commit c9b2c885be8d2bb39f1d75cc316278fa8d0fa9f0
author commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> Mon Mar 03 14:30:25 2014 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> Mon Mar 03 14:30:25 2014 +0000
tree df2fdb044740bb2e8053138fc8da37283af5e4ca
parent 0bc406df48ac6f358ab8dcff08f71fe9c32b79de

New approach for GPU font atlas

In the previous code, each GrTextStrike had exclusive access to one or more GrPlots in the texture atlas. This led to poor packing when only a few glyphs were used. This change allows GrTextStrikes to share GrPlots, thereby getting much better utilization of the entire texture.

BUG=skia:2224
R=robertphillips@google.com, bsalomon@google.com

Author: jvanverth@google.com

Review URL: https://codereview.chromium.org/177463003

git-svn-id: http://skia.googlecode.com/svn/trunk@13636 2bbb7eff-a529-9590-31e7-b0007b416f81

src/gpu/GrBitmapTextContext.cpp

diff --git a/src/gpu/GrBitmapTextContext.cpp b/src/gpu/GrBitmapTextContext.cpp
index 4f43c75..f2a6d95 100755
--- a/src/gpu/GrBitmapTextContext.cpp
+++ b/src/gpu/GrBitmapTextContext.cpp
@@ -518,13 +518,13 @@
     }
 
     if (NULL == glyph->fPlot) {
-        if (fStrike->getGlyphAtlas(glyph, scaler)) {
+        if (fStrike->addGlyphToAtlas(glyph, scaler)) {
             goto HAS_ATLAS;
         }
 
         // try to clear out an unused plot before we flush
-        fContext->getFontCache()->freePlotExceptFor(fStrike);
-        if (fStrike->getGlyphAtlas(glyph, scaler)) {
+        if (fContext->getFontCache()->freeUnusedPlot(fStrike) &&
+            fStrike->addGlyphToAtlas(glyph, scaler)) {
             goto HAS_ATLAS;
         }
 
@@ -534,14 +534,13 @@
 #endif
         }
 
-        // before we purge the cache, we must flush any accumulated draws
+        // flush any accumulated draws to allow us to free up a plot
         this->flushGlyphs();
         fContext->flush();
 
-        // try to purge
-        fContext->getFontCache()->purgeExceptFor(fStrike);
-        // need to use new flush count here
-        if (fStrike->getGlyphAtlas(glyph, scaler)) {
+        // we should have an unused plot now
+        if (fContext->getFontCache()->freeUnusedPlot(fStrike) &&
+            fStrike->addGlyphToAtlas(glyph, scaler)) {
             goto HAS_ATLAS;
         }