Using proper struct casting for event header when processing. (#2)

Also smaller stuff:

* Added logging; auto-configured at library load.
* Build target for generating intermediary C form.
* Extended `DEBUG` flag for tracing all calls.
* Less copying in the example audio buffer processing.

CHANGELOG.md

@@ -5,6 +5,16 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+### Changed
+* Using proper struct casting for event header when processing.
+* Less copying in the example audio buffer processing.
+
+### Added
+* Logging.
+* Build target for generating intermediary C form.
+* Extended DEBUG flag for tracing all calls.
+
 ## [0.1.1] - 2024-01-17
 
 ### Changed

Makefile

@@ -1,6 +1,7 @@
 SOURCEDIR = src
 BUILDDIR = build
 TARGET = $(BUILDDIR)/hello_world.clap
+V_CMD = v -cc gcc -shared -enable-globals
 
 # List all V source files
 V_SRC = $(wildcard $(SOURCEDIR)/*.v)
@@ -10,6 +11,9 @@ V_SRC = $(wildcard $(SOURCEDIR)/*.v)
 DEBUG ?= 0
 RELEASE ?= 0
 ifeq ($(DEBUG),1)
+	V_FLAGS = -cg -show-c-output
+else ifeq ($(DEBUG),2)
+	# Even more debug! Very noisy.
 	V_FLAGS = -cg -show-c-output -trace-calls
 else ifeq ($(RELEASE),1)
 	V_FLAGS = -prod -skip-unused -cflags -fvisibility=hidden
@@ -20,7 +24,7 @@ all: $(TARGET)
 
 # Use dependency on V source files to avoid recompilation
 $(TARGET): $(V_SRC) | dir
-	v -cc gcc -shared -enable-globals $(V_FLAGS) $(SOURCEDIR) -o $@.so
+	$(V_CMD) $(V_FLAGS) $(SOURCEDIR) -o $@.so
 ifeq ($(RELEASE),1)
 	strip [email protected]
 endif
@@ -35,6 +39,9 @@ clean:
 info: $(TARGET)
 	clap-info $<
 
+genc: $(V_SRC) | dir
+	$(V_CMD) $(V_FLAGS) $(SOURCEDIR) -o $(TARGET).c
+
 install: $(TARGET)
 	mkdir -p ~/.clap
 	cp $(TARGET) ~/.clap/

src/c_abi.v

@@ -1,5 +1,3 @@
-module plugin
-
 #flag -I./include
 #include "clap/clap.h"
 
@@ -103,8 +101,7 @@ mut:
 struct C.clap_input_events_t {
 	ctx  voidptr
 	size fn (&C.clap_input_events_t) u32
-	// TODO: How to avoid `voidptr` and use header/event structs instead?
-	get fn (&C.clap_input_events_t, u32) voidptr
+	get fn (&C.clap_input_events_t, u32) &C.clap_event_header_t
 }
 
 @[typedef]
@@ -116,9 +113,9 @@ struct C.clap_event_header_t {
 	flags    u32
 }
 
-// TODO: Why doesn't typedef C structs work here?
-struct ClapEventNote {
-	C.clap_event_header_t
+@[typedef]
+struct C.clap_event_note_t {
+	header C.clap_event_header_t
 	note_id    int
 	port_index i16
 	channel    i16

src/ext_audio_ports.v

@@ -1,5 +1,3 @@
-module plugin
-
 const clap_ext_audio_ports = unsafe { (&char(C.CLAP_EXT_AUDIO_PORTS)).vstring() }
 const clap_port_stereo = unsafe { (&char(C.CLAP_PORT_STEREO)).vstring() }
 const clap_port_mono = unsafe { (&char(C.CLAP_PORT_MONO)).vstring() }

src/ext_latency.v

@@ -1,5 +1,3 @@
-module plugin
-
 const clap_ext_latency = unsafe { (&char(C.CLAP_EXT_LATENCY)).vstring() }
 
 @[typedef]

src/ext_note_ports.v

@@ -1,5 +1,3 @@
-module plugin
-
 const clap_ext_note_ports = unsafe { (&char(C.CLAP_EXT_NOTE_PORTS)).vstring() }
 
 @[typedef]

src/main.v

@@ -1,9 +1,16 @@
-module plugin
-
+import log
 // Exposes the plugin to the host (DAW).
 
 // This requires modification to `clap/entry.h`.
 // Remove "const" so you get:
 // CLAP_EXPORT extern clap_plugin_entry_t clap_entry;
 @[markused]
 __global clap_entry = plugin_entry
+
+fn init() {
+	$if debug {
+		log.set_level(log.Level.debug)
+	} $else {
+		log.set_level(log.Level.info)
+	}
+}

src/plugin.v

@@ -1,12 +1,12 @@
-module plugin
+import log
 
 // This should be the actual implementation of the plugin with
 // all the interesting logic like DSP, UI, etc.
 struct MinimalPlugin {
 	host &C.clap_host_t
 mut:
 	sample_rate f64
-	latency u32
+	latency     u32
 }
 
 // Extract our actual pluging from CLAP plugin wrapper.
@@ -42,33 +42,31 @@ fn MinimalPlugin.reset(clap_plugin &C.clap_plugin_t) {
 	// Cleanup plugin members here.
 }
 
-fn (mp MinimalPlugin) process_event (raw_event voidptr) {
-	header := unsafe { &C.clap_event_header_t(raw_event) }
-
+fn (mp MinimalPlugin) process_event(header &C.clap_event_header_t) {
 	if header.space_id != clap_core_event_space_id {
 		return
 	}
 
 	match header.@type {
 		u16(ClapEventType.note_on) {
 			// Handle note playing.
-			event := unsafe { &ClapEventNote(raw_event) }
-			println("Note ON: ${event.note_id}")
+			event := &C.clap_event_note_t(header)
+			log.debug('Note ON: ${event.note_id}')
 		}
 		u16(ClapEventType.note_off) {
 			// Handle note stop playing.
-			event := unsafe { &ClapEventNote(raw_event) }
-			println("Note OFF: ${event.note_id}")
+			event := &C.clap_event_note_t(header)
+			log.debug('Note OFF: ${event.note_id}')
 		}
 		// And so on...
 		else {
 			t := unsafe { ClapEventType(header.@type) }
-			println("Unsupported event type: ${t}")
+			log.debug('Unsupported event type: ${t}')
 		}
 	}
 }
 
-fn MinimalPlugin.process(clap_plugin &C.clap_plugin_t, mut process &C.clap_process_t) ClapProcessStatus {
+fn MinimalPlugin.process(clap_plugin &C.clap_plugin_t, mut process C.clap_process_t) ClapProcessStatus {
 	p := from_clap(clap_plugin)
 
 	nframes := process.frames_count
@@ -77,17 +75,16 @@ fn MinimalPlugin.process(clap_plugin &C.clap_plugin_t, mut process &C.clap_proce
 	mut ev_index := u32(0)
 	mut next_ev_frame := if nev > 0 { 0 } else { nframes }
 
-	for i := 0 ; i < nframes ;  {
+	for i := 0; i < nframes; {
 		for ev_index < nev && next_ev_frame == i {
-			event := process.in_events.get(process.in_events, ev_index)
-			header := unsafe { &C.clap_event_header_t(event) }
+			header := process.in_events.get(process.in_events, ev_index)
 
 			if header.time != i {
 				next_ev_frame = header.time
 				break
 			}
 
-			p.process_event(event)
+			p.process_event(header)
 			ev_index++
 
 			if ev_index == nev {
@@ -96,14 +93,18 @@ fn MinimalPlugin.process(clap_plugin &C.clap_plugin_t, mut process &C.clap_proce
 			}
 		}
 
-		for  ; i < next_ev_frame ; i++ {
-			in_l := unsafe { process.audio_inputs[0].data32[0][i] }
-			in_r := unsafe { process.audio_inputs[0].data32[1][i] }
+		for ; i < next_ev_frame; i++ {
+			// In general:
+			// mut inputs := []C.clap_audio_buffer_t{cap: int(process.audio_inputs_count)}
+			// for k := 0; k < process.audio_inputs_count; k++  {
+			// 	inputs << unsafe{ process.audio_inputs[k] }
+			// }
+			input_left := unsafe { process.audio_inputs[0].data32[0][i] }
+			input_right := unsafe { process.audio_inputs[0].data32[1][i] }
+
 			// Swap left and right channels.
-			out_l := in_r
-			out_r := in_l
-			unsafe { process.audio_outputs[0].data32[0][i] = out_l }
-			unsafe { process.audio_outputs[0].data32[1][i] = out_r }
+			unsafe { process.audio_outputs[0].data32[0][i] = input_right }
+			unsafe { process.audio_outputs[0].data32[1][i] = input_left }
 		}
 	}
 
@@ -122,7 +123,6 @@ fn MinimalPlugin.get_extension(clap_plugin &C.clap_plugin_t, id &char) voidptr {
 				}
 			}
 		}
-
 		clap_ext_audio_ports {
 			return &C.clap_plugin_audio_ports_t{
 				count: fn (clap_plugin &C.clap_plugin_t, is_input bool) u32 {

src/setup.v

@@ -1,5 +1,3 @@
-module plugin
-
 // Features of the CLAP plugin.
 // Have to be defined separately here, otherwise wrong C is generated.
 const _plugin_features = [