Mesa (main): llvmpipe: use preferred attribute interpolation for wide lines

Mon Aug 23 16:06:22 UTC 2021

Module: Mesa
Branch: main
Commit: eb60d8c7b9cd9484a5afcf635f37895539f43f3d
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=eb60d8c7b9cd9484a5afcf635f37895539f43f3d

Author: Erik Faye-Lund <erik.faye-lund at collabora.com>
Date:   Wed Jun  9 14:15:54 2021 +0200

llvmpipe: use preferred attribute interpolation for wide lines

When rasterizing legacy-lines, OpenGL defines the width as being an
extrusion along the minor axis, repeating varyings. While the spec
*does* allow for an alternative method that matches our current results,
the OpenGL ES CTS doesn't allow these results even if OpenGL ES has the
same wording of an alternative method.

This is technically speaking a bug in the OpenGL ES CTS, but it seems
like nobody else is using the alternative formulation, at least not
while passing the OpenGL ES CTS. On top of this, the OpenGL specification
explicitly lists the extrusion results as the preferred method.

So it seems like a good idea for us to do this the way the OpenGL
specification prefers regardless; it's going to give less surprising
results to applications, and it's helping us pass some tests.

This math to set these up would "trivially" be:

dx = (dx * dx + dy * dy) / dx
dy = 0

and:

dy = (dx * dx + dy * dy) / dy
dx = 0

...but since we've already calculated dxdy, we can reformulate this to
save a division.

This fixes the following dEQP test-cases:
- dEQP-GLES2.functional.rasterization.interpolation.basic.line_loop_wide
- dEQP-GLES2.functional.rasterization.interpolation.basic.line_strip_wide
- dEQP-GLES2.functional.rasterization.interpolation.basic.lines_wide
- dEQP-GLES2.functional.rasterization.interpolation.projected.line_loop_wide
- dEQP-GLES2.functional.rasterization.interpolation.projected.line_strip_wide
- dEQP-GLES2.functional.rasterization.interpolation.projected.lines_wide
- dEQP-GLES3.functional.rasterization.fbo.rbo_singlesample.interpolation.lines_wide
- dEQP-GLES3.functional.rasterization.fbo.texture_2d.interpolation.lines_wide
- dEQP-GLES3.functional.rasterization.interpolation.basic.line_loop_wide
- dEQP-GLES3.functional.rasterization.interpolation.basic.line_strip_wide
- dEQP-GLES3.functional.rasterization.interpolation.basic.lines_wide
- dEQP-GLES3.functional.rasterization.interpolation.projected.line_loop_wide
- dEQP-GLES3.functional.rasterization.interpolation.projected.line_strip_wide
- dEQP-GLES3.functional.rasterization.interpolation.projected.lines_wide

Reviewed-by: Roland Scheidegger <sroland at vmware.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11315>

---

 src/gallium/drivers/llvmpipe/ci/deqp-llvmpipe-fails.txt | 14 --------------
 src/gallium/drivers/llvmpipe/lp_setup_line.c            |  8 ++++++++
 src/gallium/drivers/virgl/ci/deqp-virgl-gl-fails.txt    | 14 --------------
 src/gallium/drivers/virgl/ci/deqp-virgl-gles-fails.txt  | 14 --------------
 src/gallium/drivers/virgl/ci/traces-virgl.yml           |  4 ++--
 src/gallium/drivers/zink/ci/deqp-zink-lvp-fails.txt     | 14 --------------
 6 files changed, 10 insertions(+), 58 deletions(-)

diff --git a/src/gallium/drivers/llvmpipe/ci/deqp-llvmpipe-fails.txt b/src/gallium/drivers/llvmpipe/ci/deqp-llvmpipe-fails.txt
index 68c4c472176..e7c7b53f917 100644
--- a/src/gallium/drivers/llvmpipe/ci/deqp-llvmpipe-fails.txt
+++ b/src/gallium/drivers/llvmpipe/ci/deqp-llvmpipe-fails.txt
@@ -11,12 +11,6 @@ dEQP-EGL.functional.robustness.reset_context.shaders.infinite_loop.sync_status.v
 dEQP-GLES2.functional.clipping.line.wide_line_clip_viewport_center,Fail
 dEQP-GLES2.functional.clipping.line.wide_line_clip_viewport_corner,Fail
 dEQP-GLES2.functional.polygon_offset.default_displacement_with_units,Fail
-dEQP-GLES2.functional.rasterization.interpolation.basic.line_loop_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.basic.line_strip_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.basic.lines_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.projected.line_loop_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.projected.line_strip_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.projected.lines_wide,Fail
 dEQP-GLES3.functional.clipping.line.wide_line_clip_viewport_center,Fail
 dEQP-GLES3.functional.clipping.line.wide_line_clip_viewport_corner,Fail
 dEQP-GLES3.functional.fbo.blit.rect.nearest_consistency_mag,Fail
@@ -32,14 +26,6 @@ dEQP-GLES3.functional.fbo.blit.rect.nearest_consistency_min_reverse_src_x,Fail
 dEQP-GLES3.functional.polygon_offset.default_displacement_with_units,Fail
 dEQP-GLES3.functional.polygon_offset.fixed24_displacement_with_units,Fail
 dEQP-GLES3.functional.polygon_offset.float32_displacement_with_units,Fail
-dEQP-GLES3.functional.rasterization.fbo.rbo_singlesample.interpolation.lines_wide,Fail
-dEQP-GLES3.functional.rasterization.fbo.texture_2d.interpolation.lines_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.basic.line_loop_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.basic.line_strip_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.basic.lines_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.projected.line_loop_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.projected.line_strip_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.projected.lines_wide,Fail
 dEQP-GLES31.functional.primitive_bounding_box.wide_points.global_state.vertex_tessellation_fragment.default_framebuffer_bbox_equal,Fail
 dEQP-GLES31.functional.primitive_bounding_box.wide_points.global_state.vertex_tessellation_fragment.default_framebuffer_bbox_larger,Fail
 dEQP-GLES31.functional.primitive_bounding_box.wide_points.global_state.vertex_tessellation_fragment.fbo_bbox_equal,Fail
diff --git a/src/gallium/drivers/llvmpipe/lp_setup_line.c b/src/gallium/drivers/llvmpipe/lp_setup_line.c
index 2d1b9541629..756f24d2c33 100644
--- a/src/gallium/drivers/llvmpipe/lp_setup_line.c
+++ b/src/gallium/drivers/llvmpipe/lp_setup_line.c
@@ -426,6 +426,10 @@ try_setup_line( struct lp_setup_context *setup,
       will_draw_start = sign(-x1diff) != sign(dx);
       will_draw_end = (sign(x2diff) == sign(-dx)) || x2diff==0;
 
+      /* interpolate using the preferred wide-lines formula */
+      info.dx *= 1 + dydx * dydx;
+      info.dy = 0;
+
       if (dx < 0) {
          /* if v2 is to the right of v1, swap pointers */
          const float (*temp)[4] = v1;
@@ -523,6 +527,10 @@ try_setup_line( struct lp_setup_context *setup,
       will_draw_start = sign(y1diff) == sign(dy);
       will_draw_end = (sign(-y2diff) == sign(dy)) || y2diff==0;
 
+      /* interpolate using the preferred wide-lines formula */
+      info.dx = 0;
+      info.dy *= 1 + dxdy * dxdy;
+
       if (dy > 0) {
          /* if v2 is on top of v1, swap pointers */
          const float (*temp)[4] = v1;
diff --git a/src/gallium/drivers/virgl/ci/deqp-virgl-gl-fails.txt b/src/gallium/drivers/virgl/ci/deqp-virgl-gl-fails.txt
index 14918d83ff3..e43a699d7fe 100644
--- a/src/gallium/drivers/virgl/ci/deqp-virgl-gl-fails.txt
+++ b/src/gallium/drivers/virgl/ci/deqp-virgl-gl-fails.txt
@@ -4,12 +4,6 @@ dEQP-GLES2.functional.clipping.point.wide_point_clip,Fail
 dEQP-GLES2.functional.clipping.point.wide_point_clip_viewport_center,Fail
 dEQP-GLES2.functional.clipping.point.wide_point_clip_viewport_corner,Fail
 dEQP-GLES2.functional.polygon_offset.default_displacement_with_units,Fail
-dEQP-GLES2.functional.rasterization.interpolation.basic.line_loop_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.basic.line_strip_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.basic.lines_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.projected.line_loop_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.projected.line_strip_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.projected.lines_wide,Fail
 dEQP-GLES3.functional.clipping.line.wide_line_clip_viewport_center,Fail
 dEQP-GLES3.functional.clipping.line.wide_line_clip_viewport_corner,Fail
 dEQP-GLES3.functional.clipping.point.wide_point_clip,Fail
@@ -28,14 +22,6 @@ dEQP-GLES3.functional.fbo.blit.rect.nearest_consistency_min_reverse_src_x,Fail
 dEQP-GLES3.functional.polygon_offset.default_displacement_with_units,Fail
 dEQP-GLES3.functional.polygon_offset.fixed24_displacement_with_units,Fail
 dEQP-GLES3.functional.polygon_offset.float32_displacement_with_units,Fail
-dEQP-GLES3.functional.rasterization.fbo.rbo_singlesample.interpolation.lines_wide,Fail
-dEQP-GLES3.functional.rasterization.fbo.texture_2d.interpolation.lines_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.basic.line_loop_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.basic.line_strip_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.basic.lines_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.projected.line_loop_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.projected.line_strip_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.projected.lines_wide,Fail
 dEQP-GLES31.functional.draw_buffers_indexed.random.max_required_draw_buffers.4,Fail
 dEQP-GLES31.functional.draw_buffers_indexed.random.max_implementation_draw_buffers.8,Fail
 dEQP-GLES31.functional.image_load_store.buffer.image_size.writeonly_12,Fail
diff --git a/src/gallium/drivers/virgl/ci/deqp-virgl-gles-fails.txt b/src/gallium/drivers/virgl/ci/deqp-virgl-gles-fails.txt
index cf0ddaae9d5..29db955239d 100644
--- a/src/gallium/drivers/virgl/ci/deqp-virgl-gles-fails.txt
+++ b/src/gallium/drivers/virgl/ci/deqp-virgl-gles-fails.txt
@@ -4,12 +4,6 @@ dEQP-GLES2.functional.clipping.point.wide_point_clip,Fail
 dEQP-GLES2.functional.clipping.point.wide_point_clip_viewport_center,Fail
 dEQP-GLES2.functional.clipping.point.wide_point_clip_viewport_corner,Fail
 dEQP-GLES2.functional.polygon_offset.default_displacement_with_units,Fail
-dEQP-GLES2.functional.rasterization.interpolation.basic.line_loop_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.basic.line_strip_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.basic.lines_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.projected.line_loop_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.projected.line_strip_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.projected.lines_wide,Fail
 dEQP-GLES3.functional.clipping.line.wide_line_clip_viewport_center,Fail
 dEQP-GLES3.functional.clipping.line.wide_line_clip_viewport_corner,Fail
 dEQP-GLES3.functional.clipping.point.wide_point_clip,Fail
@@ -28,14 +22,6 @@ dEQP-GLES3.functional.fbo.blit.rect.nearest_consistency_min_reverse_src_x,Fail
 dEQP-GLES3.functional.polygon_offset.default_displacement_with_units,Fail
 dEQP-GLES3.functional.polygon_offset.fixed24_displacement_with_units,Fail
 dEQP-GLES3.functional.polygon_offset.float32_displacement_with_units,Fail
-dEQP-GLES3.functional.rasterization.fbo.rbo_singlesample.interpolation.lines_wide,Fail
-dEQP-GLES3.functional.rasterization.fbo.texture_2d.interpolation.lines_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.basic.line_loop_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.basic.line_strip_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.basic.lines_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.projected.line_loop_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.projected.line_strip_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.projected.lines_wide,Fail
 dEQP-GLES31.functional.draw_buffers_indexed.random.max_required_draw_buffers.4,Fail
 dEQP-GLES31.functional.draw_buffers_indexed.random.max_required_draw_buffers.9,Fail
 dEQP-GLES31.functional.image_load_store.buffer.image_size.readonly_12,Fail
diff --git a/src/gallium/drivers/virgl/ci/traces-virgl.yml b/src/gallium/drivers/virgl/ci/traces-virgl.yml
index baef5ecf5b2..e0c320eb013 100644
--- a/src/gallium/drivers/virgl/ci/traces-virgl.yml
+++ b/src/gallium/drivers/virgl/ci/traces-virgl.yml
@@ -179,7 +179,7 @@ traces:
   - path: gputest/plot3d.trace
     expectations:
       - device: gl-virgl
-        checksum: 0ebf993380210d9e5138f1057ddaa7ab
+        checksum: f3c0187ab2197c57e699135b7f42b8cc
 # Crash
 #  - path: gputest/tessmark.trace
 #    expectations:
@@ -192,7 +192,7 @@ traces:
   - path: humus/CelShading.trace
     expectations:
       - device: gl-virgl
-        checksum: 7d56b6ec4a1cf30406bceb9fe3e4d5c8
+        checksum: 0611c1680155a831f69a57554484c914
   - path: humus/DynamicBranching3.trace
     expectations:
       # speckling present on the ground that isn't there on other drivers.
diff --git a/src/gallium/drivers/zink/ci/deqp-zink-lvp-fails.txt b/src/gallium/drivers/zink/ci/deqp-zink-lvp-fails.txt
index a8fd68f8ae9..70823d3a26a 100644
--- a/src/gallium/drivers/zink/ci/deqp-zink-lvp-fails.txt
+++ b/src/gallium/drivers/zink/ci/deqp-zink-lvp-fails.txt
@@ -23,14 +23,6 @@ dEQP-GLES3.functional.multisample.fbo_4_samples.proportionality_sample_coverage,
 dEQP-GLES3.functional.multisample.fbo_4_samples.sample_coverage_invert,Fail
 dEQP-GLES3.functional.multisample.fbo_max_samples.proportionality_sample_coverage,Fail
 dEQP-GLES3.functional.multisample.fbo_max_samples.sample_coverage_invert,Fail
-dEQP-GLES3.functional.rasterization.fbo.rbo_singlesample.interpolation.lines_wide,Fail
-dEQP-GLES3.functional.rasterization.fbo.texture_2d.interpolation.lines_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.basic.line_loop_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.basic.line_strip_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.basic.lines_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.projected.line_loop_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.projected.line_strip_wide,Fail
-dEQP-GLES3.functional.rasterization.interpolation.projected.lines_wide,Fail
 KHR-GL32.transform_feedback.capture_geometry_separate_test,Fail
 KHR-GL32.transform_feedback.capture_vertex_interleaved_test,Fail
 KHR-GL32.transform_feedback.capture_vertex_separate_test,Fail
@@ -42,12 +34,6 @@ KHR-GL32.transform_feedback.query_vertex_interleaved_test,Fail
 KHR-GL32.transform_feedback.query_vertex_separate_test,Fail
 dEQP-GLES2.functional.clipping.line.wide_line_clip_viewport_center,Fail
 dEQP-GLES2.functional.clipping.line.wide_line_clip_viewport_corner,Fail
-dEQP-GLES2.functional.rasterization.interpolation.basic.line_loop_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.basic.line_strip_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.basic.lines_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.projected.line_loop_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.projected.line_strip_wide,Fail
-dEQP-GLES2.functional.rasterization.interpolation.projected.lines_wide,Fail
 KHR-GL32.packed_pixels.pbo_rectangle.r16i,Fail
 KHR-GL32.packed_pixels.pbo_rectangle.r16ui,Fail
 KHR-GL32.packed_pixels.pbo_rectangle.r32i,Fail

