From 345df89a45ea5b0eb6d34a59dcd54669cec0b14f Mon Sep 17 00:00:00 2001
From: UnknownShadow200 <unknownshadow200@gmail.com>
Date: Sat, 16 May 2015 07:36:55 +1000
Subject: [PATCH] Add method to check if texture IDs and vertex buffer IDs are
 valid.

---
 GraphicsAPI/IGraphicsApi.cs | 4 ++++
 GraphicsAPI/OpenGLApi.cs    | 8 ++++++++
 2 files changed, 12 insertions(+)

diff --git a/GraphicsAPI/IGraphicsApi.cs b/GraphicsAPI/IGraphicsApi.cs
index 42866445e..5c16567cb 100644
--- a/GraphicsAPI/IGraphicsApi.cs
+++ b/GraphicsAPI/IGraphicsApi.cs
@@ -40,6 +40,8 @@ namespace ClassicalSharp.GraphicsAPI {
 			DeleteTexture( ref texture.ID );
 		}
 		
+		public abstract bool IsValidTexture( int texId );
+		
 		
 		/// <summary> Whether fog is currently enabled. </summary>
 		public abstract bool Fog { set; }
@@ -123,6 +125,8 @@ namespace ClassicalSharp.GraphicsAPI {
 		public abstract IndexedVbInfo InitIndexedVb<T>( T[] vertices, ushort[] indices, DrawMode mode, 
 		                              int verticesCount, int indicesCount ) where T : struct;
 		
+		public abstract bool IsValidVb( int vb );
+		
 		public abstract void DeleteVb( int id );
 		
 		public abstract void DeleteIndexedVb( IndexedVbInfo id );
diff --git a/GraphicsAPI/OpenGLApi.cs b/GraphicsAPI/OpenGLApi.cs
index f694f394e..c75334573 100644
--- a/GraphicsAPI/OpenGLApi.cs
+++ b/GraphicsAPI/OpenGLApi.cs
@@ -165,6 +165,10 @@ namespace ClassicalSharp.GraphicsAPI {
 			texId = -1;
 		}
 		
+		public override bool IsValidTexture( int texId ) {
+			return GL.IsTexture( texId );
+		}
+		
 		public override bool Texturing {
 			set { ToggleCap( EnableCap.Texture2D, value ); }
 		}
@@ -371,6 +375,10 @@ namespace ClassicalSharp.GraphicsAPI {
 			GL.Arb.DeleteBuffers( 2, ref id.Vb );
 		}
 		
+		public override bool IsValidVb( int vb ) {
+			return useVbos ? GL.Arb.IsBuffer( vb ) : GL.IsList( vb );
+		}
+		
 		public override void DrawVbPos3fTex2f( DrawMode mode, int id, int verticesCount ) {
 			BeginVbBatch( VertexFormat.VertexPos3fTex2f );
 			DrawVbBatch( mode, id, verticesCount );