[Impeller] Implement support for RuntimeEffect samplers (flutter/engine#37026)

engine/src/flutter/impeller/display_list/display_list_dispatcher.cc

@@ -10,6 +10,7 @@
 #include <optional>
 #include <unordered_map>
 #include <utility>
+#include <vector>
 
 #include "display_list/display_list_blend_mode.h"
 #include "display_list/display_list_color_filter.h"
@@ -436,11 +437,28 @@ void DisplayListDispatcher::setColorSource(
       auto runtime_stage =
           runtime_effect_color_source->runtime_effect()->runtime_stage();
       auto uniform_data = runtime_effect_color_source->uniform_data();
+      auto samplers = runtime_effect_color_source->samplers();
 
-      paint_.color_source = [runtime_stage, uniform_data]() {
+      std::vector<RuntimeEffectContents::TextureInput> texture_inputs;
+
+      for (auto& sampler : samplers) {
+        auto* image = sampler->asImage();
+        if (!sampler->asImage()) {
+          UNIMPLEMENTED;
+          return;
+        }
+        FML_DCHECK(image->image()->impeller_texture());
+        texture_inputs.push_back({
+            .sampler_descriptor = ToSamplerDescriptor(image->sampling()),
+            .texture = image->image()->impeller_texture(),
+        });
+      }
+
+      paint_.color_source = [runtime_stage, uniform_data, texture_inputs]() {
         auto contents = std::make_shared<RuntimeEffectContents>();
         contents->SetRuntimeStage(runtime_stage);
         contents->SetUniformData(uniform_data);
+        contents->SetTextureInputs(texture_inputs);
         return contents;
       };
       return;

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

@@ -16,6 +16,7 @@
 #include "impeller/renderer/formats.h"
 #include "impeller/renderer/pipeline_library.h"
 #include "impeller/renderer/render_pass.h"
+#include "impeller/renderer/sampler_library.h"
 #include "impeller/renderer/shader_function.h"
 #include "impeller/renderer/shader_types.h"
 
@@ -31,6 +32,11 @@ void RuntimeEffectContents::SetUniformData(
   uniform_data_ = std::move(uniform_data);
 }
 
+void RuntimeEffectContents::SetTextureInputs(
+    std::vector<TextureInput> texture_inputs) {
+  texture_inputs_ = std::move(texture_inputs);
+}
+
 bool RuntimeEffectContents::Render(const ContentContext& renderer,
                                    const Entity& entity,
                                    RenderPass& pass) const {
@@ -136,21 +142,59 @@ bool RuntimeEffectContents::Render(const ContentContext& renderer,
   ///
 
   size_t buffer_index = 0;
+  size_t sampler_index = 0;
   for (auto uniform : runtime_stage_->GetUniforms()) {
     // TODO(113715): Populate this metadata once GLES is able to handle
     //               non-struct uniform names.
     ShaderMetadata metadata;
 
-    size_t alignment =
-        std::max(uniform.bit_width / 8, DefaultUniformAlignment());
-    auto buffer_view = pass.GetTransientsBuffer().Emplace(
-        uniform_data_->data() + uniform.location * sizeof(float),
-        uniform.GetSize(), alignment);
+    switch (uniform.type) {
+      case kSampledImage: {
+        FML_DCHECK(sampler_index < texture_inputs_.size());
+        auto& input = texture_inputs_[sampler_index];
 
-    ShaderUniformSlot slot;
-    slot.name = uniform.name.c_str();
-    slot.ext_res_0 = buffer_index;
-    cmd.BindResource(ShaderStage::kFragment, slot, metadata, buffer_view);
+        auto sampler =
+            context->GetSamplerLibrary()->GetSampler(input.sampler_descriptor);
+
+        SampledImageSlot image_slot;
+        image_slot.name = uniform.name.c_str();
+        image_slot.texture_index = sampler_index;
+        image_slot.sampler_index = sampler_index;
+        cmd.BindResource(ShaderStage::kFragment, image_slot, metadata,
+                         input.texture, sampler);
+
+        sampler_index++;
+        break;
+      }
+      case kFloat: {
+        size_t alignment =
+            std::max(uniform.bit_width / 8, DefaultUniformAlignment());
+        auto buffer_view = pass.GetTransientsBuffer().Emplace(
+            uniform_data_->data() + uniform.location * sizeof(float),
+            uniform.GetSize(), alignment);
+
+        ShaderUniformSlot uniform_slot;
+        uniform_slot.name = uniform.name.c_str();
+        uniform_slot.ext_res_0 = buffer_index;
+        cmd.BindResource(ShaderStage::kFragment, uniform_slot, metadata,
+                         buffer_view);
+        break;
+      }
+      case kBoolean:
+      case kSignedByte:
+      case kUnsignedByte:
+      case kSignedShort:
+      case kUnsignedShort:
+      case kSignedInt:
+      case kUnsignedInt:
+      case kSignedInt64:
+      case kUnsignedInt64:
+      case kHalfFloat:
+      case kDouble:
+        VALIDATION_LOG << "Unsupported uniform type for " << uniform.name
+                       << ".";
+        return true;
+    }
 
     buffer_index++;
   }

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

@@ -4,18 +4,27 @@
 
 #include <functional>
 #include <memory>
+#include <vector>
 
 #include "impeller/entity/contents/color_source_contents.h"
+#include "impeller/renderer/sampler_descriptor.h"
 #include "impeller/runtime_stage/runtime_stage.h"
 
 namespace impeller {
 
 class RuntimeEffectContents final : public ColorSourceContents {
  public:
+  struct TextureInput {
+    SamplerDescriptor sampler_descriptor;
+    std::shared_ptr<Texture> texture;
+  };
+
   void SetRuntimeStage(std::shared_ptr<RuntimeStage> runtime_stage);
 
   void SetUniformData(std::shared_ptr<std::vector<uint8_t>> uniform_data);
 
+  void SetTextureInputs(std::vector<TextureInput> texture_inputs);
+
   // |Contents|
   bool Render(const ContentContext& renderer,
               const Entity& entity,
@@ -24,6 +33,7 @@ class RuntimeEffectContents final : public ColorSourceContents {
  private:
   std::shared_ptr<RuntimeStage> runtime_stage_;
   std::shared_ptr<std::vector<uint8_t>> uniform_data_;
+  std::vector<TextureInput> texture_inputs_;
 };
 
 }  // namespace impeller