Transform feedback for specific transform feedback buffers is made active by calling:
void vkCmdBeginTransformFeedbackEXT( VkCommandBuffer commandBuffer, uint32_t firstCounterBuffer, uint32_t counterBufferCount, const VkBuffer* pCounterBuffers, const VkDeviceSize* pCounterBufferOffsets);
commandBufferis the command buffer into which the command is recorded.
firstCounterBufferis the index of the first transform feedback buffer corresponding to
counterBufferCountis the size of the
pCounterBuffersis an optional array of buffer handles to the counter buffers which contain a 4 byte integer value representing the byte offset from the start of the corresponding transform feedback buffer from where to start capturing vertex data. If the byte offset stored to the counter buffer location was done using vkCmdEndTransformFeedbackEXT it can be used to resume transform feedback from the previous location. If
NULL, then transform feedback will start capturing vertex data to byte offset zero in all bound transform feedback buffers. For each element of
pCounterBuffersthat is VK_NULL_HANDLE, transform feedback will start capturing vertex data to byte zero in the corresponding bound transform feedback buffer.
pCounterBufferOffsetsis an optional array of offsets within each of the
pCounterBufferswhere the counter values were previously written. The location in each counter buffer at these offsets must be large enough to contain 4 bytes of data. This data is the number of bytes captured by the previous transform feedback to this buffer. If
NULL, then it is assumed the offsets are zero.
The active transform feedback buffers will capture primitives emitted from
XfbBuffer in the bound graphics pipeline.
XfbBuffer emitted that does not output to an active transform
feedback buffer will not be captured.
For more information, see the Vulkan Specification
This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.
Copyright (c) 2014-2019 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.