Bump gl-core to v3.0.0-rc.1 and adapt local glyph rasterizer. (#520)

* Add glyph metrics class

* add keep annotation

* Bump gl-core to v3.0.0-rc.1

* Adjust Access Modifier for LocalGlyphRasterizer.

Co-authored-by: tobrun <[email protected]>
Co-authored-by: Peng Liu <[email protected]>

Author: 3 people

MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/text/LocalGlyphRasterizer.java

@@ -4,6 +4,7 @@
 import android.graphics.Color;
 import android.graphics.Paint;
 import android.graphics.Bitmap;
+import android.graphics.Rect;
 import android.graphics.Typeface;
 import androidx.annotation.Keep;
 import androidx.annotation.NonNull;
@@ -14,45 +15,81 @@
  * by the portable local_glyph_rasterizer.hpp
  */
 @Keep
-public class LocalGlyphRasterizer {
-  private final Bitmap bitmap;
+class LocalGlyphRasterizer {
+
+  @Keep
+  private class GlyphMetrics {
+    int width;
+    int height;
+    int top;
+    int left;
+    int ascender;
+    int descender;
+    int advance;
+    Bitmap glyphBitmap;
+  }
+
+  @NonNull
+  private final GlyphMetrics glyphMetrics;
+  @NonNull
+  private final Rect bounds;
   @NonNull
   private final Paint paint;
   @NonNull
   private final Canvas canvas;
 
   LocalGlyphRasterizer() {
-    /*
-      35x35px dimensions are hardwired to match local_glyph_rasterizer.cpp
-      These dimensions are large enough to draw a 24 point character in the middle
-      of the bitmap (y: 20) with some buffer around the edge
-    */
-    bitmap = Bitmap.createBitmap(35, 35, Bitmap.Config.ARGB_8888);
+    glyphMetrics = new GlyphMetrics();
+    glyphMetrics.glyphBitmap = Bitmap.createBitmap(35, 35, Bitmap.Config.ARGB_8888);
+
+    bounds = new Rect();
 
     paint = new Paint();
     paint.setAntiAlias(true);
     paint.setTextSize(24);
 
     canvas = new Canvas();
-    canvas.setBitmap(bitmap);
+    canvas.setBitmap(glyphMetrics.glyphBitmap);
   }
 
   /***
-   * Uses Android-native drawing code to rasterize a single glyph
-   * to a square {@link Bitmap} which can be returned to portable
-   * code for transformation into a Signed Distance Field glyph.
+   * Uses Android-native drawing code to encapsulate the glyph metrics and a raterized
+   * square {@link Bitmap} to a single structure which can be returned to portable
+   * code for transformation into the native glyph data structure.
    *
    * @param fontFamily Font family string to pass to Typeface.create
    * @param bold If true, use Typeface.BOLD option
    * @param glyphID 16-bit Unicode BMP codepoint to draw
    *
-   * @return Return a {@link Bitmap} to be displayed in the requested tile.
+   * @return Return GlyphMetrics that contains all the necessary information to display
+   *         the character in the requested tile.
    */
   @WorkerThread
-  protected Bitmap drawGlyphBitmap(String fontFamily, boolean bold, char glyphID) {
+  protected GlyphMetrics getGlyphMetrics(String fontFamily, boolean bold, char glyphID) {
     paint.setTypeface(Typeface.create(fontFamily, bold ? Typeface.BOLD : Typeface.NORMAL));
+
+    // Get font metrics
+    Paint.FontMetricsInt metrics = paint.getFontMetricsInt();
+    glyphMetrics.ascender = Math.abs(metrics.top);
+    glyphMetrics.descender = Math.abs(metrics.bottom);
+
+    String glyph = String.valueOf(glyphID);
+    paint.getTextBounds(glyph, 0, 1, bounds);
+    glyphMetrics.left = bounds.left;
+    glyphMetrics.width = bounds.right - bounds.left;
+    glyphMetrics.height = bounds.bottom - bounds.top;
+    glyphMetrics.top = Math.abs(bounds.top);
+    glyphMetrics.advance = Math.round(paint.measureText(glyph, 0, 1));
+
+    if (glyphMetrics.width == 0 && glyphMetrics.height == 0) {
+      return glyphMetrics;
+    }
+    // Draw glyph on the canvas with the 3 pixels' boarder padding from the left and top
+    float x = 3 - bounds.left;
+    float y = 3 - bounds.top;
     canvas.drawColor(Color.WHITE);
-    canvas.drawText(String.valueOf(glyphID), 5, 25, paint);
-    return bitmap;
+    canvas.drawText(glyph, x, y, paint);
+
+    return glyphMetrics;
   }
-}
+}

gradle/dependencies.gradle

@@ -40,7 +40,7 @@ ext {
             ktlint           : '0.34.0',
             commonsIO        : '2.6',
             mapboxSdkVersions: '1.1.0',
-            mapboxSdkCore    : '2.0.0-alpha.1',
+            mapboxSdkCore    : '3.0.0-rc.1',
             mapboxSdkRegistryPlugin: '0.2.1'
     ]