1 2/* 3 * Copyright 2011 Google Inc. 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 9 10#include "SkTableMaskFilter.h" 11 12SkTableMaskFilter::SkTableMaskFilter() { 13 for (int i = 0; i < 256; i++) { 14 fTable[i] = i; 15 } 16} 17 18SkTableMaskFilter::SkTableMaskFilter(const uint8_t table[256]) { 19 this->setTable(table); 20} 21 22SkTableMaskFilter::~SkTableMaskFilter() {} 23 24void SkTableMaskFilter::setTable(const uint8_t table[256]) { 25 memcpy(fTable, table, 256); 26} 27 28bool SkTableMaskFilter::filterMask(SkMask* dst, const SkMask& src, 29 const SkMatrix&, SkIPoint* margin) { 30 if (src.fFormat != SkMask::kA8_Format) { 31 return false; 32 } 33 34 dst->fBounds = src.fBounds; 35 dst->fRowBytes = SkAlign4(dst->fBounds.width()); 36 dst->fFormat = SkMask::kA8_Format; 37 dst->fImage = NULL; 38 39 if (src.fImage) { 40 dst->fImage = SkMask::AllocImage(dst->computeImageSize()); 41 42 const uint8_t* srcP = src.fImage; 43 uint8_t* dstP = dst->fImage; 44 const uint8_t* table = fTable; 45 int dstWidth = dst->fBounds.width(); 46 int extraZeros = dst->fRowBytes - dstWidth; 47 48 for (int y = dst->fBounds.height() - 1; y >= 0; --y) { 49 for (int x = dstWidth - 1; x >= 0; --x) { 50 dstP[x] = table[srcP[x]]; 51 } 52 srcP += src.fRowBytes; 53 // we can't just inc dstP by rowbytes, because if it has any 54 // padding between its width and its rowbytes, we need to zero those 55 // so that the bitters can read those safely if that is faster for 56 // them 57 dstP += dstWidth; 58 for (int i = extraZeros - 1; i >= 0; --i) { 59 *dstP++ = 0; 60 } 61 } 62 } 63 64 if (margin) { 65 margin->set(0, 0); 66 } 67 return true; 68} 69 70SkMask::Format SkTableMaskFilter::getFormat() { 71 return SkMask::kA8_Format; 72} 73 74void SkTableMaskFilter::flatten(SkFlattenableWriteBuffer& wb) { 75 this->INHERITED::flatten(wb); 76 wb.writePad(fTable, 256); 77} 78 79SkTableMaskFilter::SkTableMaskFilter(SkFlattenableReadBuffer& rb) 80 : INHERITED(rb) { 81 rb.read(fTable, 256); 82} 83 84SkFlattenable* SkTableMaskFilter::Factory(SkFlattenableReadBuffer& rb) { 85 return SkNEW_ARGS(SkTableMaskFilter, (rb)); 86} 87 88SkFlattenable::Factory SkTableMaskFilter::getFactory() { 89 return SkTableMaskFilter::Factory; 90} 91 92/////////////////////////////////////////////////////////////////////////////// 93 94void SkTableMaskFilter::MakeGammaTable(uint8_t table[256], SkScalar gamma) { 95 const float dx = 1 / 255.0f; 96 const float g = SkScalarToFloat(gamma); 97 98 float x = 0; 99 for (int i = 0; i < 256; i++) { 100 float ee = powf(x, g) * 255; 101 table[i] = SkPin32(sk_float_round2int(powf(x, g) * 255), 0, 255); 102 x += dx; 103 } 104} 105 106void SkTableMaskFilter::MakeClipTable(uint8_t table[256], uint8_t min, 107 uint8_t max) { 108 if (0 == max) { 109 max = 1; 110 } 111 if (min >= max) { 112 min = max - 1; 113 } 114 SkASSERT(min < max); 115 116 SkFixed scale = (1 << 16) * 255 / (max - min); 117 memset(table, 0, min + 1); 118 for (int i = min + 1; i < max; i++) { 119 int value = SkFixedRound(scale * (i - min)); 120 SkASSERT(value <= 255); 121 table[i] = value; 122 } 123 memset(table + max, 255, 256 - max); 124 125#if 0 126 int j; 127 for (j = 0; j < 256; j++) { 128 if (table[j]) { 129 break; 130 } 131 } 132 SkDebugf("%d %d start [%d]", min, max, j); 133 for (; j < 256; j++) { 134 SkDebugf(" %d", table[j]); 135 } 136 SkDebugf("\n\n"); 137#endif 138} 139 140