Adding upstream version 115.7.0esr.upstream/115.7.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1496 insertions, 0 deletions

diff --git a/gfx/wr/webrender/src/renderer/shade.rs b/gfx/wr/webrender/src/renderer/shade.rs
new file mode 100644
index 0000000000..72b6578a4f
--- /dev/null
+++ b/gfx/wr/webrender/src/renderer/shade.rs
@@ -0,0 +1,1496 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use api::{ImageBufferKind, units::DeviceSize};
+use crate::batch::{BatchKey, BatchKind, BrushBatchKind, BatchFeatures};
+use crate::composite::{CompositeFeatures, CompositeSurfaceFormat};
+use crate::device::{Device, Program, ShaderError};
+use euclid::default::Transform3D;
+use glyph_rasterizer::GlyphFormat;
+use crate::renderer::{
+    desc,
+    BlendMode, DebugFlags, RendererError, WebRenderOptions,
+    TextureSampler, VertexArrayKind, ShaderPrecacheFlags,
+};
+use crate::profiler::{self, TransactionProfile, ns_to_ms};
+
+use gleam::gl::GlType;
+use time::precise_time_ns;
+
+use std::cell::RefCell;
+use std::rc::Rc;
+
+use webrender_build::shader::{ShaderFeatures, ShaderFeatureFlags, get_shader_features};
+
+/// Which extension version to use for texture external support.
+#[derive(Clone, Copy, Debug, PartialEq)]
+enum TextureExternalVersion {
+    // GL_OES_EGL_image_external_essl3 (Compatible with ESSL 3.0 and
+    // later shaders, but not supported on all GLES 3 devices.)
+    ESSL3,
+    // GL_OES_EGL_image_external (Compatible with ESSL 1.0 shaders)
+    ESSL1,
+}
+
+fn get_feature_string(kind: ImageBufferKind, texture_external_version: TextureExternalVersion) -> &'static str {
+    match (kind, texture_external_version) {
+        (ImageBufferKind::Texture2D, _) => "TEXTURE_2D",
+        (ImageBufferKind::TextureRect, _) => "TEXTURE_RECT",
+        (ImageBufferKind::TextureExternal, TextureExternalVersion::ESSL3) => "TEXTURE_EXTERNAL",
+        (ImageBufferKind::TextureExternal, TextureExternalVersion::ESSL1) => "TEXTURE_EXTERNAL_ESSL1",
+    }
+}
+
+fn has_platform_support(kind: ImageBufferKind, gl_type: &GlType) -> bool {
+    match (kind, gl_type) {
+        (ImageBufferKind::Texture2D, _) => true,
+        (ImageBufferKind::TextureRect, &GlType::Gles) => false,
+        (ImageBufferKind::TextureRect, &GlType::Gl) => true,
+        (ImageBufferKind::TextureExternal, &GlType::Gles) => true,
+        (ImageBufferKind::TextureExternal, &GlType::Gl) => false,
+    }
+}
+
+pub const IMAGE_BUFFER_KINDS: [ImageBufferKind; 3] = [
+    ImageBufferKind::Texture2D,
+    ImageBufferKind::TextureRect,
+    ImageBufferKind::TextureExternal,
+];
+
+const ADVANCED_BLEND_FEATURE: &str = "ADVANCED_BLEND";
+const ALPHA_FEATURE: &str = "ALPHA_PASS";
+const DEBUG_OVERDRAW_FEATURE: &str = "DEBUG_OVERDRAW";
+const DITHERING_FEATURE: &str = "DITHERING";
+const DUAL_SOURCE_FEATURE: &str = "DUAL_SOURCE_BLENDING";
+const FAST_PATH_FEATURE: &str = "FAST_PATH";
+
+pub(crate) enum ShaderKind {
+    Primitive,
+    Cache(VertexArrayKind),
+    ClipCache(VertexArrayKind),
+    Brush,
+    Text,
+    #[allow(dead_code)]
+    VectorStencil,
+    #[allow(dead_code)]
+    VectorCover,
+    #[allow(dead_code)]
+    Resolve,
+    Composite,
+    Clear,
+    Copy,
+}
+
+pub struct LazilyCompiledShader {
+    program: Option<Program>,
+    name: &'static str,
+    kind: ShaderKind,
+    cached_projection: Transform3D<f32>,
+    features: Vec<&'static str>,
+}
+
+impl LazilyCompiledShader {
+    pub(crate) fn new(
+        kind: ShaderKind,
+        name: &'static str,
+        unsorted_features: &[&'static str],
+        device: &mut Device,
+        precache_flags: ShaderPrecacheFlags,
+        shader_list: &ShaderFeatures,
+        profile: &mut TransactionProfile,
+    ) -> Result<Self, ShaderError> {
+
+        let mut features = unsorted_features.to_vec();
+        features.sort();
+
+        // Ensure this shader config is in the available shader list so that we get
+        // alerted if the list gets out-of-date when shaders or features are added.
+        let config = features.join(",");
+        assert!(
+            shader_list.get(name).map_or(false, |f| f.contains(&config)),
+            "shader \"{}\" with features \"{}\" not in available shader list",
+            name,
+            config,
+        );
+
+        let mut shader = LazilyCompiledShader {
+            program: None,
+            name,
+            kind,
+            //Note: this isn't really the default state, but there is no chance
+            // an actual projection passed here would accidentally match.
+            cached_projection: Transform3D::identity(),
+            features,
+        };
+
+        if precache_flags.intersects(ShaderPrecacheFlags::ASYNC_COMPILE | ShaderPrecacheFlags::FULL_COMPILE) {
+            let t0 = precise_time_ns();
+            shader.get_internal(device, precache_flags, profile)?;
+            let t1 = precise_time_ns();
+            debug!("[C: {:.1} ms ] Precache {} {:?}",
+                (t1 - t0) as f64 / 1000000.0,
+                name,
+                unsorted_features
+            );
+        }
+
+        Ok(shader)
+    }
+
+    pub fn bind(
+        &mut self,
+        device: &mut Device,
+        projection: &Transform3D<f32>,
+        texture_size: Option<DeviceSize>,
+        renderer_errors: &mut Vec<RendererError>,
+        profile: &mut TransactionProfile,
+    ) {
+        let update_projection = self.cached_projection != *projection;
+        let program = match self.get_internal(device, ShaderPrecacheFlags::FULL_COMPILE, profile) {
+            Ok(program) => program,
+            Err(e) => {
+                renderer_errors.push(RendererError::from(e));
+                return;
+            }
+        };
+        device.bind_program(program);
+        if let Some(texture_size) = texture_size {
+            device.set_shader_texture_size(program, texture_size);
+        }
+        if update_projection {
+            device.set_uniforms(program, projection);
+            // thanks NLL for this (`program` technically borrows `self`)
+            self.cached_projection = *projection;
+        }
+    }
+
+    fn get_internal(
+        &mut self,
+        device: &mut Device,
+        precache_flags: ShaderPrecacheFlags,
+        profile: &mut TransactionProfile,
+    ) -> Result<&mut Program, ShaderError> {
+        if self.program.is_none() {
+            let start_time = precise_time_ns();
+            let program = match self.kind {
+                ShaderKind::Primitive | ShaderKind::Brush | ShaderKind::Text | ShaderKind::Resolve | ShaderKind::Clear | ShaderKind::Copy => {
+                    create_prim_shader(
+                        self.name,
+                        device,
+                        &self.features,
+                    )
+                }
+                ShaderKind::Cache(..) => {
+                    create_prim_shader(
+                        self.name,
+                        device,
+                        &self.features,
+                    )
+                }
+                ShaderKind::VectorStencil => {
+                    create_prim_shader(
+                        self.name,
+                        device,
+                        &self.features,
+                    )
+                }
+                ShaderKind::VectorCover => {
+                    create_prim_shader(
+                        self.name,
+                        device,
+                        &self.features,
+                    )
+                }
+                ShaderKind::Composite => {
+                    create_prim_shader(
+                        self.name,
+                        device,
+                        &self.features,
+                    )
+                }
+                ShaderKind::ClipCache(..) => {
+                    create_clip_shader(
+                        self.name,
+                        device,
+                        &self.features,
+                    )
+                }
+            };
+            self.program = Some(program?);
+
+            let end_time = precise_time_ns();
+            profile.add(profiler::SHADER_BUILD_TIME, ns_to_ms(end_time - start_time));
+        }
+
+        let program = self.program.as_mut().unwrap();
+
+        if precache_flags.contains(ShaderPrecacheFlags::FULL_COMPILE) && !program.is_initialized() {
+            let start_time = precise_time_ns();
+
+            let vertex_format = match self.kind {
+                ShaderKind::Primitive |
+                ShaderKind::Brush |
+                ShaderKind::Text => VertexArrayKind::Primitive,
+                ShaderKind::Cache(format) => format,
+                ShaderKind::VectorStencil => VertexArrayKind::VectorStencil,
+                ShaderKind::VectorCover => VertexArrayKind::VectorCover,
+                ShaderKind::ClipCache(format) => format,
+                ShaderKind::Resolve => VertexArrayKind::Resolve,
+                ShaderKind::Composite => VertexArrayKind::Composite,
+                ShaderKind::Clear => VertexArrayKind::Clear,
+                ShaderKind::Copy => VertexArrayKind::Copy,
+            };
+
+            let vertex_descriptor = match vertex_format {
+                VertexArrayKind::Primitive => &desc::PRIM_INSTANCES,
+                VertexArrayKind::LineDecoration => &desc::LINE,
+                VertexArrayKind::FastLinearGradient => &desc::FAST_LINEAR_GRADIENT,
+                VertexArrayKind::LinearGradient => &desc::LINEAR_GRADIENT,
+                VertexArrayKind::RadialGradient => &desc::RADIAL_GRADIENT,
+                VertexArrayKind::ConicGradient => &desc::CONIC_GRADIENT,
+                VertexArrayKind::Blur => &desc::BLUR,
+                VertexArrayKind::ClipImage => &desc::CLIP_IMAGE,
+                VertexArrayKind::ClipRect => &desc::CLIP_RECT,
+                VertexArrayKind::ClipBoxShadow => &desc::CLIP_BOX_SHADOW,
+                VertexArrayKind::VectorStencil => &desc::VECTOR_STENCIL,
+                VertexArrayKind::VectorCover => &desc::VECTOR_COVER,
+                VertexArrayKind::Border => &desc::BORDER,
+                VertexArrayKind::Scale => &desc::SCALE,
+                VertexArrayKind::Resolve => &desc::RESOLVE,
+                VertexArrayKind::SvgFilter => &desc::SVG_FILTER,
+                VertexArrayKind::Composite => &desc::COMPOSITE,
+                VertexArrayKind::Clear => &desc::CLEAR,
+                VertexArrayKind::Copy => &desc::COPY,
+                VertexArrayKind::Mask => &desc::MASK,
+            };
+
+            device.link_program(program, vertex_descriptor)?;
+            device.bind_program(program);
+            match self.kind {
+                ShaderKind::ClipCache(..) => {
+                    device.bind_shader_samplers(
+                        &program,
+                        &[
+                            ("sColor0", TextureSampler::Color0),
+                            ("sTransformPalette", TextureSampler::TransformPalette),
+                            ("sRenderTasks", TextureSampler::RenderTasks),
+                            ("sGpuCache", TextureSampler::GpuCache),
+                            ("sPrimitiveHeadersF", TextureSampler::PrimitiveHeadersF),
+                            ("sPrimitiveHeadersI", TextureSampler::PrimitiveHeadersI),
+                            ("sGpuBuffer", TextureSampler::GpuBuffer),
+                        ],
+                    );
+                }
+                _ => {
+                    device.bind_shader_samplers(
+                        &program,
+                        &[
+                            ("sColor0", TextureSampler::Color0),
+                            ("sColor1", TextureSampler::Color1),
+                            ("sColor2", TextureSampler::Color2),
+                            ("sDither", TextureSampler::Dither),
+                            ("sTransformPalette", TextureSampler::TransformPalette),
+                            ("sRenderTasks", TextureSampler::RenderTasks),
+                            ("sGpuCache", TextureSampler::GpuCache),
+                            ("sPrimitiveHeadersF", TextureSampler::PrimitiveHeadersF),
+                            ("sPrimitiveHeadersI", TextureSampler::PrimitiveHeadersI),
+                            ("sClipMask", TextureSampler::ClipMask),
+                            ("sGpuBuffer", TextureSampler::GpuBuffer),
+                        ],
+                    );
+                }
+            }
+
+            let end_time = precise_time_ns();
+            profile.add(profiler::SHADER_BUILD_TIME, ns_to_ms(end_time - start_time));
+        }
+
+        Ok(program)
+    }
+
+    fn deinit(self, device: &mut Device) {
+        if let Some(program) = self.program {
+            device.delete_program(program);
+        }
+    }
+}
+
+// A brush shader supports two modes:
+// opaque:
+//   Used for completely opaque primitives,
+//   or inside segments of partially
+//   opaque primitives. Assumes no need
+//   for clip masks, AA etc.
+// alpha:
+//   Used for brush primitives in the alpha
+//   pass. Assumes that AA should be applied
+//   along the primitive edge, and also that
+//   clip mask is present.
+struct BrushShader {
+    opaque: LazilyCompiledShader,
+    alpha: LazilyCompiledShader,
+    advanced_blend: Option<LazilyCompiledShader>,
+    dual_source: Option<LazilyCompiledShader>,
+    debug_overdraw: LazilyCompiledShader,
+}
+
+impl BrushShader {
+    fn new(
+        name: &'static str,
+        device: &mut Device,
+        features: &[&'static str],
+        precache_flags: ShaderPrecacheFlags,
+        shader_list: &ShaderFeatures,
+        use_advanced_blend: bool,
+        use_dual_source: bool,
+        profile: &mut TransactionProfile,
+    ) -> Result<Self, ShaderError> {
+        let opaque_features = features.to_vec();
+        let opaque = LazilyCompiledShader::new(
+            ShaderKind::Brush,
+            name,
+            &opaque_features,
+            device,
+            precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let mut alpha_features = opaque_features.to_vec();
+        alpha_features.push(ALPHA_FEATURE);
+
+        let alpha = LazilyCompiledShader::new(
+            ShaderKind::Brush,
+            name,
+            &alpha_features,
+            device,
+            precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let advanced_blend = if use_advanced_blend {
+            let mut advanced_blend_features = alpha_features.to_vec();
+            advanced_blend_features.push(ADVANCED_BLEND_FEATURE);
+
+            let shader = LazilyCompiledShader::new(
+                ShaderKind::Brush,
+                name,
+                &advanced_blend_features,
+                device,
+                precache_flags,
+                &shader_list,
+                profile,
+            )?;
+
+            Some(shader)
+        } else {
+            None
+        };
+
+        let dual_source = if use_dual_source {
+            let mut dual_source_features = alpha_features.to_vec();
+            dual_source_features.push(DUAL_SOURCE_FEATURE);
+
+            let shader = LazilyCompiledShader::new(
+                ShaderKind::Brush,
+                name,
+                &dual_source_features,
+                device,
+                precache_flags,
+                &shader_list,
+                profile,
+            )?;
+
+            Some(shader)
+        } else {
+            None
+        };
+
+        let mut debug_overdraw_features = features.to_vec();
+        debug_overdraw_features.push(DEBUG_OVERDRAW_FEATURE);
+
+        let debug_overdraw = LazilyCompiledShader::new(
+            ShaderKind::Brush,
+            name,
+            &debug_overdraw_features,
+            device,
+            precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        Ok(BrushShader {
+            opaque,
+            alpha,
+            advanced_blend,
+            dual_source,
+            debug_overdraw,
+        })
+    }
+
+    fn get(&mut self, blend_mode: BlendMode, features: BatchFeatures, debug_flags: DebugFlags)
+           -> &mut LazilyCompiledShader {
+        match blend_mode {
+            _ if debug_flags.contains(DebugFlags::SHOW_OVERDRAW) => &mut self.debug_overdraw,
+            BlendMode::None => &mut self.opaque,
+            BlendMode::Alpha |
+            BlendMode::PremultipliedAlpha |
+            BlendMode::PremultipliedDestOut |
+            BlendMode::SubpixelWithBgColor |
+            BlendMode::Screen |
+            BlendMode::PlusLighter |
+            BlendMode::Exclusion => {
+                if features.contains(BatchFeatures::ALPHA_PASS) {
+                    &mut self.alpha
+                } else {
+                    &mut self.opaque
+                }
+            }
+            BlendMode::Advanced(_) => {
+                self.advanced_blend
+                    .as_mut()
+                    .expect("bug: no advanced blend shader loaded")
+            }
+            BlendMode::SubpixelDualSource |
+            BlendMode::MultiplyDualSource => {
+                self.dual_source
+                    .as_mut()
+                    .expect("bug: no dual source shader loaded")
+            }
+        }
+    }
+
+    fn deinit(self, device: &mut Device) {
+        self.opaque.deinit(device);
+        self.alpha.deinit(device);
+        if let Some(advanced_blend) = self.advanced_blend {
+            advanced_blend.deinit(device);
+        }
+        if let Some(dual_source) = self.dual_source {
+            dual_source.deinit(device);
+        }
+        self.debug_overdraw.deinit(device);
+    }
+}
+
+pub struct TextShader {
+    simple: LazilyCompiledShader,
+    glyph_transform: LazilyCompiledShader,
+    debug_overdraw: LazilyCompiledShader,
+}
+
+impl TextShader {
+    fn new(
+        name: &'static str,
+        device: &mut Device,
+        features: &[&'static str],
+        precache_flags: ShaderPrecacheFlags,
+        shader_list: &ShaderFeatures,
+        profile: &mut TransactionProfile,
+    ) -> Result<Self, ShaderError> {
+        let mut simple_features = features.to_vec();
+        simple_features.push("ALPHA_PASS");
+        simple_features.push("TEXTURE_2D");
+
+        let simple = LazilyCompiledShader::new(
+            ShaderKind::Text,
+            name,
+            &simple_features,
+            device,
+            precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let mut glyph_transform_features = features.to_vec();
+        glyph_transform_features.push("GLYPH_TRANSFORM");
+        glyph_transform_features.push("ALPHA_PASS");
+        glyph_transform_features.push("TEXTURE_2D");
+
+        let glyph_transform = LazilyCompiledShader::new(
+            ShaderKind::Text,
+            name,
+            &glyph_transform_features,
+            device,
+            precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let mut debug_overdraw_features = features.to_vec();
+        debug_overdraw_features.push("DEBUG_OVERDRAW");
+        debug_overdraw_features.push("TEXTURE_2D");
+
+        let debug_overdraw = LazilyCompiledShader::new(
+            ShaderKind::Text,
+            name,
+            &debug_overdraw_features,
+            device,
+            precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        Ok(TextShader { simple, glyph_transform, debug_overdraw })
+    }
+
+    pub fn get(
+        &mut self,
+        glyph_format: GlyphFormat,
+        debug_flags: DebugFlags,
+    ) -> &mut LazilyCompiledShader {
+        match glyph_format {
+            _ if debug_flags.contains(DebugFlags::SHOW_OVERDRAW) => &mut self.debug_overdraw,
+            GlyphFormat::Alpha |
+            GlyphFormat::Subpixel |
+            GlyphFormat::Bitmap |
+            GlyphFormat::ColorBitmap => &mut self.simple,
+            GlyphFormat::TransformedAlpha |
+            GlyphFormat::TransformedSubpixel => &mut self.glyph_transform,
+        }
+    }
+
+    fn deinit(self, device: &mut Device) {
+        self.simple.deinit(device);
+        self.glyph_transform.deinit(device);
+        self.debug_overdraw.deinit(device);
+    }
+}
+
+fn create_prim_shader(
+    name: &'static str,
+    device: &mut Device,
+    features: &[&'static str],
+) -> Result<Program, ShaderError> {
+    debug!("PrimShader {}", name);
+
+    device.create_program(name, features)
+}
+
+fn create_clip_shader(
+    name: &'static str,
+    device: &mut Device,
+    features: &[&'static str],
+) -> Result<Program, ShaderError> {
+    debug!("ClipShader {}", name);
+
+    device.create_program(name, features)
+}
+
+// NB: If you add a new shader here, make sure to deinitialize it
+// in `Shaders::deinit()` below.
+pub struct Shaders {
+    // These are "cache shaders". These shaders are used to
+    // draw intermediate results to cache targets. The results
+    // of these shaders are then used by the primitive shaders.
+    pub cs_blur_a8: LazilyCompiledShader,
+    pub cs_blur_rgba8: LazilyCompiledShader,
+    pub cs_border_segment: LazilyCompiledShader,
+    pub cs_border_solid: LazilyCompiledShader,
+    pub cs_scale: Vec<Option<LazilyCompiledShader>>,
+    pub cs_line_decoration: LazilyCompiledShader,
+    pub cs_fast_linear_gradient: LazilyCompiledShader,
+    pub cs_linear_gradient: LazilyCompiledShader,
+    pub cs_radial_gradient: LazilyCompiledShader,
+    pub cs_conic_gradient: LazilyCompiledShader,
+    pub cs_svg_filter: LazilyCompiledShader,
+
+    // Brush shaders
+    brush_solid: BrushShader,
+    brush_image: Vec<Option<BrushShader>>,
+    brush_fast_image: Vec<Option<BrushShader>>,
+    brush_blend: BrushShader,
+    brush_mix_blend: BrushShader,
+    brush_yuv_image: Vec<Option<BrushShader>>,
+    brush_linear_gradient: BrushShader,
+    brush_opacity: BrushShader,
+    brush_opacity_aa: BrushShader,
+
+    /// These are "cache clip shaders". These shaders are used to
+    /// draw clip instances into the cached clip mask. The results
+    /// of these shaders are also used by the primitive shaders.
+    pub cs_clip_rectangle_slow: LazilyCompiledShader,
+    pub cs_clip_rectangle_fast: LazilyCompiledShader,
+    pub cs_clip_box_shadow: LazilyCompiledShader,
+    pub cs_clip_image: LazilyCompiledShader,
+
+    // The are "primitive shaders". These shaders draw and blend
+    // final results on screen. They are aware of tile boundaries.
+    // Most draw directly to the framebuffer, but some use inputs
+    // from the cache shaders to draw. Specifically, the box
+    // shadow primitive shader stretches the box shadow cache
+    // output, and the cache_image shader blits the results of
+    // a cache shader (e.g. blur) to the screen.
+    pub ps_text_run: TextShader,
+    pub ps_text_run_dual_source: Option<TextShader>,
+
+    ps_split_composite: LazilyCompiledShader,
+    pub ps_quad_textured: LazilyCompiledShader,
+    pub ps_mask: LazilyCompiledShader,
+    pub ps_mask_fast: LazilyCompiledShader,
+    pub ps_clear: LazilyCompiledShader,
+    pub ps_copy: LazilyCompiledShader,
+
+    pub composite: CompositorShaders,
+}
+
+impl Shaders {
+    pub fn new(
+        device: &mut Device,
+        gl_type: GlType,
+        options: &WebRenderOptions,
+    ) -> Result<Self, ShaderError> {
+        // We have to pass a profile around a bunch but we aren't recording the initialization
+        // so use a dummy one.
+        let profile = &mut TransactionProfile::new();
+
+        let use_dual_source_blending =
+            device.get_capabilities().supports_dual_source_blending &&
+            options.allow_dual_source_blending;
+        let use_advanced_blend_equation =
+            device.get_capabilities().supports_advanced_blend_equation &&
+            options.allow_advanced_blend_equation;
+
+        let texture_external_version = if device.get_capabilities().supports_image_external_essl3 {
+            TextureExternalVersion::ESSL3
+        } else {
+            TextureExternalVersion::ESSL1
+        };
+        let mut shader_flags = get_shader_feature_flags(gl_type, texture_external_version);
+        shader_flags.set(ShaderFeatureFlags::ADVANCED_BLEND_EQUATION, use_advanced_blend_equation);
+        shader_flags.set(ShaderFeatureFlags::DUAL_SOURCE_BLENDING, use_dual_source_blending);
+        shader_flags.set(ShaderFeatureFlags::DITHERING, options.enable_dithering);
+        let shader_list = get_shader_features(shader_flags);
+
+        let brush_solid = BrushShader::new(
+            "brush_solid",
+            device,
+            &[],
+            options.precache_flags,
+            &shader_list,
+            false /* advanced blend */,
+            false /* dual source */,
+            profile,
+        )?;
+
+        let brush_blend = BrushShader::new(
+            "brush_blend",
+            device,
+            &[],
+            options.precache_flags,
+            &shader_list,
+            false /* advanced blend */,
+            false /* dual source */,
+            profile,
+        )?;
+
+        let brush_mix_blend = BrushShader::new(
+            "brush_mix_blend",
+            device,
+            &[],
+            options.precache_flags,
+            &shader_list,
+            false /* advanced blend */,
+            false /* dual source */,
+            profile,
+        )?;
+
+        let brush_linear_gradient = BrushShader::new(
+            "brush_linear_gradient",
+            device,
+            if options.enable_dithering {
+               &[DITHERING_FEATURE]
+            } else {
+               &[]
+            },
+            options.precache_flags,
+            &shader_list,
+            false /* advanced blend */,
+            false /* dual source */,
+            profile,
+        )?;
+
+        let brush_opacity_aa = BrushShader::new(
+            "brush_opacity",
+            device,
+            &["ANTIALIASING"],
+            options.precache_flags,
+            &shader_list,
+            false /* advanced blend */,
+            false /* dual source */,
+            profile,
+        )?;
+
+        let brush_opacity = BrushShader::new(
+            "brush_opacity",
+            device,
+            &[],
+            options.precache_flags,
+            &shader_list,
+            false /* advanced blend */,
+            false /* dual source */,
+            profile,
+        )?;
+
+        let cs_blur_a8 = LazilyCompiledShader::new(
+            ShaderKind::Cache(VertexArrayKind::Blur),
+            "cs_blur",
+            &["ALPHA_TARGET"],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let cs_blur_rgba8 = LazilyCompiledShader::new(
+            ShaderKind::Cache(VertexArrayKind::Blur),
+            "cs_blur",
+            &["COLOR_TARGET"],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let cs_svg_filter = LazilyCompiledShader::new(
+            ShaderKind::Cache(VertexArrayKind::SvgFilter),
+            "cs_svg_filter",
+            &[],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let ps_mask = LazilyCompiledShader::new(
+            ShaderKind::Cache(VertexArrayKind::Mask),
+            "ps_quad_mask",
+            &[],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let ps_mask_fast = LazilyCompiledShader::new(
+            ShaderKind::Cache(VertexArrayKind::Mask),
+            "ps_quad_mask",
+            &[FAST_PATH_FEATURE],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let cs_clip_rectangle_slow = LazilyCompiledShader::new(
+            ShaderKind::ClipCache(VertexArrayKind::ClipRect),
+            "cs_clip_rectangle",
+            &[],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let cs_clip_rectangle_fast = LazilyCompiledShader::new(
+            ShaderKind::ClipCache(VertexArrayKind::ClipRect),
+            "cs_clip_rectangle",
+            &[FAST_PATH_FEATURE],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let cs_clip_box_shadow = LazilyCompiledShader::new(
+            ShaderKind::ClipCache(VertexArrayKind::ClipBoxShadow),
+            "cs_clip_box_shadow",
+            &["TEXTURE_2D"],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let cs_clip_image = LazilyCompiledShader::new(
+            ShaderKind::ClipCache(VertexArrayKind::ClipImage),
+            "cs_clip_image",
+            &["TEXTURE_2D"],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let mut cs_scale = Vec::new();
+        let scale_shader_num = IMAGE_BUFFER_KINDS.len();
+        // PrimitiveShader is not clonable. Use push() to initialize the vec.
+        for _ in 0 .. scale_shader_num {
+            cs_scale.push(None);
+        }
+        for image_buffer_kind in &IMAGE_BUFFER_KINDS {
+            if has_platform_support(*image_buffer_kind, &gl_type) {
+                let feature_string = get_feature_string(
+                    *image_buffer_kind,
+                    texture_external_version,
+                );
+
+                let mut features = Vec::new();
+                if feature_string != "" {
+                    features.push(feature_string);
+                }
+
+                let shader = LazilyCompiledShader::new(
+                    ShaderKind::Cache(VertexArrayKind::Scale),
+                    "cs_scale",
+                    &features,
+                    device,
+                    options.precache_flags,
+                    &shader_list,
+                    profile,
+                 )?;
+
+                 let index = Self::get_compositing_shader_index(
+                    *image_buffer_kind,
+                 );
+                 cs_scale[index] = Some(shader);
+            }
+        }
+
+        // TODO(gw): The split composite + text shader are special cases - the only
+        //           shaders used during normal scene rendering that aren't a brush
+        //           shader. Perhaps we can unify these in future?
+
+        let ps_text_run = TextShader::new("ps_text_run",
+            device,
+            &[],
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let ps_text_run_dual_source = if use_dual_source_blending {
+            let dual_source_features = vec![DUAL_SOURCE_FEATURE];
+            Some(TextShader::new("ps_text_run",
+                device,
+                &dual_source_features,
+                options.precache_flags,
+                &shader_list,
+                profile,
+            )?)
+        } else {
+            None
+        };
+
+        let ps_quad_textured = LazilyCompiledShader::new(
+            ShaderKind::Primitive,
+            "ps_quad_textured",
+            &[],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let ps_split_composite = LazilyCompiledShader::new(
+            ShaderKind::Primitive,
+            "ps_split_composite",
+            &[],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let ps_clear = LazilyCompiledShader::new(
+            ShaderKind::Clear,
+            "ps_clear",
+            &[],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let ps_copy = LazilyCompiledShader::new(
+            ShaderKind::Copy,
+            "ps_copy",
+            &[],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        // All image configuration.
+        let mut image_features = Vec::new();
+        let mut brush_image = Vec::new();
+        let mut brush_fast_image = Vec::new();
+        // PrimitiveShader is not clonable. Use push() to initialize the vec.
+        for _ in 0 .. IMAGE_BUFFER_KINDS.len() {
+            brush_image.push(None);
+            brush_fast_image.push(None);
+        }
+        for buffer_kind in 0 .. IMAGE_BUFFER_KINDS.len() {
+            if !has_platform_support(IMAGE_BUFFER_KINDS[buffer_kind], &gl_type)
+                // Brush shaders are not ESSL1 compatible
+                || (IMAGE_BUFFER_KINDS[buffer_kind] == ImageBufferKind::TextureExternal
+                    && texture_external_version == TextureExternalVersion::ESSL1)
+            {
+                continue;
+            }
+
+            let feature_string = get_feature_string(
+                IMAGE_BUFFER_KINDS[buffer_kind],
+                texture_external_version,
+            );
+            if feature_string != "" {
+                image_features.push(feature_string);
+            }
+
+            brush_fast_image[buffer_kind] = Some(BrushShader::new(
+                "brush_image",
+                device,
+                &image_features,
+                options.precache_flags,
+                &shader_list,
+                use_advanced_blend_equation,
+                use_dual_source_blending,
+                profile,
+            )?);
+
+            image_features.push("REPETITION");
+            image_features.push("ANTIALIASING");
+
+            brush_image[buffer_kind] = Some(BrushShader::new(
+                "brush_image",
+                device,
+                &image_features,
+                options.precache_flags,
+                &shader_list,
+                use_advanced_blend_equation,
+                use_dual_source_blending,
+                profile,
+            )?);
+
+            image_features.clear();
+        }
+
+        // All yuv_image configuration.
+        let mut yuv_features = Vec::new();
+        let mut rgba_features = Vec::new();
+        let mut fast_path_features = Vec::new();
+        let yuv_shader_num = IMAGE_BUFFER_KINDS.len();
+        let mut brush_yuv_image = Vec::new();
+        // PrimitiveShader is not clonable. Use push() to initialize the vec.
+        for _ in 0 .. yuv_shader_num {
+            brush_yuv_image.push(None);
+        }
+        for image_buffer_kind in &IMAGE_BUFFER_KINDS {
+            if has_platform_support(*image_buffer_kind, &gl_type) {
+                yuv_features.push("YUV");
+                fast_path_features.push("FAST_PATH");
+
+                let index = Self::get_compositing_shader_index(
+                    *image_buffer_kind,
+                );
+
+                let feature_string = get_feature_string(
+                    *image_buffer_kind,
+                    texture_external_version,
+                );
+                if feature_string != "" {
+                    yuv_features.push(feature_string);
+                    rgba_features.push(feature_string);
+                    fast_path_features.push(feature_string);
+                }
+
+                // YUV shaders are not compatible with ESSL1
+                if *image_buffer_kind != ImageBufferKind::TextureExternal ||
+                    texture_external_version == TextureExternalVersion::ESSL3 {
+                    let brush_shader = BrushShader::new(
+                        "brush_yuv_image",
+                        device,
+                        &yuv_features,
+                        options.precache_flags,
+                        &shader_list,
+                        false /* advanced blend */,
+                        false /* dual source */,
+                        profile,
+                    )?;
+                    brush_yuv_image[index] = Some(brush_shader);
+                }
+
+                yuv_features.clear();
+                rgba_features.clear();
+                fast_path_features.clear();
+            }
+        }
+
+        let cs_line_decoration = LazilyCompiledShader::new(
+            ShaderKind::Cache(VertexArrayKind::LineDecoration),
+            "cs_line_decoration",
+            &[],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let cs_fast_linear_gradient = LazilyCompiledShader::new(
+            ShaderKind::Cache(VertexArrayKind::FastLinearGradient),
+            "cs_fast_linear_gradient",
+            &[],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let cs_linear_gradient = LazilyCompiledShader::new(
+            ShaderKind::Cache(VertexArrayKind::LinearGradient),
+            "cs_linear_gradient",
+            &[],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let cs_radial_gradient = LazilyCompiledShader::new(
+            ShaderKind::Cache(VertexArrayKind::RadialGradient),
+            "cs_radial_gradient",
+            &[],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let cs_conic_gradient = LazilyCompiledShader::new(
+            ShaderKind::Cache(VertexArrayKind::ConicGradient),
+            "cs_conic_gradient",
+            &[],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let cs_border_segment = LazilyCompiledShader::new(
+            ShaderKind::Cache(VertexArrayKind::Border),
+            "cs_border_segment",
+             &[],
+             device,
+             options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let cs_border_solid = LazilyCompiledShader::new(
+            ShaderKind::Cache(VertexArrayKind::Border),
+            "cs_border_solid",
+            &[],
+            device,
+            options.precache_flags,
+            &shader_list,
+            profile,
+        )?;
+
+        let composite = CompositorShaders::new(device, options.precache_flags, gl_type)?;
+
+        Ok(Shaders {
+            cs_blur_a8,
+            cs_blur_rgba8,
+            cs_border_segment,
+            cs_line_decoration,
+            cs_fast_linear_gradient,
+            cs_linear_gradient,
+            cs_radial_gradient,
+            cs_conic_gradient,
+            cs_border_solid,
+            cs_scale,
+            cs_svg_filter,
+            brush_solid,
+            brush_image,
+            brush_fast_image,
+            brush_blend,
+            brush_mix_blend,
+            brush_yuv_image,
+            brush_linear_gradient,
+            brush_opacity,
+            brush_opacity_aa,
+            cs_clip_rectangle_slow,
+            cs_clip_rectangle_fast,
+            cs_clip_box_shadow,
+            cs_clip_image,
+            ps_text_run,
+            ps_text_run_dual_source,
+            ps_quad_textured,
+            ps_mask,
+            ps_mask_fast,
+            ps_split_composite,
+            ps_clear,
+            ps_copy,
+            composite,
+        })
+    }
+
+    fn get_compositing_shader_index(buffer_kind: ImageBufferKind) -> usize {
+        buffer_kind as usize
+    }
+
+    pub fn get_composite_shader(
+        &mut self,
+        format: CompositeSurfaceFormat,
+        buffer_kind: ImageBufferKind,
+        features: CompositeFeatures,
+    ) -> &mut LazilyCompiledShader {
+        self.composite.get(format, buffer_kind, features)
+    }
+
+    pub fn get_scale_shader(
+        &mut self,
+        buffer_kind: ImageBufferKind,
+    ) -> &mut LazilyCompiledShader {
+        let shader_index = Self::get_compositing_shader_index(buffer_kind);
+        self.cs_scale[shader_index]
+            .as_mut()
+            .expect("bug: unsupported scale shader requested")
+    }
+
+    pub fn get(&
+        mut self,
+        key: &BatchKey,
+        mut features: BatchFeatures,
+        debug_flags: DebugFlags,
+        device: &Device,
+    ) -> &mut LazilyCompiledShader {
+        match key.kind {
+            BatchKind::Primitive => {
+                &mut self.ps_quad_textured
+            }
+            BatchKind::SplitComposite => {
+                &mut self.ps_split_composite
+            }
+            BatchKind::Brush(brush_kind) => {
+                // SWGL uses a native anti-aliasing implementation that bypasses the shader.
+                // Don't consider it in that case when deciding whether or not to use
+                // an alpha-pass shader.
+                if device.get_capabilities().uses_native_antialiasing {
+                    features.remove(BatchFeatures::ANTIALIASING);
+                }
+                let brush_shader = match brush_kind {
+                    BrushBatchKind::Solid => {
+                        &mut self.brush_solid
+                    }
+                    BrushBatchKind::Image(image_buffer_kind) => {
+                        if features.contains(BatchFeatures::ANTIALIASING) ||
+                            features.contains(BatchFeatures::REPETITION) {
+
+                            self.brush_image[image_buffer_kind as usize]
+                                .as_mut()
+                                .expect("Unsupported image shader kind")
+                        } else {
+                            self.brush_fast_image[image_buffer_kind as usize]
+                                .as_mut()
+                                .expect("Unsupported image shader kind")
+                        }
+                    }
+                    BrushBatchKind::Blend => {
+                        &mut self.brush_blend
+                    }
+                    BrushBatchKind::MixBlend { .. } => {
+                        &mut self.brush_mix_blend
+                    }
+                    BrushBatchKind::LinearGradient => {
+                        // SWGL uses a native clip mask implementation that bypasses the shader.
+                        // Don't consider it in that case when deciding whether or not to use
+                        // an alpha-pass shader.
+                        if device.get_capabilities().uses_native_clip_mask {
+                            features.remove(BatchFeatures::CLIP_MASK);
+                        }
+                        // Gradient brushes can optimistically use the opaque shader even
+                        // with a blend mode if they don't require any features.
+                        if !features.intersects(
+                            BatchFeatures::ANTIALIASING
+                                | BatchFeatures::REPETITION
+                                | BatchFeatures::CLIP_MASK,
+                        ) {
+                            features.remove(BatchFeatures::ALPHA_PASS);
+                        }
+                        match brush_kind {
+                            BrushBatchKind::LinearGradient => &mut self.brush_linear_gradient,
+                            _ => panic!(),
+                        }
+                    }
+                    BrushBatchKind::YuvImage(image_buffer_kind, ..) => {
+                        let shader_index =
+                            Self::get_compositing_shader_index(image_buffer_kind);
+                        self.brush_yuv_image[shader_index]
+                            .as_mut()
+                            .expect("Unsupported YUV shader kind")
+                    }
+                    BrushBatchKind::Opacity => {
+                        if features.contains(BatchFeatures::ANTIALIASING) {
+                            &mut self.brush_opacity_aa
+                        } else {
+                            &mut self.brush_opacity
+                        }
+                    }
+                };
+                brush_shader.get(key.blend_mode, features, debug_flags)
+            }
+            BatchKind::TextRun(glyph_format) => {
+                let text_shader = match key.blend_mode {
+                    BlendMode::SubpixelDualSource => self.ps_text_run_dual_source.as_mut().unwrap(),
+                    _ => &mut self.ps_text_run,
+                };
+                text_shader.get(glyph_format, debug_flags)
+            }
+        }
+    }
+
+    pub fn deinit(mut self, device: &mut Device) {
+        for shader in self.cs_scale {
+            if let Some(shader) = shader {
+                shader.deinit(device);
+            }
+        }
+        self.cs_blur_a8.deinit(device);
+        self.cs_blur_rgba8.deinit(device);
+        self.cs_svg_filter.deinit(device);
+        self.brush_solid.deinit(device);
+        self.brush_blend.deinit(device);
+        self.brush_mix_blend.deinit(device);
+        self.brush_linear_gradient.deinit(device);
+        self.brush_opacity.deinit(device);
+        self.brush_opacity_aa.deinit(device);
+        self.cs_clip_rectangle_slow.deinit(device);
+        self.cs_clip_rectangle_fast.deinit(device);
+        self.cs_clip_box_shadow.deinit(device);
+        self.cs_clip_image.deinit(device);
+        self.ps_text_run.deinit(device);
+        if let Some(shader) = self.ps_text_run_dual_source {
+            shader.deinit(device);
+        }
+        for shader in self.brush_image {
+            if let Some(shader) = shader {
+                shader.deinit(device);
+            }
+        }
+        for shader in self.brush_fast_image {
+            if let Some(shader) = shader {
+                shader.deinit(device);
+            }
+        }
+        for shader in self.brush_yuv_image {
+            if let Some(shader) = shader {
+                shader.deinit(device);
+            }
+        }
+        self.cs_border_solid.deinit(device);
+        self.cs_fast_linear_gradient.deinit(device);
+        self.cs_linear_gradient.deinit(device);
+        self.cs_radial_gradient.deinit(device);
+        self.cs_conic_gradient.deinit(device);
+        self.cs_line_decoration.deinit(device);
+        self.cs_border_segment.deinit(device);
+        self.ps_split_composite.deinit(device);
+        self.ps_quad_textured.deinit(device);
+        self.ps_mask.deinit(device);
+        self.ps_mask_fast.deinit(device);
+        self.ps_clear.deinit(device);
+        self.ps_copy.deinit(device);
+        self.composite.deinit(device);
+    }
+}
+
+pub type SharedShaders = Rc<RefCell<Shaders>>;
+
+pub struct CompositorShaders {
+    // Composite shaders. These are very simple shaders used to composite
+    // picture cache tiles into the framebuffer on platforms that do not have an
+    // OS Compositor (or we cannot use it).  Such an OS Compositor (such as
+    // DirectComposite or CoreAnimation) handles the composition of the picture
+    // cache tiles at a lower level (e.g. in DWM for Windows); in that case we
+    // directly hand the picture cache surfaces over to the OS Compositor, and
+    // our own Composite shaders below never run.
+    // To composite external (RGB) surfaces we need various permutations of
+    // shaders with WR_FEATURE flags on or off based on the type of image
+    // buffer we're sourcing from (see IMAGE_BUFFER_KINDS).
+    rgba: Vec<Option<LazilyCompiledShader>>,
+    // A faster set of rgba composite shaders that do not support UV clamping
+    // or color modulation.
+    rgba_fast_path: Vec<Option<LazilyCompiledShader>>,
+    // The same set of composite shaders but with WR_FEATURE_YUV added.
+    yuv: Vec<Option<LazilyCompiledShader>>,
+}
+
+impl CompositorShaders {
+    pub fn new(
+        device: &mut Device,
+        precache_flags: ShaderPrecacheFlags,
+        gl_type: GlType,
+    )  -> Result<Self, ShaderError>  {
+        // We have to pass a profile around a bunch but we aren't recording the initialization
+        // so use a dummy one.
+        let mut profile = TransactionProfile::new();
+
+        let mut yuv_features = Vec::new();
+        let mut rgba_features = Vec::new();
+        let mut fast_path_features = Vec::new();
+        let mut rgba = Vec::new();
+        let mut rgba_fast_path = Vec::new();
+        let mut yuv = Vec::new();
+
+        let texture_external_version = if device.get_capabilities().supports_image_external_essl3 {
+            TextureExternalVersion::ESSL3
+        } else {
+            TextureExternalVersion::ESSL1
+        };
+
+        let feature_flags = get_shader_feature_flags(gl_type, texture_external_version);
+        let shader_list = get_shader_features(feature_flags);
+
+        for _ in 0..IMAGE_BUFFER_KINDS.len() {
+            yuv.push(None);
+            rgba.push(None);
+            rgba_fast_path.push(None);
+        }
+
+        for image_buffer_kind in &IMAGE_BUFFER_KINDS {
+            if !has_platform_support(*image_buffer_kind, &gl_type) {
+                continue;
+            }
+
+            yuv_features.push("YUV");
+            fast_path_features.push("FAST_PATH");
+    
+            let index = Self::get_shader_index(*image_buffer_kind);
+
+            let feature_string = get_feature_string(
+                *image_buffer_kind,
+                texture_external_version,
+            );
+            if feature_string != "" {
+                yuv_features.push(feature_string);
+                rgba_features.push(feature_string);
+                fast_path_features.push(feature_string);
+            }
+
+            // YUV shaders are not compatible with ESSL1
+            if *image_buffer_kind != ImageBufferKind::TextureExternal ||
+                texture_external_version == TextureExternalVersion::ESSL3 {
+
+                yuv[index] = Some(LazilyCompiledShader::new(
+                    ShaderKind::Composite,
+                    "composite",
+                    &yuv_features,
+                    device,
+                    precache_flags,
+                    &shader_list,
+                    &mut profile,
+                )?);
+            }
+
+            rgba[index] = Some(LazilyCompiledShader::new(
+                ShaderKind::Composite,
+                "composite",
+                &rgba_features,
+                device,
+                precache_flags,
+                &shader_list,
+                &mut profile,
+            )?);
+
+            rgba_fast_path[index] = Some(LazilyCompiledShader::new(
+                ShaderKind::Composite,
+                "composite",
+                &fast_path_features,
+                device,
+                precache_flags,
+                &shader_list,
+                &mut profile,
+            )?);
+
+            yuv_features.clear();
+            rgba_features.clear();
+            fast_path_features.clear();
+        }
+
+        Ok(CompositorShaders {
+            rgba,
+            rgba_fast_path,
+            yuv,
+        })
+    }
+
+    pub fn get(
+        &mut self,
+        format: CompositeSurfaceFormat,
+        buffer_kind: ImageBufferKind,
+        features: CompositeFeatures,
+    ) -> &mut LazilyCompiledShader {
+        match format {
+            CompositeSurfaceFormat::Rgba => {
+                if features.contains(CompositeFeatures::NO_UV_CLAMP)
+                    && features.contains(CompositeFeatures::NO_COLOR_MODULATION)
+                {
+                    let shader_index = Self::get_shader_index(buffer_kind);
+                    self.rgba_fast_path[shader_index]
+                        .as_mut()
+                        .expect("bug: unsupported rgba fast path shader requested")
+                } else {
+                    let shader_index = Self::get_shader_index(buffer_kind);
+                    self.rgba[shader_index]
+                        .as_mut()
+                        .expect("bug: unsupported rgba shader requested")
+                }
+            }
+            CompositeSurfaceFormat::Yuv => {
+                let shader_index = Self::get_shader_index(buffer_kind);
+                self.yuv[shader_index]
+                    .as_mut()
+                    .expect("bug: unsupported yuv shader requested")
+            }
+        }
+    }
+
+    fn get_shader_index(buffer_kind: ImageBufferKind) -> usize {
+        buffer_kind as usize
+    }
+
+    pub fn deinit(&mut self, device: &mut Device) {
+        for shader in self.rgba.drain(..) {
+            if let Some(shader) = shader {
+                shader.deinit(device);
+            }
+        }
+        for shader in self.rgba_fast_path.drain(..) {
+            if let Some(shader) = shader {
+                shader.deinit(device);
+            }
+        }
+        for shader in self.yuv.drain(..) {
+            if let Some(shader) = shader {
+                shader.deinit(device);
+            }
+        }
+    }
+}
+
+fn get_shader_feature_flags(gl_type: GlType, texture_external_version: TextureExternalVersion) -> ShaderFeatureFlags {
+    match gl_type {
+        GlType::Gl => ShaderFeatureFlags::GL,
+        GlType::Gles => {
+            let texture_external_flag = match texture_external_version {
+                TextureExternalVersion::ESSL3 => ShaderFeatureFlags::TEXTURE_EXTERNAL,
+                TextureExternalVersion::ESSL1 => ShaderFeatureFlags::TEXTURE_EXTERNAL_ESSL1,
+            };
+            ShaderFeatureFlags::GLES | texture_external_flag
+        }
+    }
+}