diff options
Diffstat (limited to 'src/gallium/docs/source')
-rw-r--r-- | src/gallium/docs/source/cso/rasterizer.rst | 5 | ||||
-rw-r--r-- | src/gallium/docs/source/screen.rst | 8 | ||||
-rw-r--r-- | src/gallium/docs/source/tgsi.rst | 29 |
3 files changed, 42 insertions, 0 deletions
diff --git a/src/gallium/docs/source/cso/rasterizer.rst b/src/gallium/docs/source/cso/rasterizer.rst index f4e24f0b438..8338243be9f 100644 --- a/src/gallium/docs/source/cso/rasterizer.rst +++ b/src/gallium/docs/source/cso/rasterizer.rst @@ -159,13 +159,18 @@ Points sprite_coord_enable ^^^^^^^^^^^^^^^^^^^ +The effect of this state depends on PIPE_CAP_TGSI_TEXCOORD ! Controls automatic texture coordinate generation for rendering sprite points. +If PIPE_CAP_TGSI_TEXCOORD is false: When bit k in the sprite_coord_enable bitfield is set, then generic input k to the fragment shader will get an automatically computed texture coordinate. +If PIPE_CAP_TGSI_TEXCOORD is true: +The bitfield refers to inputs with TEXCOORD semantic instead of generic inputs. + The texture coordinate will be of the form (s, t, 0, 1) where s varies from 0 to 1 from left to right while t varies from 0 to 1 according to the state of 'sprite_coord_mode' (see below). diff --git a/src/gallium/docs/source/screen.rst b/src/gallium/docs/source/screen.rst index 68d1a35cc73..0550a30714a 100644 --- a/src/gallium/docs/source/screen.rst +++ b/src/gallium/docs/source/screen.rst @@ -137,6 +137,14 @@ The integer capabilities: * ``PIPE_CAP_TEXTURE_BUFFER_OFFSET_ALIGNMENT``: Describes the required alignment for pipe_sampler_view::u.buf.first_element, in bytes. If a driver does not support first/last_element, it should return 0. +* ``PIPE_CAP_TGSI_TEXCOORD``: This CAP describes a hw limitation. + If true, the hardware cannot replace arbitrary shader inputs with sprite + coordinates and hence the inputs that are desired to be replaceable must + be declared with TGSI_SEMANTIC_TEXCOORD instead of TGSI_SEMANTIC_GENERIC. + The rasterizer's sprite_coord_enable state therefore also applies to the + TEXCOORD semantic. + Also, TGSI_SEMANTIC_PCOORD becomes available, which labels a fragment shader + input that will always be replaced with sprite coordinates. .. _pipe_capf: diff --git a/src/gallium/docs/source/tgsi.rst b/src/gallium/docs/source/tgsi.rst index 4c55e60cff0..28308cb9483 100644 --- a/src/gallium/docs/source/tgsi.rst +++ b/src/gallium/docs/source/tgsi.rst @@ -1949,6 +1949,35 @@ When using this semantic, be sure to set the appropriate state in the :ref:`rasterizer` first. +TGSI_SEMANTIC_TEXCOORD +"""""""""""""""""""""" + +Only available if PIPE_CAP_TGSI_TEXCOORD is exposed ! + +Vertex shader outputs and fragment shader inputs may be labeled with +this semantic to make them replaceable by sprite coordinates via the +sprite_coord_enable state in the :ref:`rasterizer`. +The semantic index permitted with this semantic is limited to <= 7. + +If the driver does not support TEXCOORD, sprite coordinate replacement +applies to inputs with the GENERIC semantic instead. + +The intended use case for this semantic is gl_TexCoord. + + +TGSI_SEMANTIC_PCOORD +"""""""""""""""""""" + +Only available if PIPE_CAP_TGSI_TEXCOORD is exposed ! + +Fragment shader inputs may be labeled with TGSI_SEMANTIC_PCOORD to indicate +that the register contains sprite coordinates in the form (x, y, 0, 1), if +the current primitive is a point and point sprites are enabled. Otherwise, +the contents of the register are undefined. + +The intended use case for this semantic is gl_PointCoord. + + TGSI_SEMANTIC_GENERIC """"""""""""""""""""" |