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-grain, low-level control of the organization, processing, and submission of graphics and computation commands and the management of the associated data and resources for these commands. A primary goal of Metal is to minimize the CPU overhead necessary for executing these 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 (i.e., graphics shader functions or data-parallel computation functions). The document then details how to use the Metal API to write an app that:

• sets hardware state necessary for graphics or data-parallel compute workloads,

• commits commands for execution by the GPU,

• manages memory allocations, including buffer and texture objects,

• and manages compiled (or compilable) graphics shader or compute function code written in the Metal shader programming language.

How to Use This Document

This document contains the following articles:

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

• Command Organization and Execution Model explains creating, committing, and executing commands on the GPU.

• 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 an 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 Tips and Techniques lists development tips, such as how to build libraries off-line with compiled code.

Prerequisites

This document assumes the reader is familiar with the Objective-C language and is experienced in programming with OpenGL, OpenCL, or similar APIs.