|  | /* | 
|  | * Copyright 2014 Google Inc. | 
|  | * | 
|  | * Use of this source code is governed by a BSD-style license that can be | 
|  | * found in the LICENSE file. | 
|  | */ | 
|  |  | 
|  | #ifndef SkFont_DEFINED | 
|  | #define SkFont_DEFINED | 
|  |  | 
|  | #include "include/core/SkFontTypes.h" | 
|  | #include "include/core/SkScalar.h" | 
|  | #include "include/core/SkTypeface.h" | 
|  |  | 
|  | class SkMatrix; | 
|  | class SkPaint; | 
|  | class SkPath; | 
|  | struct SkFontMetrics; | 
|  |  | 
|  | /** \class SkFont | 
|  | SkFont controls options applied when drawing and measuring text. | 
|  | */ | 
|  | class SK_API SkFont { | 
|  | public: | 
|  | /** Whether edge pixels draw opaque or with partial transparency. | 
|  | */ | 
|  | enum class Edging { | 
|  | kAlias,              //!< no transparent pixels on glyph edges | 
|  | kAntiAlias,          //!< may have transparent pixels on glyph edges | 
|  | kSubpixelAntiAlias,  //!< glyph positioned in pixel using transparency | 
|  | }; | 
|  |  | 
|  | /** Constructs SkFont with default values. | 
|  |  | 
|  | @return  default initialized SkFont | 
|  | */ | 
|  | SkFont(); | 
|  |  | 
|  | /** Constructs SkFont with default values with SkTypeface and size in points. | 
|  |  | 
|  | @param typeface  font and style used to draw and measure text | 
|  | @param size      typographic height of text | 
|  | @return          initialized SkFont | 
|  | */ | 
|  | SkFont(sk_sp<SkTypeface> typeface, SkScalar size); | 
|  |  | 
|  | /** Constructs SkFont with default values with SkTypeface. | 
|  |  | 
|  | @param typeface  font and style used to draw and measure text | 
|  | @return          initialized SkFont | 
|  | */ | 
|  | explicit SkFont(sk_sp<SkTypeface> typeface); | 
|  |  | 
|  |  | 
|  | /** Constructs SkFont with default values with SkTypeface and size in points, | 
|  | horizontal scale, and horizontal skew. Horizontal scale emulates condensed | 
|  | and expanded fonts. Horizontal skew emulates oblique fonts. | 
|  |  | 
|  | @param typeface  font and style used to draw and measure text | 
|  | @param size      typographic height of text | 
|  | @param scaleX    text horizontal scale | 
|  | @param skewX     additional shear on x-axis relative to y-axis | 
|  | @return          initialized SkFont | 
|  | */ | 
|  | SkFont(sk_sp<SkTypeface> typeface, SkScalar size, SkScalar scaleX, SkScalar skewX); | 
|  |  | 
|  |  | 
|  | /** Compares SkFont and font, and returns true if they are equivalent. | 
|  | May return false if SkTypeface has identical contents but different pointers. | 
|  |  | 
|  | @param font  font to compare | 
|  | @return      true if SkFont pair are equivalent | 
|  | */ | 
|  | bool operator==(const SkFont& font) const; | 
|  |  | 
|  | /** Compares SkFont and font, and returns true if they are not equivalent. | 
|  | May return true if SkTypeface has identical contents but different pointers. | 
|  |  | 
|  | @param font  font to compare | 
|  | @return      true if SkFont pair are not equivalent | 
|  | */ | 
|  | bool operator!=(const SkFont& font) const { return !(*this == font); } | 
|  |  | 
|  | /** If true, instructs the font manager to always hint glyphs. | 
|  | Returned value is only meaningful if platform uses FreeType as the font manager. | 
|  |  | 
|  | @return  true if all glyphs are hinted | 
|  | */ | 
|  | bool isForceAutoHinting() const { return SkToBool(fFlags & kForceAutoHinting_PrivFlag); } | 
|  |  | 
|  | /** Returns true if font engine may return glyphs from font bitmaps instead of from outlines. | 
|  |  | 
|  | @return  true if glyphs may be font bitmaps | 
|  | */ | 
|  | bool isEmbeddedBitmaps() const { return SkToBool(fFlags & kEmbeddedBitmaps_PrivFlag); } | 
|  |  | 
|  | /** Returns true if glyphs may be drawn at sub-pixel offsets. | 
|  |  | 
|  | @return  true if glyphs may be drawn at sub-pixel offsets. | 
|  | */ | 
|  | bool isSubpixel() const { return SkToBool(fFlags & kSubpixel_PrivFlag); } | 
|  |  | 
|  | /** Returns true if font and glyph metrics are requested to be linearly scalable. | 
|  |  | 
|  | @return  true if font and glyph metrics are requested to be linearly scalable. | 
|  | */ | 
|  | bool isLinearMetrics() const { return SkToBool(fFlags & kLinearMetrics_PrivFlag); } | 
|  |  | 
|  | /** Returns true if bold is approximated by increasing the stroke width when creating glyph | 
|  | bitmaps from outlines. | 
|  |  | 
|  | @return  bold is approximated through stroke width | 
|  | */ | 
|  | bool isEmbolden() const { return SkToBool(fFlags & kEmbolden_PrivFlag); } | 
|  |  | 
|  | /** Returns true if baselines will be snapped to pixel positions when the current transformation | 
|  | matrix is axis aligned. | 
|  |  | 
|  | @return  baselines may be snapped to pixels | 
|  | */ | 
|  | bool isBaselineSnap() const { return SkToBool(fFlags & kBaselineSnap_PrivFlag); } | 
|  |  | 
|  | /** Sets whether to always hint glyphs. | 
|  | If forceAutoHinting is set, instructs the font manager to always hint glyphs. | 
|  |  | 
|  | Only affects platforms that use FreeType as the font manager. | 
|  |  | 
|  | @param forceAutoHinting  setting to always hint glyphs | 
|  | */ | 
|  | void setForceAutoHinting(bool forceAutoHinting); | 
|  |  | 
|  | /** Requests, but does not require, to use bitmaps in fonts instead of outlines. | 
|  |  | 
|  | @param embeddedBitmaps  setting to use bitmaps in fonts | 
|  | */ | 
|  | void setEmbeddedBitmaps(bool embeddedBitmaps); | 
|  |  | 
|  | /** Requests, but does not require, that glyphs respect sub-pixel positioning. | 
|  |  | 
|  | @param subpixel  setting for sub-pixel positioning | 
|  | */ | 
|  | void setSubpixel(bool subpixel); | 
|  |  | 
|  | /** Requests, but does not require, linearly scalable font and glyph metrics. | 
|  |  | 
|  | For outline fonts 'true' means font and glyph metrics should ignore hinting and rounding. | 
|  | Note that some bitmap formats may not be able to scale linearly and will ignore this flag. | 
|  |  | 
|  | @param linearMetrics  setting for linearly scalable font and glyph metrics. | 
|  | */ | 
|  | void setLinearMetrics(bool linearMetrics); | 
|  |  | 
|  | /** Increases stroke width when creating glyph bitmaps to approximate a bold typeface. | 
|  |  | 
|  | @param embolden  setting for bold approximation | 
|  | */ | 
|  | void setEmbolden(bool embolden); | 
|  |  | 
|  | /** Requests that baselines be snapped to pixels when the current transformation matrix is axis | 
|  | aligned. | 
|  |  | 
|  | @param baselineSnap  setting for baseline snapping to pixels | 
|  | */ | 
|  | void setBaselineSnap(bool baselineSnap); | 
|  |  | 
|  | /** Whether edge pixels draw opaque or with partial transparency. | 
|  | */ | 
|  | Edging getEdging() const { return (Edging)fEdging; } | 
|  |  | 
|  | /** Requests, but does not require, that edge pixels draw opaque or with | 
|  | partial transparency. | 
|  | */ | 
|  | void setEdging(Edging edging); | 
|  |  | 
|  | /** Sets level of glyph outline adjustment. | 
|  | Does not check for valid values of hintingLevel. | 
|  | */ | 
|  | void setHinting(SkFontHinting hintingLevel); | 
|  |  | 
|  | /** Returns level of glyph outline adjustment. | 
|  | */ | 
|  | SkFontHinting getHinting() const { return (SkFontHinting)fHinting; } | 
|  |  | 
|  | /** Returns a font with the same attributes of this font, but with the specified size. | 
|  | Returns nullptr if size is less than zero, infinite, or NaN. | 
|  |  | 
|  | @param size  typographic height of text | 
|  | @return      initialized SkFont | 
|  | */ | 
|  | SkFont makeWithSize(SkScalar size) const; | 
|  |  | 
|  | /** Returns SkTypeface if set, or nullptr. | 
|  | Does not alter SkTypeface SkRefCnt. | 
|  |  | 
|  | @return  SkTypeface if previously set, nullptr otherwise | 
|  | */ | 
|  | SkTypeface* getTypeface() const {return fTypeface.get(); } | 
|  |  | 
|  | /** Returns SkTypeface if set, or the default typeface. | 
|  | Does not alter SkTypeface SkRefCnt. | 
|  |  | 
|  | @return  SkTypeface if previously set or, a pointer to the default typeface if not | 
|  | previously set. | 
|  | */ | 
|  | SkTypeface* getTypefaceOrDefault() const; | 
|  |  | 
|  | /** Returns text size in points. | 
|  |  | 
|  | @return  typographic height of text | 
|  | */ | 
|  | SkScalar    getSize() const { return fSize; } | 
|  |  | 
|  | /** Returns text scale on x-axis. | 
|  | Default value is 1. | 
|  |  | 
|  | @return  text horizontal scale | 
|  | */ | 
|  | SkScalar    getScaleX() const { return fScaleX; } | 
|  |  | 
|  | /** Returns text skew on x-axis. | 
|  | Default value is zero. | 
|  |  | 
|  | @return  additional shear on x-axis relative to y-axis | 
|  | */ | 
|  | SkScalar    getSkewX() const { return fSkewX; } | 
|  |  | 
|  | /** Increases SkTypeface SkRefCnt by one. | 
|  |  | 
|  | @return  SkTypeface if previously set, nullptr otherwise | 
|  | */ | 
|  | sk_sp<SkTypeface> refTypeface() const { return fTypeface; } | 
|  |  | 
|  | /** Increases SkTypeface SkRefCnt by one. | 
|  |  | 
|  | @return  SkTypeface if previously set or, a pointer to the default typeface if not | 
|  | previously set. | 
|  | */ | 
|  | sk_sp<SkTypeface> refTypefaceOrDefault() const; | 
|  |  | 
|  | /** Sets SkTypeface to typeface, decreasing SkRefCnt of the previous SkTypeface. | 
|  | Pass nullptr to clear SkTypeface and use the default typeface. Increments | 
|  | tf SkRefCnt by one. | 
|  |  | 
|  | @param tf  font and style used to draw text | 
|  | */ | 
|  | void setTypeface(sk_sp<SkTypeface> tf) { fTypeface = tf; } | 
|  |  | 
|  | /** Sets text size in points. | 
|  | Has no effect if textSize is not greater than or equal to zero. | 
|  |  | 
|  | @param textSize  typographic height of text | 
|  | */ | 
|  | void setSize(SkScalar textSize); | 
|  |  | 
|  | /** Sets text scale on x-axis. | 
|  | Default value is 1. | 
|  |  | 
|  | @param scaleX  text horizontal scale | 
|  | */ | 
|  | void setScaleX(SkScalar scaleX); | 
|  |  | 
|  | /** Sets text skew on x-axis. | 
|  | Default value is zero. | 
|  |  | 
|  | @param skewX  additional shear on x-axis relative to y-axis | 
|  | */ | 
|  | void setSkewX(SkScalar skewX); | 
|  |  | 
|  | /** Converts text into glyph indices. | 
|  | Returns the number of glyph indices represented by text. | 
|  | SkTextEncoding specifies how text represents characters or glyphs. | 
|  | glyphs may be nullptr, to compute the glyph count. | 
|  |  | 
|  | Does not check text for valid character codes or valid glyph indices. | 
|  |  | 
|  | If byteLength equals zero, returns zero. | 
|  | If byteLength includes a partial character, the partial character is ignored. | 
|  |  | 
|  | If encoding is SkTextEncoding::kUTF8 and text contains an invalid UTF-8 sequence, | 
|  | zero is returned. | 
|  |  | 
|  | When encoding is SkTextEncoding::kUTF8, SkTextEncoding::kUTF16, or | 
|  | SkTextEncoding::kUTF32; then each Unicode codepoint is mapped to a | 
|  | single glyph.  This function uses the default character-to-glyph | 
|  | mapping from the SkTypeface and maps characters not found in the | 
|  | SkTypeface to zero. | 
|  |  | 
|  | If maxGlyphCount is not sufficient to store all the glyphs, no glyphs are copied. | 
|  | The total glyph count is returned for subsequent buffer reallocation. | 
|  |  | 
|  | @param text          character storage encoded with SkTextEncoding | 
|  | @param byteLength    length of character storage in bytes | 
|  | @param glyphs        storage for glyph indices; may be nullptr | 
|  | @param maxGlyphCount storage capacity | 
|  | @return              number of glyphs represented by text of length byteLength | 
|  | */ | 
|  | int textToGlyphs(const void* text, size_t byteLength, SkTextEncoding encoding, | 
|  | SkGlyphID glyphs[], int maxGlyphCount) const; | 
|  |  | 
|  | /** Returns glyph index for Unicode character. | 
|  |  | 
|  | If the character is not supported by the SkTypeface, returns 0. | 
|  |  | 
|  | @param uni  Unicode character | 
|  | @return     glyph index | 
|  | */ | 
|  | SkGlyphID unicharToGlyph(SkUnichar uni) const; | 
|  |  | 
|  | void unicharsToGlyphs(const SkUnichar uni[], int count, SkGlyphID glyphs[]) const; | 
|  |  | 
|  | /** Returns number of glyphs represented by text. | 
|  |  | 
|  | If encoding is SkTextEncoding::kUTF8, SkTextEncoding::kUTF16, or | 
|  | SkTextEncoding::kUTF32; then each Unicode codepoint is mapped to a | 
|  | single glyph. | 
|  |  | 
|  | @param text          character storage encoded with SkTextEncoding | 
|  | @param byteLength    length of character storage in bytes | 
|  | @return              number of glyphs represented by text of length byteLength | 
|  | */ | 
|  | int countText(const void* text, size_t byteLength, SkTextEncoding encoding) const { | 
|  | return this->textToGlyphs(text, byteLength, encoding, nullptr, 0); | 
|  | } | 
|  |  | 
|  | /** Returns the advance width of text. | 
|  | The advance is the normal distance to move before drawing additional text. | 
|  | Returns the bounding box of text if bounds is not nullptr. | 
|  |  | 
|  | @param text        character storage encoded with SkTextEncoding | 
|  | @param byteLength  length of character storage in bytes | 
|  | @param bounds      returns bounding box relative to (0, 0) if not nullptr | 
|  | @return            number of glyphs represented by text of length byteLength | 
|  | */ | 
|  | SkScalar measureText(const void* text, size_t byteLength, SkTextEncoding encoding, | 
|  | SkRect* bounds = nullptr) const { | 
|  | return this->measureText(text, byteLength, encoding, bounds, nullptr); | 
|  | } | 
|  |  | 
|  | /** Returns the advance width of text. | 
|  | The advance is the normal distance to move before drawing additional text. | 
|  | Returns the bounding box of text if bounds is not nullptr. The paint | 
|  | stroke settings, mask filter, or path effect may modify the bounds. | 
|  |  | 
|  | @param text        character storage encoded with SkTextEncoding | 
|  | @param byteLength  length of character storage in bytes | 
|  | @param bounds      returns bounding box relative to (0, 0) if not nullptr | 
|  | @param paint       optional; may be nullptr | 
|  | @return            number of glyphs represented by text of length byteLength | 
|  | */ | 
|  | SkScalar measureText(const void* text, size_t byteLength, SkTextEncoding encoding, | 
|  | SkRect* bounds, const SkPaint* paint) const; | 
|  |  | 
|  | /** DEPRECATED | 
|  | Retrieves the advance and bounds for each glyph in glyphs. | 
|  | Both widths and bounds may be nullptr. | 
|  | If widths is not nullptr, widths must be an array of count entries. | 
|  | if bounds is not nullptr, bounds must be an array of count entries. | 
|  |  | 
|  | @param glyphs      array of glyph indices to be measured | 
|  | @param count       number of glyphs | 
|  | @param widths      returns text advances for each glyph; may be nullptr | 
|  | @param bounds      returns bounds for each glyph relative to (0, 0); may be nullptr | 
|  | */ | 
|  | void getWidths(const SkGlyphID glyphs[], int count, SkScalar widths[], SkRect bounds[]) const { | 
|  | this->getWidthsBounds(glyphs, count, widths, bounds, nullptr); | 
|  | } | 
|  |  | 
|  | // DEPRECATED | 
|  | void getWidths(const SkGlyphID glyphs[], int count, SkScalar widths[], std::nullptr_t) const { | 
|  | this->getWidths(glyphs, count, widths); | 
|  | } | 
|  |  | 
|  | /** Retrieves the advance and bounds for each glyph in glyphs. | 
|  | Both widths and bounds may be nullptr. | 
|  | If widths is not nullptr, widths must be an array of count entries. | 
|  | if bounds is not nullptr, bounds must be an array of count entries. | 
|  |  | 
|  | @param glyphs      array of glyph indices to be measured | 
|  | @param count       number of glyphs | 
|  | @param widths      returns text advances for each glyph | 
|  | */ | 
|  | void getWidths(const SkGlyphID glyphs[], int count, SkScalar widths[]) const { | 
|  | this->getWidthsBounds(glyphs, count, widths, nullptr, nullptr); | 
|  | } | 
|  |  | 
|  | /** Retrieves the advance and bounds for each glyph in glyphs. | 
|  | Both widths and bounds may be nullptr. | 
|  | If widths is not nullptr, widths must be an array of count entries. | 
|  | if bounds is not nullptr, bounds must be an array of count entries. | 
|  |  | 
|  | @param glyphs      array of glyph indices to be measured | 
|  | @param count       number of glyphs | 
|  | @param widths      returns text advances for each glyph; may be nullptr | 
|  | @param bounds      returns bounds for each glyph relative to (0, 0); may be nullptr | 
|  | @param paint       optional, specifies stroking, SkPathEffect and SkMaskFilter | 
|  | */ | 
|  | void getWidthsBounds(const SkGlyphID glyphs[], int count, SkScalar widths[], SkRect bounds[], | 
|  | const SkPaint* paint) const; | 
|  |  | 
|  |  | 
|  | /** Retrieves the bounds for each glyph in glyphs. | 
|  | bounds must be an array of count entries. | 
|  | If paint is not nullptr, its stroking, SkPathEffect, and SkMaskFilter fields are respected. | 
|  |  | 
|  | @param glyphs      array of glyph indices to be measured | 
|  | @param count       number of glyphs | 
|  | @param bounds      returns bounds for each glyph relative to (0, 0); may be nullptr | 
|  | @param paint       optional, specifies stroking, SkPathEffect, and SkMaskFilter | 
|  | */ | 
|  | void getBounds(const SkGlyphID glyphs[], int count, SkRect bounds[], | 
|  | const SkPaint* paint) const { | 
|  | this->getWidthsBounds(glyphs, count, nullptr, bounds, paint); | 
|  | } | 
|  |  | 
|  | /** Retrieves the positions for each glyph, beginning at the specified origin. The caller | 
|  | must allocated at least count number of elements in the pos[] array. | 
|  |  | 
|  | @param glyphs   array of glyph indices to be positioned | 
|  | @param count    number of glyphs | 
|  | @param pos      returns glyphs positions | 
|  | @param origin   location of the first glyph. Defaults to {0, 0}. | 
|  | */ | 
|  | void getPos(const SkGlyphID glyphs[], int count, SkPoint pos[], SkPoint origin = {0, 0}) const; | 
|  |  | 
|  | /** Retrieves the x-positions for each glyph, beginning at the specified origin. The caller | 
|  | must allocated at least count number of elements in the xpos[] array. | 
|  |  | 
|  | @param glyphs   array of glyph indices to be positioned | 
|  | @param count    number of glyphs | 
|  | @param xpos     returns glyphs x-positions | 
|  | @param origin   x-position of the first glyph. Defaults to 0. | 
|  | */ | 
|  | void getXPos(const SkGlyphID glyphs[], int count, SkScalar xpos[], SkScalar origin = 0) const; | 
|  |  | 
|  | /** Modifies path to be the outline of the glyph. | 
|  | If the glyph has an outline, modifies path to be the glyph's outline and returns true. | 
|  | The glyph outline may be empty. Degenerate contours in the glyph outline will be skipped. | 
|  | If glyph is described by a bitmap, returns false and ignores path parameter. | 
|  |  | 
|  | @param glyphID  index of glyph | 
|  | @param path     pointer to existing SkPath | 
|  | @return         true if glyphID is described by path | 
|  | */ | 
|  | bool getPath(SkGlyphID glyphID, SkPath* path) const; | 
|  |  | 
|  | /** Returns path corresponding to glyph array. | 
|  |  | 
|  | @param glyphIDs      array of glyph indices | 
|  | @param count         number of glyphs | 
|  | @param glyphPathProc function returning one glyph description as path | 
|  | @param ctx           function context | 
|  | */ | 
|  | void getPaths(const SkGlyphID glyphIDs[], int count, | 
|  | void (*glyphPathProc)(const SkPath* pathOrNull, const SkMatrix& mx, void* ctx), | 
|  | void* ctx) const; | 
|  |  | 
|  | /** Returns SkFontMetrics associated with SkTypeface. | 
|  | The return value is the recommended spacing between lines: the sum of metrics | 
|  | descent, ascent, and leading. | 
|  | If metrics is not nullptr, SkFontMetrics is copied to metrics. | 
|  | Results are scaled by text size but does not take into account | 
|  | dimensions required by text scale, text skew, fake bold, | 
|  | style stroke, and SkPathEffect. | 
|  |  | 
|  | @param metrics  storage for SkFontMetrics; may be nullptr | 
|  | @return         recommended spacing between lines | 
|  | */ | 
|  | SkScalar getMetrics(SkFontMetrics* metrics) const; | 
|  |  | 
|  | /** Returns the recommended spacing between lines: the sum of metrics | 
|  | descent, ascent, and leading. | 
|  | Result is scaled by text size but does not take into account | 
|  | dimensions required by stroking and SkPathEffect. | 
|  | Returns the same result as getMetrics(). | 
|  |  | 
|  | @return  recommended spacing between lines | 
|  | */ | 
|  | SkScalar getSpacing() const { return this->getMetrics(nullptr); } | 
|  |  | 
|  | /** Dumps fields of the font to SkDebugf. May change its output over time, so clients should | 
|  | *  not rely on this for anything specific. Used to aid in debugging. | 
|  | */ | 
|  | void dump() const; | 
|  |  | 
|  | private: | 
|  | enum PrivFlags { | 
|  | kForceAutoHinting_PrivFlag      = 1 << 0, | 
|  | kEmbeddedBitmaps_PrivFlag       = 1 << 1, | 
|  | kSubpixel_PrivFlag              = 1 << 2, | 
|  | kLinearMetrics_PrivFlag         = 1 << 3, | 
|  | kEmbolden_PrivFlag              = 1 << 4, | 
|  | kBaselineSnap_PrivFlag          = 1 << 5, | 
|  | }; | 
|  |  | 
|  | static constexpr unsigned kAllFlags = kForceAutoHinting_PrivFlag | 
|  | | kEmbeddedBitmaps_PrivFlag | 
|  | | kSubpixel_PrivFlag | 
|  | | kLinearMetrics_PrivFlag | 
|  | | kEmbolden_PrivFlag | 
|  | | kBaselineSnap_PrivFlag; | 
|  |  | 
|  | sk_sp<SkTypeface> fTypeface; | 
|  | SkScalar    fSize; | 
|  | SkScalar    fScaleX; | 
|  | SkScalar    fSkewX; | 
|  | uint8_t     fFlags; | 
|  | uint8_t     fEdging; | 
|  | uint8_t     fHinting; | 
|  |  | 
|  | SkScalar setupForAsPaths(SkPaint*); | 
|  | bool hasSomeAntiAliasing() const; | 
|  |  | 
|  | friend class SkFontPriv; | 
|  | friend class SkGlyphRunListPainter; | 
|  | friend class SkTextBlobCacheDiffCanvas; | 
|  | friend class SkStrikeSpec; | 
|  | }; | 
|  |  | 
|  | #endif |