reed@google.com | b83cb9b | 2013-05-21 21:33:11 +0000 | [diff] [blame^] | 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 |