reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame^] | 1 | /* libs/graphics/sgl/SkAutoKern.h |
| 2 | ** |
| 3 | ** Copyright 2006, The Android Open Source Project |
| 4 | ** |
| 5 | ** Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | ** you may not use this file except in compliance with the License. |
| 7 | ** You may obtain a copy of the License at |
| 8 | ** |
| 9 | ** http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | ** |
| 11 | ** Unless required by applicable law or agreed to in writing, software |
| 12 | ** distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | ** See the License for the specific language governing permissions and |
| 15 | ** limitations under the License. |
| 16 | */ |
| 17 | |
| 18 | #ifndef SkAutoKern_DEFINED |
| 19 | #define SkAutoKern_DEFINED |
| 20 | |
| 21 | #include "SkScalerContext.h" |
| 22 | |
| 23 | #define SkAutoKern_AdjustF(prev, next) (((next) - (prev) + 32) >> 6 << 16) |
| 24 | #define SkAutoKern_AdjustS(prev, next) SkIntToScalar(((next) - (prev) + 32) >> 6) |
| 25 | |
| 26 | /* this is a helper class to perform auto-kerning |
| 27 | * the adjust() method returns a SkFixed corresponding |
| 28 | * to a +1/0/-1 pixel adjustment |
| 29 | */ |
| 30 | |
| 31 | class SkAutoKern { |
| 32 | public: |
| 33 | SkAutoKern() : fPrevRsbDelta(0) {} |
| 34 | |
| 35 | SkFixed adjust(const SkGlyph& glyph) |
| 36 | { |
| 37 | // if (SkAbs32(glyph.fLsbDelta) > 47 || SkAbs32(glyph.fRsbDelta) > 47) |
| 38 | // printf("------- %d> L %d R %d\n", glyph.f_GlyphID, glyph.fLsbDelta, glyph.fRsbDelta); |
| 39 | |
| 40 | #if 0 |
| 41 | int distort = fPrevRsbDelta - glyph.fLsbDelta; |
| 42 | |
| 43 | fPrevRsbDelta = glyph.fRsbDelta; |
| 44 | |
| 45 | if (distort >= 32) |
| 46 | return -SK_Fixed1; |
| 47 | else if (distort < -32) |
| 48 | return +SK_Fixed1; |
| 49 | else |
| 50 | return 0; |
| 51 | #else |
| 52 | SkFixed adjust = SkAutoKern_AdjustF(fPrevRsbDelta, glyph.fLsbDelta); |
| 53 | fPrevRsbDelta = glyph.fRsbDelta; |
| 54 | return adjust; |
| 55 | #endif |
| 56 | } |
| 57 | private: |
| 58 | int fPrevRsbDelta; |
| 59 | }; |
| 60 | |
| 61 | #endif |
| 62 | |