[Mesa-dev] [PATCH] i965: Fix start/base_vertex_location for >1 prims but !BRW_NEW_VERTICES.
Kenneth Graunke
kenneth at whitecape.org
Thu Dec 18 04:45:40 PST 2014
This is a partial revert of c89306983c07e5a88c0d636267e5ccf263cb4213.
It split the {start,base}_vertex_location handling into several steps:
1. Set brw->draw.start_vertex_location = prim[i].start
and brw->draw.base_vertex_location = prim[i].basevertex.
(This happened once per _mesa_prim, in the main drawing loop.)
2. Add brw->vb.start_vertex_bias and brw->ib.start_vertex_offset
appropriately. (This happened in brw_prepare_shader_draw_parameters,
which was called just after brw_prepare_vertices, as part of state
upload, and only happened when BRW_NEW_VERTICES was flagged.)
3. Use those values when emitting 3DPRIMITIVE (once per _mesa_prim).
If we drew multiple _mesa_prims, but didn't flag BRW_NEW_VERTICES on
the second (or later) primitives, we would do step #1, but not #2.
The first _mesa_prim would get correct values, but subsequent ones
would only get the first half of the summation.
The reason I originally did this was because I needed the value of
gl_BaseVertexARB to exist in a buffer object prior to uploading
3DSTATE_VERTEX_BUFFERS. I believed I wanted to upload the value
of 3DPRIMITIVE's "Base Vertex Location" field, which was computed
as: (prims[i].indexed ? prims[i].start : prims[i].basevertex) +
brw->vb.start_vertex_bias. The latter value wasn't available until
after brw_prepare_vertices, and the former weren't available in the
state upload code at all. Hence the awkward split.
However, I believe that including brw->vb.start_vertex_bias was a
mistake. It's an extra bias we apply when uploading vertex data into
VBOs, to move [min_index, max_index] to [0, max_index - min_index].
>From the GL_ARB_shader_draw_parameters specification:
"<gl_BaseVertexARB> holds the integer value passed to the <baseVertex>
parameter to the command that resulted in the current shader
invocation. In the case where the command has no <baseVertex>
parameter, the value of <gl_BaseVertexARB> is zero."
I conclude that gl_BaseVertexARB should only include the baseVertex
parameter from glDraw*Elements*, not any internal biases we add for
optimization purposes.
With that in mind, gl_BaseVertexARB only needs prim[i].start or
prim[i].basevertex. We can simply store that, and go back to computing
start_vertex_location and base_vertex_location in brw_emit_prim(), like
we used to. This is much simpler, and should actually fix two bugs.
Fixes missing geometry in Unvanquished.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=85529
Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
Cc: vcelestialragev at gmail.com
Cc: andrieuguillaume42 at gmail.com
Cc: idr at freedesktop.org
---
src/mesa/drivers/dri/i965/brw_context.h | 7 ++-----
src/mesa/drivers/dri/i965/brw_draw.c | 15 ++++++++++-----
src/mesa/drivers/dri/i965/brw_draw_upload.c | 12 +-----------
3 files changed, 13 insertions(+), 21 deletions(-)
Passes Piglit on Haswell. Appears to pass all relevant tests in the
ES3 conformance suite as well...
diff --git a/src/mesa/drivers/dri/i965/brw_context.h b/src/mesa/drivers/dri/i965/brw_context.h
index a63c483..fde4177 100644
--- a/src/mesa/drivers/dri/i965/brw_context.h
+++ b/src/mesa/drivers/dri/i965/brw_context.h
@@ -1110,11 +1110,8 @@ struct brw_context
uint32_t pma_stall_bits;
struct {
- /** Does the current draw use the index buffer? */
- bool indexed;
-
- int start_vertex_location;
- int base_vertex_location;
+ /** The value of gl_BaseVertex for the current _mesa_prim. */
+ int gl_basevertex;
/**
* Buffer and offset used for GL_ARB_shader_draw_parameters
diff --git a/src/mesa/drivers/dri/i965/brw_draw.c b/src/mesa/drivers/dri/i965/brw_draw.c
index c581cc0..87cda36 100644
--- a/src/mesa/drivers/dri/i965/brw_draw.c
+++ b/src/mesa/drivers/dri/i965/brw_draw.c
@@ -182,14 +182,20 @@ static void brw_emit_prim(struct brw_context *brw,
DBG("PRIM: %s %d %d\n", _mesa_lookup_enum_by_nr(prim->mode),
prim->start, prim->count);
+ int start_vertex_location = prim->start;
+ int base_vertex_location = prim->basevertex;
+
if (prim->indexed) {
vertex_access_type = brw->gen >= 7 ?
GEN7_3DPRIM_VERTEXBUFFER_ACCESS_RANDOM :
GEN4_3DPRIM_VERTEXBUFFER_ACCESS_RANDOM;
+ start_vertex_location += brw->ib.start_vertex_offset;
+ base_vertex_location += brw->vb.start_vertex_bias;
} else {
vertex_access_type = brw->gen >= 7 ?
GEN7_3DPRIM_VERTEXBUFFER_ACCESS_SEQUENTIAL :
GEN4_3DPRIM_VERTEXBUFFER_ACCESS_SEQUENTIAL;
+ start_vertex_location += brw->vb.start_vertex_bias;
}
/* We only need to trim the primitive count on pre-Gen6. */
@@ -264,10 +270,10 @@ static void brw_emit_prim(struct brw_context *brw,
vertex_access_type);
}
OUT_BATCH(verts_per_instance);
- OUT_BATCH(brw->draw.start_vertex_location);
+ OUT_BATCH(start_vertex_location);
OUT_BATCH(prim->num_instances);
OUT_BATCH(prim->base_instance);
- OUT_BATCH(brw->draw.base_vertex_location);
+ OUT_BATCH(base_vertex_location);
ADVANCE_BATCH();
/* Only used on Sandybridge; harmless to set elsewhere. */
@@ -471,9 +477,8 @@ static void brw_try_draw_prims( struct gl_context *ctx,
}
}
- brw->draw.indexed = prims[i].indexed;
- brw->draw.start_vertex_location = prims[i].start;
- brw->draw.base_vertex_location = prims[i].basevertex;
+ brw->draw.gl_basevertex =
+ prims[i].indexed ? prims[i].basevertex : prims[i].start;
drm_intel_bo_unreference(brw->draw.draw_params_bo);
diff --git a/src/mesa/drivers/dri/i965/brw_draw_upload.c b/src/mesa/drivers/dri/i965/brw_draw_upload.c
index 6e0cf3e..8123da8 100644
--- a/src/mesa/drivers/dri/i965/brw_draw_upload.c
+++ b/src/mesa/drivers/dri/i965/brw_draw_upload.c
@@ -604,19 +604,9 @@ brw_prepare_vertices(struct brw_context *brw)
void
brw_prepare_shader_draw_parameters(struct brw_context *brw)
{
- int *gl_basevertex_value;
- if (brw->draw.indexed) {
- brw->draw.start_vertex_location += brw->ib.start_vertex_offset;
- brw->draw.base_vertex_location += brw->vb.start_vertex_bias;
- gl_basevertex_value = &brw->draw.base_vertex_location;
- } else {
- brw->draw.start_vertex_location += brw->vb.start_vertex_bias;
- gl_basevertex_value = &brw->draw.start_vertex_location;
- }
-
/* For non-indirect draws, upload gl_BaseVertex. */
if (brw->vs.prog_data->uses_vertexid && brw->draw.draw_params_bo == NULL) {
- intel_upload_data(brw, gl_basevertex_value, 4, 4,
+ intel_upload_data(brw, &brw->draw.gl_basevertex, 4, 4,
&brw->draw.draw_params_bo,
&brw->draw.draw_params_offset);
}
--
2.1.3
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