ardupilot/libraries/AP_OSD/AP_OSD_Backend.cpp

127 lines
3.9 KiB
C++

/*
* This file is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This file is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include <AP_OSD/AP_OSD_Backend.h>
#include <AP_HAL/Util.h>
#include <GCS_MAVLink/GCS.h>
#include <ctype.h>
extern const AP_HAL::HAL& hal;
constexpr uint8_t AP_OSD_Backend::symbols[AP_OSD_NUM_SYMBOLS];
#define SYM_DIG_OFS_1 0x90
#define SYM_DIG_OFS_2 0xA0
uint8_t AP_OSD_Backend::convert_to_decimal_packed_characters(char* buff, uint8_t size) {
if (size == 0) {
return 0;
}
#if OSD_ENABLED
// use packed decimal characters based on fiam idea implemented in inav osd
// search the decimal separator with a bound and always terminate the string
char* p = (char*)memchr(&buff[1],'.',size-1);
if (p && isdigit(p[1]) && isdigit(p[-1])) {
// remove the decimal separator and replace the digit before and after
p[-1] += SYM_DIG_OFS_1;
p[1] += SYM_DIG_OFS_2;
// shift anything after p[1] 1 character to the left
const char* move_start = p+1;
const uint8_t move_size = size-(move_start-buff);
memmove(p, move_start, move_size);
p[move_size] = 0x00; // terminate
return size-1;
}
#else
// we guarantee string is terminated
buff[size-1] = 0x00;
#endif
return size;
}
uint8_t AP_OSD_Backend::format_string_for_osd(char* buff, uint8_t size, bool decimal_packed, const char *fmt, va_list ap)
{
if (size == 0) {
return 0;
}
#if OSD_ENABLED
// note: vsnprintf() always terminates the string
int res = hal.util->vsnprintf(buff, size, fmt, ap);
res = MIN(res, size);
if (res > 0 && decimal_packed) {
// note: convert_to_decimal_packed_characters() always terminates the string
res = convert_to_decimal_packed_characters(buff, res);
}
return res;
#else
// we guarantee string is terminated
buff[0] = 0x00;
// and notify the caller we actually failed
return 0;
#endif
}
void AP_OSD_Backend::write(uint8_t x, uint8_t y, bool blink, const char *fmt, ...)
{
#if OSD_ENABLED
if (blink && (blink_phase < 2)) {
return;
}
va_list ap;
va_start(ap, fmt);
char buff[32+1]; // +1 for null-termination
// note: format_string_for_osd() always terminates the string
IGNORE_RETURN(format_string_for_osd(buff, sizeof(buff), check_option(AP_OSD::OPTION_DECIMAL_PACK), fmt, ap));
va_end(ap);
// buff is null terminated, this call should be safe without further checks
write(x, y, buff);
#endif
}
/*
load a font from sdcard or ROMFS
*/
FileData *AP_OSD_Backend::load_font_data(uint8_t font_num)
{
FileData *fd;
// first try from microSD
char fontname[] = "font0.bin";
fontname[4] = font_num + '0';
fd = AP::FS().load_file(fontname);
if (fd == nullptr) {
char fontname_romfs[] = "@ROMFS/font0.bin";
fontname_romfs[7+4] = font_num + '0';
fd = AP::FS().load_file(fontname_romfs);
}
if (fd == nullptr) {
GCS_SEND_TEXT(MAV_SEVERITY_ERROR, "OSD: Failed to load font %u", font_num);
if (font_num != 0) {
// fallback to font0.bin. This allows us to reduce the
// number of fonts we include in flash without breaking
// user setups
return load_font_data(0);
}
}
return fd;
}
void AP_OSD_Backend::init_symbol_set(uint8_t *lookup_table, const uint8_t size)
{
memcpy(lookup_table, symbols, size);
}