[Impeller] split vertices uber into 2 shaders. (#165938)

Works around compilation error on newer phone (ask me offline). Required
for flutter/flutter#162033

Author: Jonah Williams

engine/src/flutter/ci/licenses_golden/licenses_flutter

@@ -51303,7 +51303,9 @@ ORIGIN: ../../../flutter/impeller/entity/shaders/blending/framebuffer_blend.frag
 ORIGIN: ../../../flutter/impeller/entity/shaders/blending/framebuffer_blend.vert + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/impeller/entity/shaders/blending/porter_duff_blend.frag + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/impeller/entity/shaders/blending/porter_duff_blend.vert + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/impeller/entity/shaders/blending/vertices_uber.frag + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/impeller/entity/shaders/blending/vertices_uber.glsl + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/impeller/entity/shaders/blending/vertices_uber_1.frag + ../../../flutter/LICENSE
+ORIGIN: ../../../flutter/impeller/entity/shaders/blending/vertices_uber_2.frag + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/impeller/entity/shaders/clip.frag + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/impeller/entity/shaders/clip.vert + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/impeller/entity/shaders/downsample.glsl + ../../../flutter/LICENSE
@@ -54287,7 +54289,9 @@ FILE: ../../../flutter/impeller/entity/shaders/blending/framebuffer_blend.frag
 FILE: ../../../flutter/impeller/entity/shaders/blending/framebuffer_blend.vert
 FILE: ../../../flutter/impeller/entity/shaders/blending/porter_duff_blend.frag
 FILE: ../../../flutter/impeller/entity/shaders/blending/porter_duff_blend.vert
-FILE: ../../../flutter/impeller/entity/shaders/blending/vertices_uber.frag
+FILE: ../../../flutter/impeller/entity/shaders/blending/vertices_uber.glsl
+FILE: ../../../flutter/impeller/entity/shaders/blending/vertices_uber_1.frag
+FILE: ../../../flutter/impeller/entity/shaders/blending/vertices_uber_2.frag
 FILE: ../../../flutter/impeller/entity/shaders/clip.frag
 FILE: ../../../flutter/impeller/entity/shaders/clip.vert
 FILE: ../../../flutter/impeller/entity/shaders/downsample.glsl

engine/src/flutter/impeller/entity/BUILD.gn

@@ -59,7 +59,8 @@ impeller_shaders("entity_shaders") {
     "shaders/filters/srgb_to_linear_filter.frag",
     "shaders/filters/linear_to_srgb_filter.frag",
     "shaders/filters/morphology_filter.frag",
-    "shaders/blending/vertices_uber.frag",
+    "shaders/blending/vertices_uber_1.frag",
+    "shaders/blending/vertices_uber_2.frag",
     "shaders/gradients/fast_gradient.vert",
     "shaders/gradients/fast_gradient.frag",
     "shaders/texture_downsample.frag",

engine/src/flutter/impeller/entity/contents/atlas_contents.cc

@@ -126,15 +126,15 @@ bool AtlasContents::Render(const ContentContext& renderer,
     return pass.Draw().ok();
   }
 
-  using VUS = VerticesUberShader::VertexShader;
-  using FS = VerticesUberShader::FragmentShader;
+  using VUS = VerticesUber1Shader::VertexShader;
+  using FS = VerticesUber1Shader::FragmentShader;
 
 #ifdef IMPELLER_DEBUG
   pass.SetCommandLabel("DrawAtlas Advanced Blend");
 #endif  // IMPELLER_DEBUG
   pass.SetVertexBuffer(geometry_->CreateBlendVertexBuffer(host_buffer));
 
-  pass.SetPipeline(renderer.GetDrawVerticesUberShader(OptionsFromPass(pass)));
+  renderer.GetDrawVerticesUberPipeline(blend_mode, OptionsFromPass(pass));
   FS::BindTextureSampler(pass, geometry_->GetAtlas(), dst_sampler);
 
   VUS::FrameInfo frame_info;

engine/src/flutter/impeller/entity/contents/content_context.cc

@@ -272,7 +272,8 @@ struct ContentContext::Pipelines {
   Variants<TexturePipeline> texture;
   Variants<TextureStrictSrcPipeline> texture_strict_src;
   Variants<TiledTexturePipeline> tiled_texture;
-  Variants<VerticesUberShader> vertices_uber_shader_;
+  Variants<VerticesUber1Shader> vertices_uber_1_;
+  Variants<VerticesUber2Shader> vertices_uber_2_;
   Variants<YUVToRGBFilterPipeline> yuv_to_rgb_filter;
 
 #ifdef IMPELLER_ENABLE_OPENGLES
@@ -668,8 +669,10 @@ ContentContext::ContentContext(
                                                options_trianglestrip);
     pipelines_->color_matrix_color_filter.CreateDefault(*context_,
                                                         options_trianglestrip);
-    pipelines_->vertices_uber_shader_.CreateDefault(*context_, options,
-                                                    {supports_decal});
+    pipelines_->vertices_uber_1_.CreateDefault(*context_, options,
+                                               {supports_decal});
+    pipelines_->vertices_uber_2_.CreateDefault(*context_, options,
+                                               {supports_decal});
 
     const std::array<std::vector<Scalar>, 15> porter_duff_constants =
         GetPorterDuffSpecConstants(supports_decal);
@@ -1421,9 +1424,14 @@ PipelineRef ContentContext::GetFramebufferBlendSoftLightPipeline(
   return GetPipeline(this, pipelines_->framebuffer_blend_softlight, opts);
 }
 
-PipelineRef ContentContext::GetDrawVerticesUberShader(
+PipelineRef ContentContext::GetDrawVerticesUberPipeline(
+    BlendMode blend_mode,
     ContentContextOptions opts) const {
-  return GetPipeline(this, pipelines_->vertices_uber_shader_, opts);
+  if (blend_mode <= BlendMode::kSoftLight) {
+    return GetPipeline(this, pipelines_->vertices_uber_1_, opts);
+  } else {
+    return GetPipeline(this, pipelines_->vertices_uber_2_, opts);
+  }
 }
 
 PipelineRef ContentContext::GetLinePipeline(ContentContextOptions opts) const {

engine/src/flutter/impeller/entity/contents/content_context.h

@@ -176,7 +176,7 @@ class ContentContext {
   PipelineRef GetDestinationOutBlendPipeline(ContentContextOptions opts) const;
   PipelineRef GetDestinationOverBlendPipeline(ContentContextOptions opts) const;
   PipelineRef GetDownsamplePipeline(ContentContextOptions opts) const;
-  PipelineRef GetDrawVerticesUberShader(ContentContextOptions opts) const;
+  PipelineRef GetDrawVerticesUberPipeline(BlendMode blend_mode, ContentContextOptions opts) const;
   PipelineRef GetFastGradientPipeline(ContentContextOptions opts) const;
   PipelineRef GetFramebufferBlendColorBurnPipeline(ContentContextOptions opts) const;
   PipelineRef GetFramebufferBlendColorDodgePipeline(ContentContextOptions opts) const;

engine/src/flutter/impeller/entity/contents/pipelines.h

@@ -56,7 +56,8 @@
 #include "impeller/entity/texture_fill_strict_src.frag.h"
 #include "impeller/entity/texture_uv_fill.vert.h"
 #include "impeller/entity/tiled_texture_fill.frag.h"
-#include "impeller/entity/vertices_uber.frag.h"
+#include "impeller/entity/vertices_uber_1.frag.h"
+#include "impeller/entity/vertices_uber_2.frag.h"
 #include "impeller/entity/yuv_to_rgb_filter.frag.h"
 #include "impeller/renderer/pipeline.h"
 
@@ -146,7 +147,8 @@ using TextureDownsamplePipeline = RenderPipelineHandle<TextureFillVertexShader,
 using TexturePipeline = RenderPipelineHandle<TextureFillVertexShader, TextureFillFragmentShader>;
 using TextureStrictSrcPipeline = RenderPipelineHandle<TextureFillVertexShader, TextureFillStrictSrcFragmentShader>;
 using TiledTexturePipeline = RenderPipelineHandle<TextureUvFillVertexShader, TiledTextureFillFragmentShader>;
-using VerticesUberShader = RenderPipelineHandle<PorterDuffBlendVertexShader, VerticesUberFragmentShader>;
+using VerticesUber1Shader = RenderPipelineHandle<PorterDuffBlendVertexShader, VerticesUber1FragmentShader>;
+using VerticesUber2Shader = RenderPipelineHandle<PorterDuffBlendVertexShader, VerticesUber2FragmentShader>;
 using YUVToRGBFilterPipeline = RenderPipelineHandle<FilterPositionVertexShader, YuvToRgbFilterFragmentShader>;
 // clang-format on
 

engine/src/flutter/impeller/entity/contents/vertices_contents.cc

@@ -10,6 +10,7 @@
 #include "impeller/entity/contents/content_context.h"
 #include "impeller/entity/contents/contents.h"
 #include "impeller/entity/contents/filters/blend_filter_contents.h"
+#include "impeller/entity/contents/pipelines.h"
 #include "impeller/entity/geometry/geometry.h"
 #include "impeller/entity/geometry/vertices_geometry.h"
 #include "impeller/geometry/color.h"
@@ -177,8 +178,8 @@ bool VerticesSimpleBlendContents::Render(const ContentContext& renderer,
     return pass.Draw().ok();
   }
 
-  using VS = VerticesUberShader::VertexShader;
-  using FS = VerticesUberShader::FragmentShader;
+  using VS = VerticesUber1Shader::VertexShader;
+  using FS = VerticesUber1Shader::FragmentShader;
 
 #ifdef IMPELLER_DEBUG
   pass.SetCommandLabel(SPrintF("DrawVertices Advanced Blend (%s)",
@@ -188,7 +189,7 @@ bool VerticesSimpleBlendContents::Render(const ContentContext& renderer,
 
   auto options = OptionsFromPassAndEntity(pass, entity);
   options.primitive_type = geometry_result.type;
-  pass.SetPipeline(renderer.GetDrawVerticesUberShader(options));
+  pass.SetPipeline(renderer.GetDrawVerticesUberPipeline(blend_mode, options));
 
   FS::BindTextureSampler(pass, texture, dst_sampler);
 

engine/src/flutter/impeller/entity/shaders/blending/blend_select.glsl

@@ -70,3 +70,56 @@ f16vec3 AdvancedBlend(f16vec3 dst, f16vec3 src, int blend_type) {
   }
   return f16vec3(0.0hf);
 }
+
+f16vec3 AdvancedBlendHalf1(f16vec3 dst, f16vec3 src, int blend_type) {
+  if (blend_type == 0) {
+    return IPBlendScreen(dst, src);
+  }
+  if (blend_type == 1) {
+    return IPBlendOverlay(dst, src);
+  }
+  if (blend_type == 2) {
+    return IPBlendDarken(dst, src);
+  }
+  if (blend_type == 3) {
+    return IPBlendLighten(dst, src);
+  }
+  if (blend_type == 4) {
+    return IPBlendColorDodge(dst, src);
+  }
+  if (blend_type == 5) {
+    return IPBlendColorBurn(dst, src);
+  }
+  if (blend_type == 6) {
+    return IPBlendHardLight(dst, src);
+  }
+  if (blend_type == 7) {
+    return IPBlendSoftLight(dst, src);
+  }
+  return f16vec3(0.0hf);
+}
+
+f16vec3 AdvancedBlendHalf2(f16vec3 dst, f16vec3 src, int blend_type) {
+  if (blend_type == 8) {
+    return IPBlendDifference(dst, src);
+  }
+  if (blend_type == 9) {
+    return IPBlendExclusion(dst, src);
+  }
+  if (blend_type == 10) {
+    return IPBlendMultiply(dst, src);
+  }
+  if (blend_type == 11) {
+    return IPBlendHue(dst, src);
+  }
+  if (blend_type == 12) {
+    return IPBlendSaturation(dst, src);
+  }
+  if (blend_type == 13) {
+    return IPBlendColor(dst, src);
+  }
+  if (blend_type == 14) {
+    return IPBlendLuminosity(dst, src);
+  }
+  return f16vec3(0.0hf);
+}

engine/src/flutter/impeller/entity/shaders/blending/vertices_uber.frag renamed to engine/src/flutter/impeller/entity/shaders/blending/vertices_uber.glsl

@@ -33,17 +33,3 @@ f16vec4 Sample(f16sampler2D texture_sampler,
   }
   return IPHalfSampleWithTileMode(texture_sampler, texture_coords, tmx, tmy);
 }
-
-// A shader that implements the required src/dst blending for drawVertices and
-// drawAtlas advanced blends without requiring an offscreen render pass. This is
-// done in a single shader to reduce the permutations of PSO needed at runtime
-// for rarely used features.
-void main() {
-  f16vec4 dst = IPHalfUnpremultiply(v_color);
-  f16vec4 src = IPHalfUnpremultiply(
-      Sample(texture_sampler, v_texture_coords, frag_info.tmx, frag_info.tmy));
-  f16vec3 blend_result =
-      AdvancedBlend(dst.rgb, src.rgb, int(frag_info.blend_mode - 14.0));
-  frag_color = IPApplyBlendedColor(dst, src, blend_result);
-  frag_color *= frag_info.alpha;
-}

engine/src/flutter/impeller/entity/shaders/blending/vertices_uber_1.frag

@@ -0,0 +1,19 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "vertices_uber.glsl"
+
+// A shader that implements the required src/dst blending for drawVertices and
+// drawAtlas advanced blends without requiring an offscreen render pass. This is
+// done in a single shader to reduce the permutations of PSO needed at runtime
+// for rarely used features.
+void main() {
+  f16vec4 dst = IPHalfUnpremultiply(v_color);
+  f16vec4 src = IPHalfUnpremultiply(
+      Sample(texture_sampler, v_texture_coords, frag_info.tmx, frag_info.tmy));
+  f16vec3 blend_result =
+      AdvancedBlendHalf1(dst.rgb, src.rgb, int(frag_info.blend_mode - 14.0));
+  frag_color = IPApplyBlendedColor(dst, src, blend_result);
+  frag_color *= frag_info.alpha;
+}