diff options
Diffstat (limited to 'src/gallium/docs/source')
| -rw-r--r-- | src/gallium/docs/source/screen.rst | 5 | ||||
| -rw-r--r-- | src/gallium/docs/source/tgsi.rst | 19 |
2 files changed, 18 insertions, 6 deletions
diff --git a/src/gallium/docs/source/screen.rst b/src/gallium/docs/source/screen.rst index 39ecc6334eb..fc08bb9ac34 100644 --- a/src/gallium/docs/source/screen.rst +++ b/src/gallium/docs/source/screen.rst @@ -292,6 +292,11 @@ The integer capabilities: supported in vertex shaders. * ``PIPE_CAP_TGSI_PACK_HALF_FLOAT``: Whether the ``UP2H`` and ``PK2H`` TGSI opcodes are supported. +* ``PIPE_CAP_TGSI_FS_POSITION_IS_SYSVAL``: If state trackers should use + a system value for the POSITION fragment shader input. +* ``PIPE_CAP_TGSI_FS_FACE_IS_INTEGER_SYSVAL``: If state trackers should use + a system value for the FACE fragment shader input. + Also, the FACE system value is integer, not float. .. _pipe_capf: diff --git a/src/gallium/docs/source/tgsi.rst b/src/gallium/docs/source/tgsi.rst index 2149d08419a..8fe971b2f7a 100644 --- a/src/gallium/docs/source/tgsi.rst +++ b/src/gallium/docs/source/tgsi.rst @@ -2658,7 +2658,8 @@ space coordinate system. After clipping, the X, Y and Z components of the vertex will be divided by the W value to get normalized device coordinates. For fragment shaders, TGSI_SEMANTIC_POSITION is used to indicate that -fragment shader input contains the fragment's window position. The X +fragment shader input (or system value, depending on which one is +supported by the driver) contains the fragment's window position. The X component starts at zero and always increases from left to right. The Y component starts at zero and always increases but Y=0 may either indicate the top of the window or the bottom depending on the fragment @@ -2770,11 +2771,17 @@ typically only used for legacy graphics APIs. TGSI_SEMANTIC_FACE """""""""""""""""" -This label applies to fragment shader inputs only and indicates that -the register contains front/back-face information of the form (F, 0, -0, 1). The first component will be positive when the fragment belongs -to a front-facing polygon, and negative when the fragment belongs to a -back-facing polygon. +This label applies to fragment shader inputs (or system values, +depending on which one is supported by the driver) and indicates that +the register contains front/back-face information. + +If it is an input, it will be a floating-point vector in the form (F, 0, 0, 1), +where F will be positive when the fragment belongs to a front-facing polygon, +and negative when the fragment belongs to a back-facing polygon. + +If it is a system value, it will be an integer vector in the form (F, 0, 0, 1), +where F is 0xffffffff when the fragment belongs to a front-facing polygon and +0 when the fragment belongs to a back-facing polygon. TGSI_SEMANTIC_EDGEFLAG |