Adjust font texture cache based on device density.

The main purpose of this CL is reducing font cache size of
low-density device.

The memory usage for the small RGBA texture will be
Nexus 6P: 7,928,856 bytes (1408x1408)
Nexus 5X: 4,734,976 bytes (1088x1088)
These used to be 4,194,304 bytes

Test: manually checked
Bug: 64400885
Change-Id: Ied064a6d59909ad7fbeff74332973206436fbd34

1 files changed, 13 insertions, 4 deletions

diff --git a/libs/hwui/FontRenderer.cpp b/libs/hwui/FontRenderer.cpp
index bc4181075319..8b0346867cbc 100644
--- a/libs/hwui/FontRenderer.cpp
+++ b/libs/hwui/FontRenderer.cpp
@@ -99,13 +99,22 @@ FontRenderer::FontRenderer(const uint8_t* gammaTable)
     }
 
     auto deviceInfo = DeviceInfo::get();
+    auto displayInfo = deviceInfo->displayInfo();
     int maxTextureSize = deviceInfo->maxTextureSize();
 
+    // Adjust cache size based on Pixel's desnsity.
+    constexpr float PIXEL_DENSITY = 2.6;
+    const float densityRatio = displayInfo.density / PIXEL_DENSITY;
+
     // TODO: Most devices are hardcoded with this configuration, does it need to be dynamic?
-    mSmallCacheWidth = std::min(1024, maxTextureSize);
-    mSmallCacheHeight = std::min(1024, maxTextureSize);
-    mLargeCacheWidth = std::min(2048, maxTextureSize);
-    mLargeCacheHeight = std::min(1024, maxTextureSize);
+    mSmallCacheWidth =
+            OffscreenBuffer::computeIdealDimension(std::min(1024, maxTextureSize) * densityRatio);
+    mSmallCacheHeight =
+            OffscreenBuffer::computeIdealDimension(std::min(1024, maxTextureSize) * densityRatio);
+    mLargeCacheWidth =
+            OffscreenBuffer::computeIdealDimension(std::min(2048, maxTextureSize) * densityRatio);
+    mLargeCacheHeight =
+            OffscreenBuffer::computeIdealDimension(std::min(1024, maxTextureSize) * densityRatio);
 
     if (sLogFontRendererCreate) {
         INIT_LOGD("  Text cache sizes, in pixels: %i x %i, %i x %i, %i x %i, %i x %i",