Google Git
Sign in
android / platform / external / angle / dca16843192b1d2660e2a28a840719fb244d5bdf / . / src / libANGLE / renderer / vulkan
tree: cb6bf8624d436c96cc9ddd0cea20abe8324ccdb6 [path history] [tgz]
  1. android/
  2. doc/
  3. fuchsia/
  4. ggp/
  5. mac/
  6. shaders/
  7. win32/
  8. xcb/
  9. BufferVk.cpp
  10. BufferVk.h
  11. BUILD.gn
  12. CommandGraph.cpp
  13. CommandGraph.h
  14. CompilerVk.cpp
  15. CompilerVk.h
  16. ContextVk.cpp
  17. ContextVk.h
  18. DeviceVk.cpp
  19. DeviceVk.h
  20. DisplayVk.cpp
  21. DisplayVk.h
  22. DisplayVk_api.h
  23. FenceNVVk.cpp
  24. FenceNVVk.h
  25. FramebufferVk.cpp
  26. FramebufferVk.h
  27. gen_vk_format_table.py
  28. gen_vk_internal_shaders.py
  29. gen_vk_mandatory_format_support_table.py
  30. GlslangWrapperVk.cpp
  31. GlslangWrapperVk.h
  32. ImageVk.cpp
  33. ImageVk.h
  34. MemoryObjectVk.cpp
  35. MemoryObjectVk.h
  36. OverlayVk.cpp
  37. OverlayVk.h
  38. PersistentCommandPool.cpp
  39. PersistentCommandPool.h
  40. ProgramPipelineVk.cpp
  41. ProgramPipelineVk.h
  42. ProgramVk.cpp
  43. ProgramVk.h
  44. QueryVk.cpp
  45. QueryVk.h
  46. README.md
  47. RenderbufferVk.cpp
  48. RenderbufferVk.h
  49. RendererVk.cpp
  50. RendererVk.h
  51. RenderTargetVk.cpp
  52. RenderTargetVk.h
  53. ResourceVk.cpp
  54. ResourceVk.h
  55. SamplerVk.cpp
  56. SamplerVk.h
  57. SecondaryCommandBuffer.cpp
  58. SecondaryCommandBuffer.h
  59. SemaphoreVk.cpp
  60. SemaphoreVk.h
  61. ShaderVk.cpp
  62. ShaderVk.h
  63. SurfaceVk.cpp
  64. SurfaceVk.h
  65. SyncVk.cpp
  66. SyncVk.h
  67. TextureVk.cpp
  68. TextureVk.h
  69. TransformFeedbackVk.cpp
  70. TransformFeedbackVk.h
  71. UtilsVk.cpp
  72. UtilsVk.h
  73. VertexArrayVk.cpp
  74. VertexArrayVk.h
  75. vk_cache_utils.cpp
  76. vk_cache_utils.h
  77. vk_caps_utils.cpp
  78. vk_caps_utils.h
  79. vk_ext_provoking_vertex.h
  80. vk_format_map.json
  81. vk_format_table_autogen.cpp
  82. vk_format_utils.cpp
  83. vk_format_utils.h
  84. vk_helpers.cpp
  85. vk_helpers.h
  86. vk_internal_shaders_autogen.cpp
  87. vk_internal_shaders_autogen.gni
  88. vk_internal_shaders_autogen.h
  89. vk_mandatory_format_support_data.json
  90. vk_mandatory_format_support_table_autogen.cpp
  91. vk_utils.cpp
  92. vk_utils.h
  93. vk_wrapper.h
src/libANGLE/renderer/vulkan/README.md

ANGLE: Vulkan Back-end

ANGLE's Vulkan back-end implementation lives in this folder.

Vulkan is an explicit graphics API. It has a lot in common with other explicit APIs such as Microsoft‘s D3D12 and Apple’s Metal. Compared to APIs like OpenGL or D3D11 explicit APIs can offer a number of significant benefits:

  • Lower API call CPU overhead.
  • A smaller API surface with more direct hardware control.
  • Better support for multi-core programming.
  • Vulkan in particular has open-source tooling and tests.

Back-end Design

The RendererVk class represents an EGLDisplay. RendererVk owns shared global resources like the VkDevice, VkQueue, the Vulkan format tables and internal Vulkan shaders. The ContextVk class implements the back-end of a front-end OpenGL Context. ContextVk processes state changes and handles action commands like glDrawArrays and glDrawElements.

Command recording

The back-end records commands into command buffers via the the following ContextVk APIs:

  • endRenderPassAndGetCommandBuffer: returns a secondary command buffer outside a RenderPass instance.
  • flushAndBeginRenderPass: returns a secondary command buffer inside a RenderPass instance.
  • flushAndGetPrimaryCommandBuffer: returns the primary command buffer. You should rarely need this API.

Note: All of these commands may write out (aka flush) prior pending commands into a primary command buffer. When a RenderPass is open endRenderPassAndGetCommandBuffer will flush the pending RenderPass commands. flushAndBeginRenderPass will flush out pending commands outside a RenderPass to a primary buffer. On submit ANGLE submits the primary command buffer to a VkQueue.

If you need to record inside a RenderPass, use flushAndBeginRenderPass. Otherwise, use endRenderPassAndGetCommandBuffer. You should rarely need to call flushAndGetPrimaryCommandBuffer. It's there for commands like debug labels, barriers and queries that need to be recorded serially on the primary command buffer.

The back-end usually records Image and Buffer barriers through additional ContextVk APIs:

  • onBufferRead and onBufferWrite accumulate VkBuffer barriers.
  • onImageRead and onImageWrite accumulate VkImage barriers.
  • onRenderPassImageWrite is a special API for write barriers inside a RenderPass instance.

After the back-end records commands to the primary buffer we flush (e.g. on swap) or when we call ContextVk::finishToSerial.

See the code for more details.

Simple command recording example

In this example we'll be recording a buffer copy command:

    # Ensure that ANGLE sets proper read and write barriers for the Buffers.
    ANGLE_TRY(contextVk->onBufferWrite(VK_ACCESS_TRANSFER_WRITE_BIT, destBuffer));
    ANGLE_TRY(contextVk->onBufferRead(VK_ACCESS_TRANSFER_READ_BIT, srcBuffer));

    # Get a pointer to a secondary command buffer for command recording. May "flush" the RP.
    vk::CommandBuffer *commandBuffer;
    ANGLE_TRY(contextVk->endRenderPassAndGetCommandBuffer(&commandBuffer));

    # Record the copy command into the secondary buffer. We're done!
    commandBuffer->copyBuffer(srcBuffer->getBuffer(), destBuffer->getBuffer(), copyCount, copies);

Additional Reading

More implementation details can be found in the doc directory: