commit 1ed4f6441fc10b3e6d749606d1e44a2dca9710a5
author Seigo Nonaka <nona@google.com> Thu Sep 10 17:19:34 2020 -0700
committer Seigo Nonaka <nona@google.com> Wed Sep 23 13:01:38 2020 -0700
tree 3c180e5c17ba11a70b30cf519f13916371c814be
parent 3c99024fdbdceeb72f6545275c68eade284b9ebb

Add necessary APIs for supporting glyph level drawing

This CL adds following APIs

Font#cloneWithSettings
  This API provides a faster Font instance creation for different
  variation settings.

Font#getBounds
  This API provides glyph advance and bounding box information.

Font#getMetrics
  This API provides font metrics that will be used for deciding line
  height and/or baseline.

Bug: 168136332
Test: atest FontTest
Test: TreeHugger

Change-Id: I335557ce47ea0ca8e012c2a48b804c00bb348392

libs/hwui/jni/Graphics.cpp

diff --git a/libs/hwui/jni/Graphics.cpp b/libs/hwui/jni/Graphics.cpp
index ecbb55ec..77f46be 100644
--- a/libs/hwui/jni/Graphics.cpp
+++ b/libs/hwui/jni/Graphics.cpp
@@ -9,6 +9,7 @@
 #include "GraphicsJNI.h"
 
 #include "SkCanvas.h"
+#include "SkFontMetrics.h"
 #include "SkMath.h"
 #include "SkRegion.h"
 #include <cutils/ashmem.h>
@@ -228,6 +229,20 @@
 static jclass gTransferParameters_class;
 static jmethodID gTransferParameters_constructorMethodID;
 
+static jclass   gFontMetrics_class;
+static jfieldID gFontMetrics_top;
+static jfieldID gFontMetrics_ascent;
+static jfieldID gFontMetrics_descent;
+static jfieldID gFontMetrics_bottom;
+static jfieldID gFontMetrics_leading;
+
+static jclass   gFontMetricsInt_class;
+static jfieldID gFontMetricsInt_top;
+static jfieldID gFontMetricsInt_ascent;
+static jfieldID gFontMetricsInt_descent;
+static jfieldID gFontMetricsInt_bottom;
+static jfieldID gFontMetricsInt_leading;
+
 ///////////////////////////////////////////////////////////////////////////////
 
 void GraphicsJNI::get_jrect(JNIEnv* env, jobject obj, int* L, int* T, int* R, int* B)
@@ -468,6 +483,32 @@
     return r;
 }
 
+void GraphicsJNI::set_metrics(JNIEnv* env, jobject metrics, const SkFontMetrics& skmetrics) {
+    if (metrics == nullptr) return;
+    SkASSERT(env->IsInstanceOf(metrics, gFontMetrics_class));
+    env->SetFloatField(metrics, gFontMetrics_top, SkScalarToFloat(skmetrics.fTop));
+    env->SetFloatField(metrics, gFontMetrics_ascent, SkScalarToFloat(skmetrics.fAscent));
+    env->SetFloatField(metrics, gFontMetrics_descent, SkScalarToFloat(skmetrics.fDescent));
+    env->SetFloatField(metrics, gFontMetrics_bottom, SkScalarToFloat(skmetrics.fBottom));
+    env->SetFloatField(metrics, gFontMetrics_leading, SkScalarToFloat(skmetrics.fLeading));
+}
+
+int GraphicsJNI::set_metrics_int(JNIEnv* env, jobject metrics, const SkFontMetrics& skmetrics) {
+    int ascent = SkScalarRoundToInt(skmetrics.fAscent);
+    int descent = SkScalarRoundToInt(skmetrics.fDescent);
+    int leading = SkScalarRoundToInt(skmetrics.fLeading);
+
+    if (metrics) {
+        SkASSERT(env->IsInstanceOf(metrics, gFontMetricsInt_class));
+        env->SetIntField(metrics, gFontMetricsInt_top, SkScalarFloorToInt(skmetrics.fTop));
+        env->SetIntField(metrics, gFontMetricsInt_ascent, ascent);
+        env->SetIntField(metrics, gFontMetricsInt_descent, descent);
+        env->SetIntField(metrics, gFontMetricsInt_bottom, SkScalarCeilToInt(skmetrics.fBottom));
+        env->SetIntField(metrics, gFontMetricsInt_leading, leading);
+    }
+    return descent - ascent + leading;
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////
 
 jobject GraphicsJNI::createBitmapRegionDecoder(JNIEnv* env, skia::BitmapRegionDecoder* bitmap)
@@ -764,5 +805,23 @@
     gTransferParameters_constructorMethodID = GetMethodIDOrDie(env, gTransferParameters_class,
             "<init>", "(DDDDDDD)V");
 
+    gFontMetrics_class = FindClassOrDie(env, "android/graphics/Paint$FontMetrics");
+    gFontMetrics_class = MakeGlobalRefOrDie(env, gFontMetrics_class);
+
+    gFontMetrics_top = GetFieldIDOrDie(env, gFontMetrics_class, "top", "F");
+    gFontMetrics_ascent = GetFieldIDOrDie(env, gFontMetrics_class, "ascent", "F");
+    gFontMetrics_descent = GetFieldIDOrDie(env, gFontMetrics_class, "descent", "F");
+    gFontMetrics_bottom = GetFieldIDOrDie(env, gFontMetrics_class, "bottom", "F");
+    gFontMetrics_leading = GetFieldIDOrDie(env, gFontMetrics_class, "leading", "F");
+
+    gFontMetricsInt_class = FindClassOrDie(env, "android/graphics/Paint$FontMetricsInt");
+    gFontMetricsInt_class = MakeGlobalRefOrDie(env, gFontMetricsInt_class);
+
+    gFontMetricsInt_top = GetFieldIDOrDie(env, gFontMetricsInt_class, "top", "I");
+    gFontMetricsInt_ascent = GetFieldIDOrDie(env, gFontMetricsInt_class, "ascent", "I");
+    gFontMetricsInt_descent = GetFieldIDOrDie(env, gFontMetricsInt_class, "descent", "I");
+    gFontMetricsInt_bottom = GetFieldIDOrDie(env, gFontMetricsInt_class, "bottom", "I");
+    gFontMetricsInt_leading = GetFieldIDOrDie(env, gFontMetricsInt_class, "leading", "I");
+
     return 0;
 }