1 files changed, 42 insertions, 72 deletions

diff --git a/src/main.c b/src/main.c
index f3ab73a..196914b 100644
--- a/src/main.c
+++ b/src/main.c
@@ -26,13 +26,13 @@
 
 
 struct props {
-  int lvl;
-  int step;
-  int rate;
-  int max;
-  int cur;
-  char filebrightness[512];
-  char filemax_bright[512];
+  int lvl;  // Destination brightness
+  int step; // Step size
+  int rate; // Time in milliseconds between steps
+  int max;  // Maximum brightness of screen device
+  int cur;  // Current brightness prior to fade operation
+  char filebrightness[512]; // Path to the sysfs ent for brightness
+  char filemax_bright[512]; // Path to the sysfs ent for max brightness
 };
 
 
@@ -49,7 +49,7 @@ void props_new(struct props* p) {
 
 /**
  * fgeti:
- * @path
+ * @path Path to the file from which to read the integer
  *
  * Reads integer from the specified file. If the file does not contain only an
  * integer, returns -1.
@@ -71,18 +71,21 @@ int fgeti(char* path) {
 
 
 /**
- * fadeup:
+ * fade:
  * @props Props struct containing runtime parameters
  *
- * Fades brightness down, incremented by props->step every props->rate
- * milliseconds
+ * Fades brightness up or down, based on positive (fade up) or negative value
+ * (fade down) contained in `step` property. Rate of fade is controled by
+ * `props->rate`.
  *
  * returns: Success (0) or failure (-1)
  */
-int fadeup(struct props* props) {
+int fade(struct props* props) {
   struct timespec tim, tim2;
   int sec;  // Number of seconds to sleep
   int msec; // Number of milliseconds to sleep (less than 1 second)
+  int direction = 0; // Direction of fade. Positive for up, negative for down
+  int opcount   = 0;
 
   sec = props->rate / 1000;
   msec = props->rate - (sec * 1000);
@@ -90,72 +93,41 @@ int fadeup(struct props* props) {
   tim.tv_sec = sec;
   tim.tv_nsec = 1000000 * msec;
 
-  while(props->cur < props->lvl) {
-    nanosleep(&tim, &tim2);
+  // Determine direction
+  if(props->lvl > props->cur) {
+    // Dest brightness is higher than current
+    direction = 1;
+    opcount = (props->lvl - props->cur) / props->step;
+  } else if(props->lvl < props->cur) {
+    // Dest brightness is lower than current
+    direction = -1;
+    opcount = (props->cur - props->lvl) / props->step;
+  }
 
-    FILE* fd = fopen(props->filebrightness, "w");
-    if(! fd) {
-      if(errno == EACCES) {
-        fprintf(stderr, "Permission denied: %s\n", props->filebrightness);
-      } else {
-        fprintf(stderr, "Could not open file %s\n", props->filebrightness);
-      }
-      return -1;
+  FILE* fd = fopen(props->filebrightness, "w");
+  if(! fd) {
+    if(errno == EACCES) {
+      fprintf(stderr, "Permission denied: %s\n", props->filebrightness);
+    } else {
+      fprintf(stderr, "Could not open file %s\n", props->filebrightness);
     }
-
-    // Write the new brightness to the brightness file
-    fprintf(fd, "%d\n", props->cur);
-    fclose(fd);
-
-    if(props->cur >= props->max)
-      break;
-    props->cur += props->step;
+    return -1;
   }
-  return 0;
-}
-
-
-/**
- * fadedown:
- * @props Props struct containing runtime parameters
- *
- * Fades brightness down, decremented by props->step every props->rate
- * milliseconds
- *
- * returns: Success (0) or failure (-1)
- */
-int fadedown(struct props* props) {
-  struct timespec tim, tim2;
-  int sec;  // Number of seconds to sleep
-  int msec; // Number of milliseconds to sleep (less than 1 second)
-
-  sec = props->rate / 1000;
-  msec = props->rate - (sec * 1000);
-
-  tim.tv_sec = sec;
-  tim.tv_nsec = 1000000 * msec;
 
-  while(props->cur > props->lvl) {
+  while(opcount > 0) {
     nanosleep(&tim, &tim2);
 
-    FILE* fd = fopen(props->filebrightness, "w");
-    if(! fd) {
-      if(errno == EACCES) {
-        fprintf(stderr, "Permission denied: %s\n", props->filebrightness);
-      } else {
-        fprintf(stderr, "Could not open file %s\n", props->filebrightness);
-      }
-      return -1;
-    }
-
     // Write the new brightness to the brightness file
     fprintf(fd, "%d\n", props->cur);
-    fclose(fd);
 
-    if(props->cur <= 0)
-      break;
-    props->cur -= props->step;
+    // Flush the toil...er...buffer!
+    fflush(fd);
+
+    props->cur += props->step * direction;
+    opcount--;
   }
+
+  fclose(fd);
   return 0;
 }
 
@@ -301,10 +273,8 @@ int main(int argc, char* argv[]) {
   // Determine if we should fade up or fade down
   if(p.lvl < 0) {
     printf("%d\n", p.cur);
-  } else if(p.lvl > p.cur) {
-    r = fadeup(&p);
-  } else if (p.lvl < p.cur) {
-    r = fadedown(&p);
+  } else {
+    r = fade(&p);
   }
 
   if(r < 0) {