Create OpenGLRenderer

Pulsar4xDevs · Jan 10, 2025 · 335aa64 · 335aa64
1 parent c504dd2
commit 335aa64
Show file tree

Hide file tree

Showing 6 changed files with 125 additions and 29 deletions.
diff --git a/Pulsar4X/Pulsar4X.Client/IMGUISDL/ImGuiSDL2CSWindow.cs b/Pulsar4X/Pulsar4X.Client/IMGUISDL/ImGuiSDL2CSWindow.cs
@@ -116,31 +116,12 @@ protected unsafe virtual void Create()
             // Build texture atlas
             io.Fonts.GetTexDataAsAlpha8(out byte* pixels, out int width, out int height);
 
-            GL.GetIntegerv(GL.Enum.GL_TEXTURE_BINDING_2D, out int lastTexture);
-
-            // Create OpenGL texture
-            GL.GenTextures(1, out int fontTextureID);
-            GL.BindTexture(GL.Enum.GL_TEXTURE_2D, fontTextureID);
-            GL.TexParameteri(GL.Enum.GL_TEXTURE_2D, GL.Enum.GL_TEXTURE_MIN_FILTER, (int) GL.Enum.GL_LINEAR);
-            GL.TexParameteri(GL.Enum.GL_TEXTURE_2D, GL.Enum.GL_TEXTURE_MAG_FILTER, (int) GL.Enum.GL_LINEAR);
-            GL.PixelStorei(GL.Enum.GL_UNPACK_ROW_LENGTH, 0);
-            GL.TexImage2D(
-                GL.Enum.GL_TEXTURE_2D,
-                0,
-                (int) GL.Enum.GL_ALPHA,
-                width,
-                height,
-                0,
-                GL.Enum.GL_ALPHA,
-                GL.Enum.GL_UNSIGNED_BYTE,
-                new IntPtr(pixels)
-            );
-            g_FontTexture = new IntPtr(fontTextureID);
+            g_FontTexture = new IntPtr(Renderer.CreateDefaultFontTexture(width, height, (IntPtr)pixels));
+
             // Store the texture identifier in the ImFontAtlas substructure.
             io.Fonts.SetTexID(g_FontTexture);
             ImGuiSDL2CSHelper.FontTextureID = g_FontTexture;
             io.Fonts.ClearTexData(); // Clears CPU side texture data.
-            GL.BindTexture(GL.Enum.GL_TEXTURE_2D, lastTexture);
         }
 
         protected override void Dispose(bool disposing)

diff --git a/Pulsar4X/Pulsar4X.Client/IMGUISDL/SDL2Window.cs b/Pulsar4X/Pulsar4X.Client/IMGUISDL/SDL2Window.cs
@@ -1,4 +1,5 @@
-using SDL2;
+using Pulsar4X.Client.Rendering;
+using SDL2;
 using System;
 
 namespace ImGuiSDL2CS
@@ -10,8 +11,7 @@ public class SDL2Window : IDisposable
         protected IntPtr _Handle;
         public IntPtr Handle => _Handle;
 
-        protected IntPtr _GLContext;
-        public IntPtr GLContext => _GLContext;
+        public IRenderer Renderer { get; set; }
 
         /// <summary>
         /// Window title
@@ -112,15 +112,15 @@ public void Init(
             _Handle = SDL.SDL_CreateWindow(title, x, y, width, height, flags);
 
             if ((flags & SDL.SDL_WindowFlags.SDL_WINDOW_OPENGL) == SDL.SDL_WindowFlags.SDL_WINDOW_OPENGL) {
-                _GLContext = SDL.SDL_GL_CreateContext(_Handle);
-                SDL.SDL_GL_MakeCurrent(_Handle, _GLContext);
+                Renderer = RendererFactory.CreateRenderer(RendererType.OpenGL);
+                Renderer.Initialize(_Handle);
             }
         }
 
         public bool IsVisible => (Flags & SDL.SDL_WindowFlags.SDL_WINDOW_HIDDEN) == 0;
         public void Show() => SDL.SDL_ShowWindow(_Handle);
         public void Hide() => SDL.SDL_HideWindow(_Handle);
-        public virtual void Swap() => SDL.SDL_GL_SwapWindow(_Handle);
+        public virtual void Swap() => Renderer.EndFrame();
 
         public virtual void Run()
         {
@@ -170,6 +170,7 @@ protected virtual void Dispose(bool disposing)
 
         public void Dispose()
         {
+            Renderer.Dispose();
             Dispose(true);
             GC.SuppressFinalize(this);
         }

diff --git a/Pulsar4X/Pulsar4X.Client/PulsarMainWindow.cs b/Pulsar4X/Pulsar4X.Client/PulsarMainWindow.cs
@@ -198,8 +198,8 @@ public override void ImGuiRender()
                 systemState.PreFrameSetup();
             }
 
-            GL.ClearColor(backColor.X, backColor.Y, backColor.Z, 1f);
-            GL.Clear(GL.Enum.GL_COLOR_BUFFER_BIT);
+            Renderer.Clear(backColor.X, backColor.Y, backColor.Z, 1f);
+            Renderer.BeginFrame();
 
             _state.GalacticMap.Draw();
 

diff --git a/Pulsar4X/Pulsar4X.Client/Rendering/IRenderer.cs b/Pulsar4X/Pulsar4X.Client/Rendering/IRenderer.cs
@@ -0,0 +1,21 @@
+using System;
+
+namespace Pulsar4X.Client.Rendering;
+
+public enum RendererType
+{
+    OpenGL,
+    // TODO: someone can write these renderers if they desire :D
+    //Vulkan,
+    //DirectX
+}
+
+public interface IRenderer : IDisposable
+{
+    void Initialize(IntPtr windowHandle);
+    void BeginFrame();
+    void EndFrame();
+    void Clear(float r, float g, float b, float a);
+
+    int CreateDefaultFontTexture(int width, int height, IntPtr pixels);
+}
diff --git a/Pulsar4X/Pulsar4X.Client/Rendering/OpenGLRenderer.cs b/Pulsar4X/Pulsar4X.Client/Rendering/OpenGLRenderer.cs
@@ -0,0 +1,78 @@
+using System;
+using ImGuiSDL2CS;
+using SDL2;
+
+namespace Pulsar4X.Client.Rendering;
+
+public class OpenGLRenderer : IRenderer
+{
+    private IntPtr _glContext;
+    private IntPtr _windowHandle;
+
+    public void Initialize(IntPtr windowHandle)
+    {
+        _windowHandle = windowHandle;
+
+        // Set the OpenGL context attributes
+        SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_CONTEXT_MAJOR_VERSION, 4);
+        SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_CONTEXT_MINOR_VERSION, 5);
+        SDL.SDL_GL_SetAttribute(SDL.SDL_GLattr.SDL_GL_CONTEXT_PROFILE_MASK, (int)SDL.SDL_GLprofile.SDL_GL_CONTEXT_PROFILE_CORE);
+
+        // Create the OpenGL context
+        _glContext = SDL.SDL_GL_CreateContext(_windowHandle);
+        if(_glContext == IntPtr.Zero)
+        {
+            throw new Exception($"Failed to create OpenGL context: {SDL.SDL_GetError()}");
+        }
+
+        // Make the OpenGL context current
+        SDL.SDL_GL_MakeCurrent(_windowHandle, _glContext);
+    }
+
+    public void BeginFrame()
+    {
+        GL.Clear(GL.Enum.GL_COLOR_BUFFER_BIT);
+    }
+
+    public void EndFrame()
+    {
+        SDL.SDL_GL_SwapWindow(_windowHandle);
+    }
+
+    public void Clear(float r, float g, float b, float a)
+    {
+        GL.ClearColor(r, g, b, a);
+    }
+
+    public int CreateDefaultFontTexture(int width, int height, IntPtr pixels)
+    {
+        // Create OpenGL texture
+        GL.GenTextures(1, out int fontTextureID);
+        GL.BindTexture(GL.Enum.GL_TEXTURE_2D, fontTextureID);
+        GL.TexParameteri(GL.Enum.GL_TEXTURE_2D, GL.Enum.GL_TEXTURE_MIN_FILTER, (int) GL.Enum.GL_LINEAR);
+        GL.TexParameteri(GL.Enum.GL_TEXTURE_2D, GL.Enum.GL_TEXTURE_MAG_FILTER, (int) GL.Enum.GL_LINEAR);
+        GL.PixelStorei(GL.Enum.GL_UNPACK_ROW_LENGTH, 0);
+        GL.TexImage2D(
+            GL.Enum.GL_TEXTURE_2D,
+            0,
+            (int) GL.Enum.GL_ALPHA,
+            width,
+            height,
+            0,
+            GL.Enum.GL_ALPHA,
+            GL.Enum.GL_UNSIGNED_BYTE,
+            pixels
+        );
+
+        return fontTextureID;
+    }
+
+    public void Dispose()
+    {
+        if(_glContext != IntPtr.Zero)
+        {
+            SDL.SDL_GL_DeleteContext(_glContext);
+            _glContext = IntPtr.Zero;
+        }
+    }
+}
diff --git a/Pulsar4X/Pulsar4X.Client/Rendering/RendererFactory.cs b/Pulsar4X/Pulsar4X.Client/Rendering/RendererFactory.cs
@@ -0,0 +1,15 @@
+using System;
+
+namespace Pulsar4X.Client.Rendering;
+
+public static class RendererFactory
+{
+    public static IRenderer CreateRenderer(RendererType rendererType)
+    {
+        return rendererType switch
+        {
+            RendererType.OpenGL => new OpenGLRenderer(),
+            _ => throw new ArgumentException("Unsupported renderer backend")
+        };
+    }
+}