Allow manually changing the focus using controls

data/camera.ui

@@ -67,6 +67,16 @@
                             </style>
                           </object>
                         </child>
+                        <child>
+                          <object class="GtkButton" id="focus-controls-button">
+                            <property name="valign">start</property>
+                            <property name="icon-name">focus-auto-symbolic</property>
+                            <style>
+                              <class name="flat"/>
+                              <class name="control"/>
+                            </style>
+                          </object>
+                        </child>
                         <child>
                           <object class="GtkButton" id="flash-controls-button">
                             <property name="valign">start</property>

data/me.gapixels.Megapixels.gresource.xml

@@ -28,5 +28,7 @@
     <file preprocess="xml-stripblanks">iso-auto-symbolic.svg</file>
     <file preprocess="xml-stripblanks">shutter-man-symbolic.svg</file>
     <file preprocess="xml-stripblanks">shutter-auto-symbolic.svg</file>
+    <file preprocess="xml-stripblanks">focus-man-symbolic.svg</file>
+    <file preprocess="xml-stripblanks">focus-auto-symbolic.svg</file>
   </gresource>
 </gresources>

src/io_pipeline.c

@@ -75,6 +75,11 @@ update_process_pipeline()
                         mp_camera_control_get_int32(&state_io.exposure.control);
         }
 
+        if (!state_io.focus.manual && state_io.focus.control.id) {
+                state_io.focus.value =
+                        mp_camera_control_get_int32(&state_io.focus.control);
+        }
+
         float balance_red = 1.0f;
         float balance_blue = 1.0f;
         if (state_io.red.control.id && state_io.blue.control.id) {
@@ -245,6 +250,28 @@ update_controls()
                 start_focus();
         }
 
+        // Change focus manual/auto if it got changed by the user
+        if (state_io.focus.manual != state_io.focus.manual_req) {
+                state_io.focus.manual = state_io.focus.manual_req;
+                if (state_io.focus.auto_control.id > 0) {
+                        mp_camera_control_set_bool_bg(mpcamera,
+                                                      &state_io.focus.auto_control,
+                                                      !state_io.gain.manual_req);
+                }
+                state_changed = true;
+        }
+
+        // If focus is manual, OR auto but no auto control, and the value got
+        // updated by the program/user, update the manual control
+        if ((state_io.focus.manual ||
+             (!state_io.focus.manual && state_io.focus.auto_control.id == 0)) &&
+            state_io.focus.value != state_io.focus.value_req) {
+                mp_camera_control_set_int32_bg(
+                        mpcamera, &state_io.focus.control, state_io.focus.value_req);
+                state_io.focus.value = state_io.focus.value_req;
+                state_changed = true;
+        }
+
         if (state_io.gain.manual != state_io.gain.manual_req) {
                 mp_camera_control_set_bool_bg(mpcamera,
                                               &state_io.gain.auto_control,
@@ -420,10 +447,19 @@ static void
 init_controls()
 {
         MPControl focus_control;
-        if (mp_camera_query_control(state_io.camera->sensor_fd,
+        // V4L2_CID_FOCUS_ABSOLUTE exists on the sensor for PP, but on the lens for
+        // PPP. Check both, if applicable.
+        if ((state_io.camera->lens_fd > 0 &&
+             mp_camera_query_control(state_io.camera->lens_fd,
+                                     V4L2_CID_FOCUS_ABSOLUTE,
+                                     &focus_control)) ||
+            mp_camera_query_control(state_io.camera->sensor_fd,
                                     V4L2_CID_FOCUS_ABSOLUTE,
                                     &focus_control)) {
                 state_io.focus.control = focus_control;
+                state_io.focus.max = focus_control.max;
+                state_io.focus.value =
+                        mp_camera_control_get_int32(&state_io.focus.control);
         } else {
                 state_io.focus.control.id = 0;
         }

src/main.c

@@ -68,9 +68,10 @@ GtkWidget *preview_bottom_box;
 GtkWidget *message_box;
 GtkWidget *message_label;
 
-GtkWidget *flash_button;
 GtkWidget *iso_button;
 GtkWidget *shutter_button;
+GtkWidget *focus_button;
+GtkWidget *flash_button;
 
 LfbEvent *capture_event;
 static GtkWidget *movie;
@@ -172,6 +173,13 @@ update_state(const mp_state_main *new_state)
                 gtk_button_set_icon_name(GTK_BUTTON(iso_button), icon_name);
         }
 
+        if (state.focus.manual != new_state->focus.manual) {
+                const char *icon_name = new_state->focus.manual ?
+                                                "focus-man-symbolic" :
+                                                "focus-auto-symbolic";
+                gtk_button_set_icon_name(GTK_BUTTON(focus_button), icon_name);
+        }
+
         state.gain.control = new_state->gain.control;
         state.gain.auto_control = new_state->gain.auto_control;
         state.gain.value = new_state->gain.value;
@@ -204,6 +212,7 @@ update_state(const mp_state_main *new_state)
         // Make the right settings available for the camera
         gtk_widget_set_visible(iso_button, state.gain.control.id != 0);
         gtk_widget_set_visible(shutter_button, state.exposure.control.id != 0);
+        gtk_widget_set_visible(focus_button, state.focus.control.id != 0);
         // Even if there's no flash led/v4l, it'll just default to using the screen
         // as flash, so always enable this button
         gtk_widget_set_visible(flash_button, true);
@@ -915,6 +924,24 @@ set_shutter_auto(bool is_auto)
         }
 }
 
+static void
+set_focus(double value)
+{
+        if (state.focus.value != (int)value) {
+                state.focus.value_req = (int)value;
+                update_io_pipeline();
+        }
+}
+
+static void
+set_focus_auto(bool is_auto)
+{
+        if (state.focus.manual != !is_auto) {
+                state.focus.manual_req = !is_auto;
+                update_io_pipeline();
+        }
+}
+
 static void
 open_shutter_controls(GtkWidget *button, gpointer user_data)
 {
@@ -930,6 +957,19 @@ open_shutter_controls(GtkWidget *button, gpointer user_data)
                       set_shutter_auto);
 }
 
+static void
+open_focus_controls(GtkWidget *button, gpointer user_data)
+{
+        open_controls(button,
+                      "Focus",
+                      0,
+                      state.focus.max,
+                      state.focus.value,
+                      !state.focus.manual,
+                      set_focus,
+                      set_focus_auto);
+}
+
 static void
 flash_button_clicked(GtkWidget *button, gpointer user_data)
 {
@@ -1254,6 +1294,8 @@ activate(GtkApplication *app, gpointer data)
                 GTK_WIDGET(gtk_builder_get_object(builder, "iso-controls-button"));
         shutter_button = GTK_WIDGET(
                 gtk_builder_get_object(builder, "shutter-controls-button"));
+        focus_button =
+                GTK_WIDGET(gtk_builder_get_object(builder, "focus-controls-button"));
         flash_button =
                 GTK_WIDGET(gtk_builder_get_object(builder, "flash-controls-button"));
         GtkWidget *setting_dng_button =
@@ -1290,6 +1332,8 @@ activate(GtkApplication *app, gpointer data)
         g_signal_connect(iso_button, "clicked", G_CALLBACK(open_iso_controls), NULL);
         g_signal_connect(
                 shutter_button, "clicked", G_CALLBACK(open_shutter_controls), NULL);
+        g_signal_connect(
+                focus_button, "clicked", G_CALLBACK(open_focus_controls), NULL);
         g_signal_connect(
                 flash_button, "clicked", G_CALLBACK(flash_button_clicked), NULL);