Begin switch to SkFontStyle for legacy calls.

This adds SK_VERY_LEGACY_CREATE_TYPEFACE which, when defined, provides
only the old interface.

Ideally, everyone would switch directly to SkFontMgr and use one of the
newer calls, but there is currently no path for current users to get
there. This updates all the internals to use SkFontStyle, after
switching these over the higher level APIs can be switched.

The Chromium follow on patch can be seen at https://crrev.com/1877673002

GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1873923002

TBR=reed
This doesn't really change API, just modernizes it.

Review URL: https://codereview.chromium.org/1873923002

1 files changed, 145 insertions, 0 deletions

diff --git a/src/ports/SkFontConfigInterface_direct.cpp b/src/ports/SkFontConfigInterface_direct.cpp
index f5f494986b..1c42e2d37e 100644
--- a/src/ports/SkFontConfigInterface_direct.cpp
+++ b/src/ports/SkFontConfigInterface_direct.cpp
@@ -9,6 +9,7 @@
 
 #include "SkBuffer.h"
 #include "SkDataTable.h"
+#include "SkFixed.h"
 #include "SkFontConfigInterface_direct.h"
 #include "SkFontStyle.h"
 #include "SkMutex.h"
@@ -304,6 +305,7 @@ bool IsFallbackFontAllowed(const SkString& family) {
 }
 
 // Retrieves |is_bold|, |is_italic| and |font_family| properties from |font|.
+#ifdef SK_VERY_LEGACY_CREATE_TYPEFACE
 SkTypeface::Style GetFontStyle(FcPattern* font) {
     int resulting_bold;
     if (FcPatternGetInteger(font, FC_WEIGHT, 0, &resulting_bold))
@@ -335,6 +337,136 @@ SkTypeface::Style GetFontStyle(FcPattern* font) {
 
     return (SkTypeface::Style)styleBits;
 }
+#else
+
+static int get_int(FcPattern* pattern, const char object[], int missing) {
+    int value;
+    if (FcPatternGetInteger(pattern, object, 0, &value) != FcResultMatch) {
+        return missing;
+    }
+    return value;
+}
+
+static int map_range(SkFixed value,
+                     SkFixed old_min, SkFixed old_max,
+                     SkFixed new_min, SkFixed new_max)
+{
+    SkASSERT(old_min < old_max);
+    SkASSERT(new_min <= new_max);
+    return new_min + SkMulDiv(value - old_min, new_max - new_min, old_max - old_min);
+}
+
+struct MapRanges {
+    SkFixed old_val;
+    SkFixed new_val;
+};
+
+static SkFixed map_ranges_fixed(SkFixed val, MapRanges const ranges[], int rangesCount) {
+    // -Inf to [0]
+    if (val < ranges[0].old_val) {
+        return ranges[0].new_val;
+    }
+
+    // Linear from [i] to [i+1]
+    for (int i = 0; i < rangesCount - 1; ++i) {
+        if (val < ranges[i+1].old_val) {
+            return map_range(val, ranges[i].old_val, ranges[i+1].old_val,
+                                  ranges[i].new_val, ranges[i+1].new_val);
+        }
+    }
+
+    // From [n] to +Inf
+    // if (fcweight < Inf)
+    return ranges[rangesCount-1].new_val;
+}
+
+static int map_ranges(int val, MapRanges const ranges[], int rangesCount) {
+    return SkFixedRoundToInt(map_ranges_fixed(SkIntToFixed(val), ranges, rangesCount));
+}
+
+template<int n> struct SkTFixed {
+    static_assert(-32768 <= n && n <= 32767, "SkTFixed_n_not_in_range");
+    static const SkFixed value = static_cast<SkFixed>(n << 16);
+};
+
+static SkFontStyle skfontstyle_from_fcpattern(FcPattern* pattern) {
+    typedef SkFontStyle SkFS;
+
+    static const MapRanges weightRanges[] = {
+        { SkTFixed<FC_WEIGHT_THIN>::value,       SkTFixed<SkFS::kThin_Weight>::value },
+        { SkTFixed<FC_WEIGHT_EXTRALIGHT>::value, SkTFixed<SkFS::kExtraLight_Weight>::value },
+        { SkTFixed<FC_WEIGHT_LIGHT>::value,      SkTFixed<SkFS::kLight_Weight>::value },
+        { SkTFixed<FC_WEIGHT_REGULAR>::value,    SkTFixed<SkFS::kNormal_Weight>::value },
+        { SkTFixed<FC_WEIGHT_MEDIUM>::value,     SkTFixed<SkFS::kMedium_Weight>::value },
+        { SkTFixed<FC_WEIGHT_DEMIBOLD>::value,   SkTFixed<SkFS::kSemiBold_Weight>::value },
+        { SkTFixed<FC_WEIGHT_BOLD>::value,       SkTFixed<SkFS::kBold_Weight>::value },
+        { SkTFixed<FC_WEIGHT_EXTRABOLD>::value,  SkTFixed<SkFS::kExtraBold_Weight>::value },
+        { SkTFixed<FC_WEIGHT_BLACK>::value,      SkTFixed<SkFS::kBlack_Weight>::value },
+        { SkTFixed<FC_WEIGHT_EXTRABLACK>::value, SkTFixed<1000>::value },
+    };
+    int weight = map_ranges(get_int(pattern, FC_WEIGHT, FC_WEIGHT_REGULAR),
+                            weightRanges, SK_ARRAY_COUNT(weightRanges));
+
+    static const MapRanges widthRanges[] = {
+        { SkTFixed<FC_WIDTH_ULTRACONDENSED>::value, SkTFixed<SkFS::kUltraCondensed_Width>::value },
+        { SkTFixed<FC_WIDTH_EXTRACONDENSED>::value, SkTFixed<SkFS::kExtraCondensed_Width>::value },
+        { SkTFixed<FC_WIDTH_CONDENSED>::value,      SkTFixed<SkFS::kCondensed_Width>::value },
+        { SkTFixed<FC_WIDTH_SEMICONDENSED>::value,  SkTFixed<SkFS::kSemiCondensed_Width>::value },
+        { SkTFixed<FC_WIDTH_NORMAL>::value,         SkTFixed<SkFS::kNormal_Width>::value },
+        { SkTFixed<FC_WIDTH_SEMIEXPANDED>::value,   SkTFixed<SkFS::kSemiExpanded_Width>::value },
+        { SkTFixed<FC_WIDTH_EXPANDED>::value,       SkTFixed<SkFS::kExpanded_Width>::value },
+        { SkTFixed<FC_WIDTH_EXTRAEXPANDED>::value,  SkTFixed<SkFS::kExtraExpanded_Width>::value },
+        { SkTFixed<FC_WIDTH_ULTRAEXPANDED>::value,  SkTFixed<SkFS::kUltaExpanded_Width>::value },
+    };
+    int width = map_ranges(get_int(pattern, FC_WIDTH, FC_WIDTH_NORMAL),
+                           widthRanges, SK_ARRAY_COUNT(widthRanges));
+
+    SkFS::Slant slant = get_int(pattern, FC_SLANT, FC_SLANT_ROMAN) > 0
+                             ? SkFS::kItalic_Slant
+                             : SkFS::kUpright_Slant;
+
+    return SkFontStyle(weight, width, slant);
+}
+
+static void fcpattern_from_skfontstyle(SkFontStyle style, FcPattern* pattern) {
+    typedef SkFontStyle SkFS;
+
+    static const MapRanges weightRanges[] = {
+        { SkTFixed<SkFS::kThin_Weight>::value,       SkTFixed<FC_WEIGHT_THIN>::value },
+        { SkTFixed<SkFS::kExtraLight_Weight>::value, SkTFixed<FC_WEIGHT_EXTRALIGHT>::value },
+        { SkTFixed<SkFS::kLight_Weight>::value,      SkTFixed<FC_WEIGHT_LIGHT>::value },
+        { SkTFixed<SkFS::kNormal_Weight>::value,     SkTFixed<FC_WEIGHT_REGULAR>::value },
+        { SkTFixed<SkFS::kMedium_Weight>::value,     SkTFixed<FC_WEIGHT_MEDIUM>::value },
+        { SkTFixed<SkFS::kSemiBold_Weight>::value,   SkTFixed<FC_WEIGHT_DEMIBOLD>::value },
+        { SkTFixed<SkFS::kBold_Weight>::value,       SkTFixed<FC_WEIGHT_BOLD>::value },
+        { SkTFixed<SkFS::kExtraBold_Weight>::value,  SkTFixed<FC_WEIGHT_EXTRABOLD>::value },
+        { SkTFixed<SkFS::kBlack_Weight>::value,      SkTFixed<FC_WEIGHT_BLACK>::value },
+        { SkTFixed<1000>::value,                     SkTFixed<FC_WEIGHT_EXTRABLACK>::value },
+    };
+    int weight = map_ranges(style.weight(), weightRanges, SK_ARRAY_COUNT(weightRanges));
+
+    static const MapRanges widthRanges[] = {
+        { SkTFixed<SkFS::kUltraCondensed_Width>::value, SkTFixed<FC_WIDTH_ULTRACONDENSED>::value },
+        { SkTFixed<SkFS::kExtraCondensed_Width>::value, SkTFixed<FC_WIDTH_EXTRACONDENSED>::value },
+        { SkTFixed<SkFS::kCondensed_Width>::value,      SkTFixed<FC_WIDTH_CONDENSED>::value },
+        { SkTFixed<SkFS::kSemiCondensed_Width>::value,  SkTFixed<FC_WIDTH_SEMICONDENSED>::value },
+        { SkTFixed<SkFS::kNormal_Width>::value,         SkTFixed<FC_WIDTH_NORMAL>::value },
+        { SkTFixed<SkFS::kSemiExpanded_Width>::value,   SkTFixed<FC_WIDTH_SEMIEXPANDED>::value },
+        { SkTFixed<SkFS::kExpanded_Width>::value,       SkTFixed<FC_WIDTH_EXPANDED>::value },
+        { SkTFixed<SkFS::kExtraExpanded_Width>::value,  SkTFixed<FC_WIDTH_EXTRAEXPANDED>::value },
+        { SkTFixed<SkFS::kUltaExpanded_Width>::value,   SkTFixed<FC_WIDTH_ULTRAEXPANDED>::value },
+    };
+    int width = map_ranges(style.width(), widthRanges, SK_ARRAY_COUNT(widthRanges));
+
+    FcPatternAddInteger(pattern, FC_WEIGHT, weight);
+    FcPatternAddInteger(pattern, FC_WIDTH, width);
+    FcPatternAddInteger(pattern, FC_SLANT, style.isItalic() ? FC_SLANT_ITALIC : FC_SLANT_ROMAN);
+}
+
+SkFontStyle GetFontStyle(FcPattern* font) {
+    return skfontstyle_from_fcpattern(font);
+}
+#endif
 
 }  // anonymous namespace
 
@@ -417,11 +549,19 @@ FcPattern* SkFontConfigInterfaceDirect::MatchFont(FcFontSet* font_set,
   return match;
 }
 
+#ifdef SK_VERY_LEGACY_CREATE_TYPEFACE
 bool SkFontConfigInterfaceDirect::matchFamilyName(const char familyName[],
                                                   SkTypeface::Style style,
                                                   FontIdentity* outIdentity,
                                                   SkString* outFamilyName,
                                                   SkTypeface::Style* outStyle) {
+#else
+bool SkFontConfigInterfaceDirect::matchFamilyName(const char familyName[],
+                                                  SkFontStyle style,
+                                                  FontIdentity* outIdentity,
+                                                  SkString* outFamilyName,
+                                                  SkFontStyle* outStyle) {
+#endif
     SkString familyStr(familyName ? familyName : "");
     if (familyStr.size() > kMaxFontFamilyLength) {
         return false;
@@ -434,12 +574,17 @@ bool SkFontConfigInterfaceDirect::matchFamilyName(const char familyName[],
     if (familyName) {
         FcPatternAddString(pattern, FC_FAMILY, (FcChar8*)familyName);
     }
+#ifdef SK_VERY_LEGACY_CREATE_TYPEFACE
     FcPatternAddInteger(pattern, FC_WEIGHT,
                         (style & SkTypeface::kBold) ? FC_WEIGHT_BOLD
                                                     : FC_WEIGHT_NORMAL);
     FcPatternAddInteger(pattern, FC_SLANT,
                         (style & SkTypeface::kItalic) ? FC_SLANT_ITALIC
                                                       : FC_SLANT_ROMAN);
+#else
+    fcpattern_from_skfontstyle(style, pattern);
+#endif
+
     FcPatternAddBool(pattern, FC_SCALABLE, FcTrue);
 
     FcConfigSubstitute(nullptr, pattern, FcMatchPattern);