GPU/GL Arrays

This page describes the GPU commands used for OpenGL arrays.

Command Sets

glDrawElements()

Command Index	CommandID	Parameter	Description
0	0x00020229	u32, val<<8.	Unknown, val is 0 or 1.
1-2	0x00020253	Same as CmdID 0x00020229.	Unknown
3	0x0002025E	u32, val<<8.	This sets the GL rendering mode.
4	0x0004025E	Value 0	?
5	0x000F025F	Value 1	?
6	0x00010253	Value 0	?
7	0x000F0227	u32	This specifies the indices data-type, and the indices array address.
8	0x000F0228	u32	This specifies the number of elements in the array to use for rendering.
9	0x00010245	Value 0	?
10	0x000F022F	Value 1	?
11	0x00010245	Value 1	?
12	0x000F0231	Value 1	?
13	0x000F0111	Value 1	?
14	0x00020229	Value 0	?
15	0x00020253	Value 0	?
16	0x0002025E	Value 0	?
17	0x000C02BA	Value 0x7FFF0000	?

CmdID 0x826F0200

Command Index	CommandID	Parameter	Description
0	0x826F0200		This sets the addresses for the GL arrays.
1	0x801F02BB		?
2	0x803F0232		Unknown, this command is used multiple times for specifying each parameter-buffer entry.

GL mode values for CmdID 0x0002025E

Value	Description
0	GL_TRIANGLES
1	GL_TRIANGLE_STRIP
2	GL_TRIANGLE_FAN
3	GL_TRIANGLES
4	Unknown, this seems to have the same effect as value 0.

Parameter value format for CmdID 0x000F0227

Bit	Description
30-0	Indices array address, relative to VRAM physical address 0x18000000. Thus, when this relative address is 0x08XXXXXX, the array is located in FCRAM.
31	0 = indices data-type GL_UNSIGNED_BYTE, 1 = GL_UNSIGNED_SHORT.

Parameter structure for CmdID 0x826F0200

Index Word	Description
0x0	Base physical address >> 3, normally located in VRAM.
0x1	Every 4 bits is used for specifying the array data-type and size for each entry.
0x2	Value is: (0xF0000000 + (val<<28)) | (((0xFF<<totalentries) & 0xFF)<<16), where val is the total 4-bit value entries for the CmdID 0x801F02BB parameter buffer.(Normally val is 8)
0x3-0x26	12 entries, each entry is 3 words.

These parameters and the entries' parameters are set by gl*Pointer().

Entry structure

Index Word	Description
0	Physical address, relative to the base address.
1	Entry index
2	Value is: 0x10000000 | (arraytype<<16).

When the entry is unused, the entry data is all-zero.

Entry array types

Type	Description
0x2	?
0x3	Normals array
0x4	Texture coordinates array
0xC	Vertex array
0x10	Color array

Array data-type/size values

Value	GL type
0x0 + ((size-1)*4)	GL_BYTE
0x1 + ((size-1)*4)	GL_UNSIGNED_BYTE
0x2 + ((size-1)*4)	GL_UNSIGNED_SHORT/GL_SHORT
0x3 + ((size-1)*4)	GL_FLOAT

Size is 1-4. Using GL_FLOAT with a texture coordinates array causes the GPU to hang?

Parameter structure for CmdID 0x801F02BB

Index Word	Description
0-1	u64, every 4-bits is a value from some array.

Parameter structure for CmdID 0x803F0232

Index Word	Description
0	Entry index + total CmdID 0x826F0200 parameter-buffer entries.
1	Unknown, usually value 0x3F000000 / 0.5f.(u32 read/writes are used for this field, not float read/writes however)
2	Unknown, usually value 0.
3	Unknown, usually value 0.

Each parameter buffer for CmdID 0x803F0232 is an entry loaded from an array.