GHOST Vulkan Backend API. #93031

New Issue

Jeroen Bakker · 2021-11-12T09:20:31+01:00

Jeroen Bakker commented

2021-11-12 09:20:31 +01:00

Supported backends

GHOST_SystemSDL
GHOST_SystemWayland
GHOST_SystemWin32
GHOST_SystemX11
GHOST_SystemCocoa: using vulkan metal wrapper.

Compile directive

There will be a new compile directive WITH_VULKAN_BACKEND this compile directive will enable adding vulkan context in ghost backend systems.

Creating a vulkan context
Vulkan contexts can be created by passing GHOST_kDrawingContextTypeVulkan when creating window/context.

Device selection
There can be multiple vulkan compatible devices inside a system. User should be able to select a device via the user preferences. When selecting a different device blender should be restarted by the user. When no specific device is selected a best matching device should be selected.

GHOST_VulkanDeviceListHandle* GHOST_GetVulkanAvailableDevices(GHOST_SystemHandle,...): returns a list of all devices that match requirements. When constructing a window/context a specific device should be given.
int64_t GHOST_VulkanDeviceListNumDevices(GHOST_VulkanDeviceListHandle* handle) will return the number of devices found
GHOST_Success GHOST_GetVulkanDeviceListItem(GHOST_VulkanDeviceListHandle* handle, int64_t index, GHOST_VulkanPhysicalDevice * r_device) will fill r_device with available data return the vendor and device id and a number to make the device unique.
GHOST_DestroyVulkanDeviceList should be called to free the GHOST_VulkanDeviceListHandle.

GHOST_VulkanPhysicalDevice is based on VkPhysicalDeviceProperties but has a additional attribute to make the Vendor+Device unique. the combination of those 3 fields will allow to select a unique device.

struct GHOST_VulkanPhysicalDeviceID {
  uint32_t vendor_id;
  uint32_t device_id;
  int32_t index;
};

struct GHOST_VulkanPhysicalDevice {
  GHOST_VulkanPhysicalDeviceID device_id;
  VkPhysicalDeviceProperties device_properties;
};

GHOST_GLSettings will get an GHOST_VulkanPhysicalDeviceID* attribute for device selection.
When NULL is passed for GHOST_VulkanPhysicalDeviceID or the passed device couldn't be found during context creation GHOST will automatically select the best available device based on the device type (discrete before integrated before virtual [before cpu?]).

NOTE: The VkQueryAPI requires an VkInstance. So we can only do this on an initialized GHOST_Context We could use a offscreen context for this.

Command queues
GHOST_GetVulkanBackbuffer(GHOST_WindowHandle will get the handles of the given window.
For offscreen rendering GHOST_GetVulkanHandles will retrieve the device handles and the command queue etc should be constructed by the caller.

Smaller tasks

Remove references to OpenGL in the GHOST API that are not OpenGL specific.
rename GHOST_CreateOpenGLContext to GHOST_CreateDrawingContext. rename GHOST_DisposeOpenGLContext to GHOST_DisposeDrawingContext.
rename GHOST_ActivateOpenGLContext to GHOST_ActivateDrawingContext. rename GHOST_ReleaseOpenGLContext to GHOST_ReleaseDrawingContext.
** Unclear if we need to rename GHOST_GetDefaultOpenGLFramebuffer and GHOST_GetContextDefaultOpenGLFramebuffer or that we will have specific versions for Vulkan.

## Supported backends * GHOST_SystemSDL * GHOST_SystemWayland * GHOST_SystemWin32 * GHOST_SystemX11 * GHOST_SystemCocoa: using vulkan metal wrapper. ## Compile directive There will be a new compile directive `WITH_VULKAN_BACKEND` this compile directive will enable adding vulkan context in ghost backend systems. **Creating a vulkan context** Vulkan contexts can be created by passing `GHOST_kDrawingContextTypeVulkan` when creating window/context. **Device selection** There can be multiple vulkan compatible devices inside a system. User should be able to select a device via the user preferences. When selecting a different device blender should be restarted by the user. When no specific device is selected a best matching device should be selected. `GHOST_VulkanDeviceListHandle* GHOST_GetVulkanAvailableDevices(GHOST_SystemHandle,...)`: returns a list of all devices that match requirements. When constructing a window/context a specific device should be given. `int64_t GHOST_VulkanDeviceListNumDevices(GHOST_VulkanDeviceListHandle* handle)` will return the number of devices found `GHOST_Success GHOST_GetVulkanDeviceListItem(GHOST_VulkanDeviceListHandle* handle, int64_t index, GHOST_VulkanPhysicalDevice * r_device)` will fill r_device with available data return the vendor and device id and a number to make the device unique. `GHOST_DestroyVulkanDeviceList` should be called to free the GHOST_VulkanDeviceListHandle. `GHOST_VulkanPhysicalDevice` is based on `VkPhysicalDeviceProperties` but has a additional attribute to make the Vendor+Device unique. the combination of those 3 fields will allow to select a unique device. ``` struct GHOST_VulkanPhysicalDeviceID { uint32_t vendor_id; uint32_t device_id; int32_t index; }; struct GHOST_VulkanPhysicalDevice { GHOST_VulkanPhysicalDeviceID device_id; VkPhysicalDeviceProperties device_properties; }; ``` `GHOST_GLSettings` will get an `GHOST_VulkanPhysicalDeviceID*` attribute for device selection. When `NULL` is passed for GHOST_VulkanPhysicalDeviceID or the passed device couldn't be found during context creation GHOST will automatically select the best available device based on the device type (discrete before integrated before virtual [before cpu?]). NOTE: The VkQueryAPI requires an VkInstance. So we can only do this on an initialized GHOST_Context We could use a offscreen context for this. **Command queues** `GHOST_GetVulkanBackbuffer(GHOST_WindowHandle` will get the handles of the given window. For offscreen rendering `GHOST_GetVulkanHandles` will retrieve the device handles and the command queue etc should be constructed by the caller. ## Smaller tasks * Remove references to OpenGL in the GHOST API that are not OpenGL specific. **rename `GHOST_CreateOpenGLContext` to `GHOST_CreateDrawingContext`.** rename `GHOST_DisposeOpenGLContext` to `GHOST_DisposeDrawingContext`. **rename `GHOST_ActivateOpenGLContext` to `GHOST_ActivateDrawingContext`.** rename `GHOST_ReleaseOpenGLContext` to `GHOST_ReleaseDrawingContext`. ** Unclear if we need to rename `GHOST_GetDefaultOpenGLFramebuffer` and `GHOST_GetContextDefaultOpenGLFramebuffer` or that we will have specific versions for Vulkan.

Jeroen Bakker self-assigned this 2021-11-12 09:20:31 +01:00

Jeroen Bakker commented

2021-11-12 09:20:31 +01:00

Changed status from 'Needs Triage' to: 'Confirmed'