wined3d: Implement IWineD3DIndexBuffer::UnLoad.

dlls/wined3d/indexbuffer.c

@@ -111,7 +111,24 @@ static void WINAPI IWineD3DIndexBufferImpl_PreLoad(IWineD3DIndexBuffer *iface) {
 }
 
 static void WINAPI IWineD3DIndexBufferImpl_UnLoad(IWineD3DIndexBuffer *iface) {
-    IWineD3DResourceImpl_UnLoad((IWineD3DResource *)iface);
+    IWineD3DIndexBufferImpl *This = (IWineD3DIndexBufferImpl *) iface;
+    IWineD3DDeviceImpl *device = This->resource.wineD3DDevice;
+    TRACE("(%p)\n", This);
+
+    /* This is easy: The whole content is shadowed in This->resource.allocatedMemory,
+     * so we only have to destroy the vbo. Only do it if we have a vbo, which implies
+     * that vbos are supported.
+     * (TODO: Make a IWineD3DBuffer base class for index and vertex buffers and share
+     * this code. Also needed for D3D10)
+     */
+    if(This->vbo) {
+        ActivateContext(device, device->lastActiveRenderTarget, CTXUSAGE_RESOURCELOAD);
+        ENTER_GL();
+        GL_EXTCALL(glDeleteBuffersARB(1, &This->vbo));
+        checkGLcall("glDeleteBuffersARB");
+        LEAVE_GL();
+        This->vbo = 0;
+    }
 }
 
 static WINED3DRESOURCETYPE WINAPI IWineD3DIndexBufferImpl_GetType(IWineD3DIndexBuffer *iface) {