The actual uniform buffer class with implemented function using Vulkan API. More...

#include <VulkanBuffer.h>

Inheritance diagram for Karma::VulkanUniformBuffer:

Public Member Functions
	VulkanUniformBuffer (std::vector< ShaderDataType > dataTypes, uint32_t bindingPointIndex)
	Constructor for Vulkan buffer. Calls VulkanUniformBuffer::BufferCreation().
virtual	~VulkanUniformBuffer ()
	Destructor. For freeing up UBO resources, use VulkanUniformBuffer::ClearBuffer().
void	CreateBuffer (VkDeviceSize size, VkBufferUsageFlags usage, VkMemoryPropertyFlags properties, VkBuffer &buffer, VkDeviceMemory &bufferMemory)
	Creates Vulkan buffer (VKbuffer) for ubo use and allocates device memory appropriately.
const std::vector< VkBuffer > &	GetUniformBuffers () const
	Getter for the uniform buffers.
void	ClearBuffer ()
	Frees up the resources by destroying the buffer object(s) and clearing memory.
void	BufferCreation ()
	Based on MAX_FRAMES_IN_FLIGHT (number of images (to work upon (CPU side) whilst an image is being rendered (GPU side processing)) + 1), uniform buffers are created with appropriate buffer size.
virtual void	UpdateCameraUniform () override
void	UploadUniformBuffer (size_t frameIndex) override
	Uploads (copies) the data to GPU buffer memory (m_UniformBuffersMemory) from host-accessible (CPU) pointer, m_UniformList, to the beginning of the mapped range.
Public Member Functions inherited from Karma::UniformBufferObject
	UniformBufferObject (std::vector< ShaderDataType > dataTypes, uint32_t bindingPointIndex)
	An agnostic constructor provided for precomputation of offset and buffer size.
virtual	~UniformBufferObject ()=default
	Pure virtual destructor and sub class should have appropriate implementation.
template<typename... T>
void	UpdateUniforms (T &&... uniforms)
	Set the m_UniformList with latest supplied uniforms.
uint32_t	GetBufferSize () const
const std::vector< UBODataPointer > &	GetUniformList () const
const std::vector< ShaderDataType > &	GetUniformDataType () const
const std::vector< uint32_t > &	GetAlignedOffsets () const
const std::vector< uint32_t > &	GetUniformSize () const
uint32_t	GetBindingPointIndex () const

Additional Inherited Members
Static Public Member Functions inherited from Karma::UniformBufferObject
static UniformBufferObject *	Create (std::vector< ShaderDataType > dataTypes, uint32_t bindingPointIndex)
	A function for appropriate initialization of UBO based on programmer selected rendered (Vulkan or OpenGL).
Protected Member Functions inherited from Karma::UniformBufferObject
void	CalculateOffsetsAndBufferSize ()
	Calculate offsets and buffer size of the uniform buffer object(s).
Protected Attributes inherited from Karma::UniformBufferObject
uint32_t	m_BufferSize
	Total size of the buffer in bytes.
uint32_t	m_BindingPoint
	The binding point prescribed in vertex shader for instance https://github.com/ravimohan1991/KarmaEngine/blob/5ff57f5747c19efcea050646bc2d217c99d74015/Resources/Shaders/shader.vert#L14-L18.
std::vector< UBODataPointer >	m_UniformList
	List of uniforms to be uploaded.
std::vector< ShaderDataType >	m_UniformDataType
	List of data types (ShaderDataType) for the m_UniformList.
std::vector< uint32_t >	m_UniformAlignedOffsets
	List of individual uniform boundary aligned (with multiple of individual uniform size) offsets.
std::vector< uint32_t >	m_UniformSizes
	List of individual uniform sizes.

Detailed Description

The actual uniform buffer class with implemented function using Vulkan API.

Since: Karma 1.0.0

Constructor & Destructor Documentation

◆ VulkanUniformBuffer()

Karma::VulkanUniformBuffer::VulkanUniformBuffer	(	std::vector< ShaderDataType >	dataTypes,
		uint32_t	bindingPointIndex )

Constructor for Vulkan buffer. Calls VulkanUniformBuffer::BufferCreation().

Also registers the UBO with VulkanContext so that it can be updated appropriately during rendering.

Parameters

dataTypes	List of data types for uniforms to be uploaded to GPU (like used in shaders), for instance https://github.com/ravimohan1991/KarmaEngine/blob/138c172ccedf31acfab982af51ae130f9a37d3bb/Application/src/KarmaApp.cpp#L39 where Mat4 are for https://github.com/ravimohan1991/KarmaEngine/blob/138c172ccedf31acfab982af51ae130f9a37d3bb/Resources/Shaders/shader.vert#L9-L13
bindingPointIndex	The binding of shader specified index

Since: Karma 1.0.0

◆ ~VulkanUniformBuffer()

Karma::VulkanUniformBuffer::~VulkanUniformBuffer ( )

virtual

Destructor. For freeing up UBO resources, use VulkanUniformBuffer::ClearBuffer().

See also: VulkanContext::ClearUBO

Since: Karma 1.0.0

Member Function Documentation

◆ BufferCreation()

void Karma::VulkanUniformBuffer::BufferCreation ( )

Based on MAX_FRAMES_IN_FLIGHT (number of images (to work upon (CPU side) whilst an image is being rendered (GPU side processing)) + 1), uniform buffers are created with appropriate buffer size.

Since: Karma 1.0.0.

◆ ClearBuffer()

void Karma::VulkanUniformBuffer::ClearBuffer ( )

Frees up the resources by destroying the buffer object(s) and clearing memory.

Since: Karma 1.0.0

◆ CreateBuffer()

void Karma::VulkanUniformBuffer::CreateBuffer	(	VkDeviceSize	size,
		VkBufferUsageFlags	usage,
		VkMemoryPropertyFlags	properties,
		VkBuffer &	buffer,
		VkDeviceMemory &	bufferMemory )

Creates Vulkan buffer (VKbuffer) for ubo use and allocates device memory appropriately.

Parameters

size	The size, in bytes, of the buffer to be created
properties	The demanded properties (https://registry.khronos.org/vulkan/specs/1.3-extensions/man/html/VkBufferUsageFlagBits.html). For instance (VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT \| VK_MEMORY_PROPERTY_HOST_COHERENT_BIT)

See also: VulkanUniformBuffer::BufferCreation()

Since: Karma 1.0.0

◆ GetUniformBuffers()

const std::vector< VkBuffer > & Karma::VulkanUniformBuffer::GetUniformBuffers ( ) const

inline

Getter for the uniform buffers.

Since: Karma 1.0.0

◆ UpdateCameraUniform()

void Karma::VulkanUniformBuffer::UpdateCameraUniform ( )

overridevirtual

Implements Karma::UniformBufferObject.

◆ UploadUniformBuffer()

void Karma::VulkanUniformBuffer::UploadUniformBuffer ( size_t frameIndex )

overridevirtual

Uploads (copies) the data to GPU buffer memory (m_UniformBuffersMemory) from host-accessible (CPU) pointer, m_UniformList, to the beginning of the mapped range.

Basically copies the data from CPU side (uniforms) to GPU side (m_UniformBuffersMemory).

In summary, the process of updating uniform buffers in Vulkan involves the following steps:

Uniform data is first stored in a CPU-side structure representing the uniform buffer object.
The memory of the uniform buffer (a VkBuffer) is created with CPU-visible properties and mapped to a CPU pointer.
The updateUniformBuffer function copies the CPU-side data (like transformation matrices) into the mapped GPU buffer memory via a memcpy call.
This allows the GPU to read the fresh uniform data every frame during rendering without needing to re-record command buffers.

Mechanics: vkMapMemory returns a CPU-accessible pointer (data) to a specific range within m_UniformBuffersMemory[frameIndex], which is VkDeviceMemory allocated for GPU use but with VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT (see VulkanUniformBuffer::BufferCreation()). This pointer points directly into GPU memory, so memcpy(data, it.GetDataPointer(), uniformSize) overlays CPU data bytes onto that GPU buffer region

Parameters

frameIndex The m_CurrentFrame index representing index of MAX_FRAMES_IN_FLIGHT (number of images (to work upon (CPU side) whilst an image is being rendered (GPU side processing)) + 1)

See also: VulkanRendererAPI::SubmitCommandBuffers()

Since: Karma 1.0.0

Implements Karma::UniformBufferObject.

The documentation for this struct was generated from the following files:

Karma/src/Platform/Vulkan/VulkanBuffer.h
Karma/src/Platform/Vulkan/VulkanBuffer.cpp

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ VulkanUniformBuffer()

◆ ~VulkanUniformBuffer()

Member Function Documentation

◆ BufferCreation()

◆ ClearBuffer()

◆ CreateBuffer()

◆ GetUniformBuffers()

◆ UpdateCameraUniform()

◆ UploadUniformBuffer()