[Mesa-dev] [PATCH 2/2] draw: inject frontface info into wireframe outputs
Zack Rusin
zackr at vmware.com
Wed Jul 31 04:38:16 PDT 2013
Draw module can decompose primitives into wireframe models, which
is a fancy word for 'lines', unfortunately that decomposition means
that we weren't able to preserve the original front-face info which
could be derived from the original primitives (lines don't have a
'face'). To fix it allow draw module to inject a fake face semantic
into outputs from which the backends can figure out the original
frontfacing info of the primitives.
Signed-off-by: Zack Rusin <zackr at vmware.com>
---
src/gallium/auxiliary/draw/draw_context.c | 43 ++++++++++++++++++++
src/gallium/auxiliary/draw/draw_context.h | 6 +++
src/gallium/auxiliary/draw/draw_pipe.h | 3 ++
src/gallium/auxiliary/draw/draw_pipe_unfilled.c | 49 +++++++++++++++++++++++
src/gallium/drivers/i915/i915_state_derived.c | 2 +
src/gallium/drivers/llvmpipe/lp_context.h | 3 ++
src/gallium/drivers/llvmpipe/lp_setup.c | 1 +
src/gallium/drivers/llvmpipe/lp_setup_context.h | 1 +
src/gallium/drivers/llvmpipe/lp_setup_line.c | 14 ++++++-
src/gallium/drivers/llvmpipe/lp_state_derived.c | 9 +++++
src/gallium/drivers/r300/r300_state_derived.c | 1 +
src/gallium/drivers/softpipe/sp_state_derived.c | 2 +
src/gallium/drivers/svga/svga_swtnl_state.c | 1 +
13 files changed, 133 insertions(+), 2 deletions(-)
diff --git a/src/gallium/auxiliary/draw/draw_context.c b/src/gallium/auxiliary/draw/draw_context.c
index 4a6ba1a..2e95b5c 100644
--- a/src/gallium/auxiliary/draw/draw_context.c
+++ b/src/gallium/auxiliary/draw/draw_context.c
@@ -39,6 +39,7 @@
#include "util/u_helpers.h"
#include "util/u_prim.h"
#include "draw_context.h"
+#include "draw_pipe.h"
#include "draw_vs.h"
#include "draw_gs.h"
@@ -540,6 +541,22 @@ draw_get_shader_info(const struct draw_context *draw)
}
}
+/**
+ * Prepare outputs slots from the draw module
+ *
+ * Certain parts of the draw module can emit additional
+ * outputs that can be quite useful to the backends, a good
+ * example of it is the process of decomposing primitives
+ * into wireframes (aka. lines) which normally would lose
+ * the face-side information, but using this method we can
+ * inject another shader output which passes the original
+ * face side information to the backend.
+ */
+void
+draw_prepare_shader_outputs(struct draw_context *draw)
+{
+ draw_unfilled_prepare_outputs(draw, draw->pipeline.unfilled);
+}
/**
* Ask the draw module for the location/slot of the given vertex attribute in
@@ -973,3 +990,29 @@ draw_stats_clipper_primitives(struct draw_context *draw,
}
}
}
+
+
+/**
+ * Returns true if the draw module will inject the frontface
+ * info into the outputs.
+ *
+ * Given the specified primitive and rasterizer state
+ * the function will figure out if the draw module
+ * will inject the front-face information into shader
+ * outputs. This is done to preserve the front-facing
+ * info when decomposing primitives into wireframes.
+ */
+boolean
+draw_will_inject_frontface(const struct draw_context *draw)
+{
+ unsigned reduced_prim = u_reduced_prim(draw->pt.prim);
+ const struct pipe_rasterizer_state *rast = draw->rasterizer;
+
+ if (reduced_prim != PIPE_PRIM_TRIANGLES) {
+ return FALSE;
+ }
+
+ return (rast &&
+ (rast->fill_front != PIPE_POLYGON_MODE_FILL ||
+ rast->fill_back != PIPE_POLYGON_MODE_FILL));
+}
diff --git a/src/gallium/auxiliary/draw/draw_context.h b/src/gallium/auxiliary/draw/draw_context.h
index 4a1b27e..0815047 100644
--- a/src/gallium/auxiliary/draw/draw_context.h
+++ b/src/gallium/auxiliary/draw/draw_context.h
@@ -126,10 +126,16 @@ draw_install_pstipple_stage(struct draw_context *draw, struct pipe_context *pipe
struct tgsi_shader_info *
draw_get_shader_info(const struct draw_context *draw);
+void
+draw_prepare_shader_outputs(struct draw_context *draw);
+
int
draw_find_shader_output(const struct draw_context *draw,
uint semantic_name, uint semantic_index);
+boolean
+draw_will_inject_frontface(const struct draw_context *draw);
+
uint
draw_num_shader_outputs(const struct draw_context *draw);
diff --git a/src/gallium/auxiliary/draw/draw_pipe.h b/src/gallium/auxiliary/draw/draw_pipe.h
index 4792507..2e48b56 100644
--- a/src/gallium/auxiliary/draw/draw_pipe.h
+++ b/src/gallium/auxiliary/draw/draw_pipe.h
@@ -102,6 +102,9 @@ void draw_pipe_passthrough_line(struct draw_stage *stage, struct prim_header *he
void draw_pipe_passthrough_point(struct draw_stage *stage, struct prim_header *header);
+void draw_unfilled_prepare_outputs(struct draw_context *context,
+ struct draw_stage *stage);
+
/**
* Get a writeable copy of a vertex.
diff --git a/src/gallium/auxiliary/draw/draw_pipe_unfilled.c b/src/gallium/auxiliary/draw/draw_pipe_unfilled.c
index d87741b..d8a603f 100644
--- a/src/gallium/auxiliary/draw/draw_pipe_unfilled.c
+++ b/src/gallium/auxiliary/draw/draw_pipe_unfilled.c
@@ -47,6 +47,8 @@ struct unfilled_stage {
* and PIPE_POLYGON_MODE_POINT,
*/
unsigned mode[2];
+
+ int face_slot;
};
@@ -55,8 +57,31 @@ static INLINE struct unfilled_stage *unfilled_stage( struct draw_stage *stage )
return (struct unfilled_stage *)stage;
}
+static void
+inject_front_face_info(struct draw_stage *stage,
+ struct prim_header *header)
+{
+ struct unfilled_stage *unfilled = unfilled_stage(stage);
+ unsigned ccw = header->det < 0.0;
+ boolean is_front_face = (
+ (stage->draw->rasterizer->front_ccw && ccw) ||
+ (!stage->draw->rasterizer->front_ccw && !ccw));
+ unsigned slot = unfilled->face_slot;
+ struct vertex_header *v0 = header->v[0];
+ struct vertex_header *v1 = header->v[1];
+ struct vertex_header *v2 = header->v[2];
+
+ /* In case the backend doesn't care about it */
+ if (slot < 0) {
+ return;
+ }
+ v0->data[slot][0] = is_front_face;
+ v1->data[slot][0] = is_front_face;
+ v2->data[slot][0] = is_front_face;
+}
+
static void point( struct draw_stage *stage,
struct vertex_header *v0 )
{
@@ -83,6 +108,8 @@ static void points( struct draw_stage *stage,
struct vertex_header *v1 = header->v[1];
struct vertex_header *v2 = header->v[2];
+ inject_front_face_info(stage, header);
+
if ((header->flags & DRAW_PIPE_EDGE_FLAG_0) && v0->edgeflag) point( stage, v0 );
if ((header->flags & DRAW_PIPE_EDGE_FLAG_1) && v1->edgeflag) point( stage, v1 );
if ((header->flags & DRAW_PIPE_EDGE_FLAG_2) && v2->edgeflag) point( stage, v2 );
@@ -99,6 +126,8 @@ static void lines( struct draw_stage *stage,
if (header->flags & DRAW_PIPE_RESET_STIPPLE)
stage->next->reset_stipple_counter( stage->next );
+ inject_front_face_info(stage, header);
+
if ((header->flags & DRAW_PIPE_EDGE_FLAG_2) && v2->edgeflag) line( stage, v2, v0 );
if ((header->flags & DRAW_PIPE_EDGE_FLAG_0) && v0->edgeflag) line( stage, v0, v1 );
if ((header->flags & DRAW_PIPE_EDGE_FLAG_1) && v1->edgeflag) line( stage, v1, v2 );
@@ -192,6 +221,26 @@ static void unfilled_destroy( struct draw_stage *stage )
FREE( stage );
}
+/*
+ * Try to allocate an output slot which we can use
+ * to preserve the front face information.
+ */
+void
+draw_unfilled_prepare_outputs( struct draw_context *draw,
+ struct draw_stage *stage )
+{
+ struct unfilled_stage *unfilled = unfilled_stage(stage);
+ const struct pipe_rasterizer_state *rast = draw ? draw->rasterizer : 0;
+ if (rast &&
+ (rast->fill_front != PIPE_POLYGON_MODE_FILL ||
+ rast->fill_back != PIPE_POLYGON_MODE_FILL)) {
+ unfilled->face_slot = draw_alloc_extra_vertex_attrib(
+ stage->draw, TGSI_SEMANTIC_FACE, 0);
+ } else {
+ unfilled->face_slot = -1;
+ }
+}
+
/**
* Create unfilled triangle stage.
diff --git a/src/gallium/drivers/i915/i915_state_derived.c b/src/gallium/drivers/i915/i915_state_derived.c
index e01f16e..e1d1840 100644
--- a/src/gallium/drivers/i915/i915_state_derived.c
+++ b/src/gallium/drivers/i915/i915_state_derived.c
@@ -67,6 +67,8 @@ static void calculate_vertex_layout(struct i915_context *i915)
colors[0] = colors[1] = fog = needW = face = FALSE;
memset(&vinfo, 0, sizeof(vinfo));
+ draw_prepare_shader_outputs(i915->draw);
+
/* Determine which fragment program inputs are needed. Setup HW vertex
* layout below, in the HW-specific attribute order.
*/
diff --git a/src/gallium/drivers/llvmpipe/lp_context.h b/src/gallium/drivers/llvmpipe/lp_context.h
index 9495e42..fc948a7 100644
--- a/src/gallium/drivers/llvmpipe/lp_context.h
+++ b/src/gallium/drivers/llvmpipe/lp_context.h
@@ -122,6 +122,9 @@ struct llvmpipe_context {
/** Which geometry shader output slot contains layer */
int layer_slot;
+ /** A fake frontface output for unfilled primitives */
+ int face_slot;
+
/**< minimum resolvable depth value, for polygon offset */
double mrd;
diff --git a/src/gallium/drivers/llvmpipe/lp_setup.c b/src/gallium/drivers/llvmpipe/lp_setup.c
index 65f61ed..5fde01f 100644
--- a/src/gallium/drivers/llvmpipe/lp_setup.c
+++ b/src/gallium/drivers/llvmpipe/lp_setup.c
@@ -1053,6 +1053,7 @@ lp_setup_update_state( struct lp_setup_context *setup,
setup->psize = lp->psize_slot;
setup->viewport_index_slot = lp->viewport_index_slot;
setup->layer_slot = lp->layer_slot;
+ setup->face_slot = lp->face_slot;
assert(lp->dirty == 0);
diff --git a/src/gallium/drivers/llvmpipe/lp_setup_context.h b/src/gallium/drivers/llvmpipe/lp_setup_context.h
index 89c23bb..ea1d0d6 100644
--- a/src/gallium/drivers/llvmpipe/lp_setup_context.h
+++ b/src/gallium/drivers/llvmpipe/lp_setup_context.h
@@ -106,6 +106,7 @@ struct lp_setup_context
float psize;
unsigned viewport_index_slot;
unsigned layer_slot;
+ unsigned face_slot;
struct pipe_framebuffer_state fb;
struct u_rect framebuffer;
diff --git a/src/gallium/drivers/llvmpipe/lp_setup_line.c b/src/gallium/drivers/llvmpipe/lp_setup_line.c
index bfed59c..3b16163 100644
--- a/src/gallium/drivers/llvmpipe/lp_setup_line.c
+++ b/src/gallium/drivers/llvmpipe/lp_setup_line.c
@@ -37,6 +37,7 @@
#include "lp_state_fs.h"
#include "lp_state_setup.h"
#include "lp_context.h"
+#include "draw/draw_context.h"
#define NUM_CHANNELS 4
@@ -45,6 +46,7 @@ struct lp_line_info {
float dx;
float dy;
float oneoverarea;
+ boolean frontfacing;
const float (*v1)[4];
const float (*v2)[4];
@@ -214,7 +216,8 @@ static void setup_line_coefficients( struct lp_setup_context *setup,
case LP_INTERP_FACING:
for (i = 0; i < NUM_CHANNELS; i++)
if (usage_mask & (1 << i))
- constant_coef(setup, info, slot+1, 1.0, i);
+ constant_coef(setup, info, slot+1,
+ info->frontfacing ? 1.0f : -1.0f, i);
break;
default:
@@ -613,15 +616,22 @@ try_setup_line( struct lp_setup_context *setup,
plane[2].dcdx = y[2] - y[3];
plane[3].dcdx = y[3] - y[0];
+ if (draw_will_inject_frontface(lp_context->draw) &&
+ setup->face_slot > 0) {
+ line->inputs.frontfacing = v1[setup->face_slot][0];
+ } else {
+ line->inputs.frontfacing = TRUE;
+ }
+
/* Setup parameter interpolants:
*/
info.a0 = GET_A0(&line->inputs);
info.dadx = GET_DADX(&line->inputs);
info.dady = GET_DADY(&line->inputs);
+ info.frontfacing = line->inputs.frontfacing;
setup_line_coefficients(setup, &info);
- line->inputs.frontfacing = TRUE;
line->inputs.disable = FALSE;
line->inputs.opaque = FALSE;
line->inputs.layer = layer;
diff --git a/src/gallium/drivers/llvmpipe/lp_state_derived.c b/src/gallium/drivers/llvmpipe/lp_state_derived.c
index dc80358..5a51b50 100644
--- a/src/gallium/drivers/llvmpipe/lp_state_derived.c
+++ b/src/gallium/drivers/llvmpipe/lp_state_derived.c
@@ -53,6 +53,8 @@ compute_vertex_info(struct llvmpipe_context *llvmpipe)
int vs_index;
uint i;
+ draw_prepare_shader_outputs(llvmpipe->draw);
+
llvmpipe->color_slot[0] = -1;
llvmpipe->color_slot[1] = -1;
llvmpipe->bcolor_slot[0] = -1;
@@ -138,6 +140,13 @@ compute_vertex_info(struct llvmpipe_context *llvmpipe)
llvmpipe->layer_slot = 0;
}
+ /* Check for a fake front face for unfilled primitives*/
+ vs_index = draw_find_shader_output(llvmpipe->draw,
+ TGSI_SEMANTIC_FACE, 0);
+ if (vs_index >= 0) {
+ llvmpipe->face_slot = vinfo->num_attribs;
+ draw_emit_vertex_attr(vinfo, EMIT_4F, INTERP_CONSTANT, vs_index);
+ }
draw_compute_vertex_size(vinfo);
lp_setup_set_vertex_info(llvmpipe->setup, vinfo);
diff --git a/src/gallium/drivers/r300/r300_state_derived.c b/src/gallium/drivers/r300/r300_state_derived.c
index 1013557..da86cd2 100644
--- a/src/gallium/drivers/r300/r300_state_derived.c
+++ b/src/gallium/drivers/r300/r300_state_derived.c
@@ -1079,6 +1079,7 @@ void r300_update_derived_state(struct r300_context* r300)
if (r300->draw) {
memset(&r300->vertex_info, 0, sizeof(struct vertex_info));
+ draw_prepare_shader_outputs(r300->draw);
r300_draw_emit_all_attribs(r300);
draw_compute_vertex_size(&r300->vertex_info);
r300_swtcl_vertex_psc(r300);
diff --git a/src/gallium/drivers/softpipe/sp_state_derived.c b/src/gallium/drivers/softpipe/sp_state_derived.c
index 6115349..9aa97d2 100644
--- a/src/gallium/drivers/softpipe/sp_state_derived.c
+++ b/src/gallium/drivers/softpipe/sp_state_derived.c
@@ -65,6 +65,8 @@ softpipe_get_vertex_info(struct softpipe_context *softpipe)
{
struct vertex_info *vinfo = &softpipe->vertex_info;
+ draw_prepare_shader_outputs(softpipe->draw);
+
if (vinfo->num_attribs == 0) {
/* compute vertex layout now */
const struct tgsi_shader_info *fsInfo = &softpipe->fs_variant->info;
diff --git a/src/gallium/drivers/svga/svga_swtnl_state.c b/src/gallium/drivers/svga/svga_swtnl_state.c
index d744f18..d60af3f 100644
--- a/src/gallium/drivers/svga/svga_swtnl_state.c
+++ b/src/gallium/drivers/svga/svga_swtnl_state.c
@@ -162,6 +162,7 @@ svga_swtnl_update_vdecl( struct svga_context *svga )
memset(vinfo, 0, sizeof(*vinfo));
memset(vdecl, 0, sizeof(vdecl));
+ draw_prepare_shader_outputs(draw);
/* always add position */
src = draw_find_shader_output(draw, TGSI_SEMANTIC_POSITION, 0);
draw_emit_vertex_attr(vinfo, EMIT_4F, INTERP_LINEAR, src);
--
1.7.10.4
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