crude feedback gain control

Source/Maker/Widgets/slider.c

@@ -1,3 +1,8 @@
+#if defined(STFU_MAIN) && !defined(STFU_SLIDER)
+#define STFU_SLIDER
+
+#include <stdbool.h>
+
 #include "../config.h"
 #include "border.c"
 
@@ -8,6 +13,7 @@ struct stfu_slider {
   float width, height;
   float r, g, b;
   float min, max, cur;
+  bool integeric;
 };
 
 static void stfu_draw_slider(struct stfu_slider slider) {
@@ -36,3 +42,21 @@ static void stfu_draw_slider(struct stfu_slider slider) {
     sgl_end();
   }
 }
+
+static struct stfu_slider stfu_press_slider(struct stfu_slider slider, float x,
+                                            float y) {
+  if (x < slider.x || x > slider.x + slider.width)
+    return slider;
+  if (y < slider.y || y > slider.y + slider.height)
+    return slider;
+
+  slider.cur = slider.min +
+               ((x - slider.x) / (slider.width)) * (slider.max - slider.min);
+
+  if (slider.integeric)
+    slider.cur = floorf(slider.cur);
+
+  return slider;
+}
+
+#endif