Initial revision

src/window-mixer.c

@@ -0,0 +1,126 @@
+// SPDX-FileCopyrightText: 2022 Geoffrey D. Bennett <g@b4.vu>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include <gtk/gtk.h>
+
+#include "gtkhelper.h"
+#include "stringhelper.h"
+#include "widget-gain.h"
+#include "window-mixer.h"
+
+static struct routing_dst *get_mixer_r_dst(
+  struct alsa_card *card,
+  int               input_num
+) {
+  for (int i = 0; i < card->routing_dsts->len; i++) {
+    struct routing_dst *r_dst = &g_array_index(
+      card->routing_dsts, struct routing_dst, i
+    );
+    if (r_dst->port_category != PC_MIX)
+      continue;
+    if (r_dst->elem->lr_num == input_num)
+      return r_dst;
+  }
+  return NULL;
+}
+
+GtkWidget *create_mixer_controls(struct alsa_card *card) {
+  GtkWidget *mixer_top = gtk_grid_new();
+  GArray *elems = card->elems;
+
+  gtk_widget_set_margin(mixer_top, 5);
+  gtk_grid_set_column_homogeneous(GTK_GRID(mixer_top), TRUE);
+
+  // create the Mix X labels on the left and right of the grid
+  for (int i = 0; i < card->routing_in_count[PC_MIX]; i++) {
+    char name[10];
+    snprintf(name, 10, "Mix %c", i + 'A');
+
+    GtkWidget *l_left = gtk_label_new(name);
+    gtk_grid_attach(
+      GTK_GRID(mixer_top), l_left,
+      0, i, 1, 1
+    );
+
+    GtkWidget *l_right = gtk_label_new(name);
+    gtk_grid_attach(
+      GTK_GRID(mixer_top), l_right,
+      card->routing_out_count[PC_MIX] + 1, i, 1, 1
+    );
+  }
+
+  // go through each element and create the mixer
+  for (int i = 0; i < elems->len; i++) {
+    struct alsa_elem *elem = &g_array_index(elems, struct alsa_elem, i);
+
+    // if no card entry, it's an empty slot
+    if (!elem->card)
+      continue;
+
+    // looking for "Mix X Input Y Playback Volume" elements
+    if (strncmp(elem->name, "Mix ", 4) != 0)
+      continue;
+    if (!strstr(elem->name, "Playback Volume"))
+      continue;
+
+    // extract the mix number and input number from the element name
+    int mix_num = elem->name[4] - 'A';
+    int input_num = get_num_from_string(elem->name) - 1;
+
+    if (mix_num >= MAX_MIX_OUT) {
+      printf("mix_num %d >= MAX_MIX_OUT %d\n", mix_num, MAX_MIX_OUT);
+      continue;
+    }
+
+    // create the gain control and attach to the grid
+    GtkWidget *w = make_gain_alsa_elem(elem);
+    gtk_grid_attach(GTK_GRID(mixer_top), w, input_num + 1, mix_num, 1, 1);
+
+    // look up the r_dst entry for the mixer input number
+    struct routing_dst *r_dst = get_mixer_r_dst(card, input_num + 1);
+    if (!r_dst) {
+      printf("missing mixer input %d\n", input_num);
+      continue;
+    }
+
+    // lookup the label for the mixer input
+    GtkWidget *l = r_dst->mixer_label;
+
+    // if the label doesn't already exist, create it and attach it to
+    // the bottom of the grid
+    if (!l) {
+      l = r_dst->mixer_label = gtk_label_new("");
+
+      gtk_grid_attach(
+        GTK_GRID(mixer_top), l,
+        input_num, card->routing_in_count[PC_MIX] + input_num % 2, 3, 1
+      );
+    }
+  }
+
+  update_mixer_labels(card);
+
+  return mixer_top;
+}
+
+void update_mixer_labels(struct alsa_card *card) {
+  for (int i = 0; i < card->routing_dsts->len; i++) {
+    struct routing_dst *r_dst = &g_array_index(
+      card->routing_dsts, struct routing_dst, i
+    );
+
+    if (r_dst->port_category != PC_MIX)
+      continue;
+
+    struct alsa_elem *elem = r_dst->elem;
+
+    int routing_src_idx = alsa_get_elem_value(elem);
+
+    struct routing_src *r_src = &g_array_index(
+      card->routing_srcs, struct routing_src, routing_src_idx
+    );
+
+    if (r_dst->mixer_label)
+      gtk_label_set_text(GTK_LABEL(r_dst->mixer_label), r_src->name);
+  }
+}