[Impeller Scene] Parse GLTF primitives (#38064)

Author: bdero

ci/licenses_golden/licenses_flutter

@@ -1648,13 +1648,18 @@ FILE: ../../../flutter/impeller/scene/camera.cc
 FILE: ../../../flutter/impeller/scene/camera.h
 FILE: ../../../flutter/impeller/scene/geometry.cc
 FILE: ../../../flutter/impeller/scene/geometry.h
+FILE: ../../../flutter/impeller/scene/importer/conversions.cc
+FILE: ../../../flutter/impeller/scene/importer/conversions.h
 FILE: ../../../flutter/impeller/scene/importer/importer.h
 FILE: ../../../flutter/impeller/scene/importer/importer_gltf.cc
-FILE: ../../../flutter/impeller/scene/importer/mesh.fbs
+FILE: ../../../flutter/impeller/scene/importer/importer_unittests.cc
+FILE: ../../../flutter/impeller/scene/importer/scene.fbs
 FILE: ../../../flutter/impeller/scene/importer/scenec_main.cc
 FILE: ../../../flutter/impeller/scene/importer/switches.cc
 FILE: ../../../flutter/impeller/scene/importer/switches.h
 FILE: ../../../flutter/impeller/scene/importer/types.h
+FILE: ../../../flutter/impeller/scene/importer/vertices_builder.cc
+FILE: ../../../flutter/impeller/scene/importer/vertices_builder.h
 FILE: ../../../flutter/impeller/scene/material.cc
 FILE: ../../../flutter/impeller/scene/material.h
 FILE: ../../../flutter/impeller/scene/scene.cc

impeller/BUILD.gn

@@ -74,6 +74,7 @@ impeller_component("impeller_unittests") {
     "compiler:compiler_unittests",
     "geometry:geometry_unittests",
     "runtime_stage:runtime_stage_unittests",
+    "scene/importer:importer_unittests",
     "tessellator:tessellator_unittests",
   ]
 

impeller/fixtures/BUILD.gn

@@ -58,6 +58,7 @@ test_fixtures("file_fixtures") {
     "blue_noise.png",
     "boston.jpg",
     "embarcadero.jpg",
+    "flutter_logo.glb",
     "kalimba.jpg",
     "multiple_stages.hlsl",
     "resources_limit.vert",

impeller/scene/importer/BUILD.gn

@@ -12,22 +12,26 @@ config("runtime_stage_config") {
 }
 
 flatbuffers("importer_flatbuffers") {
-  flatbuffers = [ "mesh.fbs" ]
+  flatbuffers = [ "scene.fbs" ]
   public_configs = [ ":runtime_stage_config" ]
   public_deps = [ "//third_party/flatbuffers" ]
 }
 
-impeller_component("scenec_lib") {
+impeller_component("importer_lib") {
   # Current versions of libcxx have deprecated some of the UTF-16 string
   # conversion APIs.
   defines = [ "_LIBCPP_DISABLE_DEPRECATION_WARNINGS" ]
 
   sources = [
+    "conversions.cc",
+    "conversions.h",
     "importer.h",
     "importer_gltf.cc",
     "switches.cc",
     "switches.h",
     "types.h",
+    "vertices_builder.cc",
+    "vertices_builder.h",
   ]
 
   public_deps = [
@@ -39,8 +43,7 @@ impeller_component("scenec_lib") {
 
     # All third_party deps must be reflected below in the scenec_license
     # target.
-    # TODO(bdero): Fix tinygltf compilation warnings.
-    #"//third_party/tinygltf",
+    "//third_party/tinygltf",
   ]
 }
 
@@ -85,9 +88,24 @@ impeller_component("scenec") {
 
   sources = [ "scenec_main.cc" ]
 
-  deps = [ ":scenec_lib" ]
+  deps = [ ":importer_lib" ]
 
   metadata = {
     entitlement_file_path = [ "scenec" ]
   }
 }
+
+impeller_component("importer_unittests") {
+  testonly = true
+
+  output_name = "scenec_unittests"
+
+  sources = [ "importer_unittests.cc" ]
+
+  deps = [
+    ":importer_lib",
+    "../../fixtures",
+    "../../geometry:geometry_unittests",
+    "//flutter/testing:testing_lib",
+  ]
+}

impeller/scene/importer/conversions.cc

@@ -0,0 +1,80 @@
+// 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 "impeller/scene/importer/conversions.h"
+
+#include <cstring>
+
+#include "impeller/scene/importer/scene_flatbuffers.h"
+
+namespace impeller {
+namespace scene {
+namespace importer {
+
+Matrix ToMatrix(const std::vector<double>& m) {
+  return Matrix(m[0], m[1], m[2], m[3],    //
+                m[4], m[5], m[6], m[7],    //
+                m[8], m[9], m[10], m[11],  //
+                m[12], m[13], m[14], m[15]);
+}
+
+//-----------------------------------------------------------------------------
+/// Flatbuffers -> Impeller
+///
+
+Matrix ToMatrix(const fb::Matrix& m) {
+  auto& a = *m.m();
+  return Matrix(a[0], a[1], a[2], a[3],    //
+                a[4], a[5], a[6], a[7],    //
+                a[8], a[9], a[10], a[11],  //
+                a[12], a[13], a[14], a[15]);
+}
+
+Vector2 ToVector2(const fb::Vec2& v) {
+  return Vector2(v.x(), v.y());
+}
+
+Vector3 ToVector3(const fb::Vec3& v) {
+  return Vector3(v.x(), v.y(), v.z());
+}
+
+Vector4 ToVector4(const fb::Vec4& v) {
+  return Vector4(v.x(), v.y(), v.z(), v.w());
+}
+
+Color ToColor(const fb::Color& c) {
+  return Color(c.r(), c.g(), c.b(), c.a());
+}
+
+//-----------------------------------------------------------------------------
+/// Impeller -> Flatbuffers
+///
+
+std::unique_ptr<fb::Matrix> ToFBMatrix(const Matrix& m) {
+  auto array = std::array<Scalar, 16>{m.m[0],  m.m[1],  m.m[2],  m.m[3],   //
+                                      m.m[4],  m.m[5],  m.m[6],  m.m[7],   //
+                                      m.m[8],  m.m[9],  m.m[10], m.m[11],  //
+                                      m.m[12], m.m[13], m.m[14], m.m[15]};
+  return std::make_unique<fb::Matrix>(array);
+}
+
+fb::Vec2 ToFBVec2(const Vector2 v) {
+  return fb::Vec2(v.x, v.y);
+}
+
+fb::Vec3 ToFBVec3(const Vector3 v) {
+  return fb::Vec3(v.x, v.y, v.z);
+}
+
+fb::Vec4 ToFBVec4(const Vector4 v) {
+  return fb::Vec4(v.x, v.y, v.z, v.w);
+}
+
+fb::Color ToFBColor(const Color c) {
+  return fb::Color(c.red, c.green, c.blue, c.alpha);
+}
+
+}  // namespace importer
+}  // namespace scene
+}  // namespace impeller

impeller/scene/importer/conversions.h

@@ -0,0 +1,49 @@
+// 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.
+
+#pragma once
+
+#include <cstddef>
+#include <map>
+
+#include "impeller/geometry/matrix.h"
+#include "impeller/scene/importer/scene_flatbuffers.h"
+
+namespace impeller {
+namespace scene {
+namespace importer {
+
+Matrix ToMatrix(const std::vector<double>& m);
+
+//-----------------------------------------------------------------------------
+/// Flatbuffers -> Impeller
+///
+
+Matrix ToMatrix(const fb::Matrix& m);
+
+Vector2 ToVector2(const fb::Vec2& c);
+
+Vector3 ToVector3(const fb::Vec3& c);
+
+Vector4 ToVector4(const fb::Vec4& c);
+
+Color ToColor(const fb::Color& c);
+
+//-----------------------------------------------------------------------------
+/// Impeller -> Flatbuffers
+///
+
+std::unique_ptr<fb::Matrix> ToFBMatrix(const Matrix& m);
+
+fb::Vec2 ToFBVec2(const Vector2 v);
+
+fb::Vec3 ToFBVec3(const Vector3 v);
+
+fb::Vec4 ToFBVec4(const Vector4 v);
+
+fb::Color ToFBColor(const Color c);
+
+}  // namespace importer
+}  // namespace scene
+}  // namespace impeller

impeller/scene/importer/importer.h

@@ -2,17 +2,19 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#pragma once
+
 #include <array>
 #include <memory>
 
 #include "flutter/fml/mapping.h"
-#include "impeller/scene/importer/mesh_flatbuffers.h"
+#include "impeller/scene/importer/scene_flatbuffers.h"
 
 namespace impeller {
 namespace scene {
 namespace importer {
 
-bool ParseGLTF(const fml::Mapping& source_mapping, fb::MeshT& out_mesh);
+bool ParseGLTF(const fml::Mapping& source_mapping, fb::SceneT& out_scene);
 
 }
 }  // namespace scene