Disable dithering in framebuffer-render-to-layer.html. (#3768)

kenrussell · web-flow · commit 6fa8a28ee224 · 2026-03-04T09:28:51.000-08:00
conformance2/rendering/framebuffer-render-to-layer.html was producing
inconsistent results across devices for low-bit-depth formats with
dithering enabled.

Associated with crbug.com/488961394 .
diff --git a/sdk/tests/conformance2/rendering/framebuffer-render-to-layer.html b/sdk/tests/conformance2/rendering/framebuffer-render-to-layer.html
@@ -319,6 +319,9 @@
       gl.framebufferTextureLayer(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, texture, level, slice);
   }
 
+  // Disable dithering for more reliable results with low-bit-depth formats
+  gl.disable(gl.DITHER);
+
   const targets = {};
   targets[gl.TEXTURE_2D]       = { make: make2DTexture, attach: attach2DTexture, },
   targets[gl.TEXTURE_3D]       = { make: make3DTexture, attach: attach3DTexture, },

Original file line number	Diff line number	Diff line change
`@@ -319,6 +319,9 @@`
`319`	`319`	`gl.framebufferTextureLayer(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, texture, level, slice);`
`320`	`320`	`}`
`321`	`321`
	`322`	`+ // Disable dithering for more reliable results with low-bit-depth formats`
	`323`	`+ gl.disable(gl.DITHER);`
	`324`	`+`
`322`	`325`	`const targets = {};`
`323`	`326`	`targets[gl.TEXTURE_2D] = { make: make2DTexture, attach: attach2DTexture, },`
`324`	`327`	`targets[gl.TEXTURE_3D] = { make: make3DTexture, attach: attach3DTexture, },`