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* Copyright 2018 Google Inc.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
#ifndef SkFontPriv_DEFINED
#define SkFontPriv_DEFINED
#include "include/core/SkFont.h"
#include "include/core/SkMatrix.h"
#include "include/core/SkTypeface.h"
#include "include/private/SkTemplates.h"
class SkReadBuffer;
class SkWriteBuffer;
class SkFontPriv {
/* This is the size we use when we ask for a glyph's path. We then
* post-transform it as we draw to match the request.
* This is done to try to re-use cache entries for the path.
* This value is somewhat arbitrary. In theory, it could be 1, since
* we store paths as floats. However, we get the path from the font
* scaler, and it may represent its paths as fixed-point (or 26.6),
* so we shouldn't ask for something too big (might overflow 16.16)
* or too small (underflow 26.6).
* This value could track kMaxSizeForGlyphCache, assuming the above
* constraints, but since we ask for unhinted paths, the two values
* need not match per-se.
static constexpr int kCanonicalTextSizeForPaths = 64;
* Return a matrix that applies the paint's text values: size, scale, skew
static SkMatrix MakeTextMatrix(SkScalar size, SkScalar scaleX, SkScalar skewX) {
SkMatrix m = SkMatrix::Scale(size * scaleX, size);
if (skewX) {
m.postSkew(skewX, 0);
return m;
static SkMatrix MakeTextMatrix(const SkFont& font) {
return MakeTextMatrix(font.getSize(), font.getScaleX(), font.getSkewX());
static void ScaleFontMetrics(SkFontMetrics*, SkScalar);
Returns the union of bounds of all glyphs.
Returned dimensions are computed by font manager from font data,
ignoring SkPaint::Hinting. Includes font metrics, but not fake bold or SkPathEffect.
If text size is large, text scale is one, and text skew is zero,
returns the bounds as:
{ SkFontMetrics::fXMin, SkFontMetrics::fTop, SkFontMetrics::fXMax, SkFontMetrics::fBottom }.
@return union of bounds of all glyphs
static SkRect GetFontBounds(const SkFont&);
static bool IsFinite(const SkFont& font) {
return SkScalarIsFinite(font.getSize()) &&
SkScalarIsFinite(font.getScaleX()) &&
// Returns the number of elements (characters or glyphs) in the array.
static int CountTextElements(const void* text, size_t byteLength, SkTextEncoding);
static void GlyphsToUnichars(const SkFont&, const uint16_t glyphs[], int count, SkUnichar[]);
static void Flatten(const SkFont&, SkWriteBuffer& buffer);
static bool Unflatten(SkFont*, SkReadBuffer& buffer);
static inline uint8_t Flags(const SkFont& font) { return font.fFlags; }
class SkAutoToGlyphs {
SkAutoToGlyphs(const SkFont& font, const void* text, size_t length, SkTextEncoding encoding) {
if (encoding == SkTextEncoding::kGlyphID || length == 0) {
fGlyphs = reinterpret_cast<const uint16_t*>(text);
fCount = length >> 1;
} else {
fCount = font.countText(text, length, encoding);
if (fCount < 0) {
fCount = 0;
font.textToGlyphs(text, length, encoding, fStorage.get(), fCount);
fGlyphs = fStorage.get();
int count() const { return fCount; }
const uint16_t* glyphs() const { return fGlyphs; }
SkAutoSTArray<32, uint16_t> fStorage;
const uint16_t* fGlyphs;
int fCount;