Add ability to open multiple filter windows (#398)

* Allow opening multiple filter windows

* Add default layout for filter windows

src/filters.c

@@ -22,14 +22,19 @@
 // stb array of registered filters.
 static filter_t **g_filters = NULL;
 
-static void a_filter_open(void *data)
+static void a_filter_toggle(void *data)
 {
     filter_t *filter = data;
-    LOG_D("Open filter %s", filter->name);
-    goxel.gui.current_filter = (filter_t*)data;
-    if (filter->on_open) {
+    LOG_D("Toggle filter %s", filter->name);
+    filter->is_open = !filter->is_open;
+
+    if (filter->is_open && filter->on_open) {
         filter->on_open(filter);
     }
+
+    if (!filter->is_open && filter->on_close) {
+        filter->on_close(filter);
+    }
 }
 
 void filter_register_(filter_t *filter)
@@ -38,7 +43,7 @@ void filter_register_(filter_t *filter)
     action = (action_t) {
         .id = filter->action_id,
         .default_shortcut = filter->default_shortcut,
-        .cfunc_data = a_filter_open,
+        .cfunc_data = a_filter_toggle,
         .data = (void*)filter,
         .flags = ACTION_CAN_EDIT_SHORTCUT,
     };
@@ -48,7 +53,7 @@ void filter_register_(filter_t *filter)
 
 
 void filters_iter_all(
-        void *arg, void (*f)(void *arg, const filter_t *filter))
+        void *arg, void (*f)(void *arg, filter_t *filter))
 {
     int i;
     for (i = 0; i < arrlen(g_filters); i++) {

src/filters.h

@@ -19,6 +19,8 @@
 #ifndef FILTERS_H
 #define FILTERS_H
 
+#include <stdbool.h>
+
 typedef struct filter filter_t;
 
 struct filter {
@@ -28,6 +30,7 @@ struct filter {
     const char *name;
     const char *action_id;
     const char *default_shortcut;
+    bool is_open;
 };
 
 #define FILTER_REGISTER(id_, klass_, ...) \
@@ -47,6 +50,6 @@ void filter_register_(filter_t *filter);
  * Iter all the registered filters
  */
 void filters_iter_all(
-        void *arg, void (*f)(void *arg, const filter_t *filter));
+        void *arg, void (*f)(void *arg, filter_t *filter));
 
 #endif // FILTERS_H

src/goxel.h

@@ -553,7 +553,6 @@ typedef struct goxel
         int current_panel; // Index of the current visible control panel.
         float panel_width;
         float viewport[4];
-        filter_t *current_filter;
     } gui;
 
     char **recent_files; // stb arraw of most recently used files.

src/gui/app.c

@@ -16,6 +16,7 @@
  * goxel.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "filters.h"
 #include "goxel.h"
 
 #include "../ext_src/stb/stb_ds.h"
@@ -36,6 +37,9 @@
 #   define YOCTO 1
 #endif
 
+#define INITIAL_FILTER_OFFSET 10
+#define RELATIVE_FILTER_OFFSET 40
+
 // Note: duplicated from gui.cpp!  To remove.
 static const float ITEM_HEIGHT = 18;
 
@@ -101,6 +105,13 @@ static struct {
 #endif
 };
 
+typedef struct filter_layout_state filter_layout_state_t;
+
+struct filter_layout_state {
+    int next_x;
+    int next_y;
+};
+
 static void on_click(void) {
     if (DEFINED(GUI_SOUND))
         sound_play("click", 1.0, 1.0);
@@ -157,14 +168,37 @@ static void render_hints(const hint_t *hints)
     }
 }
 
+static void gui_filter_window(void *arg, filter_t *filter)
+{
+    filter_layout_state_t *state = arg;
+
+    if (filter->is_open) {
+        gui_window_begin(filter->name, state->next_x, state->next_y,
+                            goxel.gui.panel_width, 0, GUI_WINDOW_MOVABLE);
+
+        if (gui_panel_header(filter->name)) {
+            if (filter->on_close) {
+                filter->on_close(filter);
+            }
+            filter->is_open = false;
+        }
+        filter->gui_fn(filter);
+
+        gui_window_end();
+    }
+
+    state->next_x += RELATIVE_FILTER_OFFSET;
+    state->next_y += RELATIVE_FILTER_OFFSET;
+}
+
 void gui_app(void)
 {
     float x = 0, y = 0;
     const char *name;
     const float spacing = 8;
     int flags;
     int i;
-    filter_t *filter;
+    filter_layout_state_t filter_layout_state;
 
     goxel.show_export_viewport = false;
 
@@ -216,20 +250,10 @@ void gui_app(void)
         gui_window_end();
     }
 
-    filter = goxel.gui.current_filter;
-    if (filter) {
-        // XXX: we should have a way to center the filter window.
-        gui_window_begin(filter->name, 100, 100, goxel.gui.panel_width, 0,
-                         GUI_WINDOW_MOVABLE);
-        if (gui_panel_header(filter->name)) {
-            if (goxel.gui.current_filter->on_close) {
-                goxel.gui.current_filter->on_close(goxel.gui.current_filter);
-            }
-            goxel.gui.current_filter = NULL;
-        }
-        filter->gui_fn(filter);
-        gui_window_end();
-    }
+    filter_layout_state.next_x = x + goxel.gui.panel_width +
+                                    INITIAL_FILTER_OFFSET;
+    filter_layout_state.next_y = y;
+    filters_iter_all(&filter_layout_state, gui_filter_window);
 
     goxel.pathtrace = goxel.pathtracer.status &&
         (goxel.gui.current_panel == PANEL_RENDER ||

src/gui/menu.c

@@ -71,7 +71,7 @@ static void on_script(void *user, const char *name)
         script_execute(name);
 }
 
-static void on_filter(void *user, const filter_t *filter)
+static void on_filter(void *user, filter_t *filter)
 {
     const action_t *action;
     if (gui_menu_item(0, filter->name, true)) {