Implement a bridge to call Sointu from Go language.

The main interface is render_samples function, which renders several samples in one call,
to limit the number of calls from Go to C. This is compiled into a library, which is then
linked and called from bridge.go.

bridge/bridge.go.in

@@ -0,0 +1,55 @@
+package bridge
+
+import "fmt"
+import "unsafe"
+
+// #cgo CFLAGS: -I${INCLUDE_PATH}
+// #cgo LDFLAGS: ${LIBRARY_PATH}
+// #include <sointu.h>
+import "C"
+
+type SynthState = C.SynthState
+
+func (s *SynthState) Render(buffer []float32) int {
+  fmt.Printf("Calling Render...\n")
+  var ret = C.su_render_samples(s, C.int(len(buffer))/2, (*C.float)(&buffer[0]))
+  fmt.Printf("Returning from Render...\n")
+  return int(ret)
+}
+
+func (s *SynthState) SetCommands(c [2048]byte) {
+  pk := *((*[2048]C.uchar)(unsafe.Pointer(&c)))
+  s.Commands = pk
+}
+
+func (s *SynthState) SetValues(c [16384]byte) {
+  pk := *((*[16384]C.uchar)(unsafe.Pointer(&c)))
+  s.Values = pk
+}
+
+func (s *SynthState) Trigger(voice int,note int) {
+  fmt.Printf("Calling Trigger...\n")
+  s.Synth.Voices[voice] = C.Voice{}
+  s.Synth.Voices[voice].Note = C.int(note)
+  fmt.Printf("Returning from Trigger...\n")
+}
+
+func (s *SynthState) Release(voice int) {
+  fmt.Printf("Calling Release...\n")
+  s.Synth.Voices[voice].Release = 1
+  fmt.Printf("Returning from Release...\n")
+}
+
+func (s *SynthState) RowEnd() bool {
+  return s.RowTick == s.RowLen
+}
+
+func (s *SynthState) ResetRow() bool {
+  return s.RowTick == 0
+}
+
+func NewSynthState() *SynthState {
+  s := new(SynthState)
+  s.RandSeed = 1
+  return s
+}