Add function for changing alpha (#47)

Co-authored-by: Stein Gunnar Bakkeby <bakkeby@gmail.com>

config.def.h

@@ -393,6 +393,14 @@ static Shortcut shortcuts[] = {
 	{ TERMMOD,              XK_Home,        zoomreset,       {.f =  0} },
 	{ TERMMOD,              XK_C,           clipcopy,        {.i =  0} },
 	{ TERMMOD,              XK_V,           clippaste,       {.i =  0} },
+	#if ALPHA_PATCH
+	{ TERMMOD,              XK_O,           changealpha,     {.f = +0.05} },
+	{ TERMMOD,              XK_P,           changealpha,     {.f = -0.05} },
+	#if ALPHA_FOCUS_HIGHLIGHT_PATCH
+	//{ TERMMOD,              XK_,           changealphaunfocused, {.f = +0.05} },
+	//{ TERMMOD,              XK_,           changealphaunfocused, {.f = -0.05} },
+	#endif // ALPHA_FOCUS_HIGHLIGHT_PATCH
+	#endif // ALPHA_PATCH
 	#if SCROLLBACK_PATCH
 	{ ShiftMask,            XK_Page_Up,     kscrollup,       {.i = -1}, S_PRI },
 	{ ShiftMask,            XK_Page_Down,   kscrolldown,     {.i = -1}, S_PRI },

patch/alpha.c

@@ -0,0 +1,32 @@
+float
+clamp(float value, float lower, float upper) {
+	if (value < lower)
+		return lower;
+	if (value > upper)
+		return upper;
+	return value;
+}
+
+void
+changealpha(const Arg *arg)
+{
+	if ((alpha > 0 && arg->f < 0) || (alpha < 1 && arg->f > 0))
+		alpha += arg->f;
+	alpha = clamp(alpha, 0.0, 1.0);
+	xloadcols();
+	redraw();
+	fprintf(stderr, "changealpha %f\n", arg->f);
+}
+
+#if ALPHA_FOCUS_HIGHLIGHT_PATCH
+void
+changealphaunfocused(const Arg *arg)
+{
+	if ((alphaUnfocused > 0 && arg->f < 0) || (alphaUnfocused < 1 && arg->f > 0))
+		alphaUnfocused += arg->f;
+	alphaUnfocused = clamp(alphaUnfocused, 0.0, 1.0);
+	xloadcols();
+	redraw();
+	fprintf(stderr, "changealphaunfocused %f\n", arg->f);
+}
+#endif // ALPHA_FOCUS_HIGHLIGHT_PATCH

patch/alpha.h

@@ -0,0 +1,5 @@
+static float clamp(float value, float lower, float upper);
+static void changealpha(const Arg *);
+#if ALPHA_FOCUS_HIGHLIGHT_PATCH
+static void changealphaunfocused(const Arg *arg);
+#endif // ALPHA_FOCUS_HIGHLIGHT_PATCH

patch/x_include.c

@@ -1,4 +1,7 @@
 /* Patches */
+#if ALPHA_PATCH
+#include "alpha.c"
+#endif
 #if BACKGROUND_IMAGE_PATCH
 #include "background_image_x.c"
 #endif

patch/x_include.h

@@ -1,4 +1,7 @@
 /* Patches */
+#if ALPHA_PATCH
+#include "alpha.h"
+#endif
 #if BACKGROUND_IMAGE_PATCH
 #include "background_image_x.h"
 #endif