1 /* 2 * Copyright 2013 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #include "SkPaintPriv.h" 9 10 #include "SkBitmap.h" 11 #include "SkColorFilter.h" 12 #include "SkPaint.h" 13 #include "SkShader.h" 14 isPaintOpaque(const SkPaint * paint,const SkBitmap * bmpReplacesShader)15bool isPaintOpaque(const SkPaint* paint, 16 const SkBitmap* bmpReplacesShader) { 17 // TODO: SkXfermode should have a virtual isOpaque method, which would 18 // make it possible to test modes that do not have a Coeff representation. 19 20 if (!paint) { 21 return bmpReplacesShader ? bmpReplacesShader->isOpaque() : true; 22 } 23 24 SkXfermode::Coeff srcCoeff, dstCoeff; 25 if (SkXfermode::AsCoeff(paint->getXfermode(), &srcCoeff, &dstCoeff)){ 26 if (SkXfermode::kDA_Coeff == srcCoeff || SkXfermode::kDC_Coeff == srcCoeff || 27 SkXfermode::kIDA_Coeff == srcCoeff || SkXfermode::kIDC_Coeff == srcCoeff) { 28 return false; 29 } 30 switch (dstCoeff) { 31 case SkXfermode::kZero_Coeff: 32 return true; 33 case SkXfermode::kISA_Coeff: 34 if (paint->getAlpha() != 255) { 35 break; 36 } 37 if (bmpReplacesShader) { 38 if (!bmpReplacesShader->isOpaque()) { 39 break; 40 } 41 } else if (paint->getShader() && !paint->getShader()->isOpaque()) { 42 break; 43 } 44 if (paint->getColorFilter() && 45 ((paint->getColorFilter()->getFlags() & 46 SkColorFilter::kAlphaUnchanged_Flag) == 0)) { 47 break; 48 } 49 return true; 50 case SkXfermode::kSA_Coeff: 51 if (paint->getAlpha() != 0) { 52 break; 53 } 54 if (paint->getColorFilter() && 55 ((paint->getColorFilter()->getFlags() & 56 SkColorFilter::kAlphaUnchanged_Flag) == 0)) { 57 break; 58 } 59 return true; 60 case SkXfermode::kSC_Coeff: 61 if (paint->getColor() != 0) { // all components must be 0 62 break; 63 } 64 if (bmpReplacesShader || paint->getShader()) { 65 break; 66 } 67 if (paint->getColorFilter() && ( 68 (paint->getColorFilter()->getFlags() & 69 SkColorFilter::kAlphaUnchanged_Flag) == 0)) { 70 break; 71 } 72 return true; 73 default: 74 break; 75 } 76 } 77 return false; 78 } 79