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A fork of https://github.com/crosspoint-reader/crosspoint-reader
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3.3 kB · 85 lines
C
at master
1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586#pragma once
#include <InflateReader.h>
#include <vector>
#include "EpdFontData.h"
class FontDecompressor { public: static constexpr uint16_t MAX_PAGE_GLYPHS = 512; static constexpr uint8_t MAX_PAGE_SLOTS = 4; // One per font style (R/B/I/BI)
FontDecompressor() = default; ~FontDecompressor();
bool init(); void deinit();
// Returns pointer to decompressed bitmap data for the given glyph. // Checks the page buffer (from prewarm) first, then falls back to the hot group slot. const uint8_t* getBitmap(const EpdFontData* fontData, const EpdGlyph* glyph, uint32_t glyphIndex);
// Free all cached data (page buffer + hot group). void clearCache();
// Pre-scan UTF-8 text and extract needed glyph bitmaps into a flat page buffer. // Each group is decompressed once into a temp buffer; only needed glyphs are kept. // Returns the number of glyphs that couldn't be loaded (0 on full success). int prewarmCache(const EpdFontData* fontData, const char* utf8Text);
struct Stats { uint32_t cacheHits = 0; uint32_t cacheMisses = 0; uint32_t decompressTimeMs = 0; uint16_t uniqueGroupsAccessed = 0; uint32_t pageBufferBytes = 0; // pageBuffer allocation uint32_t pageGlyphsBytes = 0; // pageGlyphs lookup table allocation uint32_t hotGroupBytes = 0; // current hot group allocation uint32_t peakTempBytes = 0; // largest temp buffer in prewarm uint32_t getBitmapTimeUs = 0; // cumulative getBitmap time (micros) uint32_t getBitmapCalls = 0; // number of getBitmap calls }; void logStats(const char* label = "FDC"); void resetStats(); const Stats& getStats() const { return stats; }
private: Stats stats; InflateReader inflateReader;
// Page buffer slots: each style gets its own flat glyph buffer with sorted lookup. // Up to MAX_PAGE_SLOTS (4) styles can be prewarmed simultaneously. struct PageGlyphEntry { uint32_t glyphIndex; uint32_t bufferOffset; uint32_t alignedOffset; // byte-aligned offset within its decompressed group (set during prewarm pre-scan) }; struct PageSlot { uint8_t* buffer = nullptr; const EpdFontData* fontData = nullptr; PageGlyphEntry* glyphs = nullptr; uint16_t glyphCount = 0; }; PageSlot pageSlots[MAX_PAGE_SLOTS] = {}; uint8_t pageSlotCount = 0;
// Hot group: last decompressed group (byte-aligned) for non-prewarmed fallback path. // Kept in byte-aligned format; individual glyphs are compacted on demand into hotGlyphBuf. const EpdFontData* hotGroupFont = nullptr; uint16_t hotGroupIndex = UINT16_MAX; std::vector<uint8_t> hotGroup;
// Scratch buffer for compacting a single glyph from the hot group. // Valid until the next getBitmap() call. std::vector<uint8_t> hotGlyphBuf;
void freePageBuffer(); void freeHotGroup(); uint16_t getGroupIndex(const EpdFontData* fontData, uint32_t glyphIndex); uint32_t getAlignedOffset(const EpdFontData* fontData, uint16_t groupIndex, uint32_t glyphIndex); bool decompressGroup(const EpdFontData* fontData, uint16_t groupIndex, uint8_t* outBuf, uint32_t outSize); static void compactSingleGlyph(const uint8_t* alignedSrc, uint8_t* packedDst, uint8_t width, uint8_t height); static int32_t findGlyphIndex(const EpdFontData* fontData, uint32_t codepoint);};