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

Source/Maker/main.c

@@ -32,6 +32,14 @@ static unsigned int crossfade_frames_left = 0;
 // 1.0 is with A at 440
 static float octave = 0.5;
 
+static struct stfu_slider feedback_slider = {.x = 16,
+                                             .y = 16,
+                                             .width = 120,
+                                             .height = 16,
+                                             .min = 0,
+                                             .max = 1,
+                                             .cur = 0.25};
+
 static void stream(float *buffer, int num_frames, int num_channels) {
   /* Fade away */
   for (size_t i = 0; crossfade_frames_left > 0;
@@ -95,6 +103,16 @@ static void cleanup(void) { saudio_shutdown(); }
 
 static void event(const sapp_event *e) {
   switch (e->type) {
+  case SAPP_EVENTTYPE_MOUSE_DOWN: {
+    if (e->mouse_button != SAPP_MOUSEBUTTON_LEFT)
+      break;
+
+    feedback_slider =
+        stfu_press_slider(feedback_slider, e->mouse_x, e->mouse_y);
+    synth.feedback_gain = feedback_slider.cur;
+
+    break;
+  }
   case SAPP_EVENTTYPE_KEY_DOWN: {
     if (e->key_repeat)
       break;
@@ -221,13 +239,7 @@ static void frame(void) {
   sgl_load_default_pipeline();
   sgl_load_identity();
   sgl_ortho(0, STFU_MAKER_WINDOW_WIDTH, STFU_MAKER_WINDOW_HEIGHT, 0, -1, 1);
-  stfu_draw_slider((struct stfu_slider){.x = 16,
-                                        .y = 16,
-                                        .width = 120,
-                                        .height = 16,
-                                        .min = 10,
-                                        .max = 100,
-                                        .cur = 55});
+  stfu_draw_slider(feedback_slider);
   // sgl_pop_matrix();
   sgl_draw();
   sg_end_pass();