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gallium/docs: Document draw_vbo and set_index_buffer.

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Document the new unified drawing method and remove references to old
ones.
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Chia-I Wu
2010-07-17 22:00:04 +08:00
parent a57f842519
commit e7f69c459a
2 changed files with 27 additions and 58 deletions
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src/gallium/docs/source/context.rst
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@@ -45,6 +45,7 @@ buffers, surfaces) are bound to the driver.
* ``set_vertex_buffers``
* ``set_index_buffer``
Non-CSO State
^^^^^^^^^^^^^
@@ -132,50 +133,26 @@ this surface need not be bound to the framebuffer.
Drawing
^^^^^^^
``draw_arrays`` draws a specified primitive.
``draw_vbo`` draws a specified primitive. The primitive mode and other
properties are described by ``pipe_draw_info``.
This command is equivalent to calling ``draw_arrays_instanced``
with ``startInstance`` set to 0 and ``instanceCount`` set to 1.
The ``mode``, ``start``, and ``count`` fields of ``pipe_draw_info`` specify the
the mode of the primitive and the vertices to be fetched, in the range between
``start`` to ``start``+``count``-1, inclusive.
``draw_elements`` draws a specified primitive using an optional
index buffer.
Every instance with instanceID in the range between ``start_instance`` and
``start_instance``+``instance_count``-1, inclusive, will be drawn.
This command is equivalent to calling ``draw_elements_instanced``
with ``startInstance`` set to 0 and ``instanceCount`` set to 1.
All vertex indices must fall inside the range given by ``min_index`` and
``max_index``. In case non-indexed draw, ``min_index`` should be set to
``start`` and ``max_index`` should be set to ``start``+``count``-1.
``draw_range_elements``
``index_bias`` is a value added to every vertex index before fetching vertex
attributes. It does not affect ``min_index`` and ``max_index``.
XXX: this is (probably) a temporary entrypoint, as the range
information should be available from the vertex_buffer state.
Using this to quickly evaluate a specialized path in the draw
module.
``draw_arrays_instanced`` draws multiple instances of the same primitive.
This command is equivalent to calling ``draw_elements_instanced``
with ``indexBuffer`` set to NULL and ``indexSize`` set to 0.
``draw_elements_instanced`` draws multiple instances of the same primitive
using an optional index buffer.
For instanceID in the range between ``startInstance``
and ``startInstance``+``instanceCount``-1, inclusive, draw a primitive
specified by ``mode`` and sequential numbers in the range between ``start``
and ``start``+``count``-1, inclusive.
If ``indexBuffer`` is not NULL, it specifies an index buffer with index
byte size of ``indexSize``. The sequential numbers are used to lookup
the index buffer and the resulting indices in turn are used to fetch
vertex attributes.
If ``indexBuffer`` is NULL, the sequential numbers are used directly
as indices to fetch vertex attributes.
``indexBias`` is a value which is added to every index read from the index
buffer before fetching vertex attributes.
``minIndex`` and ``maxIndex`` describe minimum and maximum index contained in
the index buffer.
If there is an index buffer bound, and ``indexed`` field is true, all vertex
indices will be looked up in the index buffer. ``min_index``, ``max_index``,
and ``index_bias`` apply after index lookup.
If a given vertex element has ``instance_divisor`` set to 0, it is said
it contains per-vertex data and effective vertex attribute address needs