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Merge pull request #141 from IridescentRose/gu-docfix

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Fixed documentation -- added 8 bit notes.
This commit is contained in:
Wouter Wijsman
2023-06-27 15:41:32 +02:00
committed by GitHub
parent cec2f5e7b3 3f22a7ec08
commit 0cbce71ddf
1 changed files with 10 additions and 2 deletions
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src/gu/pspgu.h
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@@ -651,16 +651,24 @@ int sceGuSync(int mode, int what);
* @par Notes on 16 bit vertex/texture/normal formats:
* - Values are stored as 16-bit signed integers, with a range of -32768 to 32767
* - In the floating point coordinate space this is mapped as -1.0 to 1.0
* - To scale this use sceGumScale() for vertices; (see pspgum.h)
* - To scale this to be such that the value 1 in 16 bit space is 1 unit in floating point space, use sceGumScale() for vertices; (see pspgum.h)
* - You can technically use this to create whatever fixed-point space you want (a common one is 5 bits for the decimals)
* - Caveat: you need to use the sceGumDrawArray method to apply the affine transform to the vertices.
* - sceGuDrawArray() will not apply the affine transform to the vertices.
* - To scale this for texture coordinates use sceGuTexOffset() and sceGuTexScale() (see below)
* - You can't scale the normals with any functions, which is expected since normals by definition are unit vectors.
*
* @code
* sceGumScale(1.0f/32768.0f,1.0f/32768.0f,1.0f/32768.0f); // This is an identity mapping -- 1 unit in floating point space is 1 unit in 16-bit space
* sceGumScale(32768.0f, 32768.0f, 32768.0f); // This is an identity mapping -- 1 unit in floating point space is 1 unit in 16-bit space
* sceGumDrawArray(GU_TRIANGLES, GU_TEXTURE_32BITF|GU_VERTEX_16BIT, 3, 0, vertices);
* @endcode
*
* @par Notes on 8 bit vertex/texture/normal formats:
* - Values are stored as 8-bit signed integers with a range of -128 to 127
* - In the floating point coordinate space this is mapped as -1.0 to 1.0
* - To scale this to be such that the value 1 in 8 bit space is 1 unit in floating point space, use sceGumScale() for vertices; (see above).
* - The scaling factor as demonstrated will be 128.0f.
* - See above for notes on texture and normals.
*
* Vertex order:
* [for vertices(1-8)]