Image x/y extend, alpha, nearest neighbor sampling #766
Conversation
This adds support for image extend modes, alpha and nearest neighbor sampling to fine and plumbs support for all through the pipeline.
There was a problem hiding this comment.
I think this should have a changelog entry.
I'd also like to see some new tests here; these should be very similar to the existing tests, and so should be straightforward. Indeed, one of the tests needs to be updated.
Otherwise, only relatively peripheral concerns.
| image_extend_modes_helper(scene, ImageQuality::Medium); | ||
| } | ||
|
|
||
| pub(super) fn image_extend_modes_nearest_neighbor(scene: &mut Scene, params: &mut SceneParams) { |
There was a problem hiding this comment.
We could impl this in a way similar to longpathdash, which is another parameterised test scene
| @@ -415,6 +415,10 @@ impl Encoding { | |||
| .extend_from_slice(bytemuck::bytes_of(&DrawImage { | |||
| xy: 0, | |||
| width_height: (image.width << 16) | (image.height & 0xFFFF), | |||
| sample_alpha: ((image.quality as u32) << 12) | |||
| | ((image.x_extend as u32) << 10) | |||
| | ((image.y_extend as u32) << 8) | |||
There was a problem hiding this comment.
Maybe? It would be worth debug_asserting that these all fit. Since these enums are exhaustive, having an exhaustive match #[cfg(test)]ed somewhere would also be sufficient.
| @@ -164,6 +164,8 @@ pub struct DrawImage { | |||
| pub xy: u32, | |||
| /// Packed image dimensions. | |||
| pub width_height: u32, | |||
| /// Packed quality, extend mode and 8-bit alpha (bits `qqxxyyaaaaaaaa`). | |||
There was a problem hiding this comment.
| /// Packed quality, extend mode and 8-bit alpha (bits `qqxxyyaaaaaaaa`). | |
| /// Packed quality, extend mode and 8-bit alpha (bits `qqxxyyaaaaaaaa`, 18 unused prefix bits). |
| let r = extend_mode(atlas_uv.x * extents_inv.x, image.x_extend_mode); | ||
| let g = extend_mode(atlas_uv.y * extents_inv.y, image.y_extend_mode); | ||
| let fg_rgba2 = vec4(r, g, 0.0, 1.0); |
| } | ||
| } | ||
| } | ||
| case IMAGE_QUALITY_MEDIUM, default: { |
There was a problem hiding this comment.
| case IMAGE_QUALITY_MEDIUM, default: { | |
| // We don't have an implementation for `IMAGE_QUALITY_HIGH` yet, just use the same as medium | |
| case IMAGE_QUALITY_MEDIUM, default: { |
| atlas_uv = atlas_uv + image.atlas_offset; | ||
| // TODO: If the image couldn't be added to the atlas (i.e. was too big), this isn't robust | ||
| let atlas_uv_clamped = clamp(atlas_uv, image.atlas_offset, atlas_max); | ||
| let fg_rgba = premul_alpha(textureLoad(image_atlas, vec2<i32>(atlas_uv_clamped), 0)); |
There was a problem hiding this comment.
I think it would be useful to give a small comment as a hint here.
| let fg_rgba = premul_alpha(textureLoad(image_atlas, vec2<i32>(atlas_uv_clamped), 0)); | |
| // Nearest Neighbor | |
| let fg_rgba = premul_alpha(textureLoad(image_atlas, vec2<i32>(atlas_uv_clamped), 0)); |
| let b = premul_alpha(textureLoad(image_atlas, vec2<i32>(uv_quad.xw), 0)); | ||
| let c = premul_alpha(textureLoad(image_atlas, vec2<i32>(uv_quad.zy), 0)); | ||
| let d = premul_alpha(textureLoad(image_atlas, vec2<i32>(uv_quad.zw), 0)); | ||
| let fg_rgba = mix(mix(a, b, uv_frac.y), mix(c, d, uv_frac.y), uv_frac.x); |
There was a problem hiding this comment.
| let fg_rgba = mix(mix(a, b, uv_frac.y), mix(c, d, uv_frac.y), uv_frac.x); | |
| // Bilinear sampling | |
| let fg_rgba = mix(mix(a, b, uv_frac.y), mix(c, d, uv_frac.y), uv_frac.x); |
|
Thanks for the feedback, Daniel. I'm on vacation and out of town for the next week but I may have some time over the weekend to address all concerns and get this landed. |
This adds support for image extend modes, alpha and nearest neighbor sampling to fine and plumbs support for all through the pipeline.
Extend modes with bilinear filtering (bottom right is x repeat and y reflect):
Extend modes with nearest neighbor filtering:
Image alpha:
