Update ARB_texture_compression_bptc.txt
diff --git a/extensions/ARB/ARB_texture_compression_bptc.txt b/extensions/ARB/ARB_texture_compression_bptc.txt index e8c358c..8aab363 100644 --- a/extensions/ARB/ARB_texture_compression_bptc.txt +++ b/extensions/ARB/ARB_texture_compression_bptc.txt
@@ -46,8 +46,8 @@ Version - Last Modified Date: June 6, 2016 - Revision: 8 + Last Modified Date: October 30, 2019 + Revision: 9 Number @@ -369,15 +369,16 @@ subset, then green and blue stored similarly. If a block has non-zero alpha bits, the alpha data follows the color data with the same organization. If not, alpha is overridden to 1.0. These bits are treated - as the high bits of a fixed-point value in a byte. If the format has a - shared P-bit, there are two bits for endpoints 0 and 1 from low to - high. If the format has a per-endpoint P-bits, then there are 2*subsets - P-bits stored in the same order as color and alpha. Both kinds of P-bits - are added as a bit below the color data stored in the byte. So, for a - format with 5 red bits, the P-bit ends up in bit 2. For final scaling, the - top bits of the value are replicated into any remaining bits in the - byte. For the preceding example, bits 6 and 7 would be written to bits 0 - and 1. + as the high bits of a fixed-point value in a byte. If the format has + shared P-bits, there are two endpoint bits, the lower of which applies to + both endpoints of subset 0 and the upper of which applies to both + endpoints of subset 1. If the format has a per-endpoint P-bits, then there + are 2*subsets P-bits stored in the same order as color and alpha. Both + kinds of P-bits are added as a bit below the color data stored in the + byte. So, for a format with 5 red bits, the P-bit ends up in bit 2. For + final scaling, the top bits of the value are replicated into any remaining + bits in the byte. For the preceding example, bits 6 and 7 would be written + to bits 0 and 1. The endpoint colors are interpolated using index values stored in the block. The index bits are stored in x-major order. Each index has the @@ -893,6 +894,9 @@ Rev. Date Author Changes ---- -------- ----------- -------------------------------------------- + 9 30/10/19 pdaniell Fix shared p-bits specification to match + DX and the Khronos Data Format spec. + 8 06/06/16 Nanley Chery Reduce the requirements to the minimal set. 7 01/20/11 pbrown Change the base internal format of the floating-