vello_gpu: Add imports and module declarations for render/common/paint.rs

vello_gpu/src/render/common/mod.rs

diff --git a/vello_gpu/src/render/common/mod.rs b/vello_gpu/src/render/common/mod.rs
index 99a8ebf..5f48dea 100644
--- a/vello_gpu/src/render/common/mod.rs
+++ b/vello_gpu/src/render/common/mod.rs
@@ -3,10 +3,15 @@
 
 //! Backend agnostic renderer module.
 
-#![allow(
-    clippy::cast_possible_truncation,
-    reason = "GPU paint structures have small, fixed sizes that fit in u32"
-)]
+mod paint;
+
+#[cfg(all(feature = "wgpu", feature = "wgpu_external_texture"))]
+pub(crate) use paint::encode_wgpu_external_texture_paint;
+pub(crate) use paint::{
+    GpuBlurredRoundedRect, GpuEncodedImage, GpuEncodedPaint, GpuLinearGradient, GpuSweepGradient,
+    encode_native_image_paint, encode_radial_gradient, pack_image_offset, pack_image_params,
+    pack_image_size, pack_texture_width_and_extend_mode, pack_tint,
+};
 
 use crate::IntermediateTextureError;
 use crate::blend::GpuBlendInstance;
@@ -15,11 +20,8 @@
 use crate::scene::{LayersConfig, MemorySettings, RecordedDraw};
 use alloc::vec::Vec;
 use bytemuck::{Pod, Zeroable};
-use core::mem::size_of;
 use vello_common::color::{AlphaColor, Srgb};
-use vello_common::encode::{EncodedImage, FocalKind, RadialKind};
 use vello_common::geometry::{RectU16, SizeU16};
-use vello_common::paint::TintMode;
 use vello_common::record::CommandRecorder;
 
 // TODO: If we want to use native bilinear sampling for uploaded images,
@@ -325,15 +327,10 @@
 
 #[cfg(test)]
 mod tests {
-    use super::{DeviceLimits, encode_native_image_paint};
+    use super::DeviceLimits;
     use crate::scene::RecordedDraw;
     use crate::{IntermediateTextureError, LayersConfig, MemorySettings, SizeU16};
-    use vello_common::TextureId;
-    use vello_common::encode::EncodedImage;
-    use vello_common::kurbo::{Affine, Vec2};
     use vello_common::multi_atlas::AtlasConfig;
-    use vello_common::paint::{ImageSource, TextureRegion, Tint, TintMode};
-    use vello_common::peniko::{Color, ImageQuality, ImageSampler};
     use vello_common::record::CommandRecorder;
 
     fn device_limits(max_texture_dimension_2d: u16) -> DeviceLimits {

vello_gpu/src/render/common/paint.rs

diff --git a/vello_gpu/src/render/common/paint.rs b/vello_gpu/src/render/common/paint.rs
index 383482d..da11eda 100644
--- a/vello_gpu/src/render/common/paint.rs
+++ b/vello_gpu/src/render/common/paint.rs
@@ -1,3 +1,18 @@
+// Copyright 2025 the Vello Authors
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+//! GPU encodings of paints.
+
+#![allow(
+    clippy::cast_possible_truncation,
+    reason = "GPU paint structures have small, fixed sizes that fit in u32"
+)]
+
+use bytemuck::{Pod, Zeroable};
+use core::mem::size_of;
+use vello_common::encode::{EncodedImage, FocalKind, RadialKind};
+use vello_common::paint::TintMode;
+
 /// Different types of GPU encoded paints.
 #[derive(Debug)]
 pub(crate) enum GpuEncodedPaint {
@@ -351,6 +366,14 @@
     }
 }
 
+#[cfg(test)]
+mod tests {
+    use super::encode_native_image_paint;
+    use vello_common::TextureId;
+    use vello_common::encode::EncodedImage;
+    use vello_common::kurbo::{Affine, Vec2};
+    use vello_common::paint::{ImageSource, TextureRegion, Tint, TintMode};
+    use vello_common::peniko::{Color, ImageQuality, ImageSampler};
 
     #[test]
     fn native_image_encoding_accepts_opacity_but_not_color_tint_or_bicubic() {
@@ -427,3 +450,4 @@
             .is_none()
         );
     }
+}