Profiling

Introduction

Gum provides a few diagnostic tools for finding and fixing performance problems. This section discusses how you can find problems with your Gum application

Rendering

Internally Gum uses a SpriteBatch for rendering. It attempts to use as few Begin/End pairs as possible, but it will end a draw batch if necessary. The following changes require a batch to be interrupted:

• Changes in textures. Examples include:

  • Two SpriteRuntimes which use different textures

  • A TextRuntime and a non-TextRuntime (such as a NineSlice) will introduce a break in rendering unless the TextRuntime's font shares a PNG with the non-TextRuntime

  • A ColoredRectangleRuntime and a non-ColoredRectangleRuntime, unless the SinglePixelTexture is on the same PNG

• Changes in clip region by setting ClipsChildren to true

• Changes in render targets by setting IsRenderTarget to true

Gum provides a list of changes which can be inspected to spot where render problems might be occurring.

Code Example: Checking Performance

The following code shows how to check the performance of a simple project. Note that this code creates visuals instead of Forms controls to intentionally create render breaks.

protected override void Initialize()
{
    // Initialize Gum - can load a project, although it isn't used below
    GumUI.Initialize(this);

    // Create a panel to hold all children.
    var panel = new StackPanel();
    panel.AddToRoot();

    for(int i = 0; i < 5; i++)
    {
        var subContainer = new ContainerRuntime();
        // ClipsChildren sets 
        subContainer.ClipsChildren = true;
        panel.AddChild(subContainer);

        var rectangle = new ColoredRectangleRuntime();
        subContainer.AddChild(rectangle);
    }
}

protected override void Update(GameTime gameTime)
{
    GumUI.Update(gameTime);
    base.Update(gameTime);
}

protected override void Draw(GameTime gameTime)
{
    GraphicsDevice.Clear(Color.CornflowerBlue);

    GumUI.Draw();

    if(GumUI.Keyboard.KeyPushed(Keys.Space))
    {

        var spriteRenderer = GumUI.SystemManagers.Renderer.SpriteRenderer;
        var lastFrameDrawStates = spriteRenderer.LastFrameDrawStates;
        
        System.Diagnostics.Debug.WriteLine(
            $"Last Frame Draw States ({lastFrameDrawStates.Count()}):");

        foreach(var item in lastFrameDrawStates)
        {
            System.Diagnostics.Debug.WriteLine(item);
        }
    }
    base.Draw(gameTime);
}

Pressing space outputs diagnostic information about the rendering similar to the following output:

Last Frame Draw States (11):
Begin w/ 0 Textures set(s)
By ContainerRuntime w/ 1 Textures set(s)
By Un-set ContainerRuntime Clip
By ContainerRuntime w/ 1 Textures set(s)
By Un-set ContainerRuntime Clip
By ContainerRuntime w/ 1 Textures set(s)
By Un-set ContainerRuntime Clip
By ContainerRuntime w/ 1 Textures set(s)
By Un-set ContainerRuntime Clip
By ContainerRuntime w/ 1 Textures set(s)
By Un-set ContainerRuntime Clip