summaryrefslogtreecommitdiffhomepage
path: root/src/hexcolour.c
diff options
context:
space:
mode:
authorMichael Smith <mikesmiffy128@gmail.com>2024-01-21 21:01:00 +0000
committerMichael Smith <mikesmiffy128@gmail.com>2024-01-21 21:01:00 +0000
commit506f095bcb528468f25a637977efcc408590ae67 (patch)
tree2f0228fddc9fc31f3ff895703d60cf26bc8e8cab /src/hexcolour.c
parent374ae0fbc44db36d9abb6b5b1fe065bc3949e201 (diff)
Add a half-decent custom crosshair
Diffstat (limited to 'src/hexcolour.c')
-rw-r--r--src/hexcolour.c85
1 files changed, 85 insertions, 0 deletions
diff --git a/src/hexcolour.c b/src/hexcolour.c
new file mode 100644
index 0000000..7d0ad43
--- /dev/null
+++ b/src/hexcolour.c
@@ -0,0 +1,85 @@
+/*
+ * Copyright © 2024 Michael Smith <mikesmiffy128@gmail.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED “AS IS” AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <string.h>
+
+#include "intdefs.h"
+
+void hexcolour_rgb(uchar out[static 4], const char *s) {
+ const char *p = s;
+ for (uchar *q = out; q - out < 3; ++q) {
+ if (*p >= '0' && *p <= '9') {
+ *q = *p++ - '0' << 4;
+ }
+ else if ((*p | 32) >= 'a' && (*p | 32) <= 'f') {
+ *q = 10 + (*p++ | 32) - 'a' << 4;
+ }
+ else {
+ // screw it, just fall back on white, I guess.
+ // note: this also handles *p == '\0' so we don't overrun the string
+ memset(out, 255, 4); // should be a single mov
+ return;
+ }
+ // repetitive unrolled nonsense
+ if (*p >= '0' && *p <= '9') {
+ *q |= *p++ - '0';
+ }
+ else if ((*p | 32) >= 'a' && (*p | 32) <= 'f') {
+ *q |= 10 + (*p++ | 32) - 'a';
+ }
+ else {
+ memset(out, 255, 4); // should be a single mov
+ return;
+ }
+ }
+ //out[3] = 255; // never changes!
+}
+
+void hexcolour_rgba(uchar out[static 4], const char *s) {
+ const char *p = s;
+ // same again but with 4 pairs of digits instead of 3!
+ for (uchar *q = out; q - out < 4; ++q) {
+ if (*p >= '0' && *p <= '9') {
+ *q = *p++ - '0' << 4;
+ }
+ else if ((*p | 32) >= 'a' && (*p | 32) <= 'f') {
+ *q = 10 + (*p++ | 32) - 'a' << 4;
+ }
+ else {
+ if (q - out == 3 && !*p) {
+ // ONLY if both the last alpha digits are missing: use provided
+ // RGB at full opacity. otherwise same white fallback as before.
+ out[3] = 255;
+ return;
+ }
+ memset(out, 255, 4);
+ return;
+ }
+ // even more repetitive unrolled nonsense
+ if (*p >= '0' && *p <= '9') {
+ *q |= *p++ - '0';
+ }
+ else if ((*p | 32) >= 'a' && (*p | 32) <= 'f') {
+ *q |= 10 + (*p++ | 32) - 'a';
+ }
+ else {
+ memset(out, 255, 4);
+ return;
+ }
+ }
+}
+
+// vi: sw=4 ts=4 noet tw=80 cc=80