16 Apr
2008
16 Apr
'08
1:48 p.m.
This software package contains libraries and programs that should make
it easier to write LV2 plugins and GUIs.
Download it: http://ll-plugins.nongnu.org/hacking.html
Read documentation: http://ll-plugins.nongnu.org/dox/lv2-c++-tools/
Or read a nice tutorial: http://ll-plugins.nongnu.org/lv2pftci/
To build and install, run
./configure
make
su -c 'make install'
You can pass some options to configure, e.g. --prefix=/usr to install
everything in /usr (the default is /usr/local).
This is a development tool, but I'm sending it to the LAU list as well
in case there are any not-yet-hackers who would like to start writing
effects or synths. It's easy, I promise. Here's the code you would need
to write for a simple gain effect:
#include <lv2plugin.hpp>
#include "gain.peg"
class Gain : public LV2::Plugin<Gain> {
public:
Gain(double rate) : LV2::Plugin<Gain>(p_n_ports) { }
void run(uint32_t nframes) {
for (uint32_t i = 0; i < nframes; ++i)
p(p_out)[i] = p(p_gain) * p(p_in);
}
};
static int _ = Gain::register_class("http://my.plugin/");
And here's the code you would need for a GUI for a synth plugin with a
button that sends a test tone:
#include <lv2gui.hpp>
#include "mysynth.peg"
class MySynthGUI : public LV2::GUI<MySynthGUI, LV2::WriteMIDI<true> > {
public:
MySynthGUI(const std::string& URI) : m_button("Click me!") {
m_button.signal_pressed().connect(mem_fun(*this, &MySynthGUI::send_note_on));
m_button.signal_released().connect(mem_fun(*this, &MySynthGUI::send_note_off));
pack_start(m_button);
}
protected:
void send_note_on() {
uint8_t event[] = { 0x90, 0x40, 0x40 };
write_midi(p_midi, 3, event);
}
void send_note_off() {
uint8_t event[] = { 0x80, 0x40, 0x40 };
write_midi(p_midi, 3, event);
}
Gtk::Button m_button;
};
static int _ = MySynthGUI::register_class("http://my.gui/");
See? Trivial. Read more in the tutorial linked above.
--ll