SkPDF/SkAdvancedTypefaceMetrics: simplify ATM, PDF takes over

src/core/SkAdvancedTypefaceMetrics.cpp

Index: src/core/SkAdvancedTypefaceMetrics.cpp
diff --git a/src/core/SkAdvancedTypefaceMetrics.cpp b/src/core/SkAdvancedTypefaceMetrics.cpp
deleted file mode 100644
index bddd91260c460dcd8013b36cafd2a0de50d0ce86..0000000000000000000000000000000000000000
--- a/src/core/SkAdvancedTypefaceMetrics.cpp
+++ /dev/null
@@ -1,193 +0,0 @@
-/*
- * Copyright 2011 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-
-#include "SkAdvancedTypefaceMetrics.h"
-#include "SkTypes.h"
-
-SkAdvancedTypefaceMetrics::~SkAdvancedTypefaceMetrics() {}
-
-const int16_t kInvalidAdvance = SK_MinS16;
-const int16_t kDontCareAdvance = SK_MinS16 + 1;
-
-static void stripUninterestingTrailingAdvancesFromRange(
-        SkAdvancedTypefaceMetrics::WidthRange* range) {
-    SkASSERT(range);
-
-    int expectedAdvanceCount = range->fEndId - range->fStartId + 1;
-    if (range->fAdvance.count() < expectedAdvanceCount) {
-        return;
-    }
-
-    for (int i = expectedAdvanceCount - 1; i >= 0; --i) {
-        if (range->fAdvance[i] != kDontCareAdvance &&
-            range->fAdvance[i] != kInvalidAdvance &&
-            range->fAdvance[i] != 0) {
-            range->fEndId = range->fStartId + i;
-            break;
-        }
-    }
-}
-
-static void zeroWildcardsInRange(SkAdvancedTypefaceMetrics::WidthRange* range) {
-    SkASSERT(range);
-    if (range->fType != SkAdvancedTypefaceMetrics::WidthRange::kRange) {
-        return;
-    }
-    SkASSERT(range->fAdvance.count() == range->fEndId - range->fStartId + 1);
-
-    // Zero out wildcards.
-    for (int i = 0; i < range->fAdvance.count(); ++i) {
-        if (range->fAdvance[i] == kDontCareAdvance) {
-            range->fAdvance[i] = 0;
-        }
-    }
-}
-
-void SkAdvancedTypefaceMetrics::FinishRange(
-        SkAdvancedTypefaceMetrics::WidthRange* range,
-        int endId,
-        SkAdvancedTypefaceMetrics::WidthRange::MetricType type) {
-    range->fEndId = endId;
-    range->fType = type;
-    stripUninterestingTrailingAdvancesFromRange(range);
-    int newLength;
-    if (type == SkAdvancedTypefaceMetrics::WidthRange::kRange) {
-        newLength = range->fEndId - range->fStartId + 1;
-    } else {
-        if (range->fEndId == range->fStartId) {
-            range->fType = SkAdvancedTypefaceMetrics::WidthRange::kRange;
-        }
-        newLength = 1;
-    }
-    SkASSERT(range->fAdvance.count() >= newLength);
-    range->fAdvance.setCount(newLength);
-    zeroWildcardsInRange(range);
-}
-
-void SkAdvancedTypefaceMetrics::setGlyphWidths(
-        int num_glyphs,
-        const uint32_t* subsetGlyphIDs,
-        uint32_t subsetGlyphIDsLength,
-        SkAdvancedTypefaceMetrics::GetAdvance getAdvance) {
-    // Assuming that on average, the ASCII representation of an advance plus
-    // a space is 8 characters and the ASCII representation of a glyph id is 3
-    // characters, then the following cut offs for using different range types
-    // apply:
-    // The cost of stopping and starting the range is 7 characers
-    //  a. Removing 4 0's or don't care's is a win
-    // The cost of stopping and starting the range plus a run is 22
-    // characters
-    //  b. Removing 3 repeating advances is a win
-    //  c. Removing 2 repeating advances and 3 don't cares is a win
-    // When not currently in a range the cost of a run over a range is 16
-    // characaters, so:
-    //  d. Removing a leading 0/don't cares is a win because it is omitted
-    //  e. Removing 2 repeating advances is a win
-
-    WidthRange* prevRange = nullptr;
-    int16_t lastAdvance = kInvalidAdvance;
-    int repeatedAdvances = 0;
-    int wildCardsInRun = 0;
-    int trailingWildCards = 0;
-    uint32_t subsetIndex = 0;
-
-    // Limit the loop count to glyph id ranges provided.
-    int firstIndex = 0;
-    int lastIndex = num_glyphs;
-    if (subsetGlyphIDs) {
-        firstIndex = static_cast<int>(subsetGlyphIDs[0]);
-        lastIndex =
-                static_cast<int>(subsetGlyphIDs[subsetGlyphIDsLength - 1]) + 1;
-    }
-    WidthRange curRange(firstIndex);
-
-    for (int gId = firstIndex; gId <= lastIndex; gId++) {
-        int16_t advance = kInvalidAdvance;
-        if (gId < lastIndex) {
-            // Get glyph id only when subset is nullptr, or the id is in subset.
-            SkASSERT(!subsetGlyphIDs || (subsetIndex < subsetGlyphIDsLength &&
-                    static_cast<uint32_t>(gId) <= subsetGlyphIDs[subsetIndex]));
-            if (!subsetGlyphIDs ||
-                (subsetIndex < subsetGlyphIDsLength &&
-                 static_cast<uint32_t>(gId) == subsetGlyphIDs[subsetIndex])) {
-                SkAssertResult(getAdvance(gId, &advance));
-                ++subsetIndex;
-            } else {
-                advance = kDontCareAdvance;
-            }
-        }
-        if (advance == lastAdvance) {
-            repeatedAdvances++;
-            trailingWildCards = 0;
-        } else if (advance == kDontCareAdvance) {
-            wildCardsInRun++;
-            trailingWildCards++;
-        } else if (curRange.fAdvance.count() ==
-                   repeatedAdvances + 1 + wildCardsInRun) {  // All in run.
-            if (lastAdvance == 0) {
-                curRange.fStartId = gId;  // reset
-                curRange.fAdvance.setCount(0);
-                trailingWildCards = 0;
-            } else if (repeatedAdvances + 1 >= 2 || trailingWildCards >= 4) {
-                FinishRange(&curRange, gId - 1, WidthRange::kRun);
-                prevRange = fGlyphWidths.emplace_back(std::move(curRange));
-                curRange = WidthRange(gId);
-                trailingWildCards = 0;
-            }
-            repeatedAdvances = 0;
-            wildCardsInRun = trailingWildCards;
-            trailingWildCards = 0;
-        } else {
-            if (lastAdvance == 0 &&
-                    repeatedAdvances + 1 + wildCardsInRun >= 4) {
-                FinishRange(&curRange,
-                            gId - repeatedAdvances - wildCardsInRun - 2,
-                            WidthRange::kRange);
-                prevRange = fGlyphWidths.emplace_back(std::move(curRange));
-                curRange = WidthRange(gId);
-                trailingWildCards = 0;
-            } else if (trailingWildCards >= 4 && repeatedAdvances + 1 < 2) {
-                FinishRange(&curRange, gId - trailingWildCards - 1,
-                            WidthRange::kRange);
-                prevRange = fGlyphWidths.emplace_back(std::move(curRange));
-                curRange = WidthRange(gId);
-                trailingWildCards = 0;
-            } else if (lastAdvance != 0 &&
-                       (repeatedAdvances + 1 >= 3 ||
-                        (repeatedAdvances + 1 >= 2 && wildCardsInRun >= 3))) {
-                FinishRange(&curRange,
-                            gId - repeatedAdvances - wildCardsInRun - 2,
-                            WidthRange::kRange);
-                (void)fGlyphWidths.emplace_back(std::move(curRange));
-                curRange =
-                        WidthRange(gId - repeatedAdvances - wildCardsInRun - 1);
-                curRange.fAdvance.append(1, &lastAdvance);
-                FinishRange(&curRange, gId - 1, WidthRange::kRun);
-                prevRange = fGlyphWidths.emplace_back(std::move(curRange));
-                curRange = WidthRange(gId);
-                trailingWildCards = 0;
-            }
-            repeatedAdvances = 0;
-            wildCardsInRun = trailingWildCards;
-            trailingWildCards = 0;
-        }
-        curRange.fAdvance.append(1, &advance);
-        if (advance != kDontCareAdvance) {
-            lastAdvance = advance;
-        }
-    }
-    if (curRange.fStartId == lastIndex) {
-        if (!prevRange) {
-            fGlyphWidths.reset();
-            return;  // https://crbug.com/567031
-        }
-    } else {
-        FinishRange(&curRange, lastIndex - 1, WidthRange::kRange);
-        fGlyphWidths.emplace_back(std::move(curRange));
-    }
-}