commit 115096f50a560e64a7f95d37686d4861042c7aeb
author Romain Guy <romainguy@google.com> Tue Mar 19 11:32:41 2013 -0700
committer Romain Guy <romainguy@google.com> Tue Mar 19 11:32:41 2013 -0700
tree 95f72f39e1f1275bf9c51dbda3c04774dc48d3fa
parent bbb4e03ad4e86e79c9b51cbb18c563a5a79cf837

Minimize texture binds when drawing text

When several CacheTextures are used to draw text, sort the
draw batches by texture ID to minimize state changes in the
driver.

This change also tweaks the font cache size and renames
a property that was too long to be set using setprop.

Change-Id: I0a36dfffe58c9e75dd7384592d3343c192d042b1

libs/hwui/FontRenderer.cpp

diff --git a/libs/hwui/FontRenderer.cpp b/libs/hwui/FontRenderer.cpp
index f0dcb30..0c70e27 100644
--- a/libs/hwui/FontRenderer.cpp
+++ b/libs/hwui/FontRenderer.cpp
@@ -378,9 +378,9 @@
 
 void FontRenderer::updateDrawParams() {
     if (mCurrentQuadIndex != mLastQuadIndex) {
-        mDrawOffsets.add((uint16_t*)(mLastQuadIndex * sizeof(uint16_t) * 6));
-        mDrawCounts.add(mCurrentQuadIndex - mLastQuadIndex);
-        mDrawCacheTextures.add(mCurrentCacheTexture);
+        uint16_t* offset = (uint16_t*)(mLastQuadIndex * sizeof(uint16_t) * 6);
+        uint32_t count = mCurrentQuadIndex - mLastQuadIndex;
+        mDrawBatch.add(TextBatch(offset, count, mCurrentCacheTexture));
         mLastQuadIndex = mCurrentQuadIndex;
     }
 }
@@ -438,26 +438,27 @@
         caches.bindTexCoordsVertexPointer(force, buffer + offset);
     }
 
-    for (uint32_t i = 0; i < mDrawOffsets.size(); i++) {
-        uint16_t* offset = mDrawOffsets[i];
-        uint32_t count = mDrawCounts[i];
-        CacheTexture* texture = mDrawCacheTextures[i];
+    caches.activeTexture(0);
+    GLuint lastId = 0;
 
-        caches.activeTexture(0);
-        glBindTexture(GL_TEXTURE_2D, texture->getTextureId());
+    for (uint32_t i = 0; i < mDrawBatch.size(); i++) {
+        const TextBatch& batch = mDrawBatch[i];
 
-        texture->setLinearFiltering(mLinearFiltering, false);
+        GLuint id = batch.texture->getTextureId();
+        if (id != lastId) {
+            glBindTexture(GL_TEXTURE_2D, id);
+            batch.texture->setLinearFiltering(mLinearFiltering, false);
+            lastId = id;
+        }
 
-        glDrawElements(GL_TRIANGLES, count * 6, GL_UNSIGNED_SHORT, offset);
+        glDrawElements(GL_TRIANGLES, batch.count * 6, GL_UNSIGNED_SHORT, batch.offset);
     }
 
     mDrawn = true;
 
     mCurrentQuadIndex = 0;
     mLastQuadIndex = 0;
-    mDrawOffsets.clear();
-    mDrawCounts.clear();
-    mDrawCacheTextures.clear();
+    mDrawBatch.clear();
 }
 
 void FontRenderer::appendMeshQuadNoClip(float x1, float y1, float u1, float v1,