Difference between revisions of "NV2A/Vertex Shader"
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(More register info, will be refactored soon) |
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== Registers == | == Registers == | ||
| − | + | * 16 input registers v[0] to v[15] (from vertex, v[0] is fed from LAUNCH_DATA for VSPs) | |
| − | + | * output registers: o[0] to o[?] (initialized to XYZ=0x00000000 W=0x3F800000) | |
| − | * | + | * Following indices are aliased: Pos, oD0, oD1, oFog, oPts, oB0, oB1, oT0, oT1, oT2, oT3 |
| − | * | + | * 1 Address register: A0.x |
| − | * | + | * 12 temporary registers: R0 to R11 (initialized to XYZW=0x00000000) |
| − | + | * The POS register is mirrored as R12 so it can be used as source operand, so effectively you have 13 temporaries | |
| − | R12 | ||
== Instructions == | == Instructions == | ||
??? | ??? | ||
Revision as of 19:26, 21 April 2017
The Xbox implements https://www.opengl.org/registry/specs/NV/vertex_program.txt and https://www.opengl.org/registry/specs/NV/vertex_program1_1.txt This article will mainly focus on actual encoding on hardware as the behaviour is mostly outlined in those GL extensions already.
Registers
- 16 input registers v[0] to v[15] (from vertex, v[0] is fed from LAUNCH_DATA for VSPs)
- output registers: o[0] to o[?] (initialized to XYZ=0x00000000 W=0x3F800000)
* Following indices are aliased: Pos, oD0, oD1, oFog, oPts, oB0, oB1, oT0, oT1, oT2, oT3
- 1 Address register: A0.x
- 12 temporary registers: R0 to R11 (initialized to XYZW=0x00000000)
* The POS register is mirrored as R12 so it can be used as source operand, so effectively you have 13 temporaries
Instructions
???
