vulkan-3.8.1: Bindings to the Vulkan graphics API.
Safe HaskellNone
LanguageHaskell2010

Vulkan.Extensions.VK_QCOM_render_pass_transform

Description

Name

VK_QCOM_render_pass_transform - device extension

VK_QCOM_render_pass_transform

Name String
VK_QCOM_render_pass_transform
Extension Type
Device extension
Registered Extension Number
283
Revision
1
Extension and Version Dependencies
  • Requires Vulkan 1.0
  • Requires VK_KHR_swapchain
  • Requires VK_KHR_surface
Contact

Other Extension Metadata

Last Modified Date
2020-10-15
Interactions and External Dependencies
  • This extension requires VK_KHR_swapchain
  • This extension interacts with VK_EXT_fragment_density_map
Contributors
  • Jeff Leger, Qualcomm Technologies, Inc.
  • Brandon Light, Qualcomm Technologies, Inc.

Description

This extension provides a mechanism for applications to enable driver support for render pass transform.

Mobile devices can be rotated and mobile applications need to render properly when a device is held in a landscape or portrait orientation. When the current orientation differs from the device’s native orientation, a rotation is required so that the "up" direction of the rendered scene matches the current orientation.

If the Display Processing Unit (DPU) doesnt natively support rotation, the Vulkan presentation engine can handle this rotation in a separate composition pass. Alternatively, the application can render frames "pre-rotated" to avoid this extra pass. The latter is preferred to reduce power consumption and achieve the best performance because it avoids tasking the GPU with extra work to perform the copy/rotate operation.

Unlike OpenGL ES, the burden of pre-rotation in Vulkan falls on the application. To implement pre-rotation, applications render into swapchain images matching the device native aspect ratio of the display and "pre-rotate" the rendering content to match the device’s current orientation. The burden is more than adjusting the Model View Projection (MVP) matrix in the vertex shader to account for rotation and aspect ratio. The coordinate systems of scissors, viewports, derivatives and several shader built-ins may need to be adapted to produce the correct result.

It is difficult for some game engines to manage this burden; many chose to simply accept the performance/power overhead of performing rotation in the presentation engine.

This extension allows applications to achieve the performance benefits of pre-rotated rendering by moving much of the above-mentioned burden to the graphics driver. The following is unchanged with this extension:

The following is changed with this extension:

  • At cmdBeginRenderPass, the application provides extension struct RenderPassTransformBeginInfoQCOM specifying the render pass transform parameters.
  • At beginCommandBuffer for secondary command buffers, the application provides extension struct CommandBufferInheritanceRenderPassTransformInfoQCOM specifying the render pass transform parameters.
  • The renderArea, viewPorts and scissors are all provided in the current (non-rotated) coordinate system. The implementation will transform those into the native (rotated) coordinate system.
  • The implementation is responsible for transforming shader built-ins (FragCoord, PointCoord, SamplePosition, interpolateAt(), dFdx, dFdy, fWidth) into the rotated coordinate system.
  • The implementation is responsible for transforming position to the rotated coordinate system.

New Structures

New Enum Constants

Issues

1) Some early Adreno drivers (October 2019 through March 2020) advertised support for this extension but expected VK_STRUCTURE_TYPE values different from those in the vukan headers. To cover all Adreno devices on the market, applications need to detect the driver version and use the appropriate VK_STRUCTURE_TYPE values from the table below.

The driver version reported in VkPhysicalDeviceProperties.driverVersion is a uint32_t type. You can decode the uint32_t value into a major.minor.patch version as shown below:

uint32_t  major = ((driverVersion) >> 22);
uint32_t  minor = ((driverVersion) >> 12) & 0x3ff);
uint32_t  patch = ((driverVersion) & 0xfff);

If the Adreno major.minor.patch version is greater than or equal to to 512.469.0, then simply use the VK_STRUCTURE_TYPE values as defined in vulkan_core.h. If the version is less than or equal to to 512.468.0, then use the alternate values for the two VK_STRUCTURE_TYPEs in the table below.

Adreno Driver Version
512.468.0 and earlier 512.469.0 and later
VK_STRUCTURE_TYPE_ RENDER_PASS_TRANSFORM_BEGIN_INFO_QCOM 1000282000 1000282001
VK_STRUCTURE_TYPE_ COMMAND_BUFFER_INHERITANCE_RENDER_PASS_TRANSFORM_INFO_QCOM 1000282001 1000282000

Adreno Driver Requirements

2) Should the extension support only rotations (e.g. 90, 180, 270-degrees), or also mirror transforms (e.g. vertical flips)? Mobile use-cases only require rotation. Other display systems such as projectors might require a flipped transform.

RESOLVED: In this version of the extension, the functionality is restricted to 90, 180, and 270-degree rotations to address mobile use-cases.

3) How does this extension interact with VK_EXT_fragment_density_map?

RESOLVED Some implementations may not be able to support a render pass that enables both renderpass transform and fragment density maps. For simplicity, this extension disallows enabling both features within a single render pass.

4) What should this extension be named?

We considered names such as "rotated_rendering", "pre_rotation" and others. Since the functionality is limited to a render pass, it seemed the name should include "render_pass". While the current extension is limited to rotations, it could be extended to other transforms (like mirror) in the future.

RESOLVED The name "render_pass_transform" seems like the most accurate description of the introduced functionality.

Version History

  • Revision 1, 2020-02-05 (Jeff Leger)

See Also

CommandBufferInheritanceRenderPassTransformInfoQCOM, RenderPassTransformBeginInfoQCOM

Document Notes

For more information, see the Vulkan Specification

This page is a generated document. Fixes and changes should be made to the generator scripts, not directly.

Synopsis

Documentation

data RenderPassTransformBeginInfoQCOM Source #

VkRenderPassTransformBeginInfoQCOM - Structure describing transform parameters of a render pass instance

Valid Usage

Valid Usage (Implicit)

See Also

StructureType, SurfaceTransformFlagBitsKHR

Constructors

RenderPassTransformBeginInfoQCOM 

Fields

Instances

Instances details
Eq RenderPassTransformBeginInfoQCOM Source # 
Instance details

Defined in Vulkan.Extensions.VK_QCOM_render_pass_transform

Show RenderPassTransformBeginInfoQCOM Source # 
Instance details

Defined in Vulkan.Extensions.VK_QCOM_render_pass_transform

Storable RenderPassTransformBeginInfoQCOM Source # 
Instance details

Defined in Vulkan.Extensions.VK_QCOM_render_pass_transform

FromCStruct RenderPassTransformBeginInfoQCOM Source # 
Instance details

Defined in Vulkan.Extensions.VK_QCOM_render_pass_transform

ToCStruct RenderPassTransformBeginInfoQCOM Source # 
Instance details

Defined in Vulkan.Extensions.VK_QCOM_render_pass_transform

Zero RenderPassTransformBeginInfoQCOM Source # 
Instance details

Defined in Vulkan.Extensions.VK_QCOM_render_pass_transform

data CommandBufferInheritanceRenderPassTransformInfoQCOM Source #

VkCommandBufferInheritanceRenderPassTransformInfoQCOM - Structure describing transformed render pass parameters command buffer

Description

When the secondary is recorded to execute within a render pass instance using cmdExecuteCommands, the render pass transform parameters of the secondary command buffer must be consistent with the render pass transform parameters specified for the render pass instance. In particular, the transform and renderArea for command buffer must be identical to the transform and renderArea of the render pass instance.

Valid Usage (Implicit)

See Also

Rect2D, StructureType, SurfaceTransformFlagBitsKHR

Constructors

CommandBufferInheritanceRenderPassTransformInfoQCOM 

Fields

Instances

Instances details
Show CommandBufferInheritanceRenderPassTransformInfoQCOM Source # 
Instance details

Defined in Vulkan.Extensions.VK_QCOM_render_pass_transform

Storable CommandBufferInheritanceRenderPassTransformInfoQCOM Source # 
Instance details

Defined in Vulkan.Extensions.VK_QCOM_render_pass_transform

FromCStruct CommandBufferInheritanceRenderPassTransformInfoQCOM Source # 
Instance details

Defined in Vulkan.Extensions.VK_QCOM_render_pass_transform

ToCStruct CommandBufferInheritanceRenderPassTransformInfoQCOM Source # 
Instance details

Defined in Vulkan.Extensions.VK_QCOM_render_pass_transform

Zero CommandBufferInheritanceRenderPassTransformInfoQCOM Source # 
Instance details

Defined in Vulkan.Extensions.VK_QCOM_render_pass_transform

type QCOM_RENDER_PASS_TRANSFORM_EXTENSION_NAME = "VK_QCOM_render_pass_transform" Source #

newtype SurfaceTransformFlagBitsKHR Source #

Bundled Patterns

pattern SURFACE_TRANSFORM_IDENTITY_BIT_KHR :: SurfaceTransformFlagBitsKHR

SURFACE_TRANSFORM_IDENTITY_BIT_KHR specifies that image content is presented without being transformed.

pattern SURFACE_TRANSFORM_ROTATE_90_BIT_KHR :: SurfaceTransformFlagBitsKHR

SURFACE_TRANSFORM_ROTATE_90_BIT_KHR specifies that image content is rotated 90 degrees clockwise.

pattern SURFACE_TRANSFORM_ROTATE_180_BIT_KHR :: SurfaceTransformFlagBitsKHR

SURFACE_TRANSFORM_ROTATE_180_BIT_KHR specifies that image content is rotated 180 degrees clockwise.

pattern SURFACE_TRANSFORM_ROTATE_270_BIT_KHR :: SurfaceTransformFlagBitsKHR

SURFACE_TRANSFORM_ROTATE_270_BIT_KHR specifies that image content is rotated 270 degrees clockwise.

pattern SURFACE_TRANSFORM_HORIZONTAL_MIRROR_BIT_KHR :: SurfaceTransformFlagBitsKHR

SURFACE_TRANSFORM_HORIZONTAL_MIRROR_BIT_KHR specifies that image content is mirrored horizontally.

pattern SURFACE_TRANSFORM_HORIZONTAL_MIRROR_ROTATE_90_BIT_KHR :: SurfaceTransformFlagBitsKHR

SURFACE_TRANSFORM_HORIZONTAL_MIRROR_ROTATE_90_BIT_KHR specifies that image content is mirrored horizontally, then rotated 90 degrees clockwise.

pattern SURFACE_TRANSFORM_HORIZONTAL_MIRROR_ROTATE_180_BIT_KHR :: SurfaceTransformFlagBitsKHR

SURFACE_TRANSFORM_HORIZONTAL_MIRROR_ROTATE_180_BIT_KHR specifies that image content is mirrored horizontally, then rotated 180 degrees clockwise.

pattern SURFACE_TRANSFORM_HORIZONTAL_MIRROR_ROTATE_270_BIT_KHR :: SurfaceTransformFlagBitsKHR

SURFACE_TRANSFORM_HORIZONTAL_MIRROR_ROTATE_270_BIT_KHR specifies that image content is mirrored horizontally, then rotated 270 degrees clockwise.

pattern SURFACE_TRANSFORM_INHERIT_BIT_KHR :: SurfaceTransformFlagBitsKHR

SURFACE_TRANSFORM_INHERIT_BIT_KHR specifies that the presentation transform is not specified, and is instead determined by platform-specific considerations and mechanisms outside Vulkan.

Instances

Instances details
Eq SurfaceTransformFlagBitsKHR Source # 
Instance details

Defined in Vulkan.Extensions.VK_KHR_surface

Ord SurfaceTransformFlagBitsKHR Source # 
Instance details

Defined in Vulkan.Extensions.VK_KHR_surface

Read SurfaceTransformFlagBitsKHR Source # 
Instance details

Defined in Vulkan.Extensions.VK_KHR_surface

Show SurfaceTransformFlagBitsKHR Source # 
Instance details

Defined in Vulkan.Extensions.VK_KHR_surface

Storable SurfaceTransformFlagBitsKHR Source # 
Instance details

Defined in Vulkan.Extensions.VK_KHR_surface

Bits SurfaceTransformFlagBitsKHR Source # 
Instance details

Defined in Vulkan.Extensions.VK_KHR_surface

Methods

(.&.) :: SurfaceTransformFlagBitsKHR -> SurfaceTransformFlagBitsKHR -> SurfaceTransformFlagBitsKHR #

(.|.) :: SurfaceTransformFlagBitsKHR -> SurfaceTransformFlagBitsKHR -> SurfaceTransformFlagBitsKHR #

xor :: SurfaceTransformFlagBitsKHR -> SurfaceTransformFlagBitsKHR -> SurfaceTransformFlagBitsKHR #

complement :: SurfaceTransformFlagBitsKHR -> SurfaceTransformFlagBitsKHR #

shift :: SurfaceTransformFlagBitsKHR -> Int -> SurfaceTransformFlagBitsKHR #

rotate :: SurfaceTransformFlagBitsKHR -> Int -> SurfaceTransformFlagBitsKHR #

zeroBits :: SurfaceTransformFlagBitsKHR #

bit :: Int -> SurfaceTransformFlagBitsKHR #

setBit :: SurfaceTransformFlagBitsKHR -> Int -> SurfaceTransformFlagBitsKHR #

clearBit :: SurfaceTransformFlagBitsKHR -> Int -> SurfaceTransformFlagBitsKHR #

complementBit :: SurfaceTransformFlagBitsKHR -> Int -> SurfaceTransformFlagBitsKHR #

testBit :: SurfaceTransformFlagBitsKHR -> Int -> Bool #

bitSizeMaybe :: SurfaceTransformFlagBitsKHR -> Maybe Int #

bitSize :: SurfaceTransformFlagBitsKHR -> Int #

isSigned :: SurfaceTransformFlagBitsKHR -> Bool #

shiftL :: SurfaceTransformFlagBitsKHR -> Int -> SurfaceTransformFlagBitsKHR #

unsafeShiftL :: SurfaceTransformFlagBitsKHR -> Int -> SurfaceTransformFlagBitsKHR #

shiftR :: SurfaceTransformFlagBitsKHR -> Int -> SurfaceTransformFlagBitsKHR #

unsafeShiftR :: SurfaceTransformFlagBitsKHR -> Int -> SurfaceTransformFlagBitsKHR #

rotateL :: SurfaceTransformFlagBitsKHR -> Int -> SurfaceTransformFlagBitsKHR #

rotateR :: SurfaceTransformFlagBitsKHR -> Int -> SurfaceTransformFlagBitsKHR #

popCount :: SurfaceTransformFlagBitsKHR -> Int #

FiniteBits SurfaceTransformFlagBitsKHR Source # 
Instance details

Defined in Vulkan.Extensions.VK_KHR_surface

Zero SurfaceTransformFlagBitsKHR Source # 
Instance details

Defined in Vulkan.Extensions.VK_KHR_surface