[Impeller] Improve accuracy of glyph spacing (#41101)

Author: bdero

impeller/aiks/aiks_unittests.cc

@@ -1068,6 +1068,7 @@ 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(
       GetContext(), canvas, "the quick brown fox jumped over the lazy dog!.?",
       "Roboto-Regular.ttf"));
@@ -1119,6 +1120,8 @@ TEST_P(AiksTest, TextFrameSubpixelAlignment) {
 
 TEST_P(AiksTest, CanRenderItalicizedText) {
   Canvas canvas;
+  canvas.DrawPaint({.color = Color(0.1, 0.1, 0.1, 1.0)});
+
   ASSERT_TRUE(RenderTextInCanvas(
       GetContext(), canvas, "the quick brown fox jumped over the lazy dog!.?",
       "HomemadeApple.ttf"));
@@ -1127,6 +1130,8 @@ TEST_P(AiksTest, CanRenderItalicizedText) {
 
 TEST_P(AiksTest, CanRenderEmojiTextFrame) {
   Canvas canvas;
+  canvas.DrawPaint({.color = Color(0.1, 0.1, 0.1, 1.0)});
+
   ASSERT_TRUE(RenderTextInCanvas(GetContext(), canvas,
                                  "😀 😃 😄 😁 😆 😅 😂 🤣 🥲 😊",
 #if FML_OS_MACOSX
@@ -1139,6 +1144,8 @@ TEST_P(AiksTest, CanRenderEmojiTextFrame) {
 
 TEST_P(AiksTest, CanRenderEmojiTextFrameWithAlpha) {
   Canvas canvas;
+  canvas.DrawPaint({.color = Color(0.1, 0.1, 0.1, 1.0)});
+
   ASSERT_TRUE(RenderTextInCanvas(GetContext(), canvas,
                                  "😀 😃 😄 😁 😆 😅 😂 🤣 🥲 😊",
 #if FML_OS_MACOSX
@@ -1152,7 +1159,8 @@ TEST_P(AiksTest, CanRenderEmojiTextFrameWithAlpha) {
 
 TEST_P(AiksTest, CanRenderTextInSaveLayer) {
   Canvas canvas;
-  canvas.DrawPaint({.color = Color::White()});
+  canvas.DrawPaint({.color = Color(0.1, 0.1, 0.1, 1.0)});
+
   canvas.Translate({100, 100});
   canvas.Scale(Vector2{0.5, 0.5});
 
@@ -1211,12 +1219,7 @@ TEST_P(AiksTest, CanRenderTextOutsideBoundaries) {
 TEST_P(AiksTest, TextRotated) {
   Canvas canvas;
   canvas.Scale(GetContentScale());
-
-  Paint paint;
-  paint.color = Color(0.1, 0.1, 0.1, 1.0);
-  canvas.DrawRect(
-      Rect::MakeLTRB(0, 0, GetWindowSize().width, GetWindowSize().height),
-      paint);
+  canvas.DrawPaint({.color = Color(0.1, 0.1, 0.1, 1.0)});
 
   canvas.Transform(Matrix(0.25, -0.3, 0, -0.002,  //
                           0, 0.5, 0, 0,           //

impeller/typographer/backends/skia/text_frame_skia.cc

@@ -76,7 +76,7 @@ TextFrame TextFrameFromTextBlob(const sk_sp<SkTextBlob>& blob, Scalar scale) {
                                  : Glyph::Type::kPath;
 
           text_run.AddGlyph(Glyph{glyphs[i], type, ToRect(glyph_bounds[i])},
-                            Point{point->x(), point->y()}.Floor());
+                            Point{point->x(), point->y()}.Round());
         }
         break;
       }