Xteink-X4-crosspoint-reader/lib/EpdFont/EpdFont.cpp

#include "EpdFont.h"

#include <Arduino.h>
#include <Utf8.h>

#include <algorithm>

void EpdFont::getTextBounds(const char* string, const int startX, const int startY, int* minX, int* minY, int* maxX,
                            int* maxY, const EpdFontStyles::Style style) const {
  *minX = startX;
  *minY = startY;
  *maxX = startX;
  *maxY = startY;

  if (*string == '\0') {
    return;
  }

  int cursorX = startX;
  const int cursorY = startY;
  uint32_t cp;
  while ((cp = utf8NextCodepoint(reinterpret_cast<const uint8_t**>(&string)))) {
    const EpdGlyph* glyph = getGlyph(cp, style);

    if (!glyph) {
      glyph = getGlyph('?', style);
    }

    if (!glyph) {
      continue;
    }

    *minX = std::min(*minX, cursorX + glyph->left);
    *maxX = std::max(*maxX, cursorX + glyph->left + glyph->width);
    *minY = std::min(*minY, cursorY + glyph->top - glyph->height);
    *maxY = std::max(*maxY, cursorY + glyph->top);
    cursorX += glyph->advanceX;
  }
}

void EpdFont::getTextDimensions(const char* string, int* w, int* h, const EpdFontStyles::Style style) const {
  int minX = 0, minY = 0, maxX = 0, maxY = 0;

  getTextBounds(string, 0, 0, &minX, &minY, &maxX, &maxY, style);

  *w = maxX - minX;
  *h = maxY - minY;
}

int EpdFont::getTextAdvance(const char* string, const EpdFontStyles::Style style) const {
  if (string == nullptr || *string == '\0') {
    return 0;
  }

  int advance = 0;
  uint32_t cp;
  while ((cp = utf8NextCodepoint(reinterpret_cast<const uint8_t**>(&string)))) {
    const EpdGlyph* glyph = getGlyph(cp, style);
    if (!glyph) {
      glyph = getGlyph('?', style);
    }
    if (glyph) {
      advance += glyph->advanceX;
    }
  }
  return advance;
}

bool EpdFont::hasPrintableChars(const char* string, const EpdFontStyles::Style style) const {
  int w = 0, h = 0;

  getTextDimensions(string, &w, &h, style);

  return w > 0 || h > 0;
}

const EpdGlyph* EpdFont::getGlyph(const uint32_t cp, const EpdFontStyles::Style style) const {
  const EpdFontData* data = getData(style);
  if (!data) return nullptr;

  const EpdUnicodeInterval* intervals = data->intervals;
  const int count = data->intervalCount;

  if (count == 0) return nullptr;

  int left = 0;
  int right = count - 1;

  while (left <= right) {
    const int mid = left + (right - left) / 2;
    const EpdUnicodeInterval* interval = &intervals[mid];

    if (cp < interval->first) {
      right = mid - 1;
    } else if (cp > interval->last) {
      left = mid + 1;
    } else {
      if (data->glyph) {
        return &data->glyph[interval->offset + (cp - interval->first)];
      }
      return nullptr;
    }
  }

  return nullptr;
}

const uint8_t* EpdFont::loadGlyphBitmap(const EpdGlyph* glyph, uint8_t* buffer,
                                        const EpdFontStyles::Style style) const {
  const EpdFontData* data = getData(style);
  if (!data || !data->bitmap) return nullptr;
  return data->bitmap + glyph->dataOffset;
}