skia2/include/core/SkFont.h
commit-bot@chromium.org 7ae034d651 Test font created from paint
This is meant to allow clients to migrate over to a SkFont api on canvas (e.g. drawText(text, font, paint)) while still permitting the current setters in paint (e.g. setTextSize, setFlags).

R=bungeman@google.com, eae@chromium.org, fmalita@google.com, fmalita@chromium.org

Author: reed@google.com

Review URL: https://codereview.chromium.org/245953003

git-svn-id: http://skia.googlecode.com/svn/trunk@14997 2bbb7eff-a529-9590-31e7-b0007b416f81
2014-05-30 16:46:10 +00:00

162 lines
6.0 KiB
C++

/*
* 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 "SkRefCnt.h"
#include "SkScalar.h"
class SkPaint;
class SkTypeface;
enum SkTextEncoding {
kUTF8_SkTextEncoding,
kUTF16_SkTextEncoding,
kUTF32_SkTextEncoding,
kGlyphID_SkTextEncoding,
};
/*
1. The Hinting enum in SkPaint is gone entirely, absorbed into SkFont's flags.
2. SkPaint Flags look like this today
enum Flags {
kAntiAlias_Flag = 0x01, //!< mask to enable antialiasing
kDither_Flag = 0x04, //!< mask to enable dithering
kUnderlineText_Flag = 0x08, //!< mask to enable underline text
kStrikeThruText_Flag = 0x10, //!< mask to enable strike-thru text
kFakeBoldText_Flag = 0x20, //!< mask to enable fake-bold text
kLinearText_Flag = 0x40, //!< mask to enable linear-text
kSubpixelText_Flag = 0x80, //!< mask to enable subpixel text positioning
kDevKernText_Flag = 0x100, //!< mask to enable device kerning text
kLCDRenderText_Flag = 0x200, //!< mask to enable subpixel glyph renderering
kEmbeddedBitmapText_Flag = 0x400, //!< mask to enable embedded bitmap strikes
kAutoHinting_Flag = 0x800, //!< mask to force Freetype's autohinter
kVerticalText_Flag = 0x1000,
kGenA8FromLCD_Flag = 0x2000, // hack for GDI -- do not use if you can help it
};
SkFont would absorb these:
kFakeBoldText_Flag = 0x20, //!< mask to enable fake-bold text
kLinearText_Flag = 0x40, //!< mask to enable linear-text
kSubpixelText_Flag = 0x80, //!< mask to enable subpixel text positioning
kDevKernText_Flag = 0x100, //!< mask to enable device kerning text
kLCDRenderText_Flag = 0x200, //!< mask to enable subpixel glyph renderering
kEmbeddedBitmapText_Flag = 0x400, //!< mask to enable embedded bitmap strikes
kAutoHinting_Flag = 0x800, //!< mask to force Freetype's autohinter
kVerticalText_Flag = 0x1000,
kGenA8FromLCD_Flag = 0x2000, // hack for GDI -- do not use if you can help it
leaving these still in paint
kAntiAlias_Flag = 0x01, //!< mask to enable antialiasing
kDither_Flag = 0x04, //!< mask to enable dithering
kUnderlineText_Flag = 0x08, //!< mask to enable underline text
kStrikeThruText_Flag = 0x10, //!< mask to enable strike-thru text
3. Antialiasing
SkFont has a mask-type: BW, AA, LCD
SkPaint has antialias boolean
What to do if the font's mask-type disagrees with the paint?
*/
class SkFont : public SkRefCnt {
public:
enum Flags {
/**
* Use the system's automatic hinting mechanism to hint the typeface.
* If both bytecode and auto hints are specified, attempt to use the bytecodes first.
* If that fails (e.g. there are no codes), then attempt to autohint.
*/
kEnableAutoHints_Flag = 1 << 0,
/**
* If the typeface contains explicit bytecodes for hinting, use them.
* If both bytecode and auto hints are specified, attempt to use the bytecodes first;
* if that fails (e.g. there are no codes), then attempt to autohint.
*/
kEnableByteCodeHints_Flag = 1 << 1,
/**
* Use rounded metric values (e.g. advance).
* If either auto or bytecode hinting was used, apply those results to the metrics of the
* glyphs as well. If no hinting was applied, the metrics will just be rounded to the
* nearest integer.
*
* This applies to calls that return metrics (e.g. measureText) and to drawing the glyphs
* (see SkCanvas drawText and drawPosText).
*/
kUseNonlinearMetrics_Flag = 1 << 2,
kVertical_Flag = 1 << 3,
kEmbeddedBitmaps_Flag = 1 << 4,
kGenA8FromLCD_Flag = 1 << 5,
kEmbolden_Flag = 1 << 6,
kDevKern_Flag = 1 << 7, // ifdef ANDROID ?
};
enum MaskType {
kBW_MaskType,
kA8_MaskType,
kLCD_MaskType,
};
static SkFont* Create(SkTypeface*, SkScalar size, MaskType, uint32_t flags);
static SkFont* Create(SkTypeface*, SkScalar size, SkScalar scaleX, SkScalar skewX,
MaskType, uint32_t flags);
/**
* Return a font with the same attributes of this font, but with the specified size.
* If size is not supported (e.g. <= 0 or non-finite) NULL will be returned.
*/
SkFont* cloneWithSize(SkScalar size) const;
SkTypeface* getTypeface() const { return fTypeface; }
SkScalar getSize() const { return fSize; }
SkScalar getScaleX() const { return fScaleX; }
SkScalar getSkewX() const { return fSkewX; }
uint32_t getFlags() const { return fFlags; }
MaskType getMaskType() const { return (MaskType)fMaskType; }
bool isVertical() const { return SkToBool(fFlags & kVertical_Flag); }
bool isEmbolden() const { return SkToBool(fFlags & kEmbolden_Flag); }
bool isEnableAutoHints() const { return SkToBool(fFlags & kEnableAutoHints_Flag); }
bool isEnableByteCodeHints() const { return SkToBool(fFlags & kEnableByteCodeHints_Flag); }
bool isUseNonLinearMetrics() const { return SkToBool(fFlags & kUseNonlinearMetrics_Flag); }
int textToGlyphs(const void* text, size_t byteLength, SkTextEncoding,
uint16_t glyphs[], int maxGlyphCount) const;
SkScalar measureText(const void* text, size_t byteLength, SkTextEncoding) const;
static SkFont* Testing_CreateFromPaint(const SkPaint&);
private:
enum {
kAllFlags = 0xFF,
};
SkFont(SkTypeface*, SkScalar size, SkScalar scaleX, SkScalar skewX, MaskType, uint32_t flags);
virtual ~SkFont();
SkTypeface* fTypeface;
SkScalar fSize;
SkScalar fScaleX;
SkScalar fSkewX;
uint16_t fFlags;
uint8_t fMaskType;
// uint8_t fPad;
};
#endif