<?xml version="1.0"?>
<!DOCTYPE ladspa SYSTEM "ladspa-swh.dtd">
<?xml-stylesheet href="ladspa.css" type="text/css"?>

<ladspa>
  <global>
    <meta name="maker" value="Steve Harris &lt;steve@plugin.org.uk&gt;"/>
    <meta name="copyright" value="GPL"/>
    <meta name="properties" value="HARD_RT_CAPABLE"/>
    <code><![CDATA[
      #define FADE_IN  1
      #define STABLE   2
      #define FADE_OUT 3
    ]]></code>
  </global>

  <plugin label="stepMuxer" id="1212" class="UtilityPlugin">
    <name>Step Demuxer</name>
    <p>Inputs up to 8 signals and switches between them on the output when the signal on the clock input goes high.</p>
    <p>This plugin is untested, and may not work.</p>

    <callback event="instantiate"><![CDATA[
      sample_rate = s_rate;
      ch_state = malloc(sizeof(int) * 8);
      ch_gain = malloc(sizeof(float) * 8);
      current_ch = 0;
      last_clock = 0.0f;
    ]]></callback>

    <callback event="activate"><![CDATA[
      int i;

      ch_state[0] = STABLE;
      ch_gain[0] = 1.0f;
      for (i = 1; i < 8; i++) {
        ch_state[i] = STABLE;
        ch_gain[i] = 0.0f;
      }
      current_ch = 0;
      last_clock = 0.0f;
    ]]></callback>

    <callback event="cleanup"><![CDATA[
      free(plugin_data->ch_state);
      free(plugin_data->ch_gain);
    ]]></callback>

    <callback event="run"><![CDATA[
      unsigned long pos;
      float fade_inc = 1.0f / (xfadet * sample_rate * 1000.0f);
      float accum;
      int ch;

      for (pos = 0; pos < sample_count; pos++) {

	// Calculate output value for this sample
        accum = 0.0f;
        accum += input0[pos] * ch_gain[0];
        accum += input1[pos] * ch_gain[1];
        accum += input2[pos] * ch_gain[2];
        accum += input3[pos] * ch_gain[3];
        accum += input4[pos] * ch_gain[4];
        accum += input5[pos] * ch_gain[5];
        accum += input6[pos] * ch_gain[6];
        accum += input7[pos] * ch_gain[7];
        buffer_write(output[pos], accum);

	// Run crossfades
        for (ch = 0; ch < 8; ch++) {

          // Channel is still being faded in
	  if (ch_state[ch] == FADE_IN) {
	    ch_gain[ch] += fade_inc;
            if (ch_gain[ch] >= 1.0f) {
              ch_gain[ch] = 1.0f;
              ch_state[ch] = STABLE;
            }

          // Channel is still being faded out
          } else if (ch_state[ch] == FADE_OUT) {
	    ch_gain[ch] -= fade_inc;
            if (ch_gain[ch] <= 0.0f) {
              ch_gain[ch] = 0.0f;
              ch_state[ch] = STABLE;
            }
	  }
        }

	// Check for clock signal
	if (last_clock <= 0.0f && clock[pos] > 0.0f) {
	  ch_state[current_ch] = FADE_OUT;
	  current_ch = (current_ch + 1) % 8;
	  ch_state[current_ch] = FADE_IN;
        }
      }

      // Save state data
      plugin_data->current_ch = current_ch;
      plugin_data->last_clock = last_clock;
    ]]></callback>

    <port label="xfadet" dir="input" type="control" hint="default_middle">
      <name>Crossfade time (in ms)</name>
      <range min="0" max="100"/>
    </port>

    <port label="clock" dir="input" type="audio">
      <name>Clock</name>
    </port>

    <port label="input0" dir="input" type="audio">
      <name>Input 1</name>
    </port>

    <port label="input1" dir="input" type="audio">
      <name>Input 2</name>
    </port>

    <port label="input2" dir="input" type="audio">
      <name>Input 3</name>
    </port>

    <port label="input3" dir="input" type="audio">
      <name>Input 4</name>
    </port>

    <port label="input4" dir="input" type="audio">
      <name>Input 5</name>
    </port>

    <port label="input5" dir="input" type="audio">
      <name>Input 6</name>
    </port>

    <port label="input6" dir="input" type="audio">
      <name>Input 7</name>
    </port>

    <port label="input7" dir="input" type="audio">
      <name>Input 8</name>
    </port>

    <port label="output" dir="output" type="audio">
      <name>Output</name>
    </port>

    <instance-data label="sample_rate" type="float"/>
    <instance-data label="current_ch" type="int"/>
    <instance-data label="last_clock" type="LADSPA_Data"/>
    <instance-data label="ch_state" type="int *"/>
    <instance-data label="ch_gain" type="float *"/>

  </plugin>
</ladspa>