michael@0: /*
michael@0:  * Copyright 2006 The Android Open Source Project
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #ifndef SkGlyph_DEFINED
michael@0: #define SkGlyph_DEFINED
michael@0: 
michael@0: #include "SkTypes.h"
michael@0: #include "SkFixed.h"
michael@0: #include "SkMask.h"
michael@0: 
michael@0: class SkPath;
michael@0: 
michael@0: // needs to be != to any valid SkMask::Format
michael@0: #define MASK_FORMAT_UNKNOWN         (0xFF)
michael@0: #define MASK_FORMAT_JUST_ADVANCE    MASK_FORMAT_UNKNOWN
michael@0: 
michael@0: #define kMaxGlyphWidth (1<<13)
michael@0: 
michael@0: struct SkGlyph {
michael@0:     void*       fImage;
michael@0:     SkPath*     fPath;
michael@0:     SkFixed     fAdvanceX, fAdvanceY;
michael@0: 
michael@0:     uint32_t    fID;
michael@0:     uint16_t    fWidth, fHeight;
michael@0:     int16_t     fTop, fLeft;
michael@0: 
michael@0:     uint8_t     fMaskFormat;
michael@0:     int8_t      fRsbDelta, fLsbDelta;  // used by auto-kerning
michael@0: 
michael@0:     void init(uint32_t id) {
michael@0:         fID             = id;
michael@0:         fImage          = NULL;
michael@0:         fPath           = NULL;
michael@0:         fMaskFormat     = MASK_FORMAT_UNKNOWN;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      *  Compute the rowbytes for the specified width and mask-format.
michael@0:      */
michael@0:     static unsigned ComputeRowBytes(unsigned width, SkMask::Format format) {
michael@0:         unsigned rb = width;
michael@0:         if (SkMask::kBW_Format == format) {
michael@0:             rb = (rb + 7) >> 3;
michael@0:         } else if (SkMask::kARGB32_Format == format ||
michael@0:                    SkMask::kLCD32_Format == format)
michael@0:         {
michael@0:             rb <<= 2;
michael@0:         } else if (SkMask::kLCD16_Format == format) {
michael@0:             rb = SkAlign4(rb << 1);
michael@0:         } else {
michael@0:             rb = SkAlign4(rb);
michael@0:         }
michael@0:         return rb;
michael@0:     }
michael@0: 
michael@0:     unsigned rowBytes() const {
michael@0:         return ComputeRowBytes(fWidth, (SkMask::Format)fMaskFormat);
michael@0:     }
michael@0: 
michael@0:     bool isJustAdvance() const {
michael@0:         return MASK_FORMAT_JUST_ADVANCE == fMaskFormat;
michael@0:     }
michael@0: 
michael@0:     bool isFullMetrics() const {
michael@0:         return MASK_FORMAT_JUST_ADVANCE != fMaskFormat;
michael@0:     }
michael@0: 
michael@0:     uint16_t getGlyphID() const {
michael@0:         return ID2Code(fID);
michael@0:     }
michael@0: 
michael@0:     unsigned getGlyphID(unsigned baseGlyphCount) const {
michael@0:         unsigned code = ID2Code(fID);
michael@0:         SkASSERT(code >= baseGlyphCount);
michael@0:         return code - baseGlyphCount;
michael@0:     }
michael@0: 
michael@0:     unsigned getSubX() const {
michael@0:         return ID2SubX(fID);
michael@0:     }
michael@0: 
michael@0:     SkFixed getSubXFixed() const {
michael@0:         return SubToFixed(ID2SubX(fID));
michael@0:     }
michael@0: 
michael@0:     SkFixed getSubYFixed() const {
michael@0:         return SubToFixed(ID2SubY(fID));
michael@0:     }
michael@0: 
michael@0:     size_t computeImageSize() const;
michael@0: 
michael@0:     /** Call this to set all of the metrics fields to 0 (e.g. if the scaler
michael@0:         encounters an error measuring a glyph). Note: this does not alter the
michael@0:         fImage, fPath, fID, fMaskFormat fields.
michael@0:      */
michael@0:     void zeroMetrics();
michael@0: 
michael@0:     enum {
michael@0:         kSubBits = 2,
michael@0:         kSubMask = ((1 << kSubBits) - 1),
michael@0:         kSubShift = 24, // must be large enough for glyphs and unichars
michael@0:         kCodeMask = ((1 << kSubShift) - 1),
michael@0:         // relative offsets for X and Y subpixel bits
michael@0:         kSubShiftX = kSubBits,
michael@0:         kSubShiftY = 0
michael@0:     };
michael@0: 
michael@0:     static unsigned ID2Code(uint32_t id) {
michael@0:         return id & kCodeMask;
michael@0:     }
michael@0: 
michael@0:     static unsigned ID2SubX(uint32_t id) {
michael@0:         return id >> (kSubShift + kSubShiftX);
michael@0:     }
michael@0: 
michael@0:     static unsigned ID2SubY(uint32_t id) {
michael@0:         return (id >> (kSubShift + kSubShiftY)) & kSubMask;
michael@0:     }
michael@0: 
michael@0:     static unsigned FixedToSub(SkFixed n) {
michael@0:         return (n >> (16 - kSubBits)) & kSubMask;
michael@0:     }
michael@0: 
michael@0:     static SkFixed SubToFixed(unsigned sub) {
michael@0:         SkASSERT(sub <= kSubMask);
michael@0:         return sub << (16 - kSubBits);
michael@0:     }
michael@0: 
michael@0:     static uint32_t MakeID(unsigned code) {
michael@0:         return code;
michael@0:     }
michael@0: 
michael@0:     static uint32_t MakeID(unsigned code, SkFixed x, SkFixed y) {
michael@0:         SkASSERT(code <= kCodeMask);
michael@0:         x = FixedToSub(x);
michael@0:         y = FixedToSub(y);
michael@0:         return (x << (kSubShift + kSubShiftX)) |
michael@0:                (y << (kSubShift + kSubShiftY)) |
michael@0:                code;
michael@0:     }
michael@0: 
michael@0:     void toMask(SkMask* mask) const;
michael@0: };
michael@0: 
michael@0: #endif