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 "SkLerpXfermode.h" 9 #include "SkColorPriv.h" 10 #include "SkFlattenableBuffers.h" 11 #include "SkString.h" 12 13 SkXfermode* SkLerpXfermode::Create(SkScalar scale) { 14 int scale256 = SkScalarRoundToInt(scale * 256); 15 if (scale256 >= 256) { 16 return SkXfermode::Create(SkXfermode::kSrc_Mode); 17 } else if (scale256 <= 0) { 18 return SkXfermode::Create(SkXfermode::kDst_Mode); 19 } 20 return SkNEW_ARGS(SkLerpXfermode, (scale256)); 21 } 22 23 SkLerpXfermode::SkLerpXfermode(unsigned scale256) : fScale256(scale256) {} 24 25 SkLerpXfermode::SkLerpXfermode(SkFlattenableReadBuffer& buffer) 26 : INHERITED(buffer) { 27 fScale256 = buffer.readUInt(); 28 } 29 30 void SkLerpXfermode::flatten(SkFlattenableWriteBuffer& buffer) const { 31 this->INHERITED::flatten(buffer); 32 buffer.writeUInt(fScale256); 33 } 34 35 void SkLerpXfermode::xfer32(SkPMColor dst[], const SkPMColor src[], int count, 36 const SkAlpha aa[]) const { 37 const int scale = fScale256; 38 39 if (aa) { 40 for (int i = 0; i < count; ++i) { 41 unsigned a = aa[i]; 42 if (a) { 43 SkPMColor dstC = dst[i]; 44 SkPMColor resC = SkFastFourByteInterp256(src[i], dstC, scale); 45 if (a < 255) { 46 resC = SkFastFourByteInterp256(resC, dstC, a + (a >> 7)); 47 } 48 dst[i] = resC; 49 } 50 } 51 } else { 52 for (int i = 0; i < count; ++i) { 53 dst[i] = SkFastFourByteInterp256(src[i], dst[i], scale); 54 } 55 } 56 } 57 58 void SkLerpXfermode::xfer16(uint16_t dst[], const SkPMColor src[], int count, 59 const SkAlpha aa[]) const { 60 const int scale = fScale256; 61 62 if (aa) { 63 for (int i = 0; i < count; ++i) { 64 unsigned a = aa[i]; 65 if (a) { 66 SkPMColor dstC = SkPixel16ToPixel32(dst[i]); 67 SkPMColor resC = SkFastFourByteInterp256(src[i], dstC, scale); 68 if (a < 255) { 69 resC = SkFastFourByteInterp256(resC, dstC, a + (a >> 7)); 70 } 71 dst[i] = SkPixel32ToPixel16(resC); 72 } 73 } 74 } else { 75 for (int i = 0; i < count; ++i) { 76 SkPMColor dstC = SkPixel16ToPixel32(dst[i]); 77 SkPMColor resC = SkFastFourByteInterp256(src[i], dstC, scale); 78 dst[i] = SkPixel32ToPixel16(resC); 79 } 80 } 81 } 82 83 void SkLerpXfermode::xferA8(SkAlpha dst[], const SkPMColor src[], int count, 84 const SkAlpha aa[]) const { 85 const int scale = fScale256; 86 87 if (aa) { 88 for (int i = 0; i < count; ++i) { 89 unsigned a = aa[i]; 90 if (a) { 91 unsigned dstA = dst[i]; 92 unsigned resA = SkAlphaBlend(SkGetPackedA32(src[i]), dstA, scale); 93 if (a < 255) { 94 resA = SkAlphaBlend(resA, dstA, a + (a >> 7)); 95 } 96 dst[i] = resA; 97 } 98 } 99 } else { 100 for (int i = 0; i < count; ++i) { 101 dst[i] = SkAlphaBlend(SkGetPackedA32(src[i]), dst[i], scale); 102 } 103 } 104 } 105 106 #ifdef SK_DEVELOPER 107 void SkLerpXfermode::toString(SkString* str) const { 108 str->printf("SkLerpXfermode: scale: %g", fScale256 / 256.0); 109 } 110 #endif 111