1447093 - White vertical line on icon edge with WebRender enabled

Status: RESOLVED WORKSFORME

(Core :: Graphics: WebRender, defect, P1)

Description

[Chris Peterson [:cpeterson]]

Attachment: Screenshot.jpg

STR:
1. Enable gfx.webrender.all = true
2. Load https://asoftmurmur.com/
3. Look at the rain cloud icon on the left side of the page.

RESULT:
There is a faint white vertical line on the left edge of the rain cloud icon. See the attached screenshot.

I bisected this regression to bug 1437572 in pushlog:

https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=0e1ed4c7224223059730320c6de910947337c216&tochange=751d00a65e68ad9075071de8bd72e37488c398ea

Here is the graphics section from my about:support:

Application Basics
------------------

Name: Firefox
Version: 61.0a1
Build ID: 20180319100039
Update Channel: nightly
User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0
OS: Windows_NT 10.0
Multiprocess Windows: 3/3 (Enabled by user)
Web Content Processes: 8/7
Stylo: content = true (enabled by default), chrome = true (enabled by default)
Enterprise Policies: Inactive
Google Key: Found
Mozilla Location Service Key: Found
Safe Mode: false

Graphics
--------

Features
Compositing: WebRender
Asynchronous Pan/Zoom: wheel input enabled; touch input enabled; scrollbar drag enabled; keyboard enabled; autoscroll enabled
WebGL 1 Driver WSI Info: EGL_VENDOR: Google Inc. (adapter LUID: 000000000000ba78) EGL_VERSION: 1.4 (ANGLE 2.1.0.27cef491162b) EGL_EXTENSIONS: EGL_EXT_create_context_robustness EGL_ANGLE_d3d_share_handle_client_buffer EGL_ANGLE_d3d_texture_client_buffer EGL_ANGLE_surface_d3d_texture_2d_share_handle EGL_ANGLE_query_surface_pointer EGL_ANGLE_window_fixed_size EGL_ANGLE_keyed_mutex EGL_ANGLE_surface_orientation EGL_ANGLE_direct_composition EGL_NV_post_sub_buffer EGL_KHR_create_context EGL_EXT_device_query EGL_KHR_image EGL_KHR_image_base EGL_KHR_gl_texture_2D_image EGL_KHR_gl_texture_cubemap_image EGL_KHR_gl_renderbuffer_image EGL_KHR_get_all_proc_addresses EGL_KHR_stream EGL_KHR_stream_consumer_gltexture EGL_NV_stream_consumer_gltexture_yuv EGL_ANGLE_flexible_surface_compatibility EGL_ANGLE_stream_producer_d3d_texture EGL_ANGLE_create_context_webgl_compatibility EGL_CHROMIUM_create_context_bind_generates_resource EGL_CHROMIUM_sync_control EGL_EXT_pixel_format_float EGL_KHR_surfaceless_context EGL_ANGLE_display_texture_share_group EGL_ANGLE_create_context_client_arrays EGL_ANGLE_program_cache_control EGL_ANGLE_robust_resource_initialization EGL_EXTENSIONS(nullptr): EGL_EXT_client_extensions EGL_EXT_platform_base EGL_EXT_platform_device EGL_ANGLE_platform_angle EGL_ANGLE_platform_angle_d3d EGL_ANGLE_device_creation EGL_ANGLE_device_creation_d3d11 EGL_ANGLE_experimental_present_path EGL_KHR_client_get_all_proc_addresses
WebGL 1 Driver Renderer: Google Inc. -- ANGLE (Intel(R) HD Graphics 530 Direct3D11 vs_5_0 ps_5_0)
WebGL 1 Driver Version: OpenGL ES 2.0 (ANGLE 2.1.0.27cef491162b)
WebGL 1 Driver Extensions: GL_ANGLE_client_arrays GL_ANGLE_depth_texture GL_ANGLE_framebuffer_blit GL_ANGLE_framebuffer_multisample GL_ANGLE_instanced_arrays GL_ANGLE_lossy_etc_decode GL_ANGLE_pack_reverse_row_order GL_ANGLE_program_cache_control GL_ANGLE_request_extension GL_ANGLE_robust_client_memory GL_ANGLE_texture_compression_dxt3 GL_ANGLE_texture_compression_dxt5 GL_ANGLE_texture_usage GL_ANGLE_translated_shader_source GL_CHROMIUM_bind_generates_resource GL_CHROMIUM_bind_uniform_location GL_CHROMIUM_color_buffer_float_rgb GL_CHROMIUM_color_buffer_float_rgba GL_CHROMIUM_copy_compressed_texture GL_CHROMIUM_copy_texture GL_CHROMIUM_sync_query GL_EXT_blend_minmax GL_EXT_color_buffer_half_float GL_EXT_debug_marker GL_EXT_discard_framebuffer GL_EXT_disjoint_timer_query GL_EXT_draw_buffers GL_EXT_frag_depth GL_EXT_map_buffer_range GL_EXT_occlusion_query_boolean GL_EXT_read_format_bgra GL_EXT_robustness GL_EXT_sRGB GL_EXT_shader_texture_lod GL_EXT_texture_compression_dxt1 GL_EXT_texture_compression_s3tc_srgb GL_EXT_texture_filter_anisotropic GL_EXT_texture_format_BGRA8888 GL_EXT_texture_rg GL_EXT_texture_storage GL_EXT_unpack_subimage GL_KHR_debug GL_NV_EGL_stream_consumer_external GL_NV_fence GL_NV_pack_subimage GL_NV_pixel_buffer_object GL_OES_EGL_image GL_OES_EGL_image_external GL_OES_compressed_ETC1_RGB8_texture GL_OES_depth32 GL_OES_element_index_uint GL_OES_get_program_binary GL_OES_mapbuffer GL_OES_packed_depth_stencil GL_OES_rgb8_rgba8 GL_OES_standard_derivatives GL_OES_surfaceless_context GL_OES_texture_float GL_OES_texture_float_linear GL_OES_texture_half_float GL_OES_texture_half_float_linear GL_OES_texture_npot GL_OES_vertex_array_object
WebGL 1 Extensions: ANGLE_instanced_arrays EXT_blend_minmax EXT_color_buffer_half_float EXT_frag_depth EXT_sRGB EXT_shader_texture_lod EXT_texture_filter_anisotropic EXT_disjoint_timer_query OES_element_index_uint OES_standard_derivatives OES_texture_float OES_texture_float_linear OES_texture_half_float OES_texture_half_float_linear OES_vertex_array_object WEBGL_color_buffer_float WEBGL_compressed_texture_s3tc WEBGL_compressed_texture_s3tc_srgb WEBGL_debug_renderer_info WEBGL_debug_shaders WEBGL_depth_texture WEBGL_draw_buffers WEBGL_lose_context
WebGL 2 Driver WSI Info: EGL_VENDOR: Google Inc. (adapter LUID: 000000000000ba78) EGL_VERSION: 1.4 (ANGLE 2.1.0.27cef491162b) EGL_EXTENSIONS: EGL_EXT_create_context_robustness EGL_ANGLE_d3d_share_handle_client_buffer EGL_ANGLE_d3d_texture_client_buffer EGL_ANGLE_surface_d3d_texture_2d_share_handle EGL_ANGLE_query_surface_pointer EGL_ANGLE_window_fixed_size EGL_ANGLE_keyed_mutex EGL_ANGLE_surface_orientation EGL_ANGLE_direct_composition EGL_NV_post_sub_buffer EGL_KHR_create_context EGL_EXT_device_query EGL_KHR_image EGL_KHR_image_base EGL_KHR_gl_texture_2D_image EGL_KHR_gl_texture_cubemap_image EGL_KHR_gl_renderbuffer_image EGL_KHR_get_all_proc_addresses EGL_KHR_stream EGL_KHR_stream_consumer_gltexture EGL_NV_stream_consumer_gltexture_yuv EGL_ANGLE_flexible_surface_compatibility EGL_ANGLE_stream_producer_d3d_texture EGL_ANGLE_create_context_webgl_compatibility EGL_CHROMIUM_create_context_bind_generates_resource EGL_CHROMIUM_sync_control EGL_EXT_pixel_format_float EGL_KHR_surfaceless_context EGL_ANGLE_display_texture_share_group EGL_ANGLE_create_context_client_arrays EGL_ANGLE_program_cache_control EGL_ANGLE_robust_resource_initialization EGL_EXTENSIONS(nullptr): EGL_EXT_client_extensions EGL_EXT_platform_base EGL_EXT_platform_device EGL_ANGLE_platform_angle EGL_ANGLE_platform_angle_d3d EGL_ANGLE_device_creation EGL_ANGLE_device_creation_d3d11 EGL_ANGLE_experimental_present_path EGL_KHR_client_get_all_proc_addresses
WebGL 2 Driver Renderer: Google Inc. -- ANGLE (Intel(R) HD Graphics 530 Direct3D11 vs_5_0 ps_5_0)
WebGL 2 Driver Version: OpenGL ES 3.0 (ANGLE 2.1.0.27cef491162b)
WebGL 2 Driver Extensions: GL_ANGLE_client_arrays GL_ANGLE_depth_texture GL_ANGLE_framebuffer_blit GL_ANGLE_framebuffer_multisample GL_ANGLE_instanced_arrays GL_ANGLE_lossy_etc_decode GL_ANGLE_multiview GL_ANGLE_pack_reverse_row_order GL_ANGLE_program_cache_control GL_ANGLE_request_extension GL_ANGLE_robust_client_memory GL_ANGLE_texture_compression_dxt3 GL_ANGLE_texture_compression_dxt5 GL_ANGLE_texture_usage GL_ANGLE_translated_shader_source GL_CHROMIUM_bind_generates_resource GL_CHROMIUM_bind_uniform_location GL_CHROMIUM_color_buffer_float_rgb GL_CHROMIUM_color_buffer_float_rgba GL_CHROMIUM_copy_compressed_texture GL_CHROMIUM_copy_texture GL_CHROMIUM_sync_query GL_EXT_blend_minmax GL_EXT_color_buffer_float GL_EXT_color_buffer_half_float GL_EXT_debug_marker GL_EXT_discard_framebuffer GL_EXT_disjoint_timer_query GL_EXT_draw_buffers GL_EXT_frag_depth GL_EXT_map_buffer_range GL_EXT_occlusion_query_boolean GL_EXT_read_format_bgra GL_EXT_robustness GL_EXT_sRGB GL_EXT_shader_texture_lod GL_EXT_texture_compression_dxt1 GL_EXT_texture_compression_s3tc_srgb GL_EXT_texture_filter_anisotropic GL_EXT_texture_format_BGRA8888 GL_EXT_texture_norm16 GL_EXT_texture_rg GL_EXT_texture_storage GL_EXT_unpack_subimage GL_KHR_debug GL_NV_EGL_stream_consumer_external GL_NV_fence GL_NV_pack_subimage GL_NV_pixel_buffer_object GL_OES_EGL_image GL_OES_EGL_image_external GL_OES_EGL_image_external_essl3 GL_OES_compressed_ETC1_RGB8_texture GL_OES_depth32 GL_OES_element_index_uint GL_OES_get_program_binary GL_OES_mapbuffer GL_OES_packed_depth_stencil GL_OES_rgb8_rgba8 GL_OES_standard_derivatives GL_OES_surfaceless_context GL_OES_texture_float GL_OES_texture_float_linear GL_OES_texture_half_float GL_OES_texture_half_float_linear GL_OES_texture_npot GL_OES_vertex_array_object
WebGL 2 Extensions: EXT_color_buffer_float EXT_texture_filter_anisotropic EXT_disjoint_timer_query OES_texture_float_linear WEBGL_compressed_texture_s3tc WEBGL_compressed_texture_s3tc_srgb WEBGL_debug_renderer_info WEBGL_debug_shaders WEBGL_lose_context
Direct2D: true
Off Main Thread Painting Enabled: true
DirectWrite: true (10.0.17115.1)
GPU #1
Active: Yes
Description: Intel(R) HD Graphics 530
Vendor ID: 0x8086
Device ID: 0x191b
Driver Version: 23.20.16.4973
Driver Date: 2-28-2018
Drivers: igdumdim64 igd10iumd64 igd10iumd64 igd12umd64 igdumdim32 igd10iumd32 igd10iumd32 igd12umd32
Subsys ID: 674e1a58
RAM: Unknown
GPU #2
Active: No
Description: NVIDIA GeForce GTX 970M
Vendor ID: 0x10de
Device ID: 0x13d8
Driver Version: 23.21.13.8873
Driver Date: 12-18-2017
Drivers: C:\WINDOWS\System32\DriverStore\FileRepository\nvrz.inf_amd64_7550cbd75f58b6c2\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nvrz.inf_amd64_7550cbd75f58b6c2\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nvrz.inf_amd64_7550cbd75f58b6c2\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nvrz.inf_amd64_7550cbd75f58b6c2\nvldumdx.dll C:\WINDOWS\System32\DriverStore\FileRepository\nvrz.inf_amd64_7550cbd75f58b6c2\nvldumd.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nvrz.inf_amd64_7550cbd75f58b6c2\nvldumd.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nvrz.inf_amd64_7550cbd75f58b6c2\nvldumd.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nvrz.inf_amd64_7550cbd75f58b6c2\nvldumd.dll
Subsys ID: 674e1a58
RAM: 6144
Diagnostics
ClearType Parameters: Gamma: 2.2 Pixel Structure: RGB ClearType Level: 100 Enhanced Contrast: 50
AzureCanvasAccelerated: 0
AzureCanvasBackend: skia
AzureCanvasBackend (UI Process): skia
AzureContentBackend: skia
AzureContentBackend (UI Process): skia
AzureFallbackCanvasBackend (UI Process): cairo
GPUProcessPid: 11632
GPUProcess: Terminate GPU Process
Device Reset: Trigger Device Reset
ClearType Parameters: Gamma: 2.2 Pixel Structure: RGB ClearType Level: 100 Enhanced Contrast: 50
Decision Log
WEBRENDER:
opt-in by default: WebRender is an opt-in feature
available by user: Enabled by pref

Comment 1

[Milan Sreckovic [:milan] (needinfo for best results)]

Is this a type of thing we can fix?

Comment 2

[Dzmitry Malyshau [:kvark]]

Appears to be a bug with the new blend brush shader. Looking

Comment 3

[Dzmitry Malyshau [:kvark]]

Here is what happens. The page has multiple items with background image offsets and clips, assuming the 1:1 space between clip rectangles and the image texels, thus expecting the clips to effectively cut out a rectangle out of the background image.

When the page is handled by Gecko with UI scaling > 100%, it leaves the image untouched but asks WebRender to allocate 150% sized render targets. WebRender at this stage doesn't know that an image primitive is supposed to only show a specific region of a texture, since its clip rectangles are provided in render space. This leads to bleeding on the edge pixels, since linear sampling grabs the values outside of the originally intended UV rectangle.

Markus suggested Gecko to provide the UV rectangle explicitly in order to help WR to clamp the texture coordinates. It's trivial on the WR shader side (since it's already clamping, just by the whole image region) and only requires a bit of piping on the WR API to get an extra parameter. I created https://github.com/servo/webrender/issues/2612 to provide it.

Comment 4

[Markus Stange [:mstange]]

The Gecko side of this fix will involve calling ComputeSnappedImageDrawingParameters and forwarding the ImageRegion from params.region to WebRender.

Comment 5

[Markus Stange [:mstange]]

This is probably the same as bug 1452337.

Comment 6

[Jeff Muizelaar [:jrmuizel]]

Moving this too stage-wr-next. I think this is probably happening in Edge too. If you don't see it in Edge we can consider fixing it sooner.

Comment 7

[Andrew Osmond [:aosmond] (he/him)]

I can't reproduce this anymore on Windows or Linux at any zoom level.