Drawing commands (commands with Draw in the name) provoke work in a
graphics pipeline.
Drawing commands are recorded into a command buffer and when executed by a
queue, will produce work which executes according to the currently bound
graphics pipeline.
A graphics pipeline must be bound to a command buffer before any drawing
commands are recorded in that command buffer.
Each draw is made up of zero or more vertices and zero or more instances,
which are processed by the device and result in the assembly of primitives.
Primitives are assembled according to the pInputAssemblyState member
of the VkGraphicsPipelineCreateInfo structure, which is of type
VkPipelineInputAssemblyStateCreateInfo:
typedef struct VkPipelineInputAssemblyStateCreateInfo {
VkStructureType sType;
const void* pNext;
VkPipelineInputAssemblyStateCreateFlags flags;
VkPrimitiveTopology topology;
VkBool32 primitiveRestartEnable;
} VkPipelineInputAssemblyStateCreateInfo;
sType is the type of this structure.
pNext is NULL or a pointer to an extension-specific structure.
flags is reserved for future use.
topology is a VkPrimitiveTopology defining the primitive
topology, as described below.
primitiveRestartEnable controls whether a special vertex index
value is treated as restarting the assembly of primitives.
This enable only applies to indexed draws (vkCmdDrawIndexed and
vkCmdDrawIndexedIndirect), and the special index value is either
0xFFFFFFFF when the indexType parameter of
vkCmdBindIndexBuffer is equal to VK_INDEX_TYPE_UINT32, or
0xFFFF when indexType is equal to VK_INDEX_TYPE_UINT16.
Primitive restart is not allowed for “list” topologies.
Restarting the assembly of primitives discards the most recent index values
if those elements formed an incomplete primitive, and restarts the primitive
assembly using the subsequent indices, but only assembling the immediately
following element through the end of the originally specified elements.
The primitive restart index value comparison is performed before adding the
vertexOffset value to the index value.