Bug 1453935 - Ensure that we snap within the visible rect with WebRender. r=kvark

Differential Revision: https://phabricator.services.mozilla.com/D18869

gfx/wr/webrender/res/prim_shared.glsl

@@ -102,11 +102,15 @@ VertexInfo write_vertex(RectWithSize instance_rect,
     // Clamp to the two local clip rects.
     vec2 clamped_local_pos = clamp_rect(local_pos, local_clip_rect);
 
+    // Compute the visible rect to snap against. This ensures segments along the
+    // edges are snapped consistently with other nearby primitives.
+    RectWithSize visible_rect = intersect_rects(local_clip_rect, snap_rect);
+
     /// Compute the snapping offset.
     vec2 snap_offset = compute_snap_offset(
         clamped_local_pos,
         transform.m,
-        snap_rect,
+        visible_rect,
         task.common_data.device_pixel_scale
     );
 

gfx/wr/webrender/src/prim_store/mod.rs

@@ -51,7 +51,7 @@ use std::sync::atomic::{AtomicUsize, Ordering};
 use storage;
 use util::{ScaleOffset, MatrixHelpers, MaxRect, Recycler, TransformedRectKind};
 use util::{pack_as_float, project_rect, raster_rect_to_device_pixels};
-use util::{scale_factors, clamp_to_scale_factor, RectHelpers};
+use util::{scale_factors, clamp_to_scale_factor};
 use smallvec::SmallVec;
 
 pub mod borders;
@@ -3535,9 +3535,9 @@ fn compute_snap_offset_impl(
     )
 }
 
-/// Retrieve the exact device space rectangle for a primitive, taking
-/// into account the snapping that the shaders will apply if the transform
-/// is axis-aligned.
+/// Retrieve the exact unsnapped device space rectangle for a primitive.
+/// If the transform is axis-aligned, compute the snapping offsets that
+/// the shaders will apply.
 fn get_unclipped_device_rect(
     prim_spatial_node_index: SpatialNodeIndex,
     root_spatial_node_index: SpatialNodeIndex,
@@ -3582,11 +3582,7 @@ fn get_unclipped_device_rect(
                 bottom_right,
             };
 
-            let p0 = unclipped_device_rect.origin + top_left;
-            let p1 = unclipped_device_rect.bottom_right() + bottom_right;
-            let unclipped = DeviceRect::from_floats(p0.x, p0.y, p1.x, p1.y);
-
-            Some((unclipped, snap_offsets))
+            Some((unclipped_device_rect, snap_offsets))
         }
         TransformedRectKind::Complex => {
             Some((unclipped_device_rect, SnapOffsets::empty()))

gfx/wr/wrench/reftests/border/reftest.list

@@ -14,7 +14,7 @@ platform(linux,mac) == border-suite-3.yaml border-suite-3.png
 == border-double-simple-2.yaml border-double-simple-2-ref.yaml
 fuzzy(64,24) == border-groove-simple.yaml border-groove-simple-ref.yaml
 fuzzy(64,24) == border-ridge-simple.yaml border-ridge-simple-ref.yaml
-platform(linux,mac) fuzzy(1,2) == degenerate-curve.yaml degenerate-curve.png
+platform(linux,mac) fuzzy(1,3) == degenerate-curve.yaml degenerate-curve.png
 platform(linux,mac) == border-image.yaml border-image-ref.png
 == border-image-crash.yaml border-image-crash-ref.yaml
 == border-image-fill.yaml border-image-fill-ref.png

gfx/wr/wrench/reftests/boxshadow/reftest.list

@@ -34,4 +34,4 @@ fuzzy(1,5) platform(linux,mac) == box-shadow-huge-radius.yaml box-shadow-huge-ra
 
 platform(linux,mac) == box-shadow-large-blur-radius-2.yaml box-shadow-large-blur-radius-2.png
 platform(linux,mac) == box-shadow-large-blur-radius-3.yaml box-shadow-large-blur-radius-3.png
-platform(linux,mac) == scale.yaml scale.png
+platform(linux,mac) fuzzy(1,79) == scale.yaml scale.png

gfx/wr/wrench/reftests/transforms/reftest.list

@@ -25,7 +25,7 @@ platform(linux,mac) == perspective-mask.yaml perspective-mask.png
 rotate-clip.yaml rotate-clip-ref.yaml
 clip-translate.yaml clip-translate-ref.yaml
 platform(linux,mac) == perspective-clip.yaml perspective-clip.png
-platform(linux,mac) == perspective-clip-1.yaml perspective-clip-1.png
+platform(linux,mac) fuzzy(1,2) == perspective-clip-1.yaml perspective-clip-1.png
 platform(linux,mac) fuzzy(1,2) == perspective-shadow.yaml perspective-shadow.png
 == complex-preserve-3d.yaml blank.yaml
 platform(linux,mac) fuzzy(9,348) == perspective-border-radius.yaml perspective-border-radius.png

layout/reftests/border-image/reftest.list

@@ -48,14 +48,14 @@ fuzzy(0-1,0-149) fuzzy-if(OSX,0-1,0-10595) fuzzy-if(webrender,1-3,24999-25136) =
 fuzzy(0-1,0-433) fuzzy-if(skiaContent,0-1,0-2500) fuzzy-if(webrender,1-3,84138-85584) == border-image-linear-gradient-slice-fill-1.html border-image-linear-gradient-slice-fill-1-ref.html
 fuzzy(0-1,0-177) fuzzy-if(OSX,0-1,0-25771) fuzzy-if(skiaContent&&!Android,0-1,0-400) fuzzy-if(Android,0-1,0-6093) fuzzy-if(webrender,1-3,57249-57464) == border-image-linear-gradient-slice-fill-2.html border-image-linear-gradient-slice-fill-2-ref.html
 fuzzy(0-1,0-48)  fuzzy-if(OSX,0-5,0-1676) fuzzy-if(webrender,1-1,4464-4537) == border-image-linear-gradient-width.html border-image-linear-gradient-width-ref.html
-fuzzy(0-1,0-5000) fuzzy-if(OSX,0-1,0-15000) fuzzy-if(webrender,2-2,58629-58936) == border-image-linear-gradient-slice-width.html border-image-linear-gradient-slice-width-ref.html
-fuzzy(0-1,0-3000) fuzzy-if(OSX,0-1,0-6000) fuzzy-if(webrender,1-3,26067-26413) == border-image-linear-gradient-outset.html border-image-linear-gradient-outset-ref.html
+fuzzy(0-1,0-5000) fuzzy-if(OSX,0-1,0-15000) fuzzy-if(webrender,2-2,58629-58939) == border-image-linear-gradient-slice-width.html border-image-linear-gradient-slice-width-ref.html
+fuzzy(0-1,0-3000) fuzzy-if(OSX,0-1,0-6000) fuzzy-if(webrender,1-3,25940-26413) == border-image-linear-gradient-outset.html border-image-linear-gradient-outset-ref.html
 fuzzy(0-1,0-12) fuzzy-if(skiaContent,0-1,0-400) fuzzy-if(webrender,1-3,26195-26872) == border-image-linear-gradient-repeat-repeat-1.html border-image-linear-gradient-repeat-repeat-1-ref.html
 fuzzy(0-1,0-13) fuzzy-if(skiaContent,0-1,0-300) fuzzy-if(webrender,1-3,26168-27131) == border-image-linear-gradient-repeat-round-1.html border-image-linear-gradient-repeat-round-1-ref.html
 fuzzy-if(webrender,1-3,64826-67805) == border-image-linear-gradient-repeat-repeat-2.html border-image-linear-gradient-repeat-repeat-2-ref.html
 fuzzy(0-1,0-576) fuzzy-if(skiaContent,0-1,0-2000) fuzzy-if(webrender,1-2,64575-68383) == border-image-linear-gradient-repeat-round-2.html border-image-linear-gradient-repeat-round-2-ref.html
 fuzzy(0-1,0-8533) fuzzy-if(webrender,1-3,84604-85925) == border-image-linear-gradient-repeat-repeat-3.html border-image-linear-gradient-repeat-repeat-3-ref.html
-fuzzy(0-1,0-7161) fuzzy-if(webrender,2-3,92540-93290) == border-image-linear-gradient-repeat-round-3.html border-image-linear-gradient-repeat-round-3-ref.html
+fuzzy(0-1,0-7161) fuzzy-if(webrender,1-3,85706-86037) == border-image-linear-gradient-repeat-round-3.html border-image-linear-gradient-repeat-round-3-ref.html
 
 fuzzy-if(webrender,0-1,0-2096) == border-image-radial-gradient.html border-image-radial-gradient-ref.html
 fuzzy(0-1,0-42) fuzzy-if(skiaContent,0-2,0-20) fuzzy-if(webrender,0-1,0-37818) == border-image-radial-gradient-slice-1.html border-image-radial-gradient-slice-1-ref.html

layout/reftests/bugs/reftest.list

@@ -318,7 +318,7 @@ fuzzy-if(Android,0-3,0-50) fuzzy-if(skiaContent,0-1,0-133) == 273681-1.html 2736
 == 283686-2.html 283686-2-ref.html
 == 283686-3.html about:blank
 == 289384-1.xhtml 289384-ref.xhtml
-fails-if(webrender&&gtkWidget) random-if(d2d) fuzzy-if(webrender&&cocoaWidget,1-2,400-900) fuzzy-if(Android,0-8,0-1439) HTTP == 289480.html#top 289480-ref.html # basically-verbatim acid2 test, HTTP for a 404 page -- bug 578114 for the d2d failures
+random-if(d2d) fuzzy-if(Android,0-8,0-1439) fuzzy-if(webrender,0-6,0-1124) HTTP == 289480.html#top 289480-ref.html # basically-verbatim acid2 test, HTTP for a 404 page -- bug 578114 for the d2d failures
 == 290129-1.html 290129-1-ref.html
 == 291078-1.html 291078-1-ref.html
 == 291078-2.html 291078-2-ref.html

layout/reftests/css-gradients/reftest.list

@@ -27,7 +27,7 @@ fuzzy-if(!contentSameGfxBackendAsCanvas,0-3,0-88500) fuzzy-if(azureSkiaGL||skiaC
 fuzzy-if(!contentSameGfxBackendAsCanvas,0-3,0-88500) fuzzy-if(azureSkiaGL||skiaContent,0-3,0-89700) == linear-vertical-1b.html linear-vertical-1-ref.html
 fuzzy-if(!contentSameGfxBackendAsCanvas,0-3,0-88500) fuzzy-if(azureSkiaGL||skiaContent,0-3,0-89700) == linear-vertical-1c.html linear-vertical-1-ref.html
 fuzzy-if(!contentSameGfxBackendAsCanvas,0-3,0-88500) fuzzy-if(azureSkiaGL||skiaContent,0-3,0-89700) == linear-vertical-1d.html linear-vertical-1-ref.html
-fuzzy-if(webrender&&cocoaWidget,0-1,0-98) == linear-vertical-subpixel-1.html linear-vertical-subpixel-1-ref.html
+fuzzy-if(webrender,0-3,0-21070) == linear-vertical-subpixel-1.html linear-vertical-subpixel-1-ref.html
 == linear-viewport.html linear-viewport-ref.html
 == nostops.html about:blank
 == onestop.html about:blank

layout/reftests/w3c-css/submitted/images3/reftest.list

@@ -185,9 +185,9 @@ fails-if(!webrender) random-if(webrender) == object-position-svg-001e.html objec
 == object-position-svg-001i.html object-position-svg-001-ref.html
 fails-if(!webrender) random-if(webrender) == object-position-svg-001o.html object-position-svg-001-ref.html # bug 1103286
 == object-position-svg-001p.html object-position-svg-001-ref.html
-fails-if(!webrender) == object-position-svg-002e.html object-position-svg-002-ref.html # bug 1103286
+fails == object-position-svg-002e.html object-position-svg-002-ref.html # bug 1103286
 == object-position-svg-002i.html object-position-svg-002-ref.html
-fails-if(!webrender) == object-position-svg-002o.html object-position-svg-002-ref.html # bug 1103286
+fails == object-position-svg-002o.html object-position-svg-002-ref.html # bug 1103286
 == object-position-svg-002p.html object-position-svg-002-ref.html
 
 # Tests for gradient color stops with 'currentcolor'

widget/reftests/reftest.list

@@ -1,5 +1,5 @@
 == progressbar-fallback-default-style.html progressbar-fallback-default-style-ref.html
-fuzzy-if(Android,0-17,0-1120) fuzzy-if(webrender&&winWidget,0-1,0-5) == meter-native-style.html meter-native-style-ref.html
+fuzzy-if(Android,0-17,0-1120) fuzzy-if(webrender,0-8,0-480) == meter-native-style.html meter-native-style-ref.html
 skip-if(!cocoaWidget) == meter-vertical-native-style.html meter-vertical-native-style-ref.html # dithering
 == meter-fallback-default-style.html meter-fallback-default-style-ref.html
 load 664925.xhtml