[Mesa-dev] [PATCH RFC] gallium: interface changes necessary to implement transform feedback
Marek Olšák
maraeo at gmail.com
Tue Oct 4 17:51:21 PDT 2011
Namely:
- EXT_transform_feedback
- ARB_transform_feedback2
- ARB_transform_feedback_instanced
The old interface was unusable for OpenGL and had to go away.
This interface was originally designed for OpenGL, but additional
changes have been made in order to make st/d3d1x support easier.
The most notable change is the stream-out info must be linked
with a vertex or geometry shader and cannot be set independently.
This is due to limitations of existing hardware (special shader
instructions must be used to write into stream-out buffers),
and it's also how OpenGL works (stream outputs must be specified
prior to linking shaders).
Other than that, each stream output buffer has a "view" into it that
internally maintains the number of bytes which have been written
into it. (one buffer can be bound in several different transform
feedback objects in OpenGL, so we must be able to have several views
around) This counter can optionally be re-set to zero. Also,
the counter can optionally be used to provide the vertex count
for draw_vbo. Note that the counter is supposed to be stored in device
memory and the CPU never gets to know its value.
OpenGL way | Gallium way
------------------------------------
BeginTF = reset + bind
PauseTF = unbind
ResumeTF = bind
EndTF = unbind
DrawTF = use pipe_draw_info::count_from_stream_output
---
src/gallium/auxiliary/draw/draw_context.c | 4 +-
src/gallium/auxiliary/draw/draw_context.h | 2 +-
src/gallium/auxiliary/draw/draw_private.h | 2 +-
src/gallium/auxiliary/draw/draw_pt_so_emit.c | 2 +-
src/gallium/drivers/llvmpipe/lp_state.h | 2 +-
src/gallium/drivers/llvmpipe/lp_state_so.c | 2 +-
src/gallium/drivers/nvc0/nvc0_state.c | 2 +-
src/gallium/drivers/softpipe/sp_state.h | 2 +-
src/gallium/drivers/softpipe/sp_state_so.c | 2 +-
src/gallium/include/pipe/p_context.h | 47 +++++++++-----
src/gallium/include/pipe/p_defines.h | 5 +-
src/gallium/include/pipe/p_state.h | 83 ++++++++++++++++++++------
12 files changed, 109 insertions(+), 46 deletions(-)
diff --git a/src/gallium/auxiliary/draw/draw_context.c b/src/gallium/auxiliary/draw/draw_context.c
index 6a85b79..6be0e23 100644
--- a/src/gallium/auxiliary/draw/draw_context.c
+++ b/src/gallium/auxiliary/draw/draw_context.c
@@ -721,11 +721,11 @@ draw_set_mapped_so_buffers(struct draw_context *draw,
void
draw_set_so_state(struct draw_context *draw,
- struct pipe_stream_output_state *state)
+ struct pipe_stream_output_info *state)
{
memcpy(&draw->so.state,
state,
- sizeof(struct pipe_stream_output_state));
+ sizeof(struct pipe_stream_output_info));
}
void
diff --git a/src/gallium/auxiliary/draw/draw_context.h b/src/gallium/auxiliary/draw/draw_context.h
index 799eb94..93577d0 100644
--- a/src/gallium/auxiliary/draw/draw_context.h
+++ b/src/gallium/auxiliary/draw/draw_context.h
@@ -202,7 +202,7 @@ draw_set_mapped_so_buffers(struct draw_context *draw,
unsigned num_buffers);
void
draw_set_so_state(struct draw_context *draw,
- struct pipe_stream_output_state *state);
+ struct pipe_stream_output_info *state);
/***********************************************************************
diff --git a/src/gallium/auxiliary/draw/draw_private.h b/src/gallium/auxiliary/draw/draw_private.h
index ef77266..533b058 100644
--- a/src/gallium/auxiliary/draw/draw_private.h
+++ b/src/gallium/auxiliary/draw/draw_private.h
@@ -270,7 +270,7 @@ struct draw_context
/** Stream output (vertex feedback) state */
struct {
- struct pipe_stream_output_state state;
+ struct pipe_stream_output_info state;
void *buffers[PIPE_MAX_SO_BUFFERS];
uint num_buffers;
} so;
diff --git a/src/gallium/auxiliary/draw/draw_pt_so_emit.c b/src/gallium/auxiliary/draw/draw_pt_so_emit.c
index c86bdd9..6465e5c 100644
--- a/src/gallium/auxiliary/draw/draw_pt_so_emit.c
+++ b/src/gallium/auxiliary/draw/draw_pt_so_emit.c
@@ -130,7 +130,7 @@ static void so_emit_prim(struct pt_so_emit *so,
unsigned input_vertex_stride = so->input_vertex_stride;
struct draw_context *draw = so->draw;
const float (*input_ptr)[4];
- const struct pipe_stream_output_state *state =
+ const struct pipe_stream_output_info *state =
&draw->so.state;
float **buffer = 0;
diff --git a/src/gallium/drivers/llvmpipe/lp_state.h b/src/gallium/drivers/llvmpipe/lp_state.h
index 7893e9c..97ca172 100644
--- a/src/gallium/drivers/llvmpipe/lp_state.h
+++ b/src/gallium/drivers/llvmpipe/lp_state.h
@@ -86,7 +86,7 @@ struct lp_velems_state
};
struct lp_so_state {
- struct pipe_stream_output_state base;
+ struct pipe_stream_output_info base;
};
diff --git a/src/gallium/drivers/llvmpipe/lp_state_so.c b/src/gallium/drivers/llvmpipe/lp_state_so.c
index 35de52c..4874bd6 100644
--- a/src/gallium/drivers/llvmpipe/lp_state_so.c
+++ b/src/gallium/drivers/llvmpipe/lp_state_so.c
@@ -35,7 +35,7 @@
static void *
llvmpipe_create_stream_output_state(struct pipe_context *pipe,
- const struct pipe_stream_output_state *templ)
+ const struct pipe_stream_output_info *templ)
{
struct lp_so_state *so;
so = (struct lp_so_state *) CALLOC_STRUCT(lp_so_state);
diff --git a/src/gallium/drivers/nvc0/nvc0_state.c b/src/gallium/drivers/nvc0/nvc0_state.c
index 1a37d04..ebeeb7f 100644
--- a/src/gallium/drivers/nvc0/nvc0_state.c
+++ b/src/gallium/drivers/nvc0/nvc0_state.c
@@ -749,7 +749,7 @@ nvc0_vertex_state_bind(struct pipe_context *pipe, void *hwcso)
static void *
nvc0_tfb_state_create(struct pipe_context *pipe,
- const struct pipe_stream_output_state *pso)
+ const struct pipe_stream_output_info *pso)
{
struct nvc0_transform_feedback_state *so;
int n = 0;
diff --git a/src/gallium/drivers/softpipe/sp_state.h b/src/gallium/drivers/softpipe/sp_state.h
index ec4c8cf..bdda294 100644
--- a/src/gallium/drivers/softpipe/sp_state.h
+++ b/src/gallium/drivers/softpipe/sp_state.h
@@ -122,7 +122,7 @@ struct sp_velems_state {
};
struct sp_so_state {
- struct pipe_stream_output_state base;
+ struct pipe_stream_output_info base;
};
diff --git a/src/gallium/drivers/softpipe/sp_state_so.c b/src/gallium/drivers/softpipe/sp_state_so.c
index 40e5634..b0449cd 100644
--- a/src/gallium/drivers/softpipe/sp_state_so.c
+++ b/src/gallium/drivers/softpipe/sp_state_so.c
@@ -36,7 +36,7 @@
static void *
softpipe_create_stream_output_state(struct pipe_context *pipe,
- const struct pipe_stream_output_state *templ)
+ const struct pipe_stream_output_info *templ)
{
struct sp_so_state *so;
so = (struct sp_so_state *) CALLOC_STRUCT(sp_so_state);
diff --git a/src/gallium/include/pipe/p_context.h b/src/gallium/include/pipe/p_context.h
index b2d5f95..9a4d3ee 100644
--- a/src/gallium/include/pipe/p_context.h
+++ b/src/gallium/include/pipe/p_context.h
@@ -56,7 +56,7 @@ struct pipe_sampler_view;
struct pipe_scissor_state;
struct pipe_shader_state;
struct pipe_stencil_ref;
-struct pipe_stream_output_state;
+struct pipe_stream_output_target;
struct pipe_surface;
struct pipe_vertex_buffer;
struct pipe_vertex_element;
@@ -86,11 +86,6 @@ struct pipe_context {
/*@{*/
void (*draw_vbo)( struct pipe_context *pipe,
const struct pipe_draw_info *info );
-
- /**
- * Draw the stream output buffer at index 0
- */
- void (*draw_stream_output)( struct pipe_context *pipe, unsigned mode );
/*@}*/
/**
@@ -179,11 +174,6 @@ struct pipe_context {
void (*bind_vertex_elements_state)(struct pipe_context *, void *);
void (*delete_vertex_elements_state)(struct pipe_context *, void *);
- void * (*create_stream_output_state)(struct pipe_context *,
- const struct pipe_stream_output_state *);
- void (*bind_stream_output_state)(struct pipe_context *, void *);
- void (*delete_stream_output_state)(struct pipe_context*, void*);
-
/*@}*/
/**
@@ -237,13 +227,36 @@ struct pipe_context {
void (*set_index_buffer)( struct pipe_context *pipe,
const struct pipe_index_buffer * );
- void (*set_stream_output_buffers)(struct pipe_context *,
- struct pipe_resource **buffers,
- int *offsets, /*array of offsets
- from the start of each
- of the buffers */
- int num_buffers);
+ /*@}*/
+
+ /**
+ * Stream output functions.
+ */
+ /*@{*/
+
+ struct pipe_stream_output_target *(*create_stream_output_target)(
+ struct pipe_context *,
+ struct pipe_resource *,
+ unsigned buffer_offset,
+ unsigned buffer_size);
+
+ void (*stream_output_target_destroy)(struct pipe_context *,
+ struct pipe_stream_output_target *);
+ void (*set_stream_output_targets)(struct pipe_context *,
+ unsigned num_targets,
+ struct pipe_stream_output_target **targets);
+
+ /**
+ * By default, new data is appended at the end of stream output buffers.
+ * This call resets the internal offset to 0, such that new data is
+ * written starting at the beginning of the range specified by
+ * pipe_stream_output_target.
+ *
+ * This function doesn't change any context state or bindings. */
+ void (*reset_stream_output_targets)(struct pipe_context *,
+ unsigned num_targets,
+ struct pipe_stream_output_target **targets);
/*@}*/
diff --git a/src/gallium/include/pipe/p_defines.h b/src/gallium/include/pipe/p_defines.h
index acae4b1..a825fcd 100644
--- a/src/gallium/include/pipe/p_defines.h
+++ b/src/gallium/include/pipe/p_defines.h
@@ -472,7 +472,10 @@ enum pipe_cap {
PIPE_CAP_MIN_TEXEL_OFFSET = 50,
PIPE_CAP_MAX_TEXEL_OFFSET = 51,
PIPE_CAP_CONDITIONAL_RENDER = 52,
- PIPE_CAP_TEXTURE_BARRIER = 53
+ PIPE_CAP_TEXTURE_BARRIER = 53,
+ PIPE_CAP_MAX_STREAM_OUTPUT_SEPARATE_ATTRIBS = 54,
+ PIPE_CAP_MAX_STREAM_OUTPUT_SEPARATE_COMPONENTS = 55,
+ PIPE_CAP_MAX_STREAM_OUTPUT_INTERLEAVED_COMPONENTS = 56
};
/* Shader caps not specific to any single stage */
diff --git a/src/gallium/include/pipe/p_state.h b/src/gallium/include/pipe/p_state.h
index 37e0679..517d9bb 100644
--- a/src/gallium/include/pipe/p_state.h
+++ b/src/gallium/include/pipe/p_state.h
@@ -121,6 +121,12 @@ struct pipe_rasterizer_state
*/
unsigned gl_rasterization_rules:1;
+ /**
+ * When true, rasterization is disabled and no pixels are written.
+ * This only makes sense with the Stream Out functionality.
+ */
+ unsigned rasterizer_discard:1;
+
unsigned line_stipple_factor:8; /**< [1..256] actually */
unsigned line_stipple_pattern:16;
@@ -164,9 +170,28 @@ struct pipe_clip_state
};
+/**
+ * Stream output for vertex transform feedback.
+ */
+struct pipe_stream_output_info
+{
+ /** number of the output buffer to insert each element into */
+ unsigned output_buffer[PIPE_MAX_SHADER_OUTPUTS];
+ /** which register OUT[i] to grab each output from */
+ unsigned register_index[PIPE_MAX_SHADER_OUTPUTS];
+ /** TGSI_WRITEMASK signifying which components to output */
+ ubyte register_mask[PIPE_MAX_SHADER_OUTPUTS];
+ /** number of outputs */
+ unsigned num_outputs;
+ /** stride for an entire vertex, only used if all output_buffers are 0 */
+ unsigned stride;
+};
+
+
struct pipe_shader_state
{
const struct tgsi_token *tokens;
+ struct pipe_stream_output_info stream_output;
};
@@ -375,24 +400,6 @@ struct pipe_resource
/**
- * Stream output for vertex transform feedback.
- */
-struct pipe_stream_output_state
-{
- /** number of the output buffer to insert each element into */
- int output_buffer[PIPE_MAX_SHADER_OUTPUTS];
- /** which register to grab each output from */
- int register_index[PIPE_MAX_SHADER_OUTPUTS];
- /** TGSI_WRITEMASK signifying which components to output */
- ubyte register_mask[PIPE_MAX_SHADER_OUTPUTS];
- /** number of outputs */
- int num_outputs;
- /** stride for an entire vertex, only used if all output_buffers are 0 */
- unsigned stride;
-};
-
-
-/**
* Transfer object. For data transfer to/from a resource.
*/
struct pipe_transfer
@@ -422,6 +429,30 @@ struct pipe_vertex_buffer
/**
+ * A stream output target. The structure specifies the range vertices can
+ * be written to.
+ *
+ * In addition to that, the structure should internally maintain the offset
+ * into the buffer, which should be incremented everytime something is written
+ * (appended) to it. The internal offset is buffer_offset + how many bytes
+ * have been written. The internal offset can be stored on the device
+ * and the CPU actually doesn't have to query it.
+ *
+ * Use PIPE_QUERY_SO_STATISTICS to know how much vertices have
+ * actually been written.
+ */
+struct pipe_stream_output_target
+{
+ struct pipe_reference reference;
+ struct pipe_resource *buffer; /**< buffer into which this is a target view */
+ struct pipe_context *context; /**< context this view belongs to */
+
+ unsigned buffer_offset; /**< offset where data should be written, in bytes */
+ unsigned buffer_size; /**< how much data is allowed to be written */
+};
+
+
+/**
* Information to describe a vertex attribute (position, color, etc)
*/
struct pipe_vertex_element
@@ -481,6 +512,22 @@ struct pipe_draw_info
*/
boolean primitive_restart;
unsigned restart_index;
+
+ /**
+ * Stream output target. If not NULL, it's used to provide the 'count'
+ * parameter based on the number vertices captured by the stream output
+ * stage. (or generally, based on the number of bytes captured)
+ *
+ * Only 'mode', 'start_instance', and 'instance_count' are taken into
+ * account, all the other variables from pipe_draw_info are ignored.
+ *
+ * 'start' is implicitly 0 and 'count' is set as discussed above.
+ * The draw command is non-indexed.
+ *
+ * Note that this only provides the count. The vertex buffers must
+ * be set via set_vertex_buffers manually.
+ */
+ struct pipe_stream_output_target *count_from_stream_output;
};
--
1.7.4.1
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