Add LCD support for distance field text

src/gpu/GrDistanceFieldTextContext.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrDistanceFieldTextContext.h"
 #include "GrAtlas.h"
 #include "GrDrawTarget.h"
@@ skipping 66 matching lines @@
     GrDrawState* drawState = fDrawTarget->drawState();
     GrDrawState::AutoRestoreEffects are(drawState);
     drawState->setFromPaint(fPaint, fContext->getMatrix(), fContext->getRenderTarget());
 
     if (fCurrVertex > 0) {
         // setup our sampler state for our text texture/atlas
         SkASSERT(SkIsAlign4(fCurrVertex));
         SkASSERT(fCurrTexture);
         GrTextureParams params(SkShader::kRepeat_TileMode, GrTextureParams::kBilerp_FilterMode);
 
-        // This effect could be stored with one of the cache objects (atlas?)
-        drawState->addCoverageEffect(
-                         GrDistanceFieldTextureEffect::Create(fCurrTexture, params,
-                                                              fContext->getMatrix().isSimilarity()),
-                         kGlyphCoordsAttributeIndex)->unref();
+        // Effects could be stored with one of the cache objects (atlas?)
+        if (fUseLCDText) {
+            bool useBGR = SkDeviceProperties::Geometry::kBGR_Layout ==
+                                                            fDeviceProperties.fGeometry.getLayout();
+            drawState->addCoverageEffect(GrDistanceFieldLCDTextureEffect::Create(
+                                                            fCurrTexture,
+                                                            params,
+                                                            fContext->getMatrix().rectStaysRect() &&
+                                                            fContext->getMatrix().isSimilarity(),
+                                                            useBGR),
+                                         kGlyphCoordsAttributeIndex)->unref();
 
-        if (!GrPixelConfigIsAlphaOnly(fCurrTexture->config())) {
             if (kOne_GrBlendCoeff != fPaint.getSrcBlendCoeff() ||
                 kISA_GrBlendCoeff != fPaint.getDstBlendCoeff() ||
                 fPaint.numColorStages()) {
                 GrPrintf("LCD Text will not draw correctly.\n");
             }
             // We don't use the GrPaint's color in this case because it's been premultiplied by
             // alpha. Instead we feed in a non-premultiplied color, and multiply its alpha by
             // the mask texture color. The end result is that we get
             //            mask*paintAlpha*paintColor + (1-mask*paintAlpha)*dstColor
             int a = SkColorGetA(fSkPaint.getColor());
             // paintAlpha
             drawState->setColor(SkColorSetARGB(a, a, a, a));
             // paintColor
             drawState->setBlendConstant(skcolor_to_grcolor_nopremultiply(fSkPaint.getColor()));
             drawState->setBlendFunc(kConstC_GrBlendCoeff, kISC_GrBlendCoeff);
         } else {
+            drawState->addCoverageEffect(GrDistanceFieldTextureEffect::Create(fCurrTexture, params,
+                                                              fContext->getMatrix().isSimilarity()),
+                                         kGlyphCoordsAttributeIndex)->unref();
+
             // set back to normal in case we took LCD path previously.
             drawState->setBlendFunc(fPaint.getSrcBlendCoeff(), fPaint.getDstBlendCoeff());
             drawState->setColor(fPaint.getColor());
         }
 
         int nGlyphs = fCurrVertex / 4;
         fDrawTarget->setIndexSourceToBuffer(fContext->getQuadIndexBuffer());
         fDrawTarget->drawIndexedInstances(kTriangles_GrPrimitiveType,
                                           nGlyphs,
                                           4, 6);
@@ skipping 191 matching lines @@
         fTextRatio = fSkPaint.getTextSize()/kSmallDFFontSize;
         fSkPaint.setTextSize(SkIntToScalar(kSmallDFFontSize));
     } else if (fSkPaint.getTextSize() <= kMediumDFFontLimit) {
         fTextRatio = fSkPaint.getTextSize()/kMediumDFFontSize;
         fSkPaint.setTextSize(SkIntToScalar(kMediumDFFontSize));
     } else {
         fTextRatio = fSkPaint.getTextSize()/kLargeDFFontSize;
         fSkPaint.setTextSize(SkIntToScalar(kLargeDFFontSize));
     }
 
+    fUseLCDText = fSkPaint.isLCDRenderText();
+    
     fSkPaint.setLCDRenderText(false);
     fSkPaint.setAutohinted(false);
     fSkPaint.setSubpixelText(true);
 }
 
 inline void GrDistanceFieldTextContext::finish() {
     flushGlyphs();
 
     GrTextContext::finish();
 }
@@ skipping 130 matching lines @@
                                       SkScalarToFixed(y) - (glyph.fAdvanceY >> alignShift)
                                         + SK_FixedHalf, //d1g.fHalfSampleY,
                                       fontScaler);
             }
             pos += scalarsPerPosition;
         }
     }
 
     this->finish();
 }