Move vertex buffer setup out of drawPackedGlyph().

This gets a very welcome ~10% speedup on my Mac.

Committed: https://skia.googlesource.com/skia/+/1d38619389cc1100bd516b9acbf17b7bd42d33ce

R=bsalomon@google.com

Author: jvanverth@google.com

Review URL: https://codereview.chromium.org/414573002
diff --git a/src/gpu/GrBitmapTextContext.cpp b/src/gpu/GrBitmapTextContext.cpp
index 3ca98e4..cc657c6 100755
--- a/src/gpu/GrBitmapTextContext.cpp
+++ b/src/gpu/GrBitmapTextContext.cpp
@@ -54,12 +54,10 @@
                                        : GrTextContext(context, properties) {
     fStrike = NULL;
 
-    fCurrTexture = NULL;
     fCurrVertex = 0;
     fEffectTextureUniqueID = SK_InvalidUniqueID;
 
     fVertices = NULL;
-    fMaxVertices = 0;
 
     fVertexBounds.setLargestInverted();
 }
@@ -91,13 +89,14 @@
     if (fCurrVertex > 0) {
         // setup our sampler state for our text texture/atlas
         SkASSERT(SkIsAlign4(fCurrVertex));
-        SkASSERT(fCurrTexture);
         GrTextureParams params(SkShader::kRepeat_TileMode, GrTextureParams::kNone_FilterMode);
 
-        uint32_t textureUniqueID = fCurrTexture->getUniqueID();
+        GrTexture* currTexture = fStrike->getTexture();
+        SkASSERT(currTexture);
+        uint32_t textureUniqueID = currTexture->getUniqueID();
         
         if (textureUniqueID != fEffectTextureUniqueID) {
-            fCachedEffect.reset(GrCustomCoordsTextureEffect::Create(fCurrTexture, params));
+            fCachedEffect.reset(GrCustomCoordsTextureEffect::Create(currTexture, params));
             fEffectTextureUniqueID = textureUniqueID;
         }
 
@@ -152,13 +151,12 @@
                                           nGlyphs,
                                           4, 6, &fVertexBounds);
 
-        fDrawTarget->resetVertexSource();
-        fVertices = NULL;
-        fMaxVertices = 0;
         fCurrVertex = 0;
         fVertexBounds.setLargestInverted();
-        SkSafeSetNull(fCurrTexture);
     }
+
+    fDrawTarget->resetVertexSource();
+    fVertices = NULL;
 }
 
 inline void GrBitmapTextContext::init(const GrPaint& paint, const SkPaint& skPaint) {
@@ -166,11 +164,9 @@
 
     fStrike = NULL;
 
-    fCurrTexture = NULL;
     fCurrVertex = 0;
 
     fVertices = NULL;
-    fMaxVertices = 0;
 }
 
 inline void GrBitmapTextContext::finish() {
@@ -191,11 +187,18 @@
 
     this->init(paint, skPaint);
 
+    if (NULL == fDrawTarget) {
+        return;
+    }
+
     SkDrawCacheProc glyphCacheProc = fSkPaint.getDrawCacheProc();
 
     SkAutoGlyphCache    autoCache(fSkPaint, &fDeviceProperties, &fContext->getMatrix());
     SkGlyphCache*       cache = autoCache.getCache();
     GrFontScaler*       fontScaler = GetGrFontScaler(cache);
+    if (NULL == fStrike) {
+        fStrike = fContext->getFontCache()->getStrike(fontScaler, false);
+    }
 
     // transform our starting point
     {
@@ -224,6 +227,23 @@
 
     const char* stop = text + byteLength;
 
+    // allocate vertices
+    SkASSERT(NULL == fVertices);
+    bool useColorVerts = kA8_GrMaskFormat == fStrike->getMaskFormat();
+    if (useColorVerts) {
+        fDrawTarget->drawState()->setVertexAttribs<gTextVertexWithColorAttribs>(
+                                                    SK_ARRAY_COUNT(gTextVertexWithColorAttribs));
+    } else {
+        fDrawTarget->drawState()->setVertexAttribs<gTextVertexAttribs>(
+                                                    SK_ARRAY_COUNT(gTextVertexAttribs));
+    }
+    int numGlyphs = fSkPaint.textToGlyphs(text, byteLength, NULL);
+    bool success = fDrawTarget->reserveVertexAndIndexSpace(4*numGlyphs,
+                                                           0,
+                                                           &fVertices,
+                                                           NULL);
+    GrAlwaysAssert(success);
+
     SkAutoKern autokern;
 
     SkFixed fxMask = ~0;
@@ -284,17 +304,42 @@
 
     this->init(paint, skPaint);
 
+    if (NULL == fDrawTarget) {
+        return;
+    }
+
     SkDrawCacheProc glyphCacheProc = fSkPaint.getDrawCacheProc();
 
     SkAutoGlyphCache    autoCache(fSkPaint, &fDeviceProperties, &fContext->getMatrix());
     SkGlyphCache*       cache = autoCache.getCache();
     GrFontScaler*       fontScaler = GetGrFontScaler(cache);
+    
+    if (NULL == fStrike) {
+        fStrike = fContext->getFontCache()->getStrike(fontScaler, false);
+    }
 
     // store original matrix before we reset, so we can use it to transform positions
     SkMatrix ctm = fContext->getMatrix();
     GrContext::AutoMatrix  autoMatrix;
     autoMatrix.setIdentity(fContext, &fPaint);
 
+    // allocate vertices
+    SkASSERT(NULL == fVertices);
+    bool useColorVerts = kA8_GrMaskFormat == fStrike->getMaskFormat();
+    if (useColorVerts) {
+        fDrawTarget->drawState()->setVertexAttribs<gTextVertexWithColorAttribs>(
+                                                    SK_ARRAY_COUNT(gTextVertexWithColorAttribs));
+    } else {
+        fDrawTarget->drawState()->setVertexAttribs<gTextVertexAttribs>(
+                                                    SK_ARRAY_COUNT(gTextVertexAttribs));
+    }
+    int numGlyphs = fSkPaint.textToGlyphs(text, byteLength, NULL);
+    bool success = fDrawTarget->reserveVertexAndIndexSpace(4*numGlyphs,
+                                                           0,
+                                                           &fVertices,
+                                                           NULL);
+    GrAlwaysAssert(success);
+
     const char*        stop = text + byteLength;
     SkTextAlignProc    alignProc(fSkPaint.getTextAlign());
     SkTextMapStateProc tmsProc(ctm, constY, scalarsPerPosition);
@@ -426,14 +471,6 @@
 void GrBitmapTextContext::drawPackedGlyph(GrGlyph::PackedID packed,
                                           SkFixed vx, SkFixed vy,
                                           GrFontScaler* scaler) {
-    if (NULL == fDrawTarget) {
-        return;
-    }
-
-    if (NULL == fStrike) {
-        fStrike = fContext->getFontCache()->getStrike(scaler, false);
-    }
-
     GrGlyph* glyph = fStrike->getGlyph(packed, scaler);
     if (NULL == glyph || glyph->fBounds.isEmpty()) {
         return;
@@ -516,55 +553,6 @@
     GrTexture* texture = glyph->fPlot->texture();
     SkASSERT(texture);
 
-    if (fCurrTexture != texture || fCurrVertex + 4 > fMaxVertices) {
-        this->flushGlyphs();
-        fCurrTexture = texture;
-        fCurrTexture->ref();
-    }
-
-    bool useColorVerts = kA8_GrMaskFormat == fStrike->getMaskFormat();
-
-    if (NULL == fVertices) {
-       // If we need to reserve vertices allow the draw target to suggest
-        // a number of verts to reserve and whether to perform a flush.
-        fMaxVertices = kMinRequestedVerts;
-        if (useColorVerts) {
-            fDrawTarget->drawState()->setVertexAttribs<gTextVertexWithColorAttribs>(
-                SK_ARRAY_COUNT(gTextVertexWithColorAttribs));
-        } else {
-            fDrawTarget->drawState()->setVertexAttribs<gTextVertexAttribs>(
-                SK_ARRAY_COUNT(gTextVertexAttribs));
-        }
-        bool flush = fDrawTarget->geometryHints(&fMaxVertices, NULL);
-        if (flush) {
-            this->flushGlyphs();
-            fContext->flush();
-            if (useColorVerts) {
-                fDrawTarget->drawState()->setVertexAttribs<gTextVertexWithColorAttribs>(
-                  SK_ARRAY_COUNT(gTextVertexWithColorAttribs));
-            } else {
-                fDrawTarget->drawState()->setVertexAttribs<gTextVertexAttribs>(
-                  SK_ARRAY_COUNT(gTextVertexAttribs));
-            }
-        }
-        fMaxVertices = kDefaultRequestedVerts;
-        // ignore return, no point in flushing again.
-        fDrawTarget->geometryHints(&fMaxVertices, NULL);
-
-        int maxQuadVertices = 4 * fContext->getQuadIndexBuffer()->maxQuads();
-        if (fMaxVertices < kMinRequestedVerts) {
-            fMaxVertices = kDefaultRequestedVerts;
-        } else if (fMaxVertices > maxQuadVertices) {
-            // don't exceed the limit of the index buffer
-            fMaxVertices = maxQuadVertices;
-        }
-        bool success = fDrawTarget->reserveVertexAndIndexSpace(fMaxVertices,
-                                                               0,
-                                                               &fVertices,
-                                                               NULL);
-        GrAlwaysAssert(success);
-    }
-
     SkFixed tx = SkIntToFixed(glyph->fAtlasLocation.fX);
     SkFixed ty = SkIntToFixed(glyph->fAtlasLocation.fY);
 
@@ -576,6 +564,7 @@
 
     fVertexBounds.growToInclude(r);
 
+    bool useColorVerts = kA8_GrMaskFormat == fStrike->getMaskFormat();
     size_t vertSize = useColorVerts ? (2 * sizeof(SkPoint) + sizeof(GrColor)) :
                                       (2 * sizeof(SkPoint));