[android] - use RGB values instead of alpha values for local glyph generation

2020-03-23 15:31:57 +01:00
parent 3f45b0a24b
commit 99dbb3eed5
1 changed files with 3 additions and 1 deletions
--- a/platform/android/src/text/local_glyph_rasterizer.cpp
+++ b/platform/android/src/text/local_glyph_rasterizer.cpp
@@ -120,7 +120,9 @@ Glyph LocalGlyphRasterizer::rasterizeGlyph(const FontStack& fontStack, GlyphID g
    // Copy alpha values from RGBA bitmap into the AlphaImage output
    fixedMetrics.bitmap = AlphaImage(size);
    for (uint32_t i = 0; i < size.width * size.height; i++) {
-        fixedMetrics.bitmap.data[i] = rgbaBitmap.data[4 * i + 3];
+        fixedMetrics.bitmap.data[i] =
+            0xff - round(0.2126 * rgbaBitmap.data[4 * i] + 0.7152 * rgbaBitmap.data[4 * i + 1] +
+                         0.0722 * rgbaBitmap.data[4 * i + 2]);
    }

    return fixedMetrics;