Move distance field generation to the glyph cache

src/gpu/GrTextStrike.cpp

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrAtlas.h"
 #include "GrGpu.h"
 #include "GrRectanizer.h"
@@ skipping 196 matching lines @@
     ++gDumpCount;
 }
 #endif
 
 ///////////////////////////////////////////////////////////////////////////////
 
 #ifdef SK_DEBUG
     static int gCounter;
 #endif
 
-// this acts as the max magnitude for the distance field,
-// as well as the pad we need around the glyph
-#define DISTANCE_FIELD_RANGE   4
-
 /*
     The text strike is specific to a given font/style/matrix setup, which is
     represented by the GrHostFontScaler object we are given in getGlyph().
 
     We map a 32bit glyphID to a GrGlyph record, which in turn points to a
     atlas and a position within that texture.
  */
 
 GrTextStrike::GrTextStrike(GrFontCache* cache, const GrKey* key,
                            GrMaskFormat format,
@@ skipping 22 matching lines @@
 
 #ifdef SK_DEBUG
     gCounter -= 1;
 //    GrPrintf("~GrTextStrike %p %d\n", this, gCounter);
 #endif
 }
 
 GrGlyph* GrTextStrike::generateGlyph(GrGlyph::PackedID packed,
                                      GrFontScaler* scaler) {
     SkIRect bounds;
-    if (!scaler->getPackedGlyphBounds(packed, &bounds)) {
-        return NULL;
+    if (fUseDistanceField) {
+        if (!scaler->getPackedGlyphDFBounds(packed, &bounds)) {
+            return NULL;
+        }
+    } else {
+        if (!scaler->getPackedGlyphBounds(packed, &bounds)) {
+            return NULL;
+        }
     }
 
     GrGlyph* glyph = fPool.alloc();
-    // expand bounds to hold full distance field data
-    // + room for bilerp
-    int pad = DISTANCE_FIELD_RANGE+1;
-    if (fUseDistanceField) {
-        bounds.fLeft   -= pad;
-        bounds.fRight  += pad;
-        bounds.fTop    -= pad;
-        bounds.fBottom += pad;
-    }
     glyph->init(packed, bounds);
     fCache.insert(packed, glyph);
     return glyph;
 }
 
 void GrTextStrike::removePlot(const GrPlot* plot) {
     SkTDArray<GrGlyph*>& glyphArray = fCache.getArray();
     for (int i = 0; i < glyphArray.count(); ++i) {
         if (plot == glyphArray[i]->fPlot) {
             glyphArray[i]->fPlot = NULL;
@@ skipping 12 matching lines @@
 
     SkASSERT(glyph);
     SkASSERT(scaler);
     SkASSERT(fCache.contains(glyph));
     SkASSERT(NULL == glyph->fPlot);
 
     SkAutoRef ar(scaler);
 
     int bytesPerPixel = GrMaskFormatBytesPerPixel(fMaskFormat);
 
-    GrPlot* plot;
+    size_t size = glyph->fBounds.area() * bytesPerPixel;
+    SkAutoSMalloc<1024> storage(size);
     if (fUseDistanceField) {
-        // we've already expanded the glyph dimensions to match the final size
-        // but must shrink back down to get the packed glyph data
-        int dfWidth = glyph->width();
-        int dfHeight = glyph->height();
-        int pad = DISTANCE_FIELD_RANGE+1;
-        int width = dfWidth - 2*pad;
-        int height = dfHeight - 2*pad;
-        int stride = width*bytesPerPixel;
-
-        size_t size = width * height * bytesPerPixel;
-        SkAutoSMalloc<1024> storage(size);
-        if (!scaler->getPackedGlyphImage(glyph->fPackedID, width, height, stride, storage.get())) {
+        if (!scaler->getPackedGlyphDFImage(glyph->fPackedID, glyph->width(),
+                                           glyph->height(),
+                                           storage.get())) {
             return false;
         }
-
-        // alloc storage for distance field glyph
-        size_t dfSize = dfWidth * dfHeight * bytesPerPixel;
-        SkAutoSMalloc<1024> dfStorage(dfSize);
-
-        if (1 == bytesPerPixel) {
-            (void) SkGenerateDistanceFieldFromImage((unsigned char*)dfStorage.get(),
-                                                    (unsigned char*)storage.get(),
-                                                    width, height, DISTANCE_FIELD_RANGE);
-        } else {
-            // distance fields should only be used to represent alpha masks
-            SkASSERT(false);
-            return false;
-        }
-
-        // copy to atlas
-        plot = fAtlasMgr->addToAtlas(&fAtlas, dfWidth, dfHeight, dfStorage.get(),
-                                     &glyph->fAtlasLocation);
-
     } else {
-        size_t size = glyph->fBounds.area() * bytesPerPixel;
-        SkAutoSMalloc<1024> storage(size);
         if (!scaler->getPackedGlyphImage(glyph->fPackedID, glyph->width(),
                                          glyph->height(),
                                          glyph->width() * bytesPerPixel,
                                          storage.get())) {
             return false;
         }
+    }
 
-        plot = fAtlasMgr->addToAtlas(&fAtlas, glyph->width(),
-                                     glyph->height(), storage.get(),
-                                     &glyph->fAtlasLocation);
-    }
+    GrPlot* plot  = fAtlasMgr->addToAtlas(&fAtlas, glyph->width(),
+                                          glyph->height(), storage.get(),
+                                          &glyph->fAtlasLocation);
 
     if (NULL == plot) {
         return false;
     }
 
     glyph->fPlot = plot;
     return true;
 }