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.

1 files changed, 46 insertions, 0 deletions

diff --git a/quantum/utf8.c b/quantum/utf8.c
new file mode 100644
index 0000000000..4b2cd4d8d4
--- /dev/null
+++ b/quantum/utf8.c
@@ -0,0 +1,46 @@
+/* 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;
+}