From 8a66a74b95f0b50d367b325c80b87c15e4f990cb Mon Sep 17 00:00:00 2001
From: XANTRONIX Development <dev@xantronix.com>
Date: Fri, 19 Jan 2024 12:27:43 -0500
Subject: [PATCH] Add alpha property to gauges

---
 include/hexagram/gauge.h | 3 +++
 src/gauge.c              | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/include/hexagram/gauge.h b/include/hexagram/gauge.h
index 2a74e6f..012870e 100644
--- a/include/hexagram/gauge.h
+++ b/include/hexagram/gauge.h
@@ -10,6 +10,7 @@ typedef int (hexagram_gauge_draw_callback)(hexagram_gauge *,
 
 typedef struct _hexagram_gauge {
     double x, y;
+    double alpha;
 
     hexagram_gauge_draw_callback *draw_bg,
                                  *draw_fg;
@@ -23,6 +24,8 @@ void hexagram_gauge_init(hexagram_gauge *gauge,
 
 void hexagram_gauge_move(hexagram_gauge *gauge, double x, double y);
 
+void hexagram_gauge_set_alpha(hexagram_gauge *gauge, double alpha);
+
 int hexagram_gauge_draw_fg(hexagram_gauge *gauge, cairo_t *cr);
 
 int hexagram_gauge_draw_bg(hexagram_gauge *gauge, cairo_t *cr);
diff --git a/src/gauge.c b/src/gauge.c
index 8dfc297..50625b9 100644
--- a/src/gauge.c
+++ b/src/gauge.c
@@ -10,6 +10,7 @@ void hexagram_gauge_init(hexagram_gauge *gauge,
                          hexagram_gauge_draw_callback *draw_fg) {
     gauge->x       = x;
     gauge->y       = y;
+    gauge->alpha   = 1.0;
     gauge->draw_bg = draw_bg;
     gauge->draw_fg = draw_fg;
 }
@@ -18,3 +19,11 @@ void hexagram_gauge_move(hexagram_gauge *gauge, double x, double y) {
     gauge->x = x;
     gauge->y = y;
 }
+
+void hexagram_gauge_set_alpha(hexagram_gauge *gauge, double alpha) {
+    if (alpha > 1.0 || alpha < 0.0) {
+        return;
+    }
+
+    gauge->alpha = alpha;
+}