Initial commit

This fades through the rainbow spectrum. The sleep time between next
color change is confurable along with step (color hex distance).

1 files changed, 122 insertions, 0 deletions

diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..0d035b4
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,122 @@
+/**
+ * Kbd-fade fades keyboard led backlighting
+ * Copyright (C) 2019  Aaron Ball <nullspoon@oper.io>
+ *
+ * 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 3 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 <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#define COLORFILE "/sys/class/leds/system76::kbd_backlight/color_left"
+
+
+struct rgb {
+  int r;
+  int g;
+  int b;
+};
+
+
+void writecolor(struct rgb color, int usec_wait) {
+  FILE* fd;
+  fd = fopen(COLORFILE, "w");
+  fprintf(fd, "%02X%02X%02X\n", color.r, color.g, color.b);
+  fclose(fd);
+  usleep(usec_wait);
+}
+
+
+void load_current_state(struct rgb* srgb) {
+  char chan[3];
+  FILE* fd;
+
+  chan[3] = '\0';
+  fd = fopen(COLORFILE, "r");
+
+  chan[0] = fgetc(fd);
+  chan[1] = fgetc(fd);
+  srgb->r = atoi(chan);
+
+  chan[0] = fgetc(fd);
+  chan[1] = fgetc(fd);
+  srgb->g = atoi(chan);
+
+  chan[0] = fgetc(fd);
+  chan[1] = fgetc(fd);
+  srgb->b = atoi(chan);
+
+  fclose(fd);
+}
+
+
+int main(int argc, char* argv[]) {
+  int step = 4;
+  int wait = 10000;
+
+  struct rgb color;
+  load_current_state(&color);
+
+  // Set wait time between steps
+  if(argc >= 2)
+    wait = atoi(argv[1]) * 1000;
+
+  // Step size
+  if(argc == 3)
+    step = atoi(argv[2]);
+
+  while(1) {
+    // Increase green
+    while(color.g < 256) {
+      writecolor(color, wait);
+      color.g += step;
+    }
+    color.g = 255;
+
+    // Decrease red
+    while(color.r > 0) {
+      writecolor(color, wait);
+      color.r -= step;
+    }
+    color.r = 0;
+
+    // Increase blue
+    while(color.b < 256) {
+      writecolor(color, wait);
+      color.b += step;
+    }
+    color.b = 255;
+
+    // Decrease green
+    while(color.g > 0) {
+      writecolor(color, wait);
+      color.g -= step;
+    }
+    color.g = 0;
+
+    // Increase red
+    while(color.r < 256) {
+      writecolor(color, wait);
+      color.r += step;
+    }
+    color.r = 255;
+
+    // Decrease blue
+    while(color.b > 0) {
+      writecolor(color, wait);
+      color.b -= step;
+    }
+    color.b = 0;
+  }
+}