Use the additional alpha-value as offset to support a changing alpha properly

1 files changed, 13 insertions, 4 deletions

diff --git a/x.c b/x.c
index d1721d7..2580d2a 100644
--- a/x.c
+++ b/x.c
@@ -182,6 +182,7 @@ static void xsetenv(void);
 static void xseturgency(int);
 static int evcol(XEvent *);
 static int evrow(XEvent *);
+static float clamp(float, float, float);
 
 static void expose(XEvent *);
 static void visibility(XEvent *);
@@ -319,10 +320,8 @@ changealpha(const Arg *arg)
 {
     if((alpha > 0 && arg->f < 0) || (alpha < 1 && arg->f > 0))
         alpha += arg->f;
-    if(alpha < 0)
-        alpha = 0;
-    if(alpha > 1)
-        alpha = 1;
+    alpha = clamp(alpha, 0.0, 1.0);
+    alphaUnfocus = clamp(alpha-alphaOffset, 0.0, 1.0);
 
     xloadcols();
     redraw();
@@ -381,6 +380,15 @@ evrow(XEvent *e)
 	return y / win.ch;
 }
 
+float
+clamp(float value, float lower, float upper) {
+    if(value < lower)
+        return lower;
+    if(value > upper)
+        return upper;
+    return value;
+}
+
 void
 mousesel(XEvent *e, int done)
 {
@@ -2298,6 +2306,7 @@ run:
 	cols = MAX(cols, 1);
 	rows = MAX(rows, 1);
 	defaultbg = MAX(LEN(colorname), 256);
+	alphaUnfocus = alpha-alphaOffset;
 	tnew(cols, rows);
 	xinit(cols, rows);
 	xsetenv();