Optimize interactions with glyph cache

There are two fixes here:
- precaching: instead of caching-then-drawing whenever there is a new
glyph, we cache at DisplayList record time. Then when we finally draw that
DisplayList, we just upload the affected texture(s) once, instead of once
per change. This is a huge savings in upload time, especially when there are
larger glyphs being used by the app.
- packing: Previously, glyphs would line up horizontally on each cache line, leaving
potentially tons of space vertically, especially when smaller glyphs got put into cache
lines intended for large glyphs (which can happen when an app uses lots of unique
glyphs, a common case with, for example, chinese/japanese/korean languages). The new
approach packs glyphs vertically as well as horizontally to use the space more efficiently
and provide space for more glyphs in these situations.

Change-Id: I84338aa25db208c7bf13f3f92b4d05ed40c33527

1 files changed, 11 insertions, 3 deletions

diff --git a/libs/hwui/DisplayListRenderer.cpp b/libs/hwui/DisplayListRenderer.cpp
index 95fc2c5..2de70d4 100644
--- a/libs/hwui/DisplayListRenderer.cpp
+++ b/libs/hwui/DisplayListRenderer.cpp
@@ -1699,7 +1699,9 @@ status_t DisplayListRenderer::drawTextOnPath(const char* text, int bytesCount, i
     addFloat(hOffset);
     addFloat(vOffset);
     paint->setAntiAlias(true);
-    addPaint(paint);
+    SkPaint* addedPaint = addPaint(paint);
+    FontRenderer& fontRenderer = mCaches.fontRenderer->getFontRenderer(addedPaint);
+    fontRenderer.precache(addedPaint, text, count);
     return DrawGlInfo::kStatusDone;
 }
 
@@ -1711,7 +1713,9 @@ status_t DisplayListRenderer::drawPosText(const char* text, int bytesCount, int
     addInt(count);
     addFloats(positions, count * 2);
     paint->setAntiAlias(true);
-    addPaint(paint);
+    SkPaint* addedPaint = addPaint(paint);
+    FontRenderer& fontRenderer = mCaches.fontRenderer->getFontRenderer(addedPaint);
+    fontRenderer.precache(addedPaint, text, count);
     return DrawGlInfo::kStatusDone;
 }
 
@@ -1742,7 +1746,11 @@ status_t DisplayListRenderer::drawText(const char* text, int bytesCount, int cou
     addFloat(x);
     addFloat(y);
     addFloats(positions, count * 2);
-    addPaint(paint);
+    SkPaint* addedPaint = addPaint(paint);
+    if (!reject) {
+        FontRenderer& fontRenderer = mCaches.fontRenderer->getFontRenderer(addedPaint);
+        fontRenderer.precache(addedPaint, text, count);
+    }
     addFloat(length);
     addSkip(location);
     return DrawGlInfo::kStatusDone;