qmk_firmware/quantum/utf8.c
Nick Brassel 1f2b1dedcc
Quantum Painter (#10174)
* Install dependencies before executing unit tests.

* Split out UTF-8 decoder.

* Fixup python formatting rules.

* Add documentation for QGF/QFF and the RLE format used.

* Add CLI commands for converting images and fonts.

* Add stub rules.mk for QP.

* Add stream type.

* Add base driver and comms interfaces.

* Add support for SPI, SPI+D/C comms drivers.

* Include <qp.h> when enabled.

* Add base support for SPI+D/C+RST panels, as well as concrete implementation of ST7789.

* Add support for GC9A01.

* Add support for ILI9341.

* Add support for ILI9163.

* Add support for SSD1351.

* Implement qp_setpixel, including pixdata buffer management.

* Implement qp_line.

* Implement qp_rect.

* Implement qp_circle.

* Implement qp_ellipse.

* Implement palette interpolation.

* Allow for streams to work with either flash or RAM.

* Image loading.

* Font loading.

* QGF palette loading.

* Progressive decoder of pixel data supporting Raw+RLE, 1-,2-,4-,8-bpp monochrome and palette-based images.

* Image drawing.

* Animations.

* Font rendering.

* Check against 256 colours, dump out the loaded palette if debugging enabled.

* Fix build.

* AVR is not the intended audience.

* `qmk format-c`

* Generation fix.

* First batch of docs.

* More docs and examples.

* Review comments.

* Public API documentation.
2022-04-13 18:00:18 +10:00

46 lines
1.8 KiB
C

/* Copyright 2021 QMK
*
* This program 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 2 of the License, or
* (at your option) any later version.
*
* This program 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 "utf8.h"
// Borrowed from https://nullprogram.com/blog/2017/10/06/
const char *decode_utf8(const char *str, int32_t *code_point) {
const char *next;
if (str[0] < 0x80) { // U+0000-007F
*code_point = str[0];
next = str + 1;
} else if ((str[0] & 0xE0) == 0xC0) { // U+0080-07FF
*code_point = ((int32_t)(str[0] & 0x1F) << 6) | ((int32_t)(str[1] & 0x3F) << 0);
next = str + 2;
} else if ((str[0] & 0xF0) == 0xE0) { // U+0800-FFFF
*code_point = ((int32_t)(str[0] & 0x0F) << 12) | ((int32_t)(str[1] & 0x3F) << 6) | ((int32_t)(str[2] & 0x3F) << 0);
next = str + 3;
} else if ((str[0] & 0xF8) == 0xF0 && (str[0] <= 0xF4)) { // U+10000-10FFFF
*code_point = ((int32_t)(str[0] & 0x07) << 18) | ((int32_t)(str[1] & 0x3F) << 12) | ((int32_t)(str[2] & 0x3F) << 6) | ((int32_t)(str[3] & 0x3F) << 0);
next = str + 4;
} else {
*code_point = -1;
next = str + 1;
}
// part of a UTF-16 surrogate pair - invalid
if (*code_point >= 0xD800 && *code_point <= 0xDFFF) {
*code_point = -1;
}
return next;
}