.Blue;
+ }
+ }
+
+ // If not then the current location is a wall
+ else
+ {
+ // Set wall color
+ color = Color.Red;
+ }
+ }
+
+ // Draw floor
+ Raylib.DrawCubeWiresV(new Vector3(x + 0.5f, -0.5f, y + 0.5f), new Vector3(1.0f, 1.0f, 1.0f), color);
+
+ // Draw wall
+ if (map[x, y] == false) {
+ Raylib.DrawCubeWiresV(new Vector3(x + 0.5f, 0.5f, y + 0.5f), new Vector3(1.0f, 1.0f, 1.0f), color);
+ }
+
+ // Draw player indicator
+ if (Game.player.x == x && Game.player.y == y)
+ {
+ Raylib.DrawPlane(new Vector3(x + 0.5f, 0.0f, y + 0.5f), new Vector2(1.0f, 1.0f), Color.Yellow);
+ }
+
+ // Draw door indicator
+ else if (GetDoor(coord))
+ {
+ Raylib.DrawPlane(new Vector3(x + 0.5f, 0.0f, y + 0.5f), new Vector2(1.0f, 1.0f), color);
+ }
+ }
+ }
+ }
+ }
+ }
+ // Render minimap
+ public void Render2D()
+ {
+ int cellSize = 6;
+ int xOffset = Raylib.GetRenderWidth() - (width * cellSize);
+ Raylib.DrawRectangle(xOffset, 0, width * cellSize, height * cellSize, Color.DarkGray);
+ for (int y = 0; y < height; y++)
+ {
+ for (int x = 0; x < width; x++)
+ {
+ if (map[x, y] != null)
+ {
+
+ // Show player position on minimap
+ if (Game.player.x == x && Game.player.y == y)
+ {
+ Raylib.DrawRectangle(xOffset + (x * cellSize), y * cellSize, cellSize, cellSize, Color.Yellow);
+ }
+
+ else
+ {
+ // Get the coord for the current location
+ int coord = MapCoord(x, y);
+
+ // Check if location has been seen
+ if (GetSeen(coord) || Game.debugMode)
+ {
+ Color color = Color.LightGray;
+
+ // Check if location is visible
+ if (GetVisible(coord)) {
+
+ // Check if location is open space
+ if (map[x, y] == true) {
+
+ // Set floor color
+ color = Color.Green;
+
+ // Check if the current location contains a door
+ if (GetDoor(coord))
+ {
+ // Set door color
+ color = Color.Blue;
+ }
+ }
+
+ // If not then the current location is a wall
+ else
+ {
+ // Set wall color
+ color = Color.Red;
+ }
+ }
+
+ // Draw minimap cell
+ Raylib.DrawRectangleLines(xOffset + (x * cellSize), y * cellSize, cellSize, cellSize, color);
+ }
+ }
+ }
+ }
+ }
+ }
...
Game.cs:
using Raylib_cs;
using rlImGui_cs;
using ImGuiNET;
using System.Numerics;
namespace Roguelike;
static class Game
{
private static bool isRunning = true;
public static bool debugMode { get; private set; } = false;
public static Map map { get; private set; }
public static Player player { get; private set; }
private static Camera3D camera;
// Program entry point
static void Main(string[] args)
{
Init();
Run();
Exit();
}
// Initialize
private static void Init()
{
// Raylib & Imgui initialization
Raylib.InitWindow(1280, 720, "Roguelike");
Raylib.SetTargetFPS(30);
rlImGui.Setup(true);
// Create new objects
map = new Map(96, 48);
player = new Player();
// Camera setup
camera.Position = Vector3.Zero;
camera.Target = Vector3.Zero;
camera.Up = Vector3.UnitY;
camera.FovY = 45.0f;
camera.Projection = CameraProjection.Perspective;
}
// Main game loop
private static void Run()
{
while (!Raylib.WindowShouldClose())
{
Input();
Update();
Render();
}
}
// Exit game
private static void Exit()
{
rlImGui.Shutdown();
Raylib.CloseWindow();
}
// Handle user input
private static void Input()
{
// System
if (Raylib.IsKeyPressed(KeyboardKey.Tab)) { debugMode = !debugMode; }
if (Raylib.IsKeyPressed(KeyboardKey.F)) { Raylib.ToggleFullscreen(); }
// Player movement
if (Raylib.IsKeyPressed(KeyboardKey.Up)) { player.MoveUp(); }
else if (Raylib.IsKeyPressed(KeyboardKey.Down)) { player.MoveDown(); }
else if (Raylib.IsKeyPressed(KeyboardKey.Left)) { player.MoveLeft(); }
else if (Raylib.IsKeyPressed(KeyboardKey.Right)) { player.MoveRight(); }
}
// Update things in the game
private static void Update()
{
float deltaTime = Raylib.GetFrameTime();
// Camera
Vector3 cameraTargetGoal = new Vector3((float)player.x, 0f, (float)player.y);
camera.Target = Raymath.Vector3Distance(camera.Target, cameraTargetGoal) > 0.1f ? Raymath.Vector3Lerp(camera.Target, cameraTargetGoal, 0.05f) : camera.Target;
camera.Position = camera.Target + new Vector3(0f, 16.0f, 12.0f);
}
// Render things on screen
private static void Render()
{
// Start render
Raylib.BeginDrawing();
// Set background color
Raylib.ClearBackground(Color.Black);
// 3D rendering
Raylib.BeginMode3D(camera);
if (debugMode) { Raylib.DrawGrid(300, 1.0f); }
map.Render3D();
player.Render3D();
Raylib.EndMode3D();
// 2D rendering
map.Render2D();
Raylib.DrawFPS(2,2);
Raylib.DrawText("POSITION: " + player.x.ToString() + "x" + player.y.ToString(), 2, Raylib.GetRenderHeight() - 16, 16, Color.White);
// 2D rendering (debug mode)
if (debugMode) {
Raylib.DrawText("DEBUG MODE", 2, 20, 16, Color.White);
RenderImGui();
}
// End render
Raylib.EndDrawing();
}
// Render ImGui
private static void RenderImGui()
{
// Start ImGui
rlImGui.Begin();
//ImGui.ShowDemoWindow();
// Debug window
if (ImGui.Begin("Debug window"))
{
ImGui.Text("Log:");
ImGui.BeginChild("Log");
for (int i = 0; i < Logger.log.Count; i++)
{
LogEntry logEntry = Logger.log[i];
ImGui.Text(logEntry.message);
}
ImGui.EndChild();
}
// End ImGui
ImGui.End();
rlImGui.End();
}
}
Conclusion
And there we have a 3D version of the project. Move around with the arrow keys, press F for fullscreen or press Tab to enter debug mode. We can also use the Makefile now to run and build the project.
laser-wolf@arch:~/Roguelike $ make run
Here’s a short video of the result: youtu.be/4X8wz6Xd8NU
Download the source code: roguelike-devlog7.zip
Find the project on GitHub: casper-borretzen/Roguelike