86 lines
2.1 KiB
C++

#include "EpdFont.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 {
*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);
if (!glyph) {
// TODO: Replace with fallback glyph property?
glyph = getGlyph('?');
}
if (!glyph) {
// TODO: Better handle this?
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 {
int minX = 0, minY = 0, maxX = 0, maxY = 0;
getTextBounds(string, 0, 0, &minX, &minY, &maxX, &maxY);
*w = maxX - minX;
*h = maxY - minY;
}
bool EpdFont::hasPrintableChars(const char* string) const {
int w = 0, h = 0;
getTextDimensions(string, &w, &h);
return w > 0 || h > 0;
}
const EpdGlyph* EpdFont::getGlyph(const uint32_t cp) const {
const EpdUnicodeInterval* intervals = data->intervals;
const int count = data->intervalCount;
if (count == 0) return nullptr;
// Binary search for O(log n) lookup instead of O(n)
// Critical for Korean fonts with many unicode intervals
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 {
// Found: cp >= interval->first && cp <= interval->last
return &data->glyph[interval->offset + (cp - interval->first)];
}
}
return nullptr;
}