From b82333db3e88b86e36c090a5b20b20d021b54b89 Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Mon, 4 Oct 2004 17:17:49 +0000 Subject: [PATCH] Add some Savage3D stencil documentation based on discussions during the 20-Sep-2004 #dri-devel meeting. --- src/mesa/drivers/dri/savage/savage_3d_reg.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/src/mesa/drivers/dri/savage/savage_3d_reg.h b/src/mesa/drivers/dri/savage/savage_3d_reg.h index a96d581adae..067c5f7214d 100644 --- a/src/mesa/drivers/dri/savage/savage_3d_reg.h +++ b/src/mesa/drivers/dri/savage/savage_3d_reg.h @@ -461,7 +461,15 @@ typedef union unsigned drawUpdateEn : 1; unsigned zUpdateEn : 1; unsigned zBufEn : 1; + + /** + * We suspect that, in conjunction with + * \c savageRegZBufOffset::zDepthSelect, these 2 bits are actually + * \c stencilUpdateEn and \c stencilBufEn. If not, then some of + * the bits in \c reserved2 may fulfill that purpose. + */ unsigned reserved1 : 2; + unsigned zExpOffset : 8; unsigned wrZafterAlphaTst : 1; unsigned reserved2 : 15; @@ -478,6 +486,13 @@ typedef union unsigned offset : 14; unsigned reserved : 11; /* 12-bits in Utah-driver */ unsigned zBufWidthInTiles : 6; + + /** + * 0 selects 16-bit depth buffer. On Savage4 hardware, 1 selects + * 24-bit depth buffer (with 8-bits for stencil). Though it has never + * been tried, we suspect that on Savage3D hardware, 1 selects 15-bit + * depth buffer (with 1-bit for stencil). + */ unsigned zDepthSelect : 1; }ni; uint32_t ui; -- 2.30.2