First OpenGL ES 3.0 based optimization

This change uses a new OpenGL ES 3.0 feature to upload less data when
the font cache needs to be update. This can result in significant
performance improvements on device with large textures or with locales
that use a lot of glyphs (CJK for instance.)

This change also fixes various unpack alignment issues. The unpack
alignment, as well as the unpack row length, is not texture specific
but a global state that affect all glTex/SubImage2D calls. Some of
them were missing the appropriate glPixelStorei() call. This could
result in corrupted textures.

Change-Id: Iefb429d4d0d0b4e0faeadf27daafee6d30a21d85

1 files changed, 4 insertions, 3 deletions

diff --git a/libs/hwui/Layer.h b/libs/hwui/Layer.h
index 27e0cf1..715dfa4 100644
--- a/libs/hwui/Layer.h
+++ b/libs/hwui/Layer.h
@@ -255,13 +255,14 @@ struct Layer {
         texture.id = 0;
     }
 
-    inline void allocateTexture(GLenum format, GLenum storage) {
+    inline void allocateTexture() {
 #if DEBUG_LAYERS
         ALOGD("  Allocate layer: %dx%d", getWidth(), getHeight());
 #endif
         if (texture.id) {
-            glTexImage2D(renderTarget, 0, format, getWidth(), getHeight(), 0,
-                    format, storage, NULL);
+            glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
+            glTexImage2D(renderTarget, 0, GL_RGBA, getWidth(), getHeight(), 0,
+                    GL_RGBA, GL_UNSIGNED_BYTE, NULL);
         }
     }