Do image/texture caching better

also don't try to cache the sampler / avoid set sampler calls (the sampler is not pipeline specific, so it's affected by other pipelines setting the sampler)

src/BizHawk.Bizware.Graphics/ImGuiResourceCache.cs

@@ -10,11 +10,10 @@ namespace BizHawk.Bizware.Graphics
 	public sealed class ImGuiResourceCache
 	{
 		private readonly IGL _igl;
-		private ITexture2D _lastTexture;
 
 		internal readonly IPipeline Pipeline;
-		internal readonly Dictionary<Bitmap, ITexture2D> TextureCache = new();
-		internal readonly Dictionary<Color, SolidBrush> BrushCache = new();
+		internal readonly Dictionary<Bitmap, ITexture2D> TextureCache = [ ];
+		internal readonly Dictionary<Color, SolidBrush> BrushCache = [ ];
 
 		public ImGuiResourceCache(IGL igl)
 		{
@@ -51,8 +50,7 @@ namespace BizHawk.Bizware.Graphics
 				Pipeline = igl.CreatePipeline(compileArgs);
 
 				igl.BindPipeline(Pipeline);
-				Pipeline.SetUniform("uSamplerEnable", false);
-				Pipeline.SetUniformSampler("uSampler0", null);
+				SetTexture(null);
 				igl.BindPipeline(null);
 			}
 		}
@@ -65,20 +63,15 @@ namespace BizHawk.Bizware.Graphics
 
 		internal void SetTexture(ITexture2D texture2D)
 		{
-			if (_lastTexture != texture2D)
-			{
-				Pipeline.SetUniform("uSamplerEnable", texture2D != null);
-				Pipeline.SetUniformSampler("uSampler0", texture2D);
-				_lastTexture = texture2D;
-			}
+			Pipeline.SetUniform("uSamplerEnable", texture2D != null);
+			Pipeline.SetUniformSampler("uSampler0", texture2D);
 		}
 
 		public void Dispose()
 		{
-			foreach (var cache in TextureCache)
+			foreach (var cachedTex in TextureCache.Values)
 			{
-				cache.Key.Dispose();
-				cache.Value.Dispose();
+				cachedTex.Dispose();
 			}
 
 			foreach (var cachedBrush in BrushCache.Values)
@@ -91,6 +84,16 @@ namespace BizHawk.Bizware.Graphics
 			Pipeline?.Dispose();
 		}
 
+		public void ClearTextureCache()
+		{
+			foreach (var cachedTex in TextureCache.Values)
+			{
+				cachedTex.Dispose();
+			}
+
+			TextureCache.Clear();
+		}
+
 		public const string ImGuiVertexShader_d3d11 = @"
 //vertex shader uniforms
 float4x4 um44Projection;

src/BizHawk.Bizware.Graphics/Renderers/GuiRenderer.cs

@@ -94,9 +94,6 @@ namespace BizHawk.Bizware.Graphics
 			Flush();
 			CurrPipeline = pipeline;
 
-			// clobber state cache
-			sTexture = null;
-
 			// save the modulate color? user beware, I guess, for now.
 		}
 
@@ -164,8 +161,7 @@ namespace BizHawk.Bizware.Graphics
 			Owner.BindPipeline(CurrPipeline);
 			Owner.DisableBlending();
 
-			//clear state cache
-			sTexture = null;
+			// clear state cache
 			CurrPipeline.SetUniform("uSamplerEnable", false);
 			ModelView.Clear();
 			Projection.Clear();
@@ -201,12 +197,8 @@ namespace BizHawk.Bizware.Graphics
 
 		private void PrepDrawSubrectInternal(ITexture2D tex)
 		{
-			if (sTexture != tex)
-			{
-				sTexture = tex;
-				CurrPipeline.SetUniformSampler("uSampler0", tex);
-				CurrPipeline.SetUniform("uSamplerEnable", tex != null);
-			}
+			CurrPipeline.SetUniformSampler("uSampler0", tex);
+			CurrPipeline.SetUniform("uSamplerEnable", tex != null);
 
 			if (_projection.IsDirty)
 			{
@@ -267,9 +259,6 @@ namespace BizHawk.Bizware.Graphics
 		private IPipeline CurrPipeline;
 		private readonly IPipeline DefaultPipeline;
 
-		// state cache
-		private ITexture2D sTexture;
-
 		// shaders are hand-coded for each platform to make sure they stay as fast as possible
 
 		public const string DefaultVertexShader_d3d11 = @"

src/BizHawk.Bizware.Graphics/Renderers/ImGui2DRenderer.cs

@@ -52,7 +52,7 @@ namespace BizHawk.Bizware.Graphics
 			}
 		}
 
-		private readonly HashSet<GCHandle> _gcHandles = new();
+		private readonly HashSet<GCHandle> _gcHandles = [ ];
 
 		protected virtual float RenderThickness => 1;
 
@@ -105,6 +105,9 @@ namespace BizHawk.Bizware.Graphics
 			{
 				switch (gcHandle.Target)
 				{
+					// we can't actually dispose this, as the bitmap might still be cached within GuiApi
+					// it doesn't matter too much, as the finalizer would also dispose this, so no memory leaks will occur
+#if false
 					case ImGuiUserTexture userTexture:
 						// only dispose anything not cached somewhere
 						if (userTexture.Bitmap != _stringOutput
@@ -113,6 +116,7 @@ namespace BizHawk.Bizware.Graphics
 							userTexture.Bitmap.Dispose();
 						}
 						break;
+#endif
 					case DrawStringArgs args:
 						args.Font.Dispose();
 						break;

src/BizHawk.Client.Common/Api/Classes/GuiApi.cs

@@ -291,7 +291,10 @@ namespace BizHawk.Client.Common
 		}
 
 		public void ClearImageCache()
-			=> _imageCache.Clear();
+		{
+			_imageCache.Clear();
+			_displayManager.ClearApiHawkTextureCache();
+		}
 
 		public void DrawImageRegion(Image img, int source_x, int source_y, int source_width, int source_height, int dest_x, int dest_y, int? dest_width = null, int? dest_height = null, DisplaySurfaceID? surfaceID = null)
 		{

src/BizHawk.Client.Common/DisplayManager/DisplayManagerBase.cs

@@ -947,5 +947,8 @@ namespace BizHawk.Client.Common
 				renderer.Discard();
 			}
 		}
+
+		public void ClearApiHawkTextureCache()
+			=> _imGuiResourceCache.ClearTextureCache();
 	}
 }

src/BizHawk.Client.EmuHawk/tools/Lua/LuaConsole.cs

@@ -131,6 +131,7 @@ namespace BizHawk.Client.EmuHawk
 					Settings.Columns = LuaListView.AllColumns;
 					
 					DisplayManager.ClearApiHawkSurfaces();
+					DisplayManager.ClearApiHawkTextureCache();
 					ResetDrawSurfacePadding();
 					ClearFileWatches();
 					LuaImp?.Close();
@@ -948,6 +949,7 @@ namespace BizHawk.Client.EmuHawk
 
 				UpdateDialog();
 				DisplayManager.ClearApiHawkSurfaces();
+				DisplayManager.ClearApiHawkTextureCache();
 				DisplayManager.OSD.ClearGuiText();
 				if (!LuaImp.ScriptList.Any(static lf => !lf.IsSeparator)) ResetDrawSurfacePadding(); // just removed last script, reset padding
 			}