GPU/Programming Guide - Revision history

Emufan4568: Fix lin to GPUREG_FIXEDATTRIB_DATA

2023-12-15T22:20:14Z

Fix lin to GPUREG_FIXEDATTRIB_DATA

← Older revision		Revision as of 01:20, 16 December 2023
Line 15:		Line 15:
	Instead of using vertex arrays to supply vertex data, drawing can be done by directly writing vertex data to a register. This allows vertex data to be inlined directly in the command buffer. Since this is restricted to 4-component float data, it is more useful for small draws like UI elements or debug displays, to avoid using an unreasonable amount of memory and processing time appending the vertices to the command buffer.		Instead of using vertex arrays to supply vertex data, drawing can be done by directly writing vertex data to a register. This allows vertex data to be inlined directly in the command buffer. Since this is restricted to 4-component float data, it is more useful for small draws like UI elements or debug displays, to avoid using an unreasonable amount of memory and processing time appending the vertices to the command buffer.

	To use this feature, configure the number of attributes per vertex in [[GPU/Internal Registers#GPUREG_VSH_NUM_ATTR\|GPUREG_VSH_NUM_ATTR]]. (All settings in the registers related to the vertex loader are ignored.) Then setup the GPU and shaders the same as if doing a regular draw call with GPUREG_DRAWARRAYS or GPUREG_DRAWELEMENTS, but instead of writing to either register, write the value 0xF to [[GPU/Internal Registers#GPUREG_FIXEDATTRIB_INDEX\|GPUREG_FIXEDATTRIB_INDEX]] and then follow by repeatedly writing vertex data to [[GPU/Internal Registers#~~GPUREG_FIXEDATTRIB_DATA0~~\|GPUREG_FIXEDATTRIB_DATA]].		To use this feature, configure the number of attributes per vertex in [[GPU/Internal Registers#GPUREG_VSH_NUM_ATTR\|GPUREG_VSH_NUM_ATTR]]. (All settings in the registers related to the vertex loader are ignored.) Then setup the GPU and shaders the same as if doing a regular draw call with GPUREG_DRAWARRAYS or GPUREG_DRAWELEMENTS, but instead of writing to either register, write the value 0xF to [[GPU/Internal Registers#GPUREG_FIXEDATTRIB_INDEX\|GPUREG_FIXEDATTRIB_INDEX]] and then follow by repeatedly writing vertex data to [[GPU/Internal Registers#GPUREG_FIXEDATTRIB_DATAi\|GPUREG_FIXEDATTRIB_DATA]].

	Each set of writes to the 3 data registers specifies one attribute and all attributes (as configured in GPUREG_VSH_NUM_ATTR) need to be written, in order, to specify a vertex. Drawing happens automatically as vertices are specified. After finishing specifying vertices, follow with the same writes used after a draw arrays/elements.		Each set of writes to the 3 data registers specifies one attribute and all attributes (as configured in GPUREG_VSH_NUM_ATTR) need to be written, in order, to specify a vertex. Drawing happens automatically as vertices are specified. After finishing specifying vertices, follow with the same writes used after a draw arrays/elements.

Yuriks: Correct register used for immediate-mode parameter count

2016-12-19T05:01:36Z

Correct register used for immediate-mode parameter count

← Older revision		Revision as of 08:01, 19 December 2016
Line 15:		Line 15:
	Instead of using vertex arrays to supply vertex data, drawing can be done by directly writing vertex data to a register. This allows vertex data to be inlined directly in the command buffer. Since this is restricted to 4-component float data, it is more useful for small draws like UI elements or debug displays, to avoid using an unreasonable amount of memory and processing time appending the vertices to the command buffer.		Instead of using vertex arrays to supply vertex data, drawing can be done by directly writing vertex data to a register. This allows vertex data to be inlined directly in the command buffer. Since this is restricted to 4-component float data, it is more useful for small draws like UI elements or debug displays, to avoid using an unreasonable amount of memory and processing time appending the vertices to the command buffer.

	To use this feature, configure the number of attributes per vertex in [[GPU/Internal Registers#~~GPUREG_ATTRIBBUFFERS_FORMAT_HIGH~~\|~~GPUREG_ATTRIBBUFFERS_FORMAT_HIGH~~]]. (All ~~other~~ settings in related ~~registers seem~~ to be ignored.) Then setup the GPU the same as if doing a regular draw call with GPUREG_DRAWARRAYS or GPUREG_DRAWELEMENTS, but instead of writing to either register, write the value 0xF to [[GPU/Internal Registers#GPUREG_FIXEDATTRIB_INDEX\|GPUREG_FIXEDATTRIB_INDEX]] and then follow by repeatedly writing vertex data to [[GPU/Internal Registers#GPUREG_FIXEDATTRIB_DATA0\|GPUREG_FIXEDATTRIB_DATA]].		To use this feature, configure the number of attributes per vertex in [[GPU/Internal Registers#GPUREG_VSH_NUM_ATTR\|GPUREG_VSH_NUM_ATTR]]. (All settings in the registers related to the vertex loader are ignored.) Then setup the GPU and shaders the same as if doing a regular draw call with GPUREG_DRAWARRAYS or GPUREG_DRAWELEMENTS, but instead of writing to either register, write the value 0xF to [[GPU/Internal Registers#GPUREG_FIXEDATTRIB_INDEX\|GPUREG_FIXEDATTRIB_INDEX]] and then follow by repeatedly writing vertex data to [[GPU/Internal Registers#GPUREG_FIXEDATTRIB_DATA0\|GPUREG_FIXEDATTRIB_DATA]].

	Each set of writes to the 3 data registers specifies one attribute and all attributes (as configured in ~~GPUREG_ATTRIBBUFFERS_FORMAT_HIGH~~) need to be written, in order, to specify a vertex. Drawing happens automatically as vertices are specified. After finishing specifying vertices, follow with the same writes used after a draw arrays/elements.		Each set of writes to the 3 data registers specifies one attribute and all attributes (as configured in GPUREG_VSH_NUM_ATTR) need to be written, in order, to specify a vertex. Drawing happens automatically as vertices are specified. After finishing specifying vertices, follow with the same writes used after a draw arrays/elements.

	When drawing using triangle strips or fans, [[GPU/Internal Registers#GPUREG_RESTART_PRIMITIVE\|GPUREG_RESTART_PRIMITIVE]] should be used to end the previous strip before (or while) drawing.		When drawing using triangle strips or fans, [[GPU/Internal Registers#GPUREG_RESTART_PRIMITIVE\|GPUREG_RESTART_PRIMITIVE]] should be used to end the previous strip before (or while) drawing.

Steveice10 at 07:15, 5 December 2015

2015-12-05T06:15:18Z

← Older revision		Revision as of 09:15, 5 December 2015
Line 20:		Line 20:

	When drawing using triangle strips or fans, [[GPU/Internal Registers#GPUREG_RESTART_PRIMITIVE\|GPUREG_RESTART_PRIMITIVE]] should be used to end the previous strip before (or while) drawing.		When drawing using triangle strips or fans, [[GPU/Internal Registers#GPUREG_RESTART_PRIMITIVE\|GPUREG_RESTART_PRIMITIVE]] should be used to end the previous strip before (or while) drawing.

			== Drawing elements ==

			The 3DS GPU is capable of drawing vertex + index arrays, triggered by [[GPU/Internal_Registers#GPUREG_DRAWELEMENTS\|GPUREG_DRAWELEMENTS]]. A set of commands commonly used by the standard GL implementation to accomplish this is as follows:

			{\| class="wikitable" border="1"
			! Command Index
			! Register
			! Description
			\|-
			\| 0
			\| [[GPU/Internal_Registers#GPUREG_GEOSTAGE_CONFIG\|GPUREG_GEOSTAGE_CONFIG]]
			\| Set whether drawing triangle elements
			\|-
			\| 1-2
			\| [[GPU/Internal_Registers#GPUREG_GEOSTAGE_CONFIG2\|GPUREG_GEOSTAGE_CONFIG2]]
			\| Set whether drawing triangle elements
			\|-
			\| 3
			\| [[GPU/Internal_Registers#GPUREG_PRIMITIVE_CONFIG\|GPUREG_PRIMITIVE_CONFIG]]
			\| Set primitive mode
			\|-
			\| 4
			\| [[GPU/Internal_Registers#GPUREG_PRIMITIVE_CONFIG\|GPUREG_PRIMITIVE_CONFIG]]
			\| Set number of output map registers
			\|-
			\| 5
			\| [[GPU/Internal_Registers#GPUREG_RESTART_PRIMITIVE\|GPUREG_RESTART_PRIMITIVE]]
			\| Trigger reset
			\|-
			\| 6
			\| [[GPU/Internal_Registers#GPUREG_GEOSTAGE_CONFIG2\|GPUREG_GEOSTAGE_CONFIG2]]
			\| Set function indicator to 0
			\|-
			\| 7
			\| [[GPU/Internal_Registers#GPUREG_INDEXBUFFER_CONFIG\|GPUREG_INDEXBUFFER_CONFIG]]
			\| Set offset and type
			\|-
			\| 8
			\| [[GPU/Internal_Registers#GPUREG_NUMVERTICES\|GPUREG_NUMVERTICES]]
			\| Set vertex count
			\|-
			\| 9
			\| [[GPU/Internal_Registers#GPUREG_START_DRAW_FUNC0\|GPUREG_START_DRAW_FUNC0]]
			\| Set mode to drawing
			\|-
			\| 10
			\| [[GPU/Internal_Registers#GPUREG_DRAWELEMENTS\|GPUREG_DRAWELEMENTS]]
			\| Trigger draw
			\|-
			\| 11
			\| [[GPU/Internal_Registers#GPUREG_START_DRAW_FUNC0\|GPUREG_START_DRAW_FUNC0]]
			\| Set mode to configuration
			\|-
			\| 12
			\| [[GPU/Internal_Registers#GPUREG_VTX_FUNC\|GPUREG_VTX_FUNC]]
			\| Trigger post-vertex cache clear
			\|-
			\| 13
			\| [[GPU/Internal_Registers#GPUREG_FRAMEBUFFER_FLUSH\|GPUREG_FRAMEBUFFER_FLUSH]]
			\| Flush framebuffer
			\|-
			\| 14
			\| [[GPU/Internal_Registers#GPUREG_GEOSTAGE_CONFIG\|GPUREG_GEOSTAGE_CONFIG]]
			\| Clear drawing triangle elements
			\|-
			\| 15
			\| [[GPU/Internal_Registers#GPUREG_GEOSTAGE_CONFIG2\|GPUREG_GEOSTAGE_CONFIG2]]
			\| Clear drawing triangle elements
			\|-
			\| 16
			\| [[GPU/Internal_Registers#GPUREG_PRIMITIVE_CONFIG\|GPUREG_PRIMITIVE_CONFIG]]
			\| Clear primitive mode
			\|-
			\| 17
			\| [[GPU/Internal_Registers#GPUREG_VSH_ENTRYPOINT\|GPUREG_VSH_ENTRYPOINT]]
			\| Clear entry point
			\|}

	[[Category:GPU]]		[[Category:GPU]]

Steveice10 at 07:07, 5 December 2015

2015-12-05T06:07:10Z

← Older revision		Revision as of 09:07, 5 December 2015
Line 1:		Line 1:
	This page is intended to contain more higher-level explanation of concepts and features provided by the 3DS GPU. For more detailed register-level information check [[GPU/Internal Registers~~]] or [[GPU/Commands~~]].		This page is intended to contain more higher-level explanation of concepts and features provided by the 3DS GPU. For more detailed register-level information check [[GPU/Internal Registers]].

	= Geometry Pipeline =		= Geometry Pipeline =

Steveice10 at 04:47, 5 December 2015

2015-12-05T03:47:55Z

← Older revision		Revision as of 06:47, 5 December 2015
Line 1:		Line 1:
	This page is intended to contain more higher-level explanation of concepts and features provided by the 3DS GPU. For more detailed register-level information check [[GPU/Internal Registers]] or [[GPU Commands]].		This page is intended to contain more higher-level explanation of concepts and features provided by the 3DS GPU. For more detailed register-level information check [[GPU/Internal Registers]] or [[GPU/Commands]].

	= Geometry Pipeline =		= Geometry Pipeline =
Line 9:		Line 9:
	To use a fixed attribute, set the bit corresponding to the attribute in [[GPU/Internal Registers#GPUREG_ATTRIBBUFFERS_FORMAT_HIGH\|GPUREG_ATTRIBBUFFERS_FORMAT_HIGH]] and ensure that no vertex arrays are configured for the attribute. (Any configured arrays will override the fixed value, regardless of the bit setting.) Even if a vertex array isn't being used for the attribute it still needs to be counted in the number of active attributes specified in the same register.		To use a fixed attribute, set the bit corresponding to the attribute in [[GPU/Internal Registers#GPUREG_ATTRIBBUFFERS_FORMAT_HIGH\|GPUREG_ATTRIBBUFFERS_FORMAT_HIGH]] and ensure that no vertex arrays are configured for the attribute. (Any configured arrays will override the fixed value, regardless of the bit setting.) Even if a vertex array isn't being used for the attribute it still needs to be counted in the number of active attributes specified in the same register.

	To specify the actual value of the fixed attribute, write the attribute index to [[GPU/Internal Registers#GPUREG_FIXEDATTRIB_INDEX\|GPUREG_FIXEDATTRIB_INDEX]] followed by writes with packed a float24 4-tuple to the 3 [[GPU/Internal Registers#~~GPUREG_FIXEDATTRIB_DATA~~\|GPUREG_FIXEDATTRIB_DATA]] registers. The value is always specified as a float 4-component vector, the configured type is ignored.		To specify the actual value of the fixed attribute, write the attribute index to [[GPU/Internal Registers#GPUREG_FIXEDATTRIB_INDEX\|GPUREG_FIXEDATTRIB_INDEX]] followed by writes with packed a float24 4-tuple to the 3 [[GPU/Internal Registers#GPUREG_FIXEDATTRIB_DATA0\|GPUREG_FIXEDATTRIB_DATA]] registers. The value is always specified as a float 4-component vector, the configured type is ignored.

	== Immediate-Mode Vertex Submission ==		== Immediate-Mode Vertex Submission ==
Line 15:		Line 15:
	Instead of using vertex arrays to supply vertex data, drawing can be done by directly writing vertex data to a register. This allows vertex data to be inlined directly in the command buffer. Since this is restricted to 4-component float data, it is more useful for small draws like UI elements or debug displays, to avoid using an unreasonable amount of memory and processing time appending the vertices to the command buffer.		Instead of using vertex arrays to supply vertex data, drawing can be done by directly writing vertex data to a register. This allows vertex data to be inlined directly in the command buffer. Since this is restricted to 4-component float data, it is more useful for small draws like UI elements or debug displays, to avoid using an unreasonable amount of memory and processing time appending the vertices to the command buffer.

	To use this feature, configure the number of attributes per vertex in [[GPU/Internal Registers#GPUREG_ATTRIBBUFFERS_FORMAT_HIGH\|GPUREG_ATTRIBBUFFERS_FORMAT_HIGH]]. (All other settings in related registers seem to be ignored.) Then setup the GPU the same as if doing a regular draw call with GPUREG_DRAWARRAYS or GPUREG_DRAWELEMENTS, but instead of writing to either register, write the value 0xF to [[GPU/Internal Registers#GPUREG_FIXEDATTRIB_INDEX\|GPUREG_FIXEDATTRIB_INDEX]] and then follow by repeatedly writing vertex data to [[GPU/Internal Registers#~~GPUREG_FIXEDATTRIB_DATA~~\|GPUREG_FIXEDATTRIB_DATA]].		To use this feature, configure the number of attributes per vertex in [[GPU/Internal Registers#GPUREG_ATTRIBBUFFERS_FORMAT_HIGH\|GPUREG_ATTRIBBUFFERS_FORMAT_HIGH]]. (All other settings in related registers seem to be ignored.) Then setup the GPU the same as if doing a regular draw call with GPUREG_DRAWARRAYS or GPUREG_DRAWELEMENTS, but instead of writing to either register, write the value 0xF to [[GPU/Internal Registers#GPUREG_FIXEDATTRIB_INDEX\|GPUREG_FIXEDATTRIB_INDEX]] and then follow by repeatedly writing vertex data to [[GPU/Internal Registers#GPUREG_FIXEDATTRIB_DATA0\|GPUREG_FIXEDATTRIB_DATA]].

	Each set of writes to the 3 data registers specifies one attribute and all attributes (as configured in GPUREG_ATTRIBBUFFERS_FORMAT_HIGH) need to be written, in order, to specify a vertex. Drawing happens automatically as vertices are specified. After finishing specifying vertices, follow with the same writes used after a draw arrays/elements.		Each set of writes to the 3 data registers specifies one attribute and all attributes (as configured in GPUREG_ATTRIBBUFFERS_FORMAT_HIGH) need to be written, in order, to specify a vertex. Drawing happens automatically as vertices are specified. After finishing specifying vertices, follow with the same writes used after a draw arrays/elements.

Yuriks: Add to GPU category

2015-08-14T17:07:16Z

Add to GPU category

← Older revision		Revision as of 21:07, 14 August 2015
Line 20:		Line 20:

	When drawing using triangle strips or fans, [[GPU/Internal Registers#GPUREG_RESTART_PRIMITIVE\|GPUREG_RESTART_PRIMITIVE]] should be used to end the previous strip before (or while) drawing.		When drawing using triangle strips or fans, [[GPU/Internal Registers#GPUREG_RESTART_PRIMITIVE\|GPUREG_RESTART_PRIMITIVE]] should be used to end the previous strip before (or while) drawing.

			[[Category:GPU]]

Yuriks: Update links with new prefix

2015-08-14T16:50:34Z

Update links with new prefix

← Older revision		Revision as of 20:50, 14 August 2015
Line 1:		Line 1:
	This page is intended to contain more higher-level explanation of concepts and features provided by the 3DS GPU. For more detailed register-level information check [[GPU:Internal Registers]] or [[GPU Commands]].		This page is intended to contain more higher-level explanation of concepts and features provided by the 3DS GPU. For more detailed register-level information check [[GPU/Internal Registers]] or [[GPU Commands]].

	= Geometry Pipeline =		= Geometry Pipeline =
Line 7:		Line 7:
	If a certain vertex attribute is constant for the duration of a draw call, instead of specifying a vertex array with repeated contents or changing the shader to use a uniform, ''fixed vertex attributes'' can be used. They let you specify a fixed value, which will be assumed by the attribute for all vertices of the batch.		If a certain vertex attribute is constant for the duration of a draw call, instead of specifying a vertex array with repeated contents or changing the shader to use a uniform, ''fixed vertex attributes'' can be used. They let you specify a fixed value, which will be assumed by the attribute for all vertices of the batch.

	To use a fixed attribute, set the bit corresponding to the attribute in [[GPU:Internal Registers#GPUREG_ATTRIBBUFFERS_FORMAT_HIGH\|GPUREG_ATTRIBBUFFERS_FORMAT_HIGH]] and ensure that no vertex arrays are configured for the attribute. (Any configured arrays will override the fixed value, regardless of the bit setting.) Even if a vertex array isn't being used for the attribute it still needs to be counted in the number of active attributes specified in the same register.		To use a fixed attribute, set the bit corresponding to the attribute in [[GPU/Internal Registers#GPUREG_ATTRIBBUFFERS_FORMAT_HIGH\|GPUREG_ATTRIBBUFFERS_FORMAT_HIGH]] and ensure that no vertex arrays are configured for the attribute. (Any configured arrays will override the fixed value, regardless of the bit setting.) Even if a vertex array isn't being used for the attribute it still needs to be counted in the number of active attributes specified in the same register.

	To specify the actual value of the fixed attribute, write the attribute index to [[GPU:Internal Registers#GPUREG_FIXEDATTRIB_INDEX\|GPUREG_FIXEDATTRIB_INDEX]] followed by writes with packed a float24 4-tuple to the 3 [[GPU:Internal Registers#GPUREG_FIXEDATTRIB_DATA\|GPUREG_FIXEDATTRIB_DATA]] registers. The value is always specified as a float 4-component vector, the configured type is ignored.		To specify the actual value of the fixed attribute, write the attribute index to [[GPU/Internal Registers#GPUREG_FIXEDATTRIB_INDEX\|GPUREG_FIXEDATTRIB_INDEX]] followed by writes with packed a float24 4-tuple to the 3 [[GPU/Internal Registers#GPUREG_FIXEDATTRIB_DATA\|GPUREG_FIXEDATTRIB_DATA]] registers. The value is always specified as a float 4-component vector, the configured type is ignored.

	== Immediate-Mode Vertex Submission ==		== Immediate-Mode Vertex Submission ==
Line 15:		Line 15:
	Instead of using vertex arrays to supply vertex data, drawing can be done by directly writing vertex data to a register. This allows vertex data to be inlined directly in the command buffer. Since this is restricted to 4-component float data, it is more useful for small draws like UI elements or debug displays, to avoid using an unreasonable amount of memory and processing time appending the vertices to the command buffer.		Instead of using vertex arrays to supply vertex data, drawing can be done by directly writing vertex data to a register. This allows vertex data to be inlined directly in the command buffer. Since this is restricted to 4-component float data, it is more useful for small draws like UI elements or debug displays, to avoid using an unreasonable amount of memory and processing time appending the vertices to the command buffer.

	To use this feature, configure the number of attributes per vertex in [[GPU:Internal Registers#GPUREG_ATTRIBBUFFERS_FORMAT_HIGH\|GPUREG_ATTRIBBUFFERS_FORMAT_HIGH]]. (All other settings in related registers seem to be ignored.) Then setup the GPU the same as if doing a regular draw call with GPUREG_DRAWARRAYS or GPUREG_DRAWELEMENTS, but instead of writing to either register, write the value 0xF to [[GPU:Internal Registers#GPUREG_FIXEDATTRIB_INDEX\|GPUREG_FIXEDATTRIB_INDEX]] and then follow by repeatedly writing vertex data to [[GPU:Internal Registers#GPUREG_FIXEDATTRIB_DATA\|GPUREG_FIXEDATTRIB_DATA]].		To use this feature, configure the number of attributes per vertex in [[GPU/Internal Registers#GPUREG_ATTRIBBUFFERS_FORMAT_HIGH\|GPUREG_ATTRIBBUFFERS_FORMAT_HIGH]]. (All other settings in related registers seem to be ignored.) Then setup the GPU the same as if doing a regular draw call with GPUREG_DRAWARRAYS or GPUREG_DRAWELEMENTS, but instead of writing to either register, write the value 0xF to [[GPU/Internal Registers#GPUREG_FIXEDATTRIB_INDEX\|GPUREG_FIXEDATTRIB_INDEX]] and then follow by repeatedly writing vertex data to [[GPU/Internal Registers#GPUREG_FIXEDATTRIB_DATA\|GPUREG_FIXEDATTRIB_DATA]].

	Each set of writes to the 3 data registers specifies one attribute and all attributes (as configured in GPUREG_ATTRIBBUFFERS_FORMAT_HIGH) need to be written, in order, to specify a vertex. Drawing happens automatically as vertices are specified. After finishing specifying vertices, follow with the same writes used after a draw arrays/elements.		Each set of writes to the 3 data registers specifies one attribute and all attributes (as configured in GPUREG_ATTRIBBUFFERS_FORMAT_HIGH) need to be written, in order, to specify a vertex. Drawing happens automatically as vertices are specified. After finishing specifying vertices, follow with the same writes used after a draw arrays/elements.

	When drawing using triangle strips or fans, [[GPU:Internal Registers#GPUREG_RESTART_PRIMITIVE\|GPUREG_RESTART_PRIMITIVE]] should be used to end the previous strip before (or while) drawing.		When drawing using triangle strips or fans, [[GPU/Internal Registers#GPUREG_RESTART_PRIMITIVE\|GPUREG_RESTART_PRIMITIVE]] should be used to end the previous strip before (or while) drawing.

Yuriks: moved GPU:Programming Guide to GPU/Programming Guide: This is how you namespace articles in wikipedia/etc. apparently.

2015-08-14T16:45:09Z

moved GPU:Programming Guide to GPU/Programming Guide: This is how you namespace articles in wikipedia/etc. apparently.

← Older revision		Revision as of 20:45, 14 August 2015
(No difference)

Yuriks: Oops, formatting

2015-07-26T04:09:21Z

Oops, formatting

← Older revision		Revision as of 08:09, 26 July 2015
Line 5:		Line 5:
	== Fixed Vertex Attributes ==		== Fixed Vertex Attributes ==

	If a certain vertex attribute is constant for the duration of a draw call, instead of specifying a vertex array with repeated contents or changing the shader to use a uniform, fixed vertex attributes can be used. They let you specify a fixed value, which will be assumed by the attribute for all vertices of the batch.		If a certain vertex attribute is constant for the duration of a draw call, instead of specifying a vertex array with repeated contents or changing the shader to use a uniform, ''fixed vertex attributes'' can be used. They let you specify a fixed value, which will be assumed by the attribute for all vertices of the batch.

	To use a fixed attribute, set the bit corresponding to the attribute in [[GPU:Internal Registers#GPUREG_ATTRIBBUFFERS_FORMAT_HIGH\|GPUREG_ATTRIBBUFFERS_FORMAT_HIGH]] and ensure that no vertex arrays are configured for the attribute. (Any configured arrays will override the fixed value, regardless of the bit setting.) Even if a vertex array isn't being used for the attribute it still needs to be counted in the number of active attributes specified in the same register.		To use a fixed attribute, set the bit corresponding to the attribute in [[GPU:Internal Registers#GPUREG_ATTRIBBUFFERS_FORMAT_HIGH\|GPUREG_ATTRIBBUFFERS_FORMAT_HIGH]] and ensure that no vertex arrays are configured for the attribute. (Any configured arrays will override the fixed value, regardless of the bit setting.) Even if a vertex array isn't being used for the attribute it still needs to be counted in the number of active attributes specified in the same register.

Yuriks: /* Geometry Pipeline */ Added section about immediate mode

2015-07-26T04:05:20Z

Geometry Pipeline: Added section about immediate mode

← Older revision		Revision as of 08:05, 26 July 2015
Line 10:		Line 10:

	To specify the actual value of the fixed attribute, write the attribute index to [[GPU:Internal Registers#GPUREG_FIXEDATTRIB_INDEX\|GPUREG_FIXEDATTRIB_INDEX]] followed by writes with packed a float24 4-tuple to the 3 [[GPU:Internal Registers#GPUREG_FIXEDATTRIB_DATA\|GPUREG_FIXEDATTRIB_DATA]] registers. The value is always specified as a float 4-component vector, the configured type is ignored.		To specify the actual value of the fixed attribute, write the attribute index to [[GPU:Internal Registers#GPUREG_FIXEDATTRIB_INDEX\|GPUREG_FIXEDATTRIB_INDEX]] followed by writes with packed a float24 4-tuple to the 3 [[GPU:Internal Registers#GPUREG_FIXEDATTRIB_DATA\|GPUREG_FIXEDATTRIB_DATA]] registers. The value is always specified as a float 4-component vector, the configured type is ignored.

			== Immediate-Mode Vertex Submission ==

			Instead of using vertex arrays to supply vertex data, drawing can be done by directly writing vertex data to a register. This allows vertex data to be inlined directly in the command buffer. Since this is restricted to 4-component float data, it is more useful for small draws like UI elements or debug displays, to avoid using an unreasonable amount of memory and processing time appending the vertices to the command buffer.

			To use this feature, configure the number of attributes per vertex in [[GPU:Internal Registers#GPUREG_ATTRIBBUFFERS_FORMAT_HIGH\|GPUREG_ATTRIBBUFFERS_FORMAT_HIGH]]. (All other settings in related registers seem to be ignored.) Then setup the GPU the same as if doing a regular draw call with GPUREG_DRAWARRAYS or GPUREG_DRAWELEMENTS, but instead of writing to either register, write the value 0xF to [[GPU:Internal Registers#GPUREG_FIXEDATTRIB_INDEX\|GPUREG_FIXEDATTRIB_INDEX]] and then follow by repeatedly writing vertex data to [[GPU:Internal Registers#GPUREG_FIXEDATTRIB_DATA\|GPUREG_FIXEDATTRIB_DATA]].

			Each set of writes to the 3 data registers specifies one attribute and all attributes (as configured in GPUREG_ATTRIBBUFFERS_FORMAT_HIGH) need to be written, in order, to specify a vertex. Drawing happens automatically as vertices are specified. After finishing specifying vertices, follow with the same writes used after a draw arrays/elements.

			When drawing using triangle strips or fans, [[GPU:Internal Registers#GPUREG_RESTART_PRIMITIVE\|GPUREG_RESTART_PRIMITIVE]] should be used to end the previous strip before (or while) drawing.