Remove opacity multiplier field from BrushTip

It is no longer needed or desirable now that we have brush paint color functions as a path-renderer-compatible way to modify whole-stroke opacity.

PiperOrigin-RevId: 800487514

Author: Ink Open Source

ink/brush/brush_family_test.cc

@@ -111,15 +111,14 @@ TEST(BrushFamilyTest, StringifyWithNoId) {
   absl::StatusOr<BrushFamily> family = BrushFamily::Create(
       BrushTip{.scale = {3, 3},
                .corner_rounding = 0,
-               .opacity_multiplier = 0.7,
                .particle_gap_distance_scale = 0.1,
                .particle_gap_duration = Duration32::Seconds(2)},
       CreateTestPaint());
   ASSERT_EQ(family.status(), absl::OkStatus());
   EXPECT_EQ(absl::StrCat(*family),
             "BrushFamily(coats=[BrushCoat{tip=BrushTip{scale=<3, 3>, "
-            "corner_rounding=0, opacity_multiplier=0.7, "
-            "particle_gap_distance_scale=0.1, particle_gap_duration=2s}, "
+            "corner_rounding=0, particle_gap_distance_scale=0.1, "
+            "particle_gap_duration=2s}, "
             "paint_preferences={BrushPaint{texture_layers={TextureLayer{"
             "client_texture_id=test-paint, mapping=kStamping, "
             "origin=kStrokeSpaceOrigin, size_unit=kBrushSize, wrap_x=kRepeat, "
@@ -133,14 +132,13 @@ TEST(BrushFamilyTest, StringifyWithNoId) {
 }
 
 TEST(BrushFamilyTest, StringifyWithId) {
-  absl::StatusOr<BrushFamily> family = BrushFamily::Create(
-      BrushTip{
-          .scale = {3, 3}, .corner_rounding = 0, .opacity_multiplier = 0.7},
-      CreateTestPaint(), "big-square");
+  absl::StatusOr<BrushFamily> family =
+      BrushFamily::Create(BrushTip{.scale = {3, 3}, .corner_rounding = 0},
+                          CreateTestPaint(), "big-square");
   ASSERT_EQ(family.status(), absl::OkStatus());
   EXPECT_EQ(absl::StrCat(*family),
             "BrushFamily(coats=[BrushCoat{tip=BrushTip{scale=<3, 3>, "
-            "corner_rounding=0, opacity_multiplier=0.7}, "
+            "corner_rounding=0}, "
             "paint_preferences={BrushPaint{texture_layers={TextureLayer{client_"
             "texture_id=test-paint, mapping=kStamping, "
             "origin=kStrokeSpaceOrigin, size_unit=kBrushSize, wrap_x=kRepeat, "
@@ -326,39 +324,6 @@ TEST(BrushFamilyTest, CreateWithInvalidTipRotation) {
   }
 }
 
-TEST(BrushFamilyTest, CreateWithInvalidTipOpacityMultiplier) {
-  {
-    absl::Status status =
-        BrushFamily::Create({.opacity_multiplier = -kInfinity}, {}).status();
-    EXPECT_EQ(status.code(), kInvalidArgument);
-    EXPECT_THAT(status.message(), HasSubstr("opacity_multiplier"));
-  }
-  {
-    absl::Status status =
-        BrushFamily::Create({.opacity_multiplier = kInfinity}, {}).status();
-    EXPECT_EQ(status.code(), kInvalidArgument);
-    EXPECT_THAT(status.message(), HasSubstr("opacity_multiplier"));
-  }
-  {
-    absl::Status status =
-        BrushFamily::Create({.opacity_multiplier = kNan}, {}).status();
-    EXPECT_EQ(status.code(), kInvalidArgument);
-    EXPECT_THAT(status.message(), HasSubstr("opacity_multiplier"));
-  }
-  {
-    absl::Status status =
-        BrushFamily::Create({.opacity_multiplier = -1}, {}).status();
-    EXPECT_EQ(status.code(), kInvalidArgument);
-    EXPECT_THAT(status.message(), HasSubstr("opacity_multiplier"));
-  }
-  {
-    absl::Status status =
-        BrushFamily::Create({.opacity_multiplier = 5}, {}).status();
-    EXPECT_EQ(status.code(), kInvalidArgument);
-    EXPECT_THAT(status.message(), HasSubstr("opacity_multiplier"));
-  }
-}
-
 TEST(BrushFamilyTest, CreateWithInvalidTipSlant) {
   {
     absl::Status status =

ink/brush/brush_test.cc

@@ -86,8 +86,7 @@ BrushFamily CreateTestFamily() {
 
 TEST(BrushTest, Stringify) {
   absl::StatusOr<BrushFamily> family = BrushFamily::Create(
-      BrushTip{
-          .scale = {3, 3}, .corner_rounding = 0, .opacity_multiplier = 0.7},
+      BrushTip{.scale = {3, 3}, .corner_rounding = 0},
       {.texture_layers = {{.client_texture_id = std::string(kTestTextureId),
                            .mapping = BrushPaint::TextureMapping::kStamping,
                            .size_unit = BrushPaint::TextureSizeUnit::kBrushSize,
@@ -105,7 +104,7 @@ TEST(BrushTest, Stringify) {
       "Brush(color=Color({0.000000, 0.000000, 1.000000, 1.000000}, sRGB), "
       "size=3, epsilon=0.1, "
       "family=BrushFamily(coats=[BrushCoat{tip=BrushTip{scale=<3, 3>, "
-      "corner_rounding=0, opacity_multiplier=0.7}, "
+      "corner_rounding=0}, "
       "paint_preferences={BrushPaint{texture_layers={TextureLayer{client_"
       "texture_id=test-texture, mapping=kStamping, "
       "origin=kStrokeSpaceOrigin, size_unit=kBrushSize, wrap_x=kRepeat, "

ink/brush/brush_tip.cc

@@ -60,12 +60,6 @@ absl::Status ValidateBrushTipTopLevel(const BrushTip& tip) {
     return absl::InvalidArgumentError(absl::StrFormat(
         "`BrushTip::rotation` must be finite. Got %v", tip.rotation));
   }
-  if (!(tip.opacity_multiplier >= 0 && tip.opacity_multiplier <= 2)) {
-    return absl::InvalidArgumentError(
-        absl::StrFormat("`BrushTip::opacity_multiplier` must be a value in the "
-                        "interval [0, 2]. Got %f",
-                        tip.opacity_multiplier));
-  }
   if (!std::isfinite(tip.particle_gap_distance_scale) ||
       tip.particle_gap_distance_scale < 0) {
     return absl::InvalidArgumentError(
@@ -107,10 +101,6 @@ std::string ToFormattedString(const BrushTip& tip) {
   if (tip.rotation != Angle()) {
     absl::StrAppend(&formatted, ", rotation=", tip.rotation);
   }
-  if (tip.opacity_multiplier != 1.f) {
-    absl::StrAppend(&formatted,
-                    ", opacity_multiplier=", tip.opacity_multiplier);
-  }
   if (tip.particle_gap_distance_scale != 0) {
     absl::StrAppend(&formatted, ", particle_gap_distance_scale=",
                     tip.particle_gap_distance_scale);

ink/brush/brush_tip.h

@@ -83,12 +83,6 @@ struct BrushTip {
   // Angle specifying the initial rotation of the tip shape after applying
   // `scale`, `pinch`, and `slant`.
   Angle rotation = Angle::Radians(0);
-  // Scales the opacity of the base brush color for this tip, independent of
-  // `brush_behavior`s. A possible example application is a highlighter brush.
-  //
-  // The multiplier must be in the range [0, 2] and the value ultimately applied
-  // can be modified by applicable `brush_behavior`s.
-  float opacity_multiplier = 1.f;
   // Parameter controlling emission of particles as a function of distance
   // traveled by the stroke inputs. The value must be finite and non-negative.
   //

ink/brush/brush_tip_test.cc

@@ -32,15 +32,13 @@ TEST(BrushTipTest, Stringify) {
                 .slant = Angle::Degrees(45),
                 .pinch = 0.75f,
                 .rotation = Angle::Degrees(90),
-                .opacity_multiplier = 0.7f,
             }),
             "BrushTip{scale=<0.5, 2>, corner_rounding=0.25, slant=0.25π, "
-            "pinch=0.75, rotation=0.5π, opacity_multiplier=0.7}");
+            "pinch=0.75, rotation=0.5π}");
   EXPECT_EQ(
       absl::StrCat(BrushTip{
           .scale = {1.25f, 0.75f},
           .corner_rounding = 0.f,
-          .opacity_multiplier = 0.7f,
           .behaviors =
               {
                   BrushBehavior{{
@@ -65,7 +63,7 @@ TEST(BrushTipTest, Stringify) {
                   }},
               },
       }),
-      "BrushTip{scale=<1.25, 0.75>, corner_rounding=0, opacity_multiplier=0.7, "
+      "BrushTip{scale=<1.25, 0.75>, corner_rounding=0, "
       "behaviors={BrushBehavior{nodes={SourceNode{source=kTimeOfInputInMillis, "
       "source_value_range={0, 250}}, TargetNode{target=kWidthMultiplier, "
       "target_modifier_range={1.5, 2}}}}, "
@@ -81,7 +79,6 @@ TEST(BrushTipTest, EqualAndNotEqual) {
       .slant = Angle::Degrees(45),
       .pinch = 0.75f,
       .rotation = Angle::Degrees(90),
-      .opacity_multiplier = 0.7f,
       .particle_gap_distance_scale = 0.5f,
       .particle_gap_duration = Duration32::Seconds(0.5),
       .behaviors = {
@@ -105,7 +102,6 @@ TEST(BrushTipTest, EqualAndNotEqual) {
            .slant = Angle::Degrees(45),
            .pinch = 0.75f,
            .rotation = Angle::Degrees(90),
-           .opacity_multiplier = 0.7f,
            .particle_gap_distance_scale = 0.5f,
            .particle_gap_duration = Duration32::Seconds(0.5),
            .behaviors = {
@@ -127,7 +123,6 @@ TEST(BrushTipTest, EqualAndNotEqual) {
                 .slant = Angle::Degrees(45),
                 .pinch = 0.75f,
                 .rotation = Angle::Degrees(90),
-                .opacity_multiplier = 0.7f,
                 .particle_gap_distance_scale = 0.5f,
                 .particle_gap_duration = Duration32::Seconds(0.5),
                 .behaviors = {BrushBehavior{{
@@ -148,7 +143,6 @@ TEST(BrushTipTest, EqualAndNotEqual) {
            .slant = Angle::Degrees(45),
            .pinch = 0.75f,
            .rotation = Angle::Degrees(90),
-           .opacity_multiplier = 0.7f,
            .particle_gap_distance_scale = 0.5f,
            .particle_gap_duration = Duration32::Seconds(0.5),
            .behaviors = {
@@ -171,7 +165,6 @@ TEST(BrushTipTest, EqualAndNotEqual) {
            .slant = Angle::Degrees(33),  // Modified
            .pinch = 0.75f,
            .rotation = Angle::Degrees(90),
-           .opacity_multiplier = 0.7f,
            .particle_gap_distance_scale = 0.5f,
            .particle_gap_duration = Duration32::Seconds(0.5),
            .behaviors = {
@@ -194,7 +187,6 @@ TEST(BrushTipTest, EqualAndNotEqual) {
            .slant = Angle::Degrees(45),
            .pinch = 0.88f,  // Modified
            .rotation = Angle::Degrees(90),
-           .opacity_multiplier = 0.7f,
            .particle_gap_distance_scale = 0.5f,
            .particle_gap_duration = Duration32::Seconds(0.5),
            .behaviors = {
@@ -217,7 +209,6 @@ TEST(BrushTipTest, EqualAndNotEqual) {
            .slant = Angle::Degrees(45),
            .pinch = 0.75f,
            .rotation = Angle::Degrees(22),  // Modified
-           .opacity_multiplier = 0.7f,
            .particle_gap_distance_scale = 0.5f,
            .particle_gap_duration = Duration32::Seconds(0.5),
            .behaviors = {
@@ -240,30 +231,6 @@ TEST(BrushTipTest, EqualAndNotEqual) {
            .slant = Angle::Degrees(45),
            .pinch = 0.75f,
            .rotation = Angle::Degrees(90),
-           .opacity_multiplier = 0.9f,  // Modified
-           .particle_gap_distance_scale = 0.5f,
-           .particle_gap_duration = Duration32::Seconds(0.5),
-           .behaviors = {
-               BrushBehavior{{
-                   BrushBehavior::SourceNode{
-                       .source = BrushBehavior::Source::kTimeOfInputInMillis,
-                       .source_value_range = {0, 250},
-                   },
-                   BrushBehavior::TargetNode{
-                       .target = BrushBehavior::Target::kWidthMultiplier,
-                       .target_modifier_range = {1.5, 2},
-                   },
-               }},
-           }}));
-  EXPECT_NE(
-      brush_tip,
-      BrushTip(
-          {.scale = {1.25f, 0.75f},
-           .corner_rounding = 0.25f,
-           .slant = Angle::Degrees(45),
-           .pinch = 0.75f,
-           .rotation = Angle::Degrees(90),
-           .opacity_multiplier = 0.7f,
            .particle_gap_distance_scale = 0,  // Modified
            .particle_gap_duration = Duration32::Seconds(0.5),
            .behaviors = {
@@ -286,7 +253,6 @@ TEST(BrushTipTest, EqualAndNotEqual) {
            .slant = Angle::Degrees(45),
            .pinch = 0.75f,
            .rotation = Angle::Degrees(90),
-           .opacity_multiplier = 0.7f,
            .particle_gap_distance_scale = 0.5f,
            .particle_gap_duration = Duration32::Zero(),  // Modified
            .behaviors = {
@@ -309,7 +275,6 @@ TEST(BrushTipTest, EqualAndNotEqual) {
            .slant = Angle::Degrees(45),
            .pinch = 0.75f,
            .rotation = Angle::Degrees(90),
-           .opacity_multiplier = 0.7f,
            .particle_gap_distance_scale = 0.5f,
            .particle_gap_duration = Duration32::Seconds(0.5),
            // Modified:

ink/brush/fuzz_domains.cc

@@ -713,9 +713,8 @@ Domain<BrushTip> ValidBrushTip(DomainVariant variant) {
       Filter([](Vec scale) { return scale != Vec(); },
              StructOf<Vec>(FiniteNonNegativeFloat(), FiniteNonNegativeFloat())),
       InRange<float>(0.f, 1.f), AngleInRange(-kQuarterTurn, kQuarterTurn),
-      InRange<float>(0.f, 1.f), FiniteAngle(), InRange<float>(0.f, 2.f),
-      FiniteNonNegativeFloat(), FiniteNonNegativeDuration32(),
-      VectorOf(ValidBrushBehavior(variant)));
+      InRange<float>(0.f, 1.f), FiniteAngle(), FiniteNonNegativeFloat(),
+      FiniteNonNegativeDuration32(), VectorOf(ValidBrushBehavior(variant)));
 }
 
 }  // namespace

ink/brush/internal/jni/brush_tip_jni.cc

@@ -50,8 +50,8 @@ extern "C" {
 JNI_METHOD(brush, BrushTipNative, jlong, create)
 (JNIEnv* env, jobject thiz, jfloat scale_x, jfloat scale_y,
  jfloat corner_rounding, jfloat slant_radians, jfloat pinch,
- jfloat rotation_radians, jfloat opacity_multiplier,
- jfloat particle_gap_distance_scale, jlong particle_gap_duration_millis,
+ jfloat rotation_radians, jfloat particle_gap_distance_scale,
+ jlong particle_gap_duration_millis,
  jlongArray behavior_native_pointers_array) {
   std::vector<ink::BrushBehavior> behaviors;
   const jsize num_behaviors =
@@ -72,7 +72,6 @@ JNI_METHOD(brush, BrushTipNative, jlong, create)
       .slant = ink::Angle::Radians(slant_radians),
       .pinch = pinch,
       .rotation = ink::Angle::Radians(rotation_radians),
-      .opacity_multiplier = opacity_multiplier,
       .particle_gap_distance_scale = particle_gap_distance_scale,
       .particle_gap_duration = Duration32::Millis(particle_gap_duration_millis),
       .behaviors = behaviors};
@@ -118,11 +117,6 @@ JNI_METHOD(brush, BrushTipNative, jfloat, getRotationRadians)
   return CastToBrushTip(native_pointer).rotation.ValueInRadians();
 }
 
-JNI_METHOD(brush, BrushTipNative, jfloat, getOpacityMultiplier)
-(JNIEnv* env, jobject thiz, jlong native_pointer) {
-  return CastToBrushTip(native_pointer).opacity_multiplier;
-}
-
 JNI_METHOD(brush, BrushTipNative, jfloat, getParticleGapDistanceScale)
 (JNIEnv* env, jobject thiz, jlong native_pointer) {
   return CastToBrushTip(native_pointer).particle_gap_distance_scale;

ink/brush/type_matchers.cc

@@ -285,8 +285,6 @@ MATCHER_P(BrushTipEqMatcher, expected,
             Field("slant", &BrushTip::slant, AngleEq(expected.slant)),
             Field("pinch", &BrushTip::pinch, FloatEq(expected.pinch)),
             Field("rotation", &BrushTip::rotation, AngleEq(expected.rotation)),
-            Field("opacity_multiplier", &BrushTip::opacity_multiplier,
-                  FloatEq(expected.opacity_multiplier)),
             Field("particle_gap_distance_scale",
                   &BrushTip::particle_gap_distance_scale,
                   FloatEq(expected.particle_gap_distance_scale)),

ink/rendering/skia/native/internal/path_drawable.cc

@@ -93,9 +93,8 @@ void SetPaintDefaultsForPath(SkPaint& paint) {
 PathDrawable::PathDrawable(
     const MutableMesh& mesh,
     absl::Span<const absl::Span<const uint32_t>> index_outlines,
-    absl::Span<const ColorFunction> color_functions, float opacity_multiplier)
-    : color_functions_(color_functions.begin(), color_functions.end()),
-      opacity_multiplier_(opacity_multiplier) {
+    absl::Span<const ColorFunction> color_functions)
+    : color_functions_(color_functions.begin(), color_functions.end()) {
   for (absl::Span<const uint32_t> indices : index_outlines) {
     if (indices.empty()) continue;
 
@@ -106,10 +105,8 @@ PathDrawable::PathDrawable(
 
 PathDrawable::PathDrawable(const PartitionedMesh& shape,
                            uint32_t render_group_index,
-                           absl::Span<const ColorFunction> color_functions,
-                           float opacity_multiplier)
-    : color_functions_(color_functions.begin(), color_functions.end()),
-      opacity_multiplier_(opacity_multiplier) {
+                           absl::Span<const ColorFunction> color_functions)
+    : color_functions_(color_functions.begin(), color_functions.end()) {
   absl::Span<const Mesh> mesh_group =
       shape.RenderGroupMeshes(render_group_index);
   for (uint32_t i = 0; i < shape.OutlineCount(render_group_index); ++i) {
@@ -127,9 +124,8 @@ void PathDrawable::SetBrushColor(const Color& brush_color) {
                            .InColorSpace(ColorSpace::kSrgb)
                            .AsFloat(Color::Format::kLinear);
   sk_sp<SkColorSpace> srgb_linear = SkColorSpace::MakeSRGBLinear();
-  paint_.setColor(
-      {.fR = c.r, .fG = c.g, .fB = c.b, .fA = c.a * opacity_multiplier_},
-      srgb_linear.get());
+  paint_.setColor({.fR = c.r, .fG = c.g, .fB = c.b, .fA = c.a},
+                  srgb_linear.get());
 }
 
 void PathDrawable::SetImageFilter(sk_sp<SkImageFilter> image_filter) {

ink/rendering/skia/native/internal/path_drawable.h

@@ -44,13 +44,11 @@ class PathDrawable {
   // function will need to change to accept a `span<const MutableMesh>`.
   PathDrawable(const MutableMesh& mesh,
                absl::Span<const absl::Span<const uint32_t>> index_outlines,
-               absl::Span<const ColorFunction> color_functions,
-               float opacity_multiplier);
+               absl::Span<const ColorFunction> color_functions);
 
   // Constructs the drawable from one render group of a `PartitionedMesh`.
   PathDrawable(const PartitionedMesh& shape, uint32_t render_group_index,
-               absl::Span<const ColorFunction> color_functions,
-               float opacity_multiplier);
+               absl::Span<const ColorFunction> color_functions);
 
   PathDrawable() = default;
   PathDrawable(const PathDrawable&) = default;
@@ -60,9 +58,8 @@ class PathDrawable {
   ~PathDrawable() = default;
 
   // Sets the brush color to be used for this drawable. The passed-in
-  // `brush_color` will be transformed by the `color_functions` and
-  // `opacity_multiplier` passed in during construction before being applied to
-  // the underlying `SkPaint`.
+  // `brush_color` will be transformed by the `color_functions` passed in during
+  // construction before being applied to the underlying `SkPaint`.
   void SetBrushColor(const Color& brush_color);
 
   void SetImageFilter(sk_sp<SkImageFilter> image_filter);
@@ -73,7 +70,6 @@ class PathDrawable {
   absl::InlinedVector<SkPath, 1> paths_;
   SkPaint paint_;
   absl::InlinedVector<ColorFunction, 1> color_functions_;
-  float opacity_multiplier_;
 };
 
 }  // namespace ink::skia_native_internal