About Metal and This Guide

The Metal framework supports GPU-accelerated advanced 3D graphics rendering and data-parallel computation workloads. Metal provides a modern and streamlined API for fine-grained, low-level control of the organization, processing, and submission of graphics and computation commands, as well as the management of the associated data and resources for these commands. A primary goal of Metal is to minimize the CPU overhead incurred by executing GPU workloads.

At a Glance

This document describes the fundamental concepts of Metal: the command submission model, the memory management model, and the use of independently compiled code for graphics shader and data-parallel computation functions. The document then details how to use the Metal API to write an app.

You can find more details in the following chapters:

• Fundamental Metal Concepts briefly describes the main features of Metal.

• Command Organization and Execution Model explains how to create and submit commands to the GPU for execution.

• Resource Objects: Buffers and Textures discusses the management of device memory, including buffer and texture objects that represent GPU memory allocations.

• Functions and Libraries describes how Metal shading language code can be represented in a Metal app, and how Metal shading language code is loaded onto and executed by the GPU.

• Graphics Rendering: Render Command Encoder describes how to render 3D graphics, including how to distribute graphics operations across multiple threads.

• Data-Parallel Compute Processing: Compute Command Encoder explains how to perform data-parallel processing.

• Buffer and Texture Operations: Blit Command Encoder describes how to copy data between textures and buffers.

• Metal Tools lists the tools available to help you customize and improve your development workflow.

• Metal Feature Set Tables lists the feature availability, implementation limits, and pixel format capabilities of each Metal feature set.

• What's New in iOS 9 and OS X 10.11 summarizes the new features introduced in iOS 9 and OS X 10.11.

• What’s New in iOS 10, tvOS 10, and OS X 10.12 summarizes the new features introduced in iOS 10, tvOS 10, and OS X 10.12.

• Tessellation describes the Metal tessellation pipeline used to tessellate a patch, including the use of a compute kernel, tessellator, and post-tessellation vertex function.

• Resource Heaps describes how to sub-allocate resources from a heap, alias between them, and track them with a fence.

Prerequisites

You should be familiar with the Objective-C language and experienced in programming with OpenGL, OpenCL, or similar APIs.