From bd43ba6465330b3a09819c080042306cc8f70b41 Mon Sep 17 00:00:00 2001
From: daemyung jang <dm86.jang@gmail.com>
Date: Fri, 15 Apr 2022 09:39:47 +0900
Subject: [PATCH] Summerize Chapter 23: Debugging & Profiling

---
 23-debugging-and-profiling/README.md | 31 ++++++++++++++++++++++++++++
 README.md                            |  1 +
 2 files changed, 32 insertions(+)
 create mode 100644 23-debugging-and-profiling/README.md

diff --git a/23-debugging-and-profiling/README.md b/23-debugging-and-profiling/README.md
new file mode 100644
index 0000000..2646833
--- /dev/null
+++ b/23-debugging-and-profiling/README.md
@@ -0,0 +1,31 @@
+# Chapter 23: Debugging & Profiling
+
+As I read this book, I summarize what I think is wrong. If you think my comments are wrong then please let me know. We can dicuss more and update your opinion.
+
+## GPU frame capture
+
+Maybe you can't find Capture GPU Frame from the Action drop-down. Capture GPU Frame is renamed to **Capture GPU Workload**.
+
+This book mentions that you can capture GPU frame programmatically but the code isn't given.
+
+In Renderer.swift, in draw(in view:), add this at the top of this function:
+
+```
+let captureManager = MTLCaptureManager.shared()
+let captureDescriptor = MTLCaptureDescriptor()
+captureDescriptor.captureObject = Renderer.device
+do {
+    try captureManager.startCapture(with: captureDescriptor)
+} catch {
+    fatalError("error when trying to capture: \(error)")
+}
+
+```
+
+Add this at the bottom of this function:
+
+```
+captureManager.stopCapture()
+```
+
+If you want to know more, you can get more detail at [here](https://developer.apple.com/documentation/metal/debugging_tools/capturing_gpu_command_data_programmatically).
diff --git a/README.md b/README.md
index 847beae..5899d10 100644
--- a/README.md
+++ b/README.md
@@ -36,6 +36,7 @@ You can see color images in this book at [here](https://www.raywenderlich.com/bo
  * [Chapter 20: Advanced Lighting](https://github.com/daemyung/metal-by-tutorials/tree/main/20-advanced-lighting)
  * [Chapter 21: Metal Performance Shaders](https://github.com/daemyung/metal-by-tutorials/tree/main/21-metal-performance-shaders)
  * [Chapter 22: Integrating SpirteKit & SceneKit](https://github.com/daemyung/metal-by-tutorials/tree/main/22-integrating-spritekit-scenekit)
+ * [Chapter 23: Debugging & Profiling](https://github.com/daemyung/metal-by-tutorials/tree/main/23-debugging-and-profiling)
 
 ## Copyright