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esphome/esphome/components/font/font.cpp

289 lines
8.5 KiB
C++

#include "font.h"
#include "esphome/core/color.h"
#include "esphome/core/hal.h"
#include "esphome/core/log.h"
namespace esphome {
namespace font {
static const char *const TAG = "font";
#ifdef USE_LVGL_FONT
const uint8_t *Font::get_glyph_bitmap(const lv_font_t *font, uint32_t unicode_letter) {
auto *fe = (Font *) font->dsc;
const auto *gd = fe->get_glyph_data_(unicode_letter);
if (gd == nullptr) {
return nullptr;
}
return gd->data;
}
bool Font::get_glyph_dsc_cb(const lv_font_t *font, lv_font_glyph_dsc_t *dsc, uint32_t unicode_letter, uint32_t next) {
auto *fe = (Font *) font->dsc;
const auto *gd = fe->get_glyph_data_(unicode_letter);
if (gd == nullptr) {
return false;
}
dsc->adv_w = gd->advance;
dsc->ofs_x = gd->offset_x;
dsc->ofs_y = fe->height_ - gd->height - gd->offset_y - fe->lv_font_.base_line;
dsc->box_w = gd->width;
dsc->box_h = gd->height;
dsc->is_placeholder = 0;
dsc->bpp = fe->get_bpp();
return true;
}
const Glyph *Font::get_glyph_data_(uint32_t unicode_letter) {
if (unicode_letter == this->last_letter_ && this->last_letter_ != 0)
return this->last_data_;
auto *glyph = this->find_glyph(unicode_letter);
if (glyph == nullptr) {
return nullptr;
}
this->last_data_ = glyph;
this->last_letter_ = unicode_letter;
return glyph;
}
#endif
/**
* Attempt to extract a 32 bit Unicode codepoint from a UTF-8 string.
* If successful, return the codepoint and set the length to the number of bytes read.
* If the end of the string has been reached and a valid codepoint has not been found, return 0 and set the length to
* 0.
*
* @param utf8_str The input string
* @param length Pointer to length storage
* @return The extracted code point
*/
static uint32_t extract_unicode_codepoint(const char *utf8_str, size_t *length) {
// Safely cast to uint8_t* for correct bitwise operations on bytes
const uint8_t *current = reinterpret_cast<const uint8_t *>(utf8_str);
uint32_t code_point = 0;
uint8_t c1 = *current++;
// check for end of string
if (c1 == 0) {
*length = 0;
return 0;
}
// --- 1-Byte Sequence: 0xxxxxxx (ASCII) ---
if (c1 < 0x80) {
// Valid ASCII byte.
code_point = c1;
// Optimization: No need to check for continuation bytes.
}
// --- 2-Byte Sequence: 110xxxxx 10xxxxxx ---
else if ((c1 & 0xE0) == 0xC0) {
uint8_t c2 = *current++;
// Error Check 1: Check if c2 is a valid continuation byte (10xxxxxx)
if ((c2 & 0xC0) != 0x80) {
*length = 0;
return 0;
}
code_point = (c1 & 0x1F) << 6;
code_point |= (c2 & 0x3F);
// Error Check 2: Overlong check (2-byte must be > 0x7F)
if (code_point <= 0x7F) {
*length = 0;
return 0;
}
}
// --- 3-Byte Sequence: 1110xxxx 10xxxxxx 10xxxxxx ---
else if ((c1 & 0xF0) == 0xE0) {
uint8_t c2 = *current++;
uint8_t c3 = *current++;
// Error Check 1: Check continuation bytes
if (((c2 & 0xC0) != 0x80) || ((c3 & 0xC0) != 0x80)) {
*length = 0;
return 0;
}
code_point = (c1 & 0x0F) << 12;
code_point |= (c2 & 0x3F) << 6;
code_point |= (c3 & 0x3F);
// Error Check 2: Overlong check (3-byte must be > 0x7FF)
// Also check for surrogates (0xD800-0xDFFF)
if (code_point <= 0x7FF || (code_point >= 0xD800 && code_point <= 0xDFFF)) {
*length = 0;
return 0;
}
}
// --- 4-Byte Sequence: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx ---
else if ((c1 & 0xF8) == 0xF0) {
uint8_t c2 = *current++;
uint8_t c3 = *current++;
uint8_t c4 = *current++;
// Error Check 1: Check continuation bytes
if (((c2 & 0xC0) != 0x80) || ((c3 & 0xC0) != 0x80) || ((c4 & 0xC0) != 0x80)) {
*length = 0;
return 0;
}
code_point = (c1 & 0x07) << 18;
code_point |= (c2 & 0x3F) << 12;
code_point |= (c3 & 0x3F) << 6;
code_point |= (c4 & 0x3F);
// Error Check 2: Overlong check (4-byte must be > 0xFFFF)
// Also check for valid Unicode range (must be <= 0x10FFFF)
if (code_point <= 0xFFFF || code_point > 0x10FFFF) {
*length = 0;
return 0;
}
}
// --- Invalid leading byte (e.g., 10xxxxxx or 11111xxx) ---
else {
*length = 0;
return 0;
}
*length = current - reinterpret_cast<const uint8_t *>(utf8_str);
return code_point;
}
Font::Font(const Glyph *data, int data_nr, int baseline, int height, int descender, int xheight, int capheight,
uint8_t bpp)
: glyphs_(ConstVector(data, data_nr)),
baseline_(baseline),
height_(height),
descender_(descender),
linegap_(height - baseline - descender),
xheight_(xheight),
capheight_(capheight),
bpp_(bpp) {
#ifdef USE_LVGL_FONT
this->lv_font_.dsc = this;
this->lv_font_.line_height = this->get_height();
this->lv_font_.base_line = this->lv_font_.line_height - this->get_baseline();
this->lv_font_.get_glyph_dsc = get_glyph_dsc_cb;
this->lv_font_.get_glyph_bitmap = get_glyph_bitmap;
this->lv_font_.subpx = LV_FONT_SUBPX_NONE;
this->lv_font_.underline_position = -1;
this->lv_font_.underline_thickness = 1;
#endif
}
const Glyph *Font::find_glyph(uint32_t codepoint) const {
int lo = 0;
int hi = this->glyphs_.size() - 1;
while (lo != hi) {
int mid = (lo + hi + 1) / 2;
if (this->glyphs_[mid].is_less_or_equal(codepoint)) {
lo = mid;
} else {
hi = mid - 1;
}
}
auto *result = &this->glyphs_[lo];
if (result->code_point == codepoint)
return result;
return nullptr;
}
#ifdef USE_DISPLAY
void Font::measure(const char *str, int *width, int *x_offset, int *baseline, int *height) {
*baseline = this->baseline_;
*height = this->height_;
int min_x = 0;
bool has_char = false;
int x = 0;
for (;;) {
size_t length;
auto code_point = extract_unicode_codepoint(str, &length);
if (length == 0)
break;
str += length;
auto *glyph = this->find_glyph(code_point);
if (glyph == nullptr) {
// Unknown char, skip
if (!this->glyphs_.empty())
x += this->glyphs_[0].advance;
continue;
}
if (!has_char) {
min_x = glyph->offset_x;
} else {
min_x = std::min(min_x, x + glyph->offset_x);
}
x += glyph->advance;
has_char = true;
}
*x_offset = min_x;
*width = x - min_x;
}
void Font::print(int x_start, int y_start, display::Display *display, Color color, const char *text, Color background) {
int x_at = x_start;
for (;;) {
size_t length;
auto code_point = extract_unicode_codepoint(text, &length);
if (length == 0)
break;
text += length;
auto *glyph = this->find_glyph(code_point);
if (glyph == nullptr) {
// Unknown char, skip
ESP_LOGW(TAG, "Codepoint 0x%08" PRIx32 " not found in font", code_point);
if (!this->glyphs_.empty()) {
uint8_t glyph_width = this->glyphs_[0].advance;
display->rectangle(x_at, y_start, glyph_width, this->height_, color);
x_at += glyph_width;
}
continue;
}
const uint8_t *data = glyph->data;
const int max_x = x_at + glyph->offset_x + glyph->width;
const int max_y = y_start + glyph->offset_y + glyph->height;
uint8_t bitmask = 0;
uint8_t pixel_data = 0;
uint8_t bpp_max = (1 << this->bpp_) - 1;
auto diff_r = (float) color.r - (float) background.r;
auto diff_g = (float) color.g - (float) background.g;
auto diff_b = (float) color.b - (float) background.b;
auto diff_w = (float) color.w - (float) background.w;
auto b_r = (float) background.r;
auto b_g = (float) background.g;
auto b_b = (float) background.b;
auto b_w = (float) background.w;
for (int glyph_y = y_start + glyph->offset_y; glyph_y != max_y; glyph_y++) {
for (int glyph_x = x_at + glyph->offset_x; glyph_x != max_x; glyph_x++) {
uint8_t pixel = 0;
for (uint8_t bit_num = 0; bit_num != this->bpp_; bit_num++) {
if (bitmask == 0) {
pixel_data = progmem_read_byte(data++);
bitmask = 0x80;
}
pixel <<= 1;
if ((pixel_data & bitmask) != 0)
pixel |= 1;
bitmask >>= 1;
}
if (pixel == bpp_max) {
display->draw_pixel_at(glyph_x, glyph_y, color);
} else if (pixel != 0) {
auto on = (float) pixel / (float) bpp_max;
auto blended = Color((uint8_t) (diff_r * on + b_r), (uint8_t) (diff_g * on + b_g),
(uint8_t) (diff_b * on + b_b), (uint8_t) (diff_w * on + b_w));
display->draw_pixel_at(glyph_x, glyph_y, blended);
}
}
}
x_at += glyph->advance;
}
}
#endif
} // namespace font
} // namespace esphome