Engine-fy, upgrade to head, add TextFrame shaper factory, and add Aiks test

Author: bdero

impeller/aiks/aiks_unittests.cc

@@ -37,6 +37,9 @@
 #include "impeller/scene/node.h"
 #include "impeller/typographer/backends/skia/text_frame_skia.h"
 #include "impeller/typographer/backends/skia/text_render_context_skia.h"
+#include "impeller/typographer/backends/stb/text_frame_stb.h"
+#include "impeller/typographer/backends/stb/text_render_context_stb.h"
+#include "impeller/typographer/backends/stb/typeface_stb.h"
 #include "third_party/imgui/imgui.h"
 #include "third_party/skia/include/core/SkData.h"
 
@@ -1249,11 +1252,11 @@ struct TextRenderOptions {
   Point position = Vector2(100, 200);
 };
 
-bool RenderTextInCanvas(const std::shared_ptr<Context>& context,
-                        Canvas& canvas,
-                        const std::string& text,
-                        const std::string& font_fixture,
-                        TextRenderOptions options = {}) {
+bool RenderTextInCanvasSkia(const std::shared_ptr<Context>& context,
+                            Canvas& canvas,
+                            const std::string& text,
+                            const std::string& font_fixture,
+                            TextRenderOptions options = {}) {
   // Draw the baseline.
   canvas.DrawRect({options.position.x - 50, options.position.y, 900, 10},
                   Paint{.color = Color::Aqua().WithAlpha(0.25)});
@@ -1274,7 +1277,36 @@ bool RenderTextInCanvas(const std::shared_ptr<Context>& context,
   }
 
   // Create the Impeller text frame and draw it at the designated baseline.
-  auto frame = TextFrameFromTextBlob(blob);
+  auto frame = MakeTextFrameFromTextBlobSkia(blob);
+
+  Paint text_paint;
+  text_paint.color = Color::Yellow().WithAlpha(options.alpha);
+  canvas.DrawTextFrame(frame, options.position, text_paint);
+  return true;
+}
+
+bool RenderTextInCanvasSTB(const std::shared_ptr<Context>& context,
+                           Canvas& canvas,
+                           const std::string& text,
+                           const std::string& font_fixture,
+                           TextRenderOptions options = {}) {
+  // Draw the baseline.
+  canvas.DrawRect({options.position.x - 50, options.position.y, 900, 10},
+                  Paint{.color = Color::Aqua().WithAlpha(0.25)});
+
+  // Mark the point at which the text is drawn.
+  canvas.DrawCircle(options.position, 5.0,
+                    Paint{.color = Color::Red().WithAlpha(0.25)});
+
+  // Construct the text blob.
+  auto mapping = flutter::testing::OpenFixtureAsMapping(font_fixture.c_str());
+  if (!mapping) {
+    return false;
+  }
+  auto typeface_stb = std::make_shared<TypefaceSTB>(std::move(mapping));
+
+  auto frame = MakeTextFrameSTB(
+      typeface_stb, Font::Metrics{.point_size = options.font_size}, text);
 
   Paint text_paint;
   text_paint.color = Color::Yellow().WithAlpha(options.alpha);
@@ -1285,12 +1317,22 @@ bool RenderTextInCanvas(const std::shared_ptr<Context>& context,
 TEST_P(AiksTest, CanRenderTextFrame) {
   Canvas canvas;
   canvas.DrawPaint({.color = Color(0.1, 0.1, 0.1, 1.0)});
-  ASSERT_TRUE(RenderTextInCanvas(
+  ASSERT_TRUE(RenderTextInCanvasSkia(
       GetContext(), canvas, "the quick brown fox jumped over the lazy dog!.?",
       "Roboto-Regular.ttf"));
   ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
 }
 
+TEST_P(AiksTest, CanRenderTextFrameSTB) {
+  Canvas canvas;
+  canvas.DrawPaint({.color = Color(0.1, 0.1, 0.1, 1.0)});
+  ASSERT_TRUE(RenderTextInCanvasSTB(
+      GetContext(), canvas, "the quick brown fox jumped over the lazy dog!.?",
+      "Roboto-Regular.ttf"));
+  ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture(),
+                                 TextRenderContextSTB::Make()));
+}
+
 TEST_P(AiksTest, TextFrameSubpixelAlignment) {
   std::array<Scalar, 20> phase_offsets;
   for (Scalar& offset : phase_offsets) {
@@ -1320,11 +1362,12 @@ TEST_P(AiksTest, TextFrameSubpixelAlignment) {
                                       GetSecondsElapsed() * speed)),  //
           200 + i * font_size * 1.1                                   //
       );
-      if (!RenderTextInCanvas(GetContext(), canvas,
-                              "the quick brown fox jumped over "
-                              "the lazy dog!.?",
-                              "Roboto-Regular.ttf",
-                              {.font_size = font_size, .position = position})) {
+      if (!RenderTextInCanvasSkia(
+              GetContext(), canvas,
+              "the quick brown fox jumped over "
+              "the lazy dog!.?",
+              "Roboto-Regular.ttf",
+              {.font_size = font_size, .position = position})) {
         return false;
       }
     }
@@ -1338,7 +1381,7 @@ TEST_P(AiksTest, CanRenderItalicizedText) {
   Canvas canvas;
   canvas.DrawPaint({.color = Color(0.1, 0.1, 0.1, 1.0)});
 
-  ASSERT_TRUE(RenderTextInCanvas(
+  ASSERT_TRUE(RenderTextInCanvasSkia(
       GetContext(), canvas, "the quick brown fox jumped over the lazy dog!.?",
       "HomemadeApple.ttf"));
   ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
@@ -1348,12 +1391,12 @@ TEST_P(AiksTest, CanRenderEmojiTextFrame) {
   Canvas canvas;
   canvas.DrawPaint({.color = Color(0.1, 0.1, 0.1, 1.0)});
 
-  ASSERT_TRUE(RenderTextInCanvas(GetContext(), canvas,
-                                 "😀 😃 😄 😁 😆 😅 😂 🤣 🥲 😊",
+  ASSERT_TRUE(RenderTextInCanvasSkia(GetContext(), canvas,
+                                     "😀 😃 😄 😁 😆 😅 😂 🤣 🥲 😊",
 #if FML_OS_MACOSX
-                                 "Apple Color Emoji.ttc"));
+                                     "Apple Color Emoji.ttc"));
 #else
-                                 "NotoColorEmoji.ttf"));
+                                     "NotoColorEmoji.ttf"));
 #endif
   ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
 }
@@ -1362,14 +1405,14 @@ TEST_P(AiksTest, CanRenderEmojiTextFrameWithAlpha) {
   Canvas canvas;
   canvas.DrawPaint({.color = Color(0.1, 0.1, 0.1, 1.0)});
 
-  ASSERT_TRUE(RenderTextInCanvas(GetContext(), canvas,
-                                 "😀 😃 😄 😁 😆 😅 😂 🤣 🥲 😊",
+  ASSERT_TRUE(RenderTextInCanvasSkia(GetContext(), canvas,
+                                     "😀 😃 😄 😁 😆 😅 😂 🤣 🥲 😊",
 #if FML_OS_MACOSX
-                                 "Apple Color Emoji.ttc", { .alpha = 0.5 }
+                                     "Apple Color Emoji.ttc", { .alpha = 0.5 }
 #else
-                                 "NotoColorEmoji.ttf", {.alpha = 0.5}
+                                     "NotoColorEmoji.ttf", {.alpha = 0.5}
 #endif
-                                 ));
+                                     ));
   ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
 }
 
@@ -1382,13 +1425,13 @@ TEST_P(AiksTest, CanRenderTextInSaveLayer) {
 
   // Blend the layer with the parent pass using kClear to expose the coverage.
   canvas.SaveLayer({.blend_mode = BlendMode::kClear});
-  ASSERT_TRUE(RenderTextInCanvas(
+  ASSERT_TRUE(RenderTextInCanvasSkia(
       GetContext(), canvas, "the quick brown fox jumped over the lazy dog!.?",
       "Roboto-Regular.ttf"));
   canvas.Restore();
 
   // Render the text again over the cleared coverage rect.
-  ASSERT_TRUE(RenderTextInCanvas(
+  ASSERT_TRUE(RenderTextInCanvasSkia(
       GetContext(), canvas, "the quick brown fox jumped over the lazy dog!.?",
       "Roboto-Regular.ttf"));
 
@@ -1423,7 +1466,7 @@ TEST_P(AiksTest, CanRenderTextOutsideBoundaries) {
     {
       auto blob = SkTextBlob::MakeFromString(t.text, sk_font);
       ASSERT_NE(blob, nullptr);
-      auto frame = TextFrameFromTextBlob(blob);
+      auto frame = MakeTextFrameFromTextBlobSkia(blob);
       canvas.DrawTextFrame(frame, Point(), text_paint);
     }
     canvas.Restore();
@@ -1441,7 +1484,7 @@ TEST_P(AiksTest, TextRotated) {
                           0, 0.5, 0, 0,           //
                           0, 0, 0.3, 0,           //
                           100, 100, 0, 1.3));
-  ASSERT_TRUE(RenderTextInCanvas(
+  ASSERT_TRUE(RenderTextInCanvasSkia(
       GetContext(), canvas, "the quick brown fox jumped over the lazy dog!.?",
       "Roboto-Regular.ttf"));
 
@@ -3011,7 +3054,7 @@ TEST_P(AiksTest, TextForegroundShaderWithTransform) {
 
   auto blob = SkTextBlob::MakeFromString("Hello", sk_font);
   ASSERT_NE(blob, nullptr);
-  auto frame = TextFrameFromTextBlob(blob);
+  auto frame = MakeTextFrameFromTextBlobSkia(blob);
   canvas.DrawTextFrame(frame, Point(), text_paint);
 
   ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
@@ -3033,12 +3076,12 @@ TEST_P(AiksTest, CanCanvasDrawPicture) {
 
 TEST_P(AiksTest, DrawPictureWithText) {
   Canvas subcanvas;
-  ASSERT_TRUE(RenderTextInCanvas(
+  ASSERT_TRUE(RenderTextInCanvasSkia(
       GetContext(), subcanvas,
       "the quick brown fox jumped over the lazy dog!.?", "Roboto-Regular.ttf"));
   subcanvas.Translate({0, 10});
   subcanvas.Scale(Vector2(3, 3));
-  ASSERT_TRUE(RenderTextInCanvas(
+  ASSERT_TRUE(RenderTextInCanvasSkia(
       GetContext(), subcanvas,
       "the quick brown fox jumped over the very big lazy dog!.?",
       "Roboto-Regular.ttf"));
@@ -3053,7 +3096,7 @@ TEST_P(AiksTest, DrawPictureWithText) {
   canvas.Restore();
 
   canvas.Scale(Vector2(1.5, 1.5));
-  ASSERT_TRUE(RenderTextInCanvas(
+  ASSERT_TRUE(RenderTextInCanvasSkia(
       GetContext(), canvas,
       "the quick brown fox jumped over the smaller lazy dog!.?",
       "Roboto-Regular.ttf"));
@@ -3181,8 +3224,8 @@ TEST_P(AiksTest, DrawScaledTextWithPerspectiveNoSaveLayer) {
   ));
   // clang-format on
 
-  ASSERT_TRUE(RenderTextInCanvas(GetContext(), canvas, "Hello world",
-                                 "Roboto-Regular.ttf"));
+  ASSERT_TRUE(RenderTextInCanvasSkia(GetContext(), canvas, "Hello world",
+                                     "Roboto-Regular.ttf"));
 
   ASSERT_TRUE(OpenPlaygroundHere(canvas.EndRecordingAsPicture()));
 }
@@ -3200,8 +3243,8 @@ TEST_P(AiksTest, DrawScaledTextWithPerspectiveSaveLayer) {
   ));
   // clang-format on
 
-  ASSERT_TRUE(RenderTextInCanvas(GetContext(), canvas, "Hello world",
-                                 "Roboto-Regular.ttf"));
+  ASSERT_TRUE(RenderTextInCanvasSkia(GetContext(), canvas, "Hello world",
+                                     "Roboto-Regular.ttf"));
 }
 
 TEST_P(AiksTest, PipelineBlendSingleParameter) {

impeller/display_list/dl_dispatcher.cc

@@ -1108,7 +1108,7 @@ void DlDispatcher::drawDisplayList(
 void DlDispatcher::drawTextBlob(const sk_sp<SkTextBlob> blob,
                                 SkScalar x,
                                 SkScalar y) {
-  const auto text_frame = TextFrameFromTextBlob(blob);
+  const auto text_frame = MakeTextFrameFromTextBlobSkia(blob);
   if (paint_.style == Paint::Style::kStroke) {
     auto path = skia_conversions::PathDataFromTextBlob(blob);
     auto bounds = text_frame.GetBounds();

impeller/entity/entity_unittests.cc

@@ -2174,7 +2174,7 @@ TEST_P(EntityTest, InheritOpacityTest) {
   SkFont font;
   font.setSize(30);
   auto blob = SkTextBlob::MakeFromString("A", font);
-  auto frame = TextFrameFromTextBlob(blob);
+  auto frame = MakeTextFrameFromTextBlobSkia(blob);
   auto lazy_glyph_atlas =
       std::make_shared<LazyGlyphAtlas>(TextRenderContextSkia::Make());
   lazy_glyph_atlas->AddTextFrame(frame, 1.0f);

impeller/typographer/backends/skia/text_frame_skia.cc

@@ -39,7 +39,7 @@ static Rect ToRect(const SkRect& rect) {
 
 static constexpr Scalar kScaleSize = 100000.0f;
 
-TextFrame TextFrameFromTextBlob(const sk_sp<SkTextBlob>& blob) {
+TextFrame MakeTextFrameFromTextBlobSkia(const sk_sp<SkTextBlob>& blob) {
   if (!blob) {
     return {};
   }

impeller/typographer/backends/skia/text_frame_skia.h

@@ -10,6 +10,6 @@
 
 namespace impeller {
 
-TextFrame TextFrameFromTextBlob(const sk_sp<SkTextBlob>& blob);
+TextFrame MakeTextFrameFromTextBlobSkia(const sk_sp<SkTextBlob>& blob);
 
 }  // namespace impeller

impeller/typographer/backends/stb/BUILD.gn

@@ -8,6 +8,8 @@ impeller_component("typographer_stb_backend") {
   testonly = true
 
   sources = [
+    "text_frame_stb.cc",
+    "text_frame_stb.h",
     "text_render_context_stb.cc",
     "text_render_context_stb.h",
     "typeface_stb.cc",

impeller/typographer/backends/stb/text_frame_stb.cc

@@ -0,0 +1,61 @@
+// 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/typographer/backends/stb/text_frame_stb.h"
+
+#include "impeller/typographer/font.h"
+
+namespace impeller {
+
+TextFrame MakeTextFrameSTB(const std::shared_ptr<TypefaceSTB>& typeface_stb,
+                           Font::Metrics metrics,
+                           const std::string& text) {
+  TextRun run(Font(typeface_stb, metrics));
+
+  // Shape the text run using STB. The glyph positions could also be resolved
+  // using a more advanced text shaper such as harfbuzz.
+
+  float scale = stbtt_ScaleForPixelHeight(
+      typeface_stb->GetFontInfo(),
+      metrics.point_size * TypefaceSTB::kPointsToPixels);
+
+  int ascent, descent, line_gap;
+  stbtt_GetFontVMetrics(typeface_stb->GetFontInfo(), &ascent, &descent,
+                        &line_gap);
+  ascent = std::round(ascent * scale);
+  descent = std::round(descent * scale);
+
+  float x = 0;
+  for (size_t i = 0; i < text.size(); i++) {
+    int glyph_index =
+        stbtt_FindGlyphIndex(typeface_stb->GetFontInfo(), text[i]);
+
+    int x0, y0, x1, y1;
+    stbtt_GetGlyphBitmapBox(typeface_stb->GetFontInfo(), glyph_index, scale,
+                            scale, &x0, &y0, &x1, &y1);
+    float y = y0;
+
+    int advance_width;
+    int left_side_bearing;
+    stbtt_GetGlyphHMetrics(typeface_stb->GetFontInfo(), glyph_index,
+                           &advance_width, &left_side_bearing);
+
+    Glyph glyph(glyph_index, Glyph::Type::kPath,
+                Rect::MakeXYWH(0, 0, x1 - x0, y1 - y0));
+    run.AddGlyph(glyph, {x + (left_side_bearing * scale), y});
+
+    if (i + 1 < text.size()) {
+      int kerning = stbtt_GetCodepointKernAdvance(typeface_stb->GetFontInfo(),
+                                                  text[i], text[i + 1]);
+      x += std::round((advance_width + kerning) * scale);
+    }
+  }
+
+  TextFrame frame;
+  frame.AddTextRun(run);
+
+  return frame;
+}
+
+}  // namespace impeller

impeller/typographer/backends/stb/text_frame_stb.h

@@ -0,0 +1,17 @@
+// 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 "flutter/fml/macros.h"
+#include "impeller/typographer/backends/stb/typeface_stb.h"
+#include "impeller/typographer/text_frame.h"
+
+namespace impeller {
+
+TextFrame MakeTextFrameSTB(const std::shared_ptr<TypefaceSTB>& typeface_stb,
+                           Font::Metrics metrics,
+                           const std::string& text);
+
+}  // namespace impeller