Vulkan Cookbook

By : Pawel Lapinski

Vulkan Cookbook

By: Pawel Lapinski

Overview of this book

Vulkan is the next generation graphics API released by the Khronos group. It is expected to be the successor to OpenGL and OpenGL ES, which it shares some similarities with such as its cross-platform capabilities, programmed pipeline stages, or nomenclature. Vulkan is a low-level API that gives developers much more control over the hardware, but also adds new responsibilities such as explicit memory and resources management. With it, though, Vulkan is expected to be much faster. This book is your guide to understanding Vulkan through a series of recipes. We start off by teaching you how to create instances in Vulkan and choose the device on which operations will be performed. You will then explore more complex topics such as command buffers, resources and memory management, pipelines, GLSL shaders, render passes, and more. Gradually, the book moves on to teach you advanced rendering techniques, how to draw 3D scenes, and how to improve the performance of your applications. By the end of the book, you will be familiar with the latest advanced techniques implemented with the Vulkan API, which can be used on a wide range of platforms.

Preface

What this book covers

What you need for this book

Free Chapter

Instance and Devices

Introduction

Downloading Vulkan's SDK

Enabling validation layers

Connecting with a Vulkan Loader library

Preparing for loading Vulkan API functions

Loading functions exported from a Vulkan Loader library

Loading global-level functions

Checking available Instance extensions

Creating a Vulkan Instance

Loading instance-level functions

Enumerating available physical devices

Checking available device extensions

Getting features and properties of a physical device

Checking available queue families and their properties

Selecting the index of a queue family with the desired capabilities

Creating a logical device

Loading device-level functions

Getting a device queue

Creating a logical device with geometry shaders, graphics, and compute queues

Destroying a logical device

Destroying a Vulkan Instance

Releasing a Vulkan Loader library

Image Presentation

Introduction

Creating a Vulkan Instance with WSI extensions enabled

Creating a presentation surface

Selecting a queue family that supports presentation to a given surface

Creating a logical device with WSI extensions enabled

Selecting a desired presentation mode

Getting the capabilities of a presentation surface

Selecting a number of swapchain images

Choosing a size of swapchain images

Selecting desired usage scenarios of swapchain images

Selecting a transformation of swapchain images

Selecting a format of swapchain images

Creating a swapchain

Getting handles of swapchain images

Creating a swapchain with R8G8B8A8 format and a mailbox present mode

Acquiring a swapchain image

Presenting an image

Destroying a swapchain

Destroying a presentation surface

Command Buffers and Synchronization

Introduction

Creating a command pool

Allocating command buffers

Beginning a command buffer recording operation

Ending a command buffer recording operation

Resetting a command buffer

Resetting a command pool

Submitting command buffers to a queue

Synchronizing two command buffers

Checking if processing of a submitted command buffer has finished

Waiting until all commands submitted to a queue are finished

Waiting for all submitted commands to be finished

Destroying a fence

Destroying a semaphore

Freeing command buffers

Destroying a command pool

Resources and Memory

Introduction

Creating a buffer

Allocating and binding a memory object for a buffer

Setting a buffer memory barrier

Creating a buffer view

Creating an image

Allocating and binding a memory object to an image

Setting an image memory barrier

Creating an image view

Creating a 2D image and view

Creating a layered 2D image with a CUBEMAP view

Mapping, updating and unmapping host-visible memory

Copying data between buffers

Copying data from a buffer to an image

Copying data from an image to a buffer

Using a staging buffer to update a buffer with a device-local memory bound

Using a staging buffer to update an image with a device-local memory bound

Destroying an image view

Destroying an image

Destroying a buffer view

Freeing a memory object

Destroying a buffer

Descriptor Sets

Introduction

Creating a sampler

Creating a sampled image

Creating a combined image sampler

Creating a storage image

Creating a uniform texel buffer

Creating a storage texel buffer

Creating a uniform buffer

Creating a storage buffer

Creating an input attachment

Creating a descriptor set layout

Creating a descriptor pool

Allocating descriptor sets

Updating descriptor sets

Binding descriptor sets

Creating descriptors with a texture and a uniform buffer

Freeing descriptor sets

Resetting a descriptor pool

Destroying a descriptor pool

Destroying a descriptor set layout

Destroying a sampler

Render Passes and Framebuffers

Introduction

Specifying attachments descriptions

Specifying subpass descriptions

Specifying dependencies between subpasses

Creating a render pass

Creating a framebuffer

Preparing a render pass for geometry rendering and postprocess subpasses

Preparing a render pass and a framebuffer with color and depth attachments

Beginning a render pass

Progressing to the next subpass

Ending a render pass

Destroying a framebuffer

Destroying a render pass

Shaders

Introduction

Converting GLSL shaders to SPIR-V assemblies

Writing vertex shaders

Writing tessellation control shaders

Writing tessellation evaluation shaders

Writing geometry shaders

Writing fragment shaders

Writing compute shaders

Writing a vertex shader that multiplies vertex position by a projection matrix

Using push constants in shaders

Writing texturing vertex and fragment shaders

Displaying polygon normals with a geometry shader

Graphics and Compute Pipelines

Introduction

Creating a shader module

Specifying pipeline shader stages

Specifying a pipeline vertex binding description, attribute description, and input state

Specifying a pipeline input assembly state

Specifying a pipeline tessellation state

Specifying a pipeline viewport and scissor test state

Specifying a pipeline rasterization state

Specifying a pipeline multisample state

Specifying a pipeline depth and stencil state

Specifying a pipeline blend state

Specifying pipeline dynamic states

Creating a pipeline layout

Specifying graphics pipeline creation parameters

Creating a pipeline cache object

Retrieving data from a pipeline cache

Merging multiple pipeline cache objects

Creating a graphics pipeline

Creating a compute pipeline

Binding a pipeline object

Creating a pipeline layout with a combined image sampler, a buffer, and push constant ranges

Creating a graphics pipeline with vertex and fragment shaders, depth test enabled, and with dynamic viewport and scissor tests

Creating multiple graphics pipelines on multiple threads

Destroying a pipeline

Destroying a pipeline cache

Destroying a pipeline layout

Destroying a shader module

Command Recording and Drawing

Introduction

Clearing a color image

Clearing a depth-stencil image

Clearing render pass attachments

Binding vertex buffers

Binding an index buffer

Providing data to shaders through push constants

Setting viewport states dynamically

Setting scissor states dynamically

Setting line width states dynamically

Setting depth bias states dynamically

Setting blend constants states dynamically

Drawing a geometry

Drawing an indexed geometry

Dispatching compute work

Executing a secondary command buffer inside a primary command buffer

Recording a command buffer that draws a geometry with dynamic viewport and scissor states

Recording command buffers on multiple threads

Preparing a single frame of animation

Increasing the performance through increasing the number of separately rendered frames

Helper Recipes

Introduction

Preparing a translation matrix

Preparing a rotation matrix

Preparing a scaling matrix

Preparing a perspective projection matrix

Preparing an orthographic projection matrix

Loading texture data from a file

Loading a 3D model from an OBJ file

Lighting

Introduction

Rendering a geometry with a vertex diffuse lighting

Rendering a geometry with a fragment specular lighting

Rendering a normal mapped geometry

Drawing a reflective and refractive geometry using cubemaps

Adding shadows to the scene

Advanced Rendering Techniques

Introduction

Drawing a skybox

Drawing billboards using geometry shaders

Drawing particles using compute and graphics pipelines

Rendering a tessellated terrain

Rendering a full-screen quad for post-processing

Using input attachments for a color correction post-process effect

Customer Reviews

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Checking available queue families and their properties

In Vulkan, when we want to perform operations on hardware, we submit them to queues. The operations within a single queue are processed one after another, in the same order they were submitted--that's why it's called a queue. However, operations submitted to different queues are processed independently (if we need, we can synchronize them):

Different queues may represent different parts of the hardware, and thus may support different kinds of operations. Not all operations may be performed on all queues.

Queues with the same capabilities are grouped into families. A device may expose any number of queue families, and each family may contain one or more queues. To check what operations can be performed on the given hardware, we need to query the properties of all queue families.

How to do it...

Take one of the physical device handles returned by the vkEnumeratePhysicalDevices() function and store it in a variable of type VkPhysicalDevice called physical_device.
Prepare a variable of type uint32_t named queue_families_count.
Call vkGetPhysicalDeviceQueueFamilyProperties( physical_device, &queue_families_count, nullptr ). Provide the handle of a physical device in the first parameter; the second parameter should point to the queue_families_count variable, and the final parameter should be set to nullptr.
After the successful call, the queue_families_count variable will contain the number of all queue families exposed by a given physical device.
Prepare a storage for the list of queue families and their properties. A very convenient solution is to use a variable of type std::vector. Its elements must be of type VkQueueFamilyProperties. Call the variable queue_families.
Resize the vector to be able to hold at least the queue_families_count elements.
Call vkGetPhysicalDeviceQueueFamilyProperties( physical_device, &queue_families_count, &queue_families[0] ). The first and second argument should be the same as in the previous call; the last parameter should point to the first element of the queue_families vector.
To be sure that everything went okay, check that the queue_families_count variable is greater than zero. If successful, the properties of all queue families will be stored in the queue_families vector.

How it works...

The implementation of the preceding recipe, similarly to other queries, can be divided into two stages: Firstly, we acquire information about the total number of queue families available on a given physical device. This is done by calling a vkGetPhysicalDeviceQueueFamilyProperties() function, with the last argument set to nullptr:

uint32_t queue_families_count = 0; 

vkGetPhysicalDeviceQueueFamilyProperties( physical_device, &queue_families_count, nullptr ); 
if( queue_families_count == 0 ) { 
  std::cout << "Could not get the number of queue families." << std::endl; 
  return false; 
}

Secondly, when we know how many queue families there are, we can prepare sufficient memory to be able to store the properties of all of them. In the presented example, we create a variable of type std::vector with VkQueueFamilyProperties elements and resize it to the value returned by the first query. After that, we perform a second vkGetPhysicalDeviceQueueFamilyProperties() function call, with the last parameter pointing to the first element of the created vector. In this vector, the parameters of all available queue families will be stored.

queue_families.resize( queue_families_count ); 
vkGetPhysicalDeviceQueueFamilyProperties( physical_device, &queue_families_count, &queue_families[0] ); 
if( queue_families_count == 0 ) { 
  std::cout << "Could not acquire properties of queue families." << std::endl; 
  return false; 
} 

return true;

The most important information we can get from properties is the types of operations that can be performed by the queues in a given family. Types of operations supported by queues are divided into:

Graphics: For creating graphics pipelines and drawing
Compute: For creating compute pipelines and dispatching compute shaders
Transfer: Used for very fast memory-copying operations
Sparse: Allows for additional memory management features

Queues from the given family may support more than one type of operation. There may also be a situation where different queue families support exactly the same types of operation.

Family properties also inform us about the number of queues that are available in the given family, about the timestamp support (for time measurements), and the granularity of image transfer operations (how small parts of image can be specified during copy/blit operations).

With the knowledge of the number of queue families, their properties, and the available number of queues in each family, we can prepare for logical device creation. All this information is needed, because we don't create queues by ourselves. We just request them during logical device creation, for which we must specify how many queues are needed and from which families. When a device is created, queues are created automatically along with it. We just need to acquire the handles of all requested queues.

Vulkan Cookbook

By : Pawel Lapinski

Vulkan Cookbook

By: Pawel Lapinski

Overview of this book

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