webrender fails to build with --default-features=false + features = "pathfinder"

[fschutt]

[dependencies.webrender]
git = "https://github.com/servo/webrender"
rev = "f9ddc5261ad2cd35c60851c4091b682c900dbb0a"
features = ["pathfinder"]

Since now both pathfinder and webrender link to freetype, this fails to build with:

error: multiple packages link to native library `freetype`, but a native library can be linked only once

package `freetype-sys v0.6.0`
    ... which is depended on by `pathfinder_font_renderer v0.1.0 (https://github.com/pcwalton/pathfinder#fcfd157c)`
    ... which is depended on by `webrender v0.57.2 (https://github.com/servo/webrender?rev=f9ddc5261ad2cd35c60851c4091b682c900dbb0a#f9ddc526)`
    ... which is depended on by `azul v0.1.0 (file:///home/felix/Development/azul)`
links to native library `freetype`

package `servo-freetype-sys v4.0.3`
    ... which is depended on by `freetype v0.4.0`
    ... which is depended on by `webrender v0.57.2 (https://github.com/servo/webrender?rev=f9ddc5261ad2cd35c60851c4091b682c900dbb0a#f9ddc526)`
    ... which is depended on by `azul v0.1.0 (file:///home/felix/Development/azul)`
also links to native library `freetype`

So, my next course of action was to disable the default freetype feature (also note that with the migration to pathfinder, it shouldn't be a default feature anymore IMO):

[dependencies.webrender]
git = "https://github.com/servo/webrender"
rev = "f9ddc5261ad2cd35c60851c4091b682c900dbb0a"
default-features = false
features = ["pathfinder"]

Which fails to build with a few compile errors:

   Compiling pathfinder_partitioner v0.1.0 (https://github.com/pcwalton/pathfinder#fcfd157c)
error[E0599]: no method named `add_native_font` found for type `&mut pathfinder_font_renderer::FontContext<webrender_api::FontKey>` in the current scope
   --> /home/felix/.cargo/git/checkouts/webrender-c3596abe1cf4f320/f9ddc52/webrender/src/glyph_rasterizer.rs:867:27
    |
867 |                 drop(self.add_native_font(&font_key, (*native_font_handle).clone().0));
    |                           ^^^^^^^^^^^^^^^

error[E0609]: no field `0` on type `webrender_api::NativeFontHandle`
   --> /home/felix/.cargo/git/checkouts/webrender-c3596abe1cf4f320/f9ddc52/webrender/src/glyph_rasterizer.rs:867:54
    |
867 |                 drop(self.add_native_font(&font_key, (*native_font_handle).clone().0));
    |                                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0599]: no method named `compute_scale` found for type `glyph_rasterizer::FontTransform` in the current scope
   --> /home/felix/.cargo/git/checkouts/webrender-c3596abe1cf4f320/f9ddc52/webrender/src/platform/unix/font.rs:280:49
    |
280 |         let (x_scale, y_scale) = font.transform.compute_scale().unwrap_or((1.0, 1.0));
    |                                                 ^^^^^^^^^^^^^
    |
   ::: /home/felix/.cargo/git/checkouts/webrender-c3596abe1cf4f320/f9ddc52/webrender/src/glyph_rasterizer.rs:83:1
    |
83  | pub struct FontTransform {
    | ------------------------ method `compute_scale` not found for this

error[E0599]: no method named `invert_scale` found for type `glyph_rasterizer::FontTransform` in the current scope
   --> /home/felix/.cargo/git/checkouts/webrender-c3596abe1cf4f320/f9ddc52/webrender/src/platform/unix/font.rs:289:44
    |
289 |             let mut shape = font.transform.invert_scale(x_scale, y_scale);
    |                                            ^^^^^^^^^^^^
    |
   ::: /home/felix/.cargo/git/checkouts/webrender-c3596abe1cf4f320/f9ddc52/webrender/src/glyph_rasterizer.rs:83:1
    |
83  | pub struct FontTransform {
    | ------------------------ method `invert_scale` not found for this

error: aborting due to 4 previous errors

error: Could not compile `webrender`.
warning: build failed, waiting for other jobs to finish...
error: build failed

rustc 1.25 stable
Debian 9.4 (note: in the pathfinder repo, the add_native_font uses macOS Quartz fonts?)

[fschutt]

Well, it seems that freetype is still needed on Linux. The pathfinder feature really only works on macOS. So, I'd rather just update the version of freetype in the pathfinder repository.

[fschutt]

Even with https://github.com/pcwalton/pathfinder/pull/78 merged, I still can't get rid of the "no method named XXX" errors. But at least I don't get version conflicts anymore.

[pcwalton]

I'll look into this.

[fschutt]

I know what the issue is. servo expects a FontContext. When using pathfinder, the FontContext is swapped to be a PathfinderFontContext. However, the PathfinderFontContext is missing the add_native_font function (which can be trivially copied from webrender/src/platform/unix/font.rs to pathfinder). The add_native_font function is missing for non-macOS targets. I've fixed this for Linux here, but for Windows, this is currently just a shim so that it should compile, the add_native_font function does nothing on windows.

[fschutt]

https://github.com/pcwalton/pathfinder/blob/fcfd157c702d5ca6cabb30c0239af2d7308f3eb4/font-renderer/src/core_graphics.rs#L71-L79

Next, the signature for add_native_font should look like this:

pub fn add_native_font(&mut self, font_key: &FK, handle: NativeFontHandle) -> Result<(), ()> { }

instead of:

pub fn add_native_font(&mut self, font_key: &FK, handle: CGFont) -> Result<(), ()> { }

... because CgFont is only available on macOS. If you look closely, NativeFontHandle is defined (in webrender) as:

// every other OS, except for windows
#[cfg(not(any(target_os = "macos", target_os = "windows")))]
#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct NativeFontHandle {
    pub pathname: String,
    pub index: u32,
}

// macOS special case
#[cfg(target_os = "macos")]
#[derive(Clone)]
pub struct NativeFontHandle(pub CGFont);

.. which means that NativeFontHandle is just a wrapper around CGFont on macOS. So, instead of accepting a CGFont, it's better to accept a NativeFontHandle to keep the function signature consistent with the other OS.

[pcwalton]

The fix for this is pretty involved and required changes to both Pathfinder and WebRender. I have work-in-progress branches that fix this pushed and will be porting the changes to macOS before submitting.

…

On Sun, Apr 8, 2018 at 3:58 AM, fschutt ***@***.***> wrote: https://github.com/pcwalton/pathfinder/blob/fcfd157c702d5ca6cabb30c0239af2 d7308f3eb4/font-renderer/src/core_graphics.rs#L71-L79 Next, the signature for add_native_font should look like this: pub fn add_native_font(&mut self, font_key: &FK, handle: NativeFontHandle) -> Result<(), ()> { } instead of: pub fn add_native_font(&mut self, font_key: &FK, handle: CGFont) -> Result<(), ()> { } ... because CgFont is only available on macOS. If you look closely, NativeFontHandle is defined (in webrender) as: // every other OS, except for windows #[cfg(not(any(target_os = "macos", target_os = "windows")))] #[derive(Clone, Debug, Serialize, Deserialize)] pub struct NativeFontHandle { pub pathname: String, pub index: u32, } // macOS special case #[cfg(target_os = "macos")] #[derive(Clone)] pub struct NativeFontHandle(pub CGFont); .. which means that NativeFontHandle is just a wrapper around CGFont on macOS. So, instead of accepting a CGFont, it's better to accept a NativeFontHandle to keep the function signature consistent with the other OS. — You are receiving this because you were assigned. Reply to this email directly, view it on GitHub <#2617 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAJoyVlKpy-NeRTZUCkAruiDMo0tNVxxks5tme1SgaJpZM4TH2Pi> .