// Copyright 2015-2023 The Khronos Group Inc. // // SPDX-License-Identifier: CC-BY-4.0 [[drawing]] = Drawing Commands _Drawing commands_ (commands with ftext: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 bound graphics ifndef::VK_EXT_shader_object[pipeline.] ifdef::VK_EXT_shader_object[] pipeline, or if the <> feature is enabled, any <> bound to graphics stages. endif::VK_EXT_shader_object[] A graphics pipeline ifdef::VK_EXT_shader_object[] or a combination of one or more graphics shader objects endif::VK_EXT_shader_object[] must: be bound to a command buffer before any drawing commands are recorded in that command buffer. [open,refpage='VkPipelineInputAssemblyStateCreateInfo',desc='Structure specifying parameters of a newly created pipeline input assembly state',type='structs'] -- ifdef::VK_NV_mesh_shader,VK_EXT_mesh_shader[] Drawing can be achieved in two modes: * <>, the mesh shader assembles primitives, or * <>, the input primitives are assembled as follows. endif::VK_NV_mesh_shader,VK_EXT_mesh_shader[] 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 pname:pInputAssemblyState member of the slink:VkGraphicsPipelineCreateInfo structure, which is of type sname:VkPipelineInputAssemblyStateCreateInfo: include::{generated}/api/structs/VkPipelineInputAssemblyStateCreateInfo.adoc[] * pname:sType is a elink:VkStructureType value identifying this structure. * pname:pNext is `NULL` or a pointer to a structure extending this structure. * pname:flags is reserved for future use. * pname:topology is a elink:VkPrimitiveTopology defining the primitive topology, as described below. * pname:primitiveRestartEnable controls whether a special vertex index value is treated as restarting the assembly of primitives. This enable only applies to indexed draws (flink:vkCmdDrawIndexed, ifdef::VK_EXT_multi_draw[] flink:vkCmdDrawMultiIndexedEXT, endif::VK_EXT_multi_draw[] and flink:vkCmdDrawIndexedIndirect), and the special index value is either 0xFFFFFFFF when the pname:indexType parameter of ifdef::VK_KHR_maintenance5[fname:vkCmdBindIndexBuffer2KHR or] fname:vkCmdBindIndexBuffer is equal to ename:VK_INDEX_TYPE_UINT32, ifdef::VK_EXT_index_type_uint8[] 0xFF when pname:indexType is equal to ename:VK_INDEX_TYPE_UINT8_EXT, endif::VK_EXT_index_type_uint8[] or 0xFFFF when pname:indexType is equal to ename:VK_INDEX_TYPE_UINT16. ifndef::VK_EXT_primitive_topology_list_restart[] Primitive restart is not allowed for "`list`" topologies. endif::VK_EXT_primitive_topology_list_restart[] ifdef::VK_EXT_primitive_topology_list_restart[] Primitive restart is not allowed for "`list`" topologies, unless one of the features <> (for ename:VK_PRIMITIVE_TOPOLOGY_PATCH_LIST) or <> (for all other list topologies) is enabled. endif::VK_EXT_primitive_topology_list_restart[] 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 pname:vertexOffset value to the index value. .Valid Usage **** * [[VUID-VkPipelineInputAssemblyStateCreateInfo-topology-06252]] If ifdef::VK_EXT_primitive_topology_list_restart[] the <> feature is not enabled, and endif::VK_EXT_primitive_topology_list_restart[] pname:topology is ename:VK_PRIMITIVE_TOPOLOGY_POINT_LIST, ename:VK_PRIMITIVE_TOPOLOGY_LINE_LIST, ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST, ename:VK_PRIMITIVE_TOPOLOGY_LINE_LIST_WITH_ADJACENCY, or ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST_WITH_ADJACENCY, pname:primitiveRestartEnable must: be ename:VK_FALSE * [[VUID-VkPipelineInputAssemblyStateCreateInfo-topology-06253]] If ifdef::VK_EXT_primitive_topology_list_restart[] the <> feature is not enabled, and endif::VK_EXT_primitive_topology_list_restart[] pname:topology is ename:VK_PRIMITIVE_TOPOLOGY_PATCH_LIST, pname:primitiveRestartEnable must: be ename:VK_FALSE * [[VUID-VkPipelineInputAssemblyStateCreateInfo-topology-00429]] If the <> feature is not enabled, pname:topology must: not be any of ename:VK_PRIMITIVE_TOPOLOGY_LINE_LIST_WITH_ADJACENCY, ename:VK_PRIMITIVE_TOPOLOGY_LINE_STRIP_WITH_ADJACENCY, ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST_WITH_ADJACENCY or ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP_WITH_ADJACENCY * [[VUID-VkPipelineInputAssemblyStateCreateInfo-topology-00430]] If the <> feature is not enabled, pname:topology must: not be ename:VK_PRIMITIVE_TOPOLOGY_PATCH_LIST ifdef::VK_KHR_portability_subset[] * [[VUID-VkPipelineInputAssemblyStateCreateInfo-triangleFans-04452]] If the `apiext:VK_KHR_portability_subset` extension is enabled, and slink:VkPhysicalDevicePortabilitySubsetFeaturesKHR::pname:triangleFans is ename:VK_FALSE, pname:topology must: not be ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_FAN endif::VK_KHR_portability_subset[] **** include::{generated}/validity/structs/VkPipelineInputAssemblyStateCreateInfo.adoc[] -- [open,refpage='VkPipelineInputAssemblyStateCreateFlags',desc='Reserved for future use',type='flags'] -- include::{generated}/api/flags/VkPipelineInputAssemblyStateCreateFlags.adoc[] tname:VkPipelineInputAssemblyStateCreateFlags is a bitmask type for setting a mask, but is currently reserved for future use. -- ifdef::VK_VERSION_1_3,VK_EXT_extended_dynamic_state2,VK_EXT_shader_object[] [open,refpage='vkCmdSetPrimitiveRestartEnable',desc='Set primitive assembly restart state dynamically for a command buffer',type='protos',alias='vkCmdSetPrimitiveRestartEnableEXT'] -- To <> whether a special vertex index value is treated as restarting the assembly of primitives, call: ifdef::VK_VERSION_1_3[] include::{generated}/api/protos/vkCmdSetPrimitiveRestartEnable.adoc[] ifdef::VK_EXT_extended_dynamic_state2,VK_EXT_shader_object[or the equivalent command] endif::VK_VERSION_1_3[] ifdef::VK_EXT_extended_dynamic_state2,VK_EXT_shader_object[] include::{generated}/api/protos/vkCmdSetPrimitiveRestartEnableEXT.adoc[] endif::VK_EXT_extended_dynamic_state2,VK_EXT_shader_object[] * pname:commandBuffer is the command buffer into which the command will be recorded. * pname:primitiveRestartEnable controls whether a special vertex index value is treated as restarting the assembly of primitives. It behaves in the same way as sname:VkPipelineInputAssemblyStateCreateInfo::pname:primitiveRestartEnable This command sets the primitive restart enable for subsequent drawing commands ifdef::VK_EXT_shader_object[] ifdef::VK_VERSION_1_3,VK_EXT_extended_dynamic_state2[when drawing using <>, or] ifndef::VK_VERSION_1_3,VK_EXT_extended_dynamic_state2[when drawing using <>.] endif::VK_EXT_shader_object[] ifdef::VK_VERSION_1_3,VK_EXT_extended_dynamic_state2[] when the graphics pipeline is created with ename:VK_DYNAMIC_STATE_PRIMITIVE_RESTART_ENABLE set in slink:VkPipelineDynamicStateCreateInfo::pname:pDynamicStates. endif::VK_VERSION_1_3,VK_EXT_extended_dynamic_state2[] Otherwise, this state is specified by the slink:VkPipelineInputAssemblyStateCreateInfo::pname:primitiveRestartEnable value used to create the currently active pipeline. :refpage: vkCmdSetPrimitiveRestartEnable .Valid Usage **** include::{chapters}/commonvalidity/dynamic_state2_feature_common.adoc[] **** include::{generated}/validity/protos/vkCmdSetPrimitiveRestartEnable.adoc[] -- endif::VK_VERSION_1_3,VK_EXT_extended_dynamic_state2,VK_EXT_shader_object[] [[drawing-primitive-topologies]] == Primitive Topologies _Primitive topology_ determines how consecutive vertices are organized into primitives, and determines the type of primitive that is used at the beginning of the graphics pipeline. The effective topology for later stages of the pipeline is altered by tessellation or geometry shading (if either is in use) and depends on the execution modes of those shaders. ifdef::VK_NV_mesh_shader,VK_EXT_mesh_shader[] In the case of mesh shading the only effective topology is defined by the execution mode of the mesh shader. endif::VK_NV_mesh_shader,VK_EXT_mesh_shader[] [open,refpage='VkPrimitiveTopology',desc='Supported primitive topologies',type='enums'] -- The primitive topologies defined by elink:VkPrimitiveTopology are: include::{generated}/api/enums/VkPrimitiveTopology.adoc[] * ename:VK_PRIMITIVE_TOPOLOGY_POINT_LIST specifies a series of <>. * ename:VK_PRIMITIVE_TOPOLOGY_LINE_LIST specifies a series of <>. * ename:VK_PRIMITIVE_TOPOLOGY_LINE_STRIP specifies a series of <> with consecutive lines sharing a vertex. * ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST specifies a series of <>. * ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP specifies a series of <> with consecutive triangles sharing an edge. * ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_FAN specifies a series of <> with all triangles sharing a common vertex. ifdef::VK_KHR_portability_subset[] If the `apiext:VK_KHR_portability_subset` extension is enabled, and slink:VkPhysicalDevicePortabilitySubsetFeaturesKHR::pname:triangleFans is ename:VK_FALSE, then triangle fans are not supported by the implementation, and ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_FAN must: not be used. endif::VK_KHR_portability_subset[] * ename:VK_PRIMITIVE_TOPOLOGY_LINE_LIST_WITH_ADJACENCY specifies a series of <>. * ename:VK_PRIMITIVE_TOPOLOGY_LINE_STRIP_WITH_ADJACENCY specifies a series of <>, with consecutive primitives sharing three vertices. * ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST_WITH_ADJACENCY specifies a series of <>. * ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP_WITH_ADJACENCY specifies <>, with consecutive triangles sharing an edge. * ename:VK_PRIMITIVE_TOPOLOGY_PATCH_LIST specifies <>. Each primitive topology, and its construction from a list of vertices, is described in detail below with a supporting diagram, according to the following key: [cols="1,2,9"] |==== ^.^| image:{images}/primitive_topology_key_vertex.svg[pdfwidth=6pt,align="center",opts="{imageopts}"] .^| Vertex | A point in 3-dimensional space. Positions chosen within the diagrams are arbitrary and for illustration only. ^.^| image:{images}/primitive_topology_key_vertex_number.svg[pdfwidth=6pt,align="center",opts="{imageopts}"] .^| Vertex Number | Sequence position of a vertex within the provided vertex data. ^.^| image:{images}/primitive_topology_key_provoking_vertex.svg[pdfwidth=30pt,align="center",opts="{imageopts}"] .^| Provoking Vertex | Provoking vertex within the main primitive. The tail is angled towards the relevant primitive. Used in <>. ^.^| image:{images}/primitive_topology_key_edge.svg[pdfwidth=30pt,align="center",opts="{imageopts}"] .^| Primitive Edge | An edge connecting the points of a main primitive. ^.^| image:{images}/primitive_topology_key_adjacency_edge.svg[pdfwidth=30pt,align="center",opts="{imageopts}"] .^| Adjacency Edge | Points connected by these lines do not contribute to a main primitive, and are only accessible in a <>. ^.^| image:{images}/primitive_topology_key_winding_order.svg[pdfwidth=30pt,align="center",opts="{imageopts}"] .^| Winding Order | The relative order in which vertices are defined within a primitive, used in the <>. This ordering has no specific start or end point. |==== The diagrams are supported with mathematical definitions where the vertices ([eq]#v#) and primitives ([eq]#p#) are numbered starting from [eq]#0#; [eq]#v~0~# is the first vertex in the provided data and [eq]#p~0~# is the first primitive in the set of primitives defined by the vertices and topology. -- ifdef::VK_VERSION_1_3,VK_EXT_extended_dynamic_state,VK_EXT_shader_object[] [open,refpage='vkCmdSetPrimitiveTopology',desc='Set primitive topology state dynamically for a command buffer',type='protos',alias='vkCmdSetPrimitiveTopologyEXT'] -- To <> primitive topology, call: ifdef::VK_VERSION_1_3[] include::{generated}/api/protos/vkCmdSetPrimitiveTopology.adoc[] ifdef::VK_EXT_extended_dynamic_state,VK_EXT_shader_object[or the equivalent command] endif::VK_VERSION_1_3[] ifdef::VK_EXT_extended_dynamic_state,VK_EXT_shader_object[] include::{generated}/api/protos/vkCmdSetPrimitiveTopologyEXT.adoc[] endif::VK_EXT_extended_dynamic_state,VK_EXT_shader_object[] * pname:commandBuffer is the command buffer into which the command will be recorded. * pname:primitiveTopology specifies the primitive topology to use for drawing. This command sets the primitive topology for subsequent drawing commands ifdef::VK_EXT_shader_object[] ifdef::VK_VERSION_1_3,VK_EXT_extended_dynamic_state[when drawing using <>, or] ifndef::VK_VERSION_1_3,VK_EXT_extended_dynamic_state[when drawing using <>.] endif::VK_EXT_shader_object[] ifdef::VK_VERSION_1_3,VK_EXT_extended_dynamic_state[] when the graphics pipeline is created with ename:VK_DYNAMIC_STATE_PRIMITIVE_TOPOLOGY set in slink:VkPipelineDynamicStateCreateInfo::pname:pDynamicStates. endif::VK_VERSION_1_3,VK_EXT_extended_dynamic_state[] Otherwise, this state is specified by the slink:VkPipelineInputAssemblyStateCreateInfo::pname:topology value used to create the currently active pipeline. :refpage: vkCmdSetPrimitiveTopology .Valid Usage **** include::{chapters}/commonvalidity/dynamic_state_feature_common.adoc[] **** include::{generated}/validity/protos/vkCmdSetPrimitiveTopology.adoc[] -- [[drawing-primitive-topology-class]] === Topology Class The primitive topologies are grouped into the following topology classes: [[topology-classes]] .Topology classes [options="header"] |=== | Topology Class | Primitive Topology | Point | ename:VK_PRIMITIVE_TOPOLOGY_POINT_LIST | Line | ename:VK_PRIMITIVE_TOPOLOGY_LINE_LIST, ename:VK_PRIMITIVE_TOPOLOGY_LINE_STRIP, ename:VK_PRIMITIVE_TOPOLOGY_LINE_LIST_WITH_ADJACENCY, ename:VK_PRIMITIVE_TOPOLOGY_LINE_STRIP_WITH_ADJACENCY | Triangle | ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST, ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP, ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_FAN, ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST_WITH_ADJACENCY, ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP_WITH_ADJACENCY | Patch | ename:VK_PRIMITIVE_TOPOLOGY_PATCH_LIST |=== endif::VK_VERSION_1_3,VK_EXT_extended_dynamic_state,VK_EXT_shader_object[] [[drawing-point-lists]] === Point Lists When the topology is ename:VK_PRIMITIVE_TOPOLOGY_POINT_LIST, each consecutive vertex defines a single point primitive, according to the equation: {empty}:: [eq]#p~i~ = {v~i~}# As there is only one vertex, that vertex is the provoking vertex. The number of primitives generated is equal to [eq]#pname:vertexCount#. image::{images}/primitive_topology_point_list.svg[align="center",opts="{imageopts}"] [[drawing-line-lists]] === Line Lists When the primitive topology is ename:VK_PRIMITIVE_TOPOLOGY_LINE_LIST, each consecutive pair of vertices defines a single line primitive, according to the equation: {empty}:: [eq]#p~i~ = {v~2i~, v~2i+1~}# The number of primitives generated is equal to [eq]#{lfloor}pname:vertexCount/2{rfloor}#. ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_FIRST_VERTEX_EXT, the endif::VK_EXT_provoking_vertex[] ifndef::VK_EXT_provoking_vertex[] The endif::VK_EXT_provoking_vertex[] provoking vertex for [eq]#p~i~# is [eq]#v~2i~#. image::{images}/primitive_topology_line_list.svg[align="center",opts="{imageopts}"] ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_LAST_VERTEX_EXT, the provoking vertex for [eq]#p~i~# is [eq]#v~2i+1~#. image::{images}/primitive_topology_line_list_last.svg[align="center",opts="{imageopts}"] endif::VK_EXT_provoking_vertex[] [[drawing-line-strips]] === Line Strips When the primitive topology is ename:VK_PRIMITIVE_TOPOLOGY_LINE_STRIP, one line primitive is defined by each vertex and the following vertex, according to the equation: {empty}:: [eq]#p~i~ = {v~i~, v~i+1~}# The number of primitives generated is equal to [eq]#max(0,pname:vertexCount-1)#. ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_FIRST_VERTEX_EXT, the endif::VK_EXT_provoking_vertex[] ifndef::VK_EXT_provoking_vertex[] The endif::VK_EXT_provoking_vertex[] provoking vertex for [eq]#p~i~# is [eq]#v~i~#. image::{images}/primitive_topology_line_strip.svg[align="center",opts="{imageopts}"] ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_LAST_VERTEX_EXT, the provoking vertex for [eq]#p~i~# is [eq]#v~i+1~#. image::{images}/primitive_topology_line_strip_last.svg[align="center",opts="{imageopts}"] endif::VK_EXT_provoking_vertex[] [[drawing-triangle-lists]] === Triangle Lists When the primitive topology is ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST, each consecutive set of three vertices defines a single triangle primitive, according to the equation: {empty}:: [eq]#p~i~ = {v~3i~, v~3i+1~, v~3i+2~}# The number of primitives generated is equal to [eq]#{lfloor}pname:vertexCount/3{rfloor}#. ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_FIRST_VERTEX_EXT, the endif::VK_EXT_provoking_vertex[] ifndef::VK_EXT_provoking_vertex[] The endif::VK_EXT_provoking_vertex[] provoking vertex for [eq]#p~i~# is [eq]#v~3i~#. image::{images}/primitive_topology_triangle_list.svg[align="center",opts="{imageopts}"] ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_LAST_VERTEX_EXT, the provoking vertex for [eq]#p~i~# is [eq]#v~3i+2~#. image::{images}/primitive_topology_triangle_list_last.svg[align="center",opts="{imageopts}"] endif::VK_EXT_provoking_vertex[] [[drawing-triangle-strips]] === Triangle Strips When the primitive topology is ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP, one triangle primitive is defined by each vertex and the two vertices that follow it, according to the equation: {empty}:: [eq]#p~i~ = {v~i~, v~i+(1+i%2)~, v~i+(2-i%2)~}# The number of primitives generated is equal to [eq]#max(0,pname:vertexCount-2)#. ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_FIRST_VERTEX_EXT, the endif::VK_EXT_provoking_vertex[] ifndef::VK_EXT_provoking_vertex[] The endif::VK_EXT_provoking_vertex[] provoking vertex for [eq]#p~i~# is [eq]#v~i~#. image::{images}/primitive_topology_triangle_strip.svg[align="center",opts="{imageopts}"] ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_LAST_VERTEX_EXT, the provoking vertex for [eq]#p~i~# is [eq]#v~i+2~#. image::{images}/primitive_topology_triangle_strip_last.svg[align="center",opts="{imageopts}"] endif::VK_EXT_provoking_vertex[] [NOTE] .Note ==== The ordering of the vertices in each successive triangle is reversed, so that the winding order is consistent throughout the strip. ==== [[drawing-triangle-fans]] === Triangle Fans When the primitive topology is ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_FAN, triangle primitives are defined around a shared common vertex, according to the equation: {empty}:: [eq]#p~i~ = {v~i+1~, v~i+2~, v~0~}# The number of primitives generated is equal to [eq]#max(0,pname:vertexCount-2)#. ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_FIRST_VERTEX_EXT, the endif::VK_EXT_provoking_vertex[] ifndef::VK_EXT_provoking_vertex[] The endif::VK_EXT_provoking_vertex[] provoking vertex for [eq]#p~i~# is [eq]#v~i+1~#. image::{images}/primitive_topology_triangle_fan.svg[align="center",opts="{imageopts}"] ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_LAST_VERTEX_EXT, the provoking vertex for [eq]#p~i~# is [eq]#v~i+2~#. image::{images}/primitive_topology_triangle_fan_last.svg[align="center",opts="{imageopts}"] endif::VK_EXT_provoking_vertex[] ifdef::VK_KHR_portability_subset[] [NOTE] .Note ==== If the `apiext:VK_KHR_portability_subset` extension is enabled, and slink:VkPhysicalDevicePortabilitySubsetFeaturesKHR::pname:triangleFans is ename:VK_FALSE, then triangle fans are not supported by the implementation, and ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_FAN must: not be used. ==== endif::VK_KHR_portability_subset[] [[drawing-line-lists-with-adjacency]] === Line Lists With Adjacency When the primitive topology is ename:VK_PRIMITIVE_TOPOLOGY_LINE_LIST_WITH_ADJACENCY, each consecutive set of four vertices defines a single line primitive with adjacency, according to the equation: {empty}:: [eq]#p~i~ = {v~4i~, v~4i+1~, v~4i+2~,v~4i+3~}# A line primitive is described by the second and third vertices of the total primitive, with the remaining two vertices only accessible in a <>. The number of primitives generated is equal to [eq]#{lfloor}pname:vertexCount/4{rfloor}#. ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_FIRST_VERTEX_EXT, the endif::VK_EXT_provoking_vertex[] ifndef::VK_EXT_provoking_vertex[] The endif::VK_EXT_provoking_vertex[] provoking vertex for [eq]#p~i~# is [eq]#v~4i+1~#. image::{images}/primitive_topology_line_list_with_adjacency.svg[align="center",opts="{imageopts}"] ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_LAST_VERTEX_EXT, the provoking vertex for [eq]#p~i~# is [eq]#v~4i+2~#. image::{images}/primitive_topology_line_list_with_adjacency_last.svg[align="center",opts="{imageopts}"] endif::VK_EXT_provoking_vertex[] [[drawing-line-strips-with-adjacency]] === Line Strips With Adjacency When the primitive topology is ename:VK_PRIMITIVE_TOPOLOGY_LINE_STRIP_WITH_ADJACENCY, one line primitive with adjacency is defined by each vertex and the following vertex, according to the equation: {empty}:: [eq]#p~i~ = {v~i~, v~i+1~, v~i+2~, v~i+3~}# A line primitive is described by the second and third vertices of the total primitive, with the remaining two vertices only accessible in a <>. The number of primitives generated is equal to [eq]#max(0,pname:vertexCount-3)#. ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_FIRST_VERTEX_EXT, the endif::VK_EXT_provoking_vertex[] ifndef::VK_EXT_provoking_vertex[] The endif::VK_EXT_provoking_vertex[] provoking vertex for [eq]#p~i~# is [eq]#v~i+1~#. image::{images}/primitive_topology_line_strip_with_adjacency.svg[align="center",opts="{imageopts}"] ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_LAST_VERTEX_EXT, the provoking vertex for [eq]#p~i~# is [eq]#v~i+2~#. image::{images}/primitive_topology_line_strip_with_adjacency_last.svg[align="center",opts="{imageopts}"] endif::VK_EXT_provoking_vertex[] [[drawing-triangle-lists-with-adjacency]] === Triangle Lists With Adjacency When the primitive topology is ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST_WITH_ADJACENCY, each consecutive set of six vertices defines a single triangle primitive with adjacency, according to the equations: {empty}:: [eq]#p~i~ = {v~6i~, v~6i+1~, v~6i+2~, v~6i+3~, v~6i+4~, v~6i+5~}# A triangle primitive is described by the first, third, and fifth vertices of the total primitive, with the remaining three vertices only accessible in a <>. The number of primitives generated is equal to [eq]#{lfloor}pname:vertexCount/6{rfloor}#. ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_FIRST_VERTEX_EXT, the endif::VK_EXT_provoking_vertex[] ifndef::VK_EXT_provoking_vertex[] The endif::VK_EXT_provoking_vertex[] provoking vertex for [eq]#p~i~# is [eq]#v~6i~#. image::{images}/primitive_topology_triangle_list_with_adjacency.svg[align="center",opts="{imageopts}"] ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_LAST_VERTEX_EXT, the provoking vertex for [eq]#p~i~# is [eq]#v~6i+4~#. image::{images}/primitive_topology_triangle_list_with_adjacency_last.svg[align="center",opts="{imageopts}"] endif::VK_EXT_provoking_vertex[] [[drawing-triangle-strips-with-adjacency]] === Triangle Strips With Adjacency When the primitive topology is ename:VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP_WITH_ADJACENCY, one triangle primitive with adjacency is defined by each vertex and the following 5 vertices. The number of primitives generated, [eq]#n#, is equal to [eq]#{lfloor}max(0, pname:vertexCount - 4)/2{rfloor}#. If [eq]#n=1#, the primitive is defined as: {empty}:: [eq]#p = {v~0~, v~1~, v~2~, v~5~, v~4~, v~3~}# If [eq]#n>1#, the total primitive consists of different vertices according to where it is in the strip: {empty}:: [eq]#p~i~ = {v~2i~, v~2i+1~, v~2i+2~, v~2i+6~, v~2i+4~, v~2i+3~}# when [eq]#i=0# {empty}:: [eq]#p~i~ = {v~2i~, v~2i+3~, v~2i+4~, v~2i+6~, v~2i+2~, v~2i-2~}# when [eq]#i>0#, [eq]#i0#, [eq]#i>. [NOTE] .Note ==== The ordering of the vertices in each successive triangle is altered so that the winding order is consistent throughout the strip. ==== ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_FIRST_VERTEX_EXT, the endif::VK_EXT_provoking_vertex[] ifndef::VK_EXT_provoking_vertex[] The endif::VK_EXT_provoking_vertex[] provoking vertex for [eq]#p~i~# is always [eq]#v~2i~#. image::{images}/primitive_topology_triangle_strip_with_adjacency.svg[align="center",opts="{imageopts}"] ifdef::VK_EXT_provoking_vertex[] When the pname:provokingVertexMode is ename:VK_PROVOKING_VERTEX_MODE_LAST_VERTEX_EXT, the provoking vertex for [eq]#p~i~# is always [eq]#v~2i+4~#. image::{images}/primitive_topology_triangle_strip_with_adjacency_last.svg[align="center",opts="{imageopts}"] endif::VK_EXT_provoking_vertex[] [[drawing-patch-lists]] === Patch Lists When the primitive topology is ename:VK_PRIMITIVE_TOPOLOGY_PATCH_LIST, each consecutive set of [eq]#m# vertices defines a single patch primitive, according to the equation: {empty}:: [eq]#p~i~ = {v~mi~, v~mi+1~, ..., v~mi+(m-2)~, v~mi+(m-1)~}# where [eq]#m# is equal to slink:VkPipelineTessellationStateCreateInfo::pname:patchControlPoints. Patch lists are never passed to <>, and as such no provoking vertex is defined for patch primitives. The number of primitives generated is equal to [eq]#{lfloor}pname:vertexCount/m{rfloor}#. The vertices comprising a patch have no implied geometry, and are used as inputs to tessellation shaders and the fixed-function tessellator to generate new point, line, or triangle primitives. [[drawing-primitive-order]] == Primitive Order Primitives generated by <> progress through the stages of the <> in _primitive order_. Primitive order is initially determined in the following way: . Submission order determines the initial ordering . For indirect drawing commands, the order in which accessed instances of the slink:VkDrawIndirectCommand are stored in pname:buffer, from lower indirect buffer addresses to higher addresses. . If a drawing command includes multiple instances, the order in which instances are executed, from lower numbered instances to higher. . The order in which primitives are specified by a drawing command: ** For non-indexed draws, from vertices with a lower numbered code:vertexIndex to a higher numbered code:vertexIndex. ** For indexed draws, vertices sourced from a lower index buffer addresses to higher addresses. ifdef::VK_NV_mesh_shader,VK_EXT_mesh_shader[] ** For draws using mesh shaders, the order is provided by <>. endif::VK_NV_mesh_shader,VK_EXT_mesh_shader[] ifdef::VK_HUAWEI_cluster_culling_shader[] ** For draws using cluster culling shaders, the order is provided by <>. endif::VK_HUAWEI_cluster_culling_shader[] Within this order implementations further sort primitives: [start=5] . If tessellation shading is active, by an implementation-dependent order of new primitives generated by <>. . If geometry shading is active, by the order new primitives are generated by <>. . If the <> is not ename:VK_POLYGON_MODE_FILL, ifdef::VK_NV_fill_rectangle[] or ename:VK_POLYGON_MODE_FILL_RECTANGLE_NV, endif::VK_NV_fill_rectangle[] by an implementation-dependent ordering of the new primitives generated within the original primitive. Primitive order is later used to define <>, which determines the order in which fragments output results to a framebuffer. [[drawing-primitive-shading]] == Programmable Primitive Shading Once primitives are assembled, they proceed to the vertex shading stage of the pipeline. If the draw includes multiple instances, then the set of primitives is sent to the vertex shading stage multiple times, once for each instance. It is implementation-dependent whether vertex shading occurs on vertices that are discarded as part of incomplete primitives, but if it does occur then it operates as if they were vertices in complete primitives and such invocations can: have side effects. Vertex shading receives two per-vertex inputs from the primitive assembly stage - the code:vertexIndex and the code:instanceIndex. How these values are generated is defined below, with each command. Drawing commands fall roughly into two categories: * Non-indexed drawing commands present a sequential code:vertexIndex to the vertex shader. The sequential index is generated automatically by the device (see <> for details on both specifying the vertex attributes indexed by code:vertexIndex, as well as binding vertex buffers containing those attributes to a command buffer). These commands are: ** flink:vkCmdDraw ** flink:vkCmdDrawIndirect ifdef::VK_VERSION_1_2[] ** flink:vkCmdDrawIndirectCount endif::VK_VERSION_1_2[] ifdef::VK_KHR_draw_indirect_count[] ** flink:vkCmdDrawIndirectCountKHR endif::VK_KHR_draw_indirect_count[] ifdef::VK_AMD_draw_indirect_count[] ** flink:vkCmdDrawIndirectCountAMD endif::VK_AMD_draw_indirect_count[] ifdef::VK_EXT_multi_draw[] ** flink:vkCmdDrawMultiEXT endif::VK_EXT_multi_draw[] * Indexed drawing commands read index values from an _index buffer_ and use this to compute the code:vertexIndex value for the vertex shader. These commands are: ** flink:vkCmdDrawIndexed ** flink:vkCmdDrawIndexedIndirect ifdef::VK_VERSION_1_2[] ** flink:vkCmdDrawIndexedIndirectCount endif::VK_VERSION_1_2[] ifdef::VK_KHR_draw_indirect_count[] ** flink:vkCmdDrawIndexedIndirectCountKHR endif::VK_KHR_draw_indirect_count[] ifdef::VK_AMD_draw_indirect_count[] ** flink:vkCmdDrawIndexedIndirectCountAMD endif::VK_AMD_draw_indirect_count[] ifdef::VK_EXT_multi_draw[] ** flink:vkCmdDrawMultiIndexedEXT endif::VK_EXT_multi_draw[] [open,refpage='vkCmdBindIndexBuffer',desc='Bind an index buffer to a command buffer',type='protos'] -- :refpage: vkCmdBindIndexBuffer To bind an index buffer to a command buffer, call: include::{generated}/api/protos/vkCmdBindIndexBuffer.adoc[] * pname:commandBuffer is the command buffer into which the command is recorded. * pname:buffer is the buffer being bound. * pname:offset is the starting offset in bytes within pname:buffer used in index buffer address calculations. * pname:indexType is a elink:VkIndexType value specifying the size of the indices. .Valid Usage **** include::{chapters}/commonvalidity/bind_index_buffer_common.adoc[] **** include::{generated}/validity/protos/vkCmdBindIndexBuffer.adoc[] -- ifdef::VK_KHR_maintenance5[] [open,refpage='vkCmdBindIndexBuffer2KHR',desc='Bind an index buffer to a command buffer',type='protos'] -- :refpage: vkCmdBindIndexBuffer2KHR To bind an index buffer, along with its size, to a command buffer, call: include::{generated}/api/protos/vkCmdBindIndexBuffer2KHR.adoc[] * pname:commandBuffer is the command buffer into which the command is recorded. * pname:buffer is the buffer being bound. * pname:offset is the starting offset in bytes within pname:buffer used in index buffer address calculations. * pname:size is the size in bytes of index data bound from pname:buffer. * pname:indexType is a elink:VkIndexType value specifying the size of the indices. pname:size specifies the bound size of the index buffer starting from pname:offset. If pname:size is ename:VK_WHOLE_SIZE then the bound size is from pname:offset to the end of the pname:buffer. .Valid Usage **** include::{chapters}/commonvalidity/bind_index_buffer_common.adoc[] * [[VUID-vkCmdBindIndexBuffer2KHR-size-08767]] If pname:size is not ename:VK_WHOLE_SIZE, pname:size must: be a multiple of the size of the type indicated by pname:indexType * [[VUID-vkCmdBindIndexBuffer2KHR-size-08768]] If pname:size is not ename:VK_WHOLE_SIZE, the sum of pname:offset and pname:size must: be less than or equal to the size of pname:buffer **** include::{generated}/validity/protos/vkCmdBindIndexBuffer2KHR.adoc[] -- endif::VK_KHR_maintenance5[] [open,refpage='VkIndexType',desc='Type of index buffer indices',type='enums'] -- Possible values of ifdef::VK_KHR_maintenance5[flink:vkCmdBindIndexBuffer2KHR::pname:indexType and] flink:vkCmdBindIndexBuffer::pname:indexType, specifying the size of indices, are: include::{generated}/api/enums/VkIndexType.adoc[] * ename:VK_INDEX_TYPE_UINT16 specifies that indices are 16-bit unsigned integer values. * ename:VK_INDEX_TYPE_UINT32 specifies that indices are 32-bit unsigned integer values. ifdef::VK_NV_ray_tracing,VK_KHR_acceleration_structure[] * ename:VK_INDEX_TYPE_NONE_KHR specifies that no indices are provided. endif::VK_NV_ray_tracing,VK_KHR_acceleration_structure[] ifdef::VK_EXT_index_type_uint8[] * ename:VK_INDEX_TYPE_UINT8_EXT specifies that indices are 8-bit unsigned integer values. endif::VK_EXT_index_type_uint8[] -- The parameters for each drawing command are specified directly in the command or read from buffer memory, depending on the command. Drawing commands that source their parameters from buffer memory are known as _indirect_ drawing commands. All drawing commands interact with the <> feature. [open,refpage='vkCmdDraw',desc='Draw primitives',type='protos'] -- :refpage: vkCmdDraw To record a non-indexed draw, call: include::{generated}/api/protos/vkCmdDraw.adoc[] * pname:commandBuffer is the command buffer into which the command is recorded. * pname:vertexCount is the number of vertices to draw. * pname:instanceCount is the number of instances to draw. * pname:firstVertex is the index of the first vertex to draw. * pname:firstInstance is the instance ID of the first instance to draw. When the command is executed, primitives are assembled using the current primitive topology and pname:vertexCount consecutive vertex indices with the first code:vertexIndex value equal to pname:firstVertex. The primitives are drawn pname:instanceCount times with code:instanceIndex starting with pname:firstInstance and increasing sequentially for each instance. The assembled primitives execute the bound graphics pipeline. .Valid Usage **** include::{chapters}/commonvalidity/draw_common.adoc[] include::{chapters}/commonvalidity/draw_dispatch_nonindirect_common.adoc[] include::{chapters}/commonvalidity/draw_vertex_binding.adoc[] **** include::{generated}/validity/protos/vkCmdDraw.adoc[] -- [open,refpage='vkCmdDrawIndexed',desc='Draw primitives with indexed vertices',type='protos'] -- :refpage: vkCmdDrawIndexed To record an indexed draw, call: include::{generated}/api/protos/vkCmdDrawIndexed.adoc[] * pname:commandBuffer is the command buffer into which the command is recorded. * pname:indexCount is the number of vertices to draw. * pname:instanceCount is the number of instances to draw. * pname:firstIndex is the base index within the index buffer. * pname:vertexOffset is the value added to the vertex index before indexing into the vertex buffer. * pname:firstInstance is the instance ID of the first instance to draw. When the command is executed, primitives are assembled using the current primitive topology and pname:indexCount vertices whose indices are retrieved from the index buffer. The index buffer is treated as an array of tightly packed unsigned integers of size defined by the ifdef::VK_KHR_maintenance5[flink:vkCmdBindIndexBuffer2KHR::pname:indexType or the] flink:vkCmdBindIndexBuffer::pname:indexType parameter with which the buffer was bound. The first vertex index is at an offset of [eq]#pname:firstIndex {times} code:indexSize {plus} pname:offset# within the bound index buffer, where pname:offset is the offset specified by fname:vkCmdBindIndexBuffer ifdef::VK_KHR_maintenance5[or fname:vkCmdBindIndexBuffer2KHR,] and code:indexSize is the byte size of the type specified by pname:indexType. Subsequent index values are retrieved from consecutive locations in the index buffer. Indices are first compared to the primitive restart value, then zero extended to 32 bits (if the code:indexType is ifdef::VK_EXT_index_type_uint8[] ename:VK_INDEX_TYPE_UINT8_EXT or endif::VK_EXT_index_type_uint8[] ename:VK_INDEX_TYPE_UINT16) and have pname:vertexOffset added to them, before being supplied as the code:vertexIndex value. The primitives are drawn pname:instanceCount times with code:instanceIndex starting with pname:firstInstance and increasing sequentially for each instance. The assembled primitives execute the bound graphics pipeline. .Valid Usage **** include::{chapters}/commonvalidity/draw_common.adoc[] include::{chapters}/commonvalidity/draw_dispatch_nonindirect_common.adoc[] include::{chapters}/commonvalidity/draw_vertex_binding.adoc[] include::{chapters}/commonvalidity/draw_indexed_common.adoc[] include::{chapters}/commonvalidity/draw_index_binding.adoc[] **** include::{generated}/validity/protos/vkCmdDrawIndexed.adoc[] -- ifdef::VK_EXT_multi_draw[] [open,refpage='vkCmdDrawMultiEXT',desc='Draw primitives',type='protos'] -- :refpage: vkCmdDrawMultiEXT To record an ordered sequence of draws which have no state changes between them, call: include::{generated}/api/protos/vkCmdDrawMultiEXT.adoc[] * pname:commandBuffer is the command buffer into which the command is recorded. * pname:drawCount is the number of draws to execute, and can: be zero. * pname:pVertexInfo is a pointer to an array of slink:VkMultiDrawInfoEXT with vertex information to be drawn. * pname:instanceCount is the number of instances per draw. * pname:firstInstance is the instance ID of the first instance in each draw. * pname:stride is the byte stride between consecutive elements of pname:pVertexInfo. The number of draws recorded is pname:drawCount, with each draw reading, sequentially, a pname:firstVertex and a pname:vertexCount from pname:pVertexInfo. For each recorded draw, primitives are assembled as for flink:vkCmdDraw, and drawn pname:instanceCount times with code:instanceIndex starting with pname:firstInstance and sequentially for each instance. .Valid Usage **** include::{chapters}/commonvalidity/draw_common.adoc[] include::{chapters}/commonvalidity/draw_dispatch_nonindirect_common.adoc[] include::{chapters}/commonvalidity/draw_vertex_binding.adoc[] * [[VUID-vkCmdDrawMultiEXT-None-04933]] The <> feature must: be enabled * [[VUID-vkCmdDrawMultiEXT-drawCount-04934]] pname:drawCount must: be less than sname:VkPhysicalDeviceMultiDrawPropertiesEXT::pname:maxMultiDrawCount * [[VUID-vkCmdDrawMultiEXT-drawCount-04935]] If pname:drawCount is greater than zero, pname:pVertexInfo must: be a valid pointer to memory containing one or more valid instances of slink:VkMultiDrawInfoEXT structures * [[VUID-vkCmdDrawMultiEXT-stride-04936]] pname:stride must be a multiple of 4 **** include::{generated}/validity/protos/vkCmdDrawMultiEXT.adoc[] -- [open,refpage='vkCmdDrawMultiIndexedEXT',desc='Draw primitives',type='protos'] -- :refpage: vkCmdDrawMultiIndexedEXT To record an ordered sequence of indexed draws which have no state changes between them, call: include::{generated}/api/protos/vkCmdDrawMultiIndexedEXT.adoc[] * pname:commandBuffer is the command buffer into which the command is recorded. * pname:drawCount is the number of draws to execute, and can: be zero. * pname:pIndexInfo is a pointer to an array of slink:VkMultiDrawIndexedInfoEXT with index information to be drawn. * pname:instanceCount is the number of instances per draw. * pname:firstInstance is the instance ID of the first instance in each draw. * pname:stride is the byte stride between consecutive elements of pname:pIndexInfo. * pname:pVertexOffset is `NULL` or a pointer to the value added to the vertex index before indexing into the vertex buffer. When specified, sname:VkMultiDrawIndexedInfoEXT::pname:offset is ignored. The number of draws recorded is pname:drawCount, with each draw reading, sequentially, a pname:firstIndex and an pname:indexCount from pname:pIndexInfo. For each recorded draw, primitives are assembled as for flink:vkCmdDrawIndexed, and drawn pname:instanceCount times with code:instanceIndex starting with pname:firstInstance and sequentially for each instance. If pname:pVertexOffset is `NULL`, a pname:vertexOffset is also read from pname:pIndexInfo, otherwise the value from dereferencing pname:pVertexOffset is used. .Valid Usage **** include::{chapters}/commonvalidity/draw_common.adoc[] include::{chapters}/commonvalidity/draw_dispatch_nonindirect_common.adoc[] include::{chapters}/commonvalidity/draw_vertex_binding.adoc[] include::{chapters}/commonvalidity/draw_indexed_common.adoc[] include::{chapters}/commonvalidity/draw_index_binding.adoc[] * [[VUID-vkCmdDrawMultiIndexedEXT-None-04937]] The <> feature must: be enabled * [[VUID-vkCmdDrawMultiIndexedEXT-drawCount-04939]] pname:drawCount must: be less than sname:VkPhysicalDeviceMultiDrawPropertiesEXT::pname:maxMultiDrawCount * [[VUID-vkCmdDrawMultiIndexedEXT-drawCount-04940]] If pname:drawCount is greater than zero, pname:pIndexInfo must: be a valid pointer to memory containing one or more valid instances of slink:VkMultiDrawIndexedInfoEXT structures * [[VUID-vkCmdDrawMultiIndexedEXT-stride-04941]] pname:stride must be a multiple of 4 **** include::{generated}/validity/protos/vkCmdDrawMultiIndexedEXT.adoc[] -- [open,refpage='VkMultiDrawInfoEXT',desc='Structure specifying a multi-draw command',type='structs',xrefs='vkCmdDrawMultiEXT'] -- The sname:VkMultiDrawInfoEXT structure is defined as: include::{generated}/api/structs/VkMultiDrawInfoEXT.adoc[] * pname:firstVertex is the first vertex to draw. * pname:vertexCount is the number of vertices to draw. The members of sname:VkMultiDrawInfoEXT have the same meaning as the pname:firstVertex and pname:vertexCount parameters in flink:vkCmdDraw. include::{generated}/validity/structs/VkMultiDrawInfoEXT.adoc[] -- [open,refpage='VkMultiDrawIndexedInfoEXT',desc='Structure specifying a multi-draw command',type='structs',xrefs='vkCmdDrawMultiIndexedEXT'] -- The sname:VkMultiDrawIndexedInfoEXT structure is defined as: include::{generated}/api/structs/VkMultiDrawIndexedInfoEXT.adoc[] * pname:firstIndex is the first index to draw. * pname:indexCount is the number of vertices to draw. * pname:vertexOffset is the value added to the vertex index before indexing into the vertex buffer for indexed multidraws. The pname:firstIndex, pname:indexCount, and pname:vertexOffset members of sname:VkMultiDrawIndexedInfoEXT have the same meaning as the pname:firstIndex, pname:indexCount, and pname:vertexOffset parameters, respectively, of flink:vkCmdDrawIndexed. include::{generated}/validity/structs/VkMultiDrawIndexedInfoEXT.adoc[] -- endif::VK_EXT_multi_draw[] [open,refpage='vkCmdDrawIndirect',desc='Draw primitives with indirect parameters',type='protos'] -- :refpage: vkCmdDrawIndirect To record a non-indexed indirect drawing command, call: include::{generated}/api/protos/vkCmdDrawIndirect.adoc[] * pname:commandBuffer is the command buffer into which the command is recorded. * pname:buffer is the buffer containing draw parameters. * pname:offset is the byte offset into pname:buffer where parameters begin. * pname:drawCount is the number of draws to execute, and can: be zero. * pname:stride is the byte stride between successive sets of draw parameters. fname:vkCmdDrawIndirect behaves similarly to flink:vkCmdDraw except that the parameters are read by the device from a buffer during execution. pname:drawCount draws are executed by the command, with parameters taken from pname:buffer starting at pname:offset and increasing by pname:stride bytes for each successive draw. The parameters of each draw are encoded in an array of slink:VkDrawIndirectCommand structures. If pname:drawCount is less than or equal to one, pname:stride is ignored. .Valid Usage **** include::{chapters}/commonvalidity/draw_common.adoc[] include::{chapters}/commonvalidity/draw_vertex_binding.adoc[] include::{chapters}/commonvalidity/draw_dispatch_indirect_common.adoc[] include::{chapters}/commonvalidity/draw_indirect_drawcount.adoc[] * [[VUID-vkCmdDrawIndirect-drawCount-00476]] If pname:drawCount is greater than `1`, pname:stride must: be a multiple of `4` and must: be greater than or equal to code:sizeof(sname:VkDrawIndirectCommand) * [[VUID-vkCmdDrawIndirect-drawCount-00487]] If pname:drawCount is equal to `1`, [eq]#(pname:offset {plus} code:sizeof(slink:VkDrawIndirectCommand))# must: be less than or equal to the size of pname:buffer * [[VUID-vkCmdDrawIndirect-drawCount-00488]] If pname:drawCount is greater than `1`, [eq]#(pname:stride {times} (pname:drawCount - 1) {plus} pname:offset {plus} code:sizeof(slink:VkDrawIndirectCommand))# must: be less than or equal to the size of pname:buffer **** include::{generated}/validity/protos/vkCmdDrawIndirect.adoc[] -- [open,refpage='VkDrawIndirectCommand',desc='Structure specifying a indirect drawing command',type='structs',xrefs='vkCmdDrawIndirect'] -- The sname:VkDrawIndirectCommand structure is defined as: include::{generated}/api/structs/VkDrawIndirectCommand.adoc[] * pname:vertexCount is the number of vertices to draw. * pname:instanceCount is the number of instances to draw. * pname:firstVertex is the index of the first vertex to draw. * pname:firstInstance is the instance ID of the first instance to draw. The members of sname:VkDrawIndirectCommand have the same meaning as the similarly named parameters of flink:vkCmdDraw. .Valid Usage **** * [[VUID-VkDrawIndirectCommand-None-00500]] For a given vertex buffer binding, any attribute data fetched must: be entirely contained within the corresponding vertex buffer binding, as described in <> * [[VUID-VkDrawIndirectCommand-firstInstance-00501]] If the <> feature is not enabled, pname:firstInstance must: be code:0 **** include::{generated}/validity/structs/VkDrawIndirectCommand.adoc[] -- ifdef::VK_VERSION_1_2,VK_KHR_draw_indirect_count[] [open,refpage='vkCmdDrawIndirectCount',desc='Draw primitives with indirect parameters and draw count',type='protos',alias='vkCmdDrawIndirectCountKHR vkCmdDrawIndirectCountAMD'] -- :refpage: vkCmdDrawIndirectCount To record a non-indexed draw call with a draw call count sourced from a buffer, call: ifdef::VK_VERSION_1_2[] include::{generated}/api/protos/vkCmdDrawIndirectCount.adoc[] endif::VK_VERSION_1_2[] // Jon: conditional logic on connective clauses with 3 forms of the command including VK_VERSION_1_2 needs work. ifdef::VK_VERSION_1_2+VK_KHR_draw_indirect_count[or the equivalent command] ifdef::VK_KHR_draw_indirect_count[] include::{generated}/api/protos/vkCmdDrawIndirectCountKHR.adoc[] endif::VK_KHR_draw_indirect_count[] ifdef::VK_KHR_draw_indirect_count+VK_AMD_draw_indirect_count[or the equivalent command] ifdef::VK_AMD_draw_indirect_count[] include::{generated}/api/protos/vkCmdDrawIndirectCountAMD.adoc[] endif::VK_AMD_draw_indirect_count[] * pname:commandBuffer is the command buffer into which the command is recorded. * pname:buffer is the buffer containing draw parameters. * pname:offset is the byte offset into pname:buffer where parameters begin. * pname:countBuffer is the buffer containing the draw count. * pname:countBufferOffset is the byte offset into pname:countBuffer where the draw count begins. * pname:maxDrawCount specifies the maximum number of draws that will be executed. The actual number of executed draw calls is the minimum of the count specified in pname:countBuffer and pname:maxDrawCount. * pname:stride is the byte stride between successive sets of draw parameters. fname:vkCmdDrawIndirectCount behaves similarly to flink:vkCmdDrawIndirect except that the draw count is read by the device from a buffer during execution. The command will read an unsigned 32-bit integer from pname:countBuffer located at pname:countBufferOffset and use this as the draw count. .Valid Usage **** include::{chapters}/commonvalidity/draw_common.adoc[] include::{chapters}/commonvalidity/draw_vertex_binding.adoc[] include::{chapters}/commonvalidity/draw_dispatch_indirect_common.adoc[] include::{chapters}/commonvalidity/draw_indirect_count_common.adoc[] * [[VUID-vkCmdDrawIndirectCount-stride-03110]] pname:stride must: be a multiple of `4` and must: be greater than or equal to sizeof(sname:VkDrawIndirectCommand) * [[VUID-vkCmdDrawIndirectCount-maxDrawCount-03111]] If pname:maxDrawCount is greater than or equal to `1`, [eq]#(pname:stride {times} (pname:maxDrawCount - 1) {plus} pname:offset {plus} sizeof(sname:VkDrawIndirectCommand))# must: be less than or equal to the size of pname:buffer * [[VUID-vkCmdDrawIndirectCount-countBuffer-03121]] If the count stored in pname:countBuffer is equal to `1`, [eq]#(pname:offset {plus} sizeof(sname:VkDrawIndirectCommand))# must: be less than or equal to the size of pname:buffer * [[VUID-vkCmdDrawIndirectCount-countBuffer-03122]] If the count stored in pname:countBuffer is greater than `1`, [eq]#(pname:stride {times} (pname:drawCount - 1) {plus} pname:offset {plus} sizeof(sname:VkDrawIndirectCommand))# must: be less than or equal to the size of pname:buffer **** include::{generated}/validity/protos/vkCmdDrawIndirectCount.adoc[] -- endif::VK_VERSION_1_2,VK_KHR_draw_indirect_count[] [open,refpage='vkCmdDrawIndexedIndirect',desc='Draw primitives with indirect parameters and indexed vertices',type='protos'] -- :refpage: vkCmdDrawIndexedIndirect To record an indexed indirect drawing command, call: include::{generated}/api/protos/vkCmdDrawIndexedIndirect.adoc[] * pname:commandBuffer is the command buffer into which the command is recorded. * pname:buffer is the buffer containing draw parameters. * pname:offset is the byte offset into pname:buffer where parameters begin. * pname:drawCount is the number of draws to execute, and can: be zero. * pname:stride is the byte stride between successive sets of draw parameters. fname:vkCmdDrawIndexedIndirect behaves similarly to flink:vkCmdDrawIndexed except that the parameters are read by the device from a buffer during execution. pname:drawCount draws are executed by the command, with parameters taken from pname:buffer starting at pname:offset and increasing by pname:stride bytes for each successive draw. The parameters of each draw are encoded in an array of slink:VkDrawIndexedIndirectCommand structures. If pname:drawCount is less than or equal to one, pname:stride is ignored. .Valid Usage **** include::{chapters}/commonvalidity/draw_common.adoc[] include::{chapters}/commonvalidity/draw_vertex_binding.adoc[] include::{chapters}/commonvalidity/draw_dispatch_indirect_common.adoc[] include::{chapters}/commonvalidity/draw_indirect_drawcount.adoc[] include::{chapters}/commonvalidity/draw_indexed_common.adoc[] * [[VUID-vkCmdDrawIndexedIndirect-drawCount-00528]] If pname:drawCount is greater than `1`, pname:stride must: be a multiple of `4` and must: be greater than or equal to code:sizeof(sname:VkDrawIndexedIndirectCommand) * [[VUID-vkCmdDrawIndexedIndirect-drawCount-00539]] If pname:drawCount is equal to `1`, [eq]#(pname:offset {plus} code:sizeof(sname:VkDrawIndexedIndirectCommand))# must: be less than or equal to the size of pname:buffer * [[VUID-vkCmdDrawIndexedIndirect-drawCount-00540]] If pname:drawCount is greater than `1`, [eq]#(pname:stride {times} (pname:drawCount - 1) {plus} pname:offset {plus} code:sizeof(sname:VkDrawIndexedIndirectCommand))# must: be less than or equal to the size of pname:buffer **** include::{generated}/validity/protos/vkCmdDrawIndexedIndirect.adoc[] -- [open,refpage='VkDrawIndexedIndirectCommand',desc='Structure specifying a indexed indirect drawing command',type='structs',xrefs='vkCmdDrawIndexedIndirect'] -- :refpage: VkDrawIndexedIndirectCommand The sname:VkDrawIndexedIndirectCommand structure is defined as: include::{generated}/api/structs/VkDrawIndexedIndirectCommand.adoc[] * pname:indexCount is the number of vertices to draw. * pname:instanceCount is the number of instances to draw. * pname:firstIndex is the base index within the index buffer. * pname:vertexOffset is the value added to the vertex index before indexing into the vertex buffer. * pname:firstInstance is the instance ID of the first instance to draw. The members of sname:VkDrawIndexedIndirectCommand have the same meaning as the similarly named parameters of flink:vkCmdDrawIndexed. .Valid Usage **** include::{chapters}/commonvalidity/draw_index_binding.adoc[] * [[VUID-VkDrawIndexedIndirectCommand-None-00552]] For a given vertex buffer binding, any attribute data fetched must: be entirely contained within the corresponding vertex buffer binding, as described in <> * [[VUID-VkDrawIndexedIndirectCommand-firstInstance-00554]] If the <> feature is not enabled, pname:firstInstance must: be code:0 **** include::{generated}/validity/structs/VkDrawIndexedIndirectCommand.adoc[] -- ifdef::VK_VERSION_1_2,VK_KHR_draw_indirect_count[] [open,refpage='vkCmdDrawIndexedIndirectCount',desc='Draw parameters with indirect parameters, indexed vertices, and draw count',type='protos',alias='vkCmdDrawIndexedIndirectCountKHR vkCmdDrawIndexedIndirectCountAMD'] -- :refpage: vkCmdDrawIndexedIndirectCount To record an indexed draw call with a draw call count sourced from a buffer, call: ifdef::VK_VERSION_1_2[] include::{generated}/api/protos/vkCmdDrawIndexedIndirectCount.adoc[] endif::VK_VERSION_1_2[] // Jon: conditional logic on connective clauses with 3 forms of the command including VK_VERSION_1_2 needs work. ifdef::VK_VERSION_1_2+VK_KHR_draw_indirect_count[or the equivalent command] ifdef::VK_KHR_draw_indirect_count[] include::{generated}/api/protos/vkCmdDrawIndexedIndirectCountKHR.adoc[] endif::VK_KHR_draw_indirect_count[] ifdef::VK_KHR_draw_indirect_count+VK_AMD_draw_indirect_count[or the equivalent command] ifdef::VK_AMD_draw_indirect_count[] include::{generated}/api/protos/vkCmdDrawIndexedIndirectCountAMD.adoc[] endif::VK_AMD_draw_indirect_count[] * pname:commandBuffer is the command buffer into which the command is recorded. * pname:buffer is the buffer containing draw parameters. * pname:offset is the byte offset into pname:buffer where parameters begin. * pname:countBuffer is the buffer containing the draw count. * pname:countBufferOffset is the byte offset into pname:countBuffer where the draw count begins. * pname:maxDrawCount specifies the maximum number of draws that will be executed. The actual number of executed draw calls is the minimum of the count specified in pname:countBuffer and pname:maxDrawCount. * pname:stride is the byte stride between successive sets of draw parameters. fname:vkCmdDrawIndexedIndirectCount behaves similarly to flink:vkCmdDrawIndexedIndirect except that the draw count is read by the device from a buffer during execution. The command will read an unsigned 32-bit integer from pname:countBuffer located at pname:countBufferOffset and use this as the draw count. .Valid Usage **** include::{chapters}/commonvalidity/draw_common.adoc[] include::{chapters}/commonvalidity/draw_vertex_binding.adoc[] include::{chapters}/commonvalidity/draw_dispatch_indirect_common.adoc[] include::{chapters}/commonvalidity/draw_indirect_count_common.adoc[] include::{chapters}/commonvalidity/draw_indexed_common.adoc[] * [[VUID-vkCmdDrawIndexedIndirectCount-stride-03142]] pname:stride must: be a multiple of `4` and must: be greater than or equal to sizeof(sname:VkDrawIndexedIndirectCommand) * [[VUID-vkCmdDrawIndexedIndirectCount-maxDrawCount-03143]] If pname:maxDrawCount is greater than or equal to `1`, [eq]#(pname:stride {times} (pname:maxDrawCount - 1) {plus} pname:offset {plus} sizeof(sname:VkDrawIndexedIndirectCommand))# must: be less than or equal to the size of pname:buffer * [[VUID-vkCmdDrawIndexedIndirectCount-countBuffer-03153]] If count stored in pname:countBuffer is equal to `1`, [eq]#(pname:offset {plus} sizeof(sname:VkDrawIndexedIndirectCommand))# must: be less than or equal to the size of pname:buffer * [[VUID-vkCmdDrawIndexedIndirectCount-countBuffer-03154]] If count stored in pname:countBuffer is greater than `1`, [eq]#(pname:stride {times} (pname:drawCount - 1) {plus} pname:offset {plus} sizeof(sname:VkDrawIndexedIndirectCommand))# must: be less than or equal to the size of pname:buffer **** include::{generated}/validity/protos/vkCmdDrawIndexedIndirectCount.adoc[] -- endif::VK_VERSION_1_2,VK_KHR_draw_indirect_count[] ifdef::VK_EXT_transform_feedback[] [[drawing-transform-feedback]] === Drawing Transform Feedback It is possible to draw vertex data that was previously captured during active <> by binding one or more of the transform feedback buffers as vertex buffers. A pipeline barrier is required between using the buffers as transform feedback buffers and vertex buffers to ensure all writes to the transform feedback buffers are visible when the data is read as vertex attributes. The source access is ename:VK_ACCESS_TRANSFORM_FEEDBACK_WRITE_BIT_EXT and the destination access is ename:VK_ACCESS_VERTEX_ATTRIBUTE_READ_BIT for the pipeline stages ename:VK_PIPELINE_STAGE_TRANSFORM_FEEDBACK_BIT_EXT and ename:VK_PIPELINE_STAGE_VERTEX_INPUT_BIT respectively. The value written to the counter buffer by flink:vkCmdEndTransformFeedbackEXT can: be used to determine the vertex count for the draw. A pipeline barrier is required between using the counter buffer for fname:vkCmdEndTransformFeedbackEXT and fname:vkCmdDrawIndirectByteCountEXT where the source access is ename:VK_ACCESS_TRANSFORM_FEEDBACK_COUNTER_WRITE_BIT_EXT and the destination access is ename:VK_ACCESS_INDIRECT_COMMAND_READ_BIT for the pipeline stages ename:VK_PIPELINE_STAGE_TRANSFORM_FEEDBACK_BIT_EXT and ename:VK_PIPELINE_STAGE_DRAW_INDIRECT_BIT respectively. [open,refpage='vkCmdDrawIndirectByteCountEXT',desc='Draw primitives with indirect parameters where the vertex count is derived from the counter byte value in the counter buffer',type='protos'] -- :refpage: vkCmdDrawIndirectByteCountEXT To record a non-indexed draw call, where the vertex count is based on a byte count read from a buffer and the passed in vertex stride parameter, call: include::{generated}/api/protos/vkCmdDrawIndirectByteCountEXT.adoc[] * pname:commandBuffer is the command buffer into which the command is recorded. * pname:instanceCount is the number of instances to draw. * pname:firstInstance is the instance ID of the first instance to draw. * pname:counterBuffer is the buffer handle from where the byte count is read. * pname:counterBufferOffset is the offset into the buffer used to read the byte count, which is used to calculate the vertex count for this draw call. * pname:counterOffset is subtracted from the byte count read from the pname:counterBuffer at the pname:counterBufferOffset * pname:vertexStride is the stride in bytes between each element of the vertex data that is used to calculate the vertex count from the counter value. This value is typically the same value that was used in the graphics pipeline state when the transform feedback was captured as the code:XfbStride. When the command is executed, primitives are assembled in the same way as done with flink:vkCmdDraw except the pname:vertexCount is calculated based on the byte count read from pname:counterBuffer at offset pname:counterBufferOffset. The assembled primitives execute the bound graphics pipeline. The effective pname:vertexCount is calculated as follows: [source,c] ---- const uint32_t * counterBufferPtr = (const uint8_t *)counterBuffer.address + counterBufferOffset; vertexCount = floor(max(0, (*counterBufferPtr - counterOffset)) / vertexStride); ---- The effective pname:firstVertex is zero. .Valid Usage **** include::{chapters}/commonvalidity/draw_common.adoc[] include::{chapters}/commonvalidity/draw_vertex_binding.adoc[] * [[VUID-vkCmdDrawIndirectByteCountEXT-transformFeedback-02287]] sname:VkPhysicalDeviceTransformFeedbackFeaturesEXT::pname:transformFeedback must: be enabled * [[VUID-vkCmdDrawIndirectByteCountEXT-transformFeedbackDraw-02288]] The implementation must: support sname:VkPhysicalDeviceTransformFeedbackPropertiesEXT::pname:transformFeedbackDraw * [[VUID-vkCmdDrawIndirectByteCountEXT-vertexStride-02289]] pname:vertexStride must: be greater than 0 and less than or equal to sname:VkPhysicalDeviceTransformFeedbackPropertiesEXT::pname:maxTransformFeedbackBufferDataStride * [[VUID-vkCmdDrawIndirectByteCountEXT-counterBuffer-04567]] If pname:counterBuffer is non-sparse then it must: be bound completely and contiguously to a single sname:VkDeviceMemory object * [[VUID-vkCmdDrawIndirectByteCountEXT-counterBuffer-02290]] pname:counterBuffer must: have been created with the ename:VK_BUFFER_USAGE_INDIRECT_BUFFER_BIT bit set * [[VUID-vkCmdDrawIndirectByteCountEXT-counterBufferOffset-04568]] pname:counterBufferOffset must: be a multiple of `4` ifdef::VK_VERSION_1_1[] * [[VUID-vkCmdDrawIndirectByteCountEXT-commandBuffer-02646]] pname:commandBuffer must: not be a protected command buffer endif::VK_VERSION_1_1[] **** include::{generated}/validity/protos/vkCmdDrawIndirectByteCountEXT.adoc[] -- endif::VK_EXT_transform_feedback[] ifdef::VK_EXT_conditional_rendering[] [[drawing-conditional-rendering]] == Conditional Rendering Certain rendering commands can: be executed conditionally based on a value in buffer memory. These rendering commands are limited to <>, <>, and clearing attachments with flink:vkCmdClearAttachments within a conditional rendering block which is defined by commands flink:vkCmdBeginConditionalRenderingEXT and flink:vkCmdEndConditionalRenderingEXT. Other rendering commands remain unaffected by conditional rendering. [[active-conditional-rendering]] After beginning conditional rendering, it is considered _active_ within the command buffer it was called until it is ended with flink:vkCmdEndConditionalRenderingEXT. Conditional rendering must: begin and end in the same command buffer. When conditional rendering is active, a primary command buffer can: execute secondary command buffers if the <> feature is enabled. For a secondary command buffer to be executed while conditional rendering is active in the primary command buffer, it must: set the pname:conditionalRenderingEnable flag of slink:VkCommandBufferInheritanceConditionalRenderingInfoEXT, as described in the <> section. Conditional rendering must: also either begin and end inside the same subpass of a render pass instance, or must: both begin and end outside of a render pass instance (i.e. contain entire render pass instances). [open,refpage='vkCmdBeginConditionalRenderingEXT',desc='Define the beginning of a conditional rendering block',type='protos'] -- To begin conditional rendering, call: include::{generated}/api/protos/vkCmdBeginConditionalRenderingEXT.adoc[] * pname:commandBuffer is the command buffer into which this command will be recorded. * pname:pConditionalRenderingBegin is a pointer to a slink:VkConditionalRenderingBeginInfoEXT structure specifying parameters of conditional rendering. .Valid Usage **** * [[VUID-vkCmdBeginConditionalRenderingEXT-None-01980]] Conditional rendering must: not already be <> **** include::{generated}/validity/protos/vkCmdBeginConditionalRenderingEXT.adoc[] -- [open,refpage='VkConditionalRenderingBeginInfoEXT',desc='Structure specifying conditional rendering begin information',type='structs'] -- The sname:VkConditionalRenderingBeginInfoEXT structure is defined as: include::{generated}/api/structs/VkConditionalRenderingBeginInfoEXT.adoc[] * pname:sType is a elink:VkStructureType value identifying this structure. * pname:pNext is `NULL` or a pointer to a structure extending this structure. * pname:buffer is a buffer containing the predicate for conditional rendering. * pname:offset is the byte offset into pname:buffer where the predicate is located. * pname:flags is a bitmask of tlink:VkConditionalRenderingFlagsEXT specifying the behavior of conditional rendering. If the 32-bit value at pname:offset in pname:buffer memory is zero, then the rendering commands are discarded, otherwise they are executed as normal. If the value of the predicate in buffer memory changes while conditional rendering is active, the rendering commands may: be discarded in an implementation-dependent way. Some implementations may latch the value of the predicate upon beginning conditional rendering while others may read it before every rendering command. .Valid Usage **** * [[VUID-VkConditionalRenderingBeginInfoEXT-buffer-01981]] If pname:buffer is non-sparse then it must: be bound completely and contiguously to a single sname:VkDeviceMemory object * [[VUID-VkConditionalRenderingBeginInfoEXT-buffer-01982]] pname:buffer must: have been created with the ename:VK_BUFFER_USAGE_CONDITIONAL_RENDERING_BIT_EXT bit set * [[VUID-VkConditionalRenderingBeginInfoEXT-offset-01983]] pname:offset must: be less than the size of pname:buffer by at least 32 bits * [[VUID-VkConditionalRenderingBeginInfoEXT-offset-01984]] pname:offset must: be a multiple of 4 **** include::{generated}/validity/structs/VkConditionalRenderingBeginInfoEXT.adoc[] -- [open,refpage='VkConditionalRenderingFlagBitsEXT',desc='Specify the behavior of conditional rendering',type='enums'] -- Bits which can: be set in flink:vkCmdBeginConditionalRenderingEXT::pname:flags, specifying the behavior of conditional rendering, are: include::{generated}/api/enums/VkConditionalRenderingFlagBitsEXT.adoc[] * ename:VK_CONDITIONAL_RENDERING_INVERTED_BIT_EXT specifies the condition used to determine whether to discard rendering commands or not. That is, if the 32-bit predicate read from pname:buffer memory at pname:offset is zero, the rendering commands are not discarded, and if non zero, then they are discarded. -- [open,refpage='VkConditionalRenderingFlagsEXT',desc='Bitmask of VkConditionalRenderingFlagBitsEXT',type='flags'] -- include::{generated}/api/flags/VkConditionalRenderingFlagsEXT.adoc[] tname:VkConditionalRenderingFlagsEXT is a bitmask type for setting a mask of zero or more elink:VkConditionalRenderingFlagBitsEXT. -- [open,refpage='vkCmdEndConditionalRenderingEXT',desc='Define the end of a conditional rendering block',type='protos'] -- To end conditional rendering, call: include::{generated}/api/protos/vkCmdEndConditionalRenderingEXT.adoc[] * pname:commandBuffer is the command buffer into which this command will be recorded. Once ended, conditional rendering becomes inactive. .Valid Usage **** * [[VUID-vkCmdEndConditionalRenderingEXT-None-01985]] Conditional rendering must: be <> * [[VUID-vkCmdEndConditionalRenderingEXT-None-01986]] If conditional rendering was made <> outside of a render pass instance, it must: not be ended inside a render pass instance * [[VUID-vkCmdEndConditionalRenderingEXT-None-01987]] If conditional rendering was made <> within a subpass it must: be ended in the same subpass **** include::{generated}/validity/protos/vkCmdEndConditionalRenderingEXT.adoc[] -- endif::VK_EXT_conditional_rendering[] ifdef::VK_NV_mesh_shader,VK_EXT_mesh_shader[] include::{chapters}/VK_NV_mesh_shader/drawing.adoc[] endif::VK_NV_mesh_shader,VK_EXT_mesh_shader[] ifdef::VK_HUAWEI_cluster_culling_shader[] include::{chapters}/VK_HUAWEI_cluster_culling_shader/drawing.adoc[] endif::VK_HUAWEI_cluster_culling_shader[]