AHardwareBuffer_UsageFlags

The buffer will never be locked for direct CPU reads using the AHardwareBuffer_lock() function. Note that reading the buffer using OpenGL or Vulkan functions or memory mappings is still allowed.

The buffer will sometimes be locked for direct CPU reads using the AHardwareBuffer_lock() function. Note that reading the buffer using OpenGL or Vulkan functions or memory mappings does not require the presence of this flag.

The buffer will often be locked for direct CPU reads using the AHardwareBuffer_lock() function. Note that reading the buffer using OpenGL or Vulkan functions or memory mappings does not require the presence of this flag.

CPU read value mask.

The buffer will never be locked for direct CPU writes using the AHardwareBuffer_lock() function. Note that writing the buffer using OpenGL or Vulkan functions or memory mappings is still allowed.

The buffer will sometimes be locked for direct CPU writes using the AHardwareBuffer_lock() function. Note that writing the buffer using OpenGL or Vulkan functions or memory mappings does not require the presence of this flag.

The buffer will often be locked for direct CPU writes using the AHardwareBuffer_lock() function. Note that writing the buffer using OpenGL or Vulkan functions or memory mappings does not require the presence of this flag.

CPU write value mask.

The buffer will be read from by the GPU as a texture.

The buffer will be written to by the GPU as a framebuffer attachment.

The buffer will be written to by the GPU as a framebuffer attachment.

Note that the name of this flag is somewhat misleading: it does not imply that the buffer contains a color format. A buffer with depth or stencil format that will be used as a framebuffer attachment should also have this flag. Use the equivalent flag AHARDWAREBUFFER_USAGE_GPU_FRAMEBUFFER to avoid this confusion.

The buffer will be used as a composer HAL overlay layer.

This flag is currently only needed when using ASurfaceTransaction_setBuffer to set a buffer. In all other cases, the framework adds this flag internally to buffers that could be presented in a composer overlay. ASurfaceTransaction_setBuffer is special because it uses buffers allocated directly through AHardwareBuffer_allocate instead of buffers allocated by the framework.

The buffer is protected from direct CPU access or being read by non-secure hardware, such as video encoders.

This flag is incompatible with CPU read and write flags. It is mainly used when handling DRM video. Refer to the EGL extension EGL_EXT_protected_content and GL extension GL_EXT_protected_textures for more information on how these buffers are expected to behave.

The buffer will be read by a hardware video encoder.

The buffer will be used for direct writes from sensors. When this flag is present, the format must be AHARDWAREBUFFER_FORMAT_BLOB.

The buffer will be used as a shader storage or uniform buffer object. When this flag is present, the format must be AHARDWAREBUFFER_FORMAT_BLOB.

The buffer will be used as a cube map texture. When this flag is present, the buffer must have a layer count that is a multiple of 6. Note that buffers with this flag must be bound to OpenGL textures using the extension GL_EXT_EGL_image_storage instead of GL_KHR_EGL_image.

The buffer contains a complete mipmap hierarchy. Note that buffers with this flag must be bound to OpenGL textures using the extension GL_EXT_EGL_image_storage instead of GL_KHR_EGL_image.