/*
	BASS simple DSP test
	Copyright (c) 2000-2017 Un4seen Developments Ltd.
*/

#include <gtk/gtk.h>
#include <glade/glade.h>
#include <string.h>
#include <regex.h>
#include <math.h>
#include "bass.h"

#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

// path to glade file
#ifndef GLADE_PATH
#define GLADE_PATH ""
#endif

GladeXML *glade;
GtkWidget *win = 0;
GtkWidget *filesel;

DWORD chan;	// the channel... HMUSIC or HSTREAM

// display error messages
void Error(const char *es)
{
	GtkWidget *dialog = gtk_message_dialog_new(GTK_WINDOW(win), GTK_DIALOG_DESTROY_WITH_PARENT,
		GTK_MESSAGE_ERROR, GTK_BUTTONS_OK, "%s\n(error code: %d)", es, BASS_ErrorGetCode());
	gtk_dialog_run(GTK_DIALOG(dialog));
	gtk_widget_destroy(dialog);
}

// "rotate"
HDSP rotdsp = 0;	// DSP handle
float rotpos;	// cur.pos
void CALLBACK Rotate(HDSP handle, DWORD channel, void *buffer, DWORD length, void *user)
{
	float *d = (float*)buffer;
	DWORD a;

	for (a = 0; a < length / 4; a += 2) {
		d[a] *= fabs(sin(rotpos));
		d[a + 1] *= fabs(cos(rotpos));
		rotpos += 0.00003;
	}
	rotpos = fmod(rotpos, 2 * M_PI);
}

// "echo"
HDSP echdsp = 0;	// DSP handle
#define ECHBUFLEN 1200	// buffer length
float echbuf[ECHBUFLEN][2];	// buffer
int echpos;	// cur.pos
void CALLBACK Echo(HDSP handle, DWORD channel, void *buffer, DWORD length, void *user)
{
	float *d = (float*)buffer;
	DWORD a;

	for (a = 0; a < length / 4; a += 2) {
		float l = d[a] + (echbuf[echpos][1] / 2);
		float r = d[a + 1] + (echbuf[echpos][0] / 2);
#if 1 // 0=echo, 1=basic "bathroom" reverb
		echbuf[echpos][0] = d[a] = l;
		echbuf[echpos][1] = d[a + 1] = r;
#else
		echbuf[echpos][0] = d[a];
		echbuf[echpos][1] = d[a + 1];
		d[a] = l;
		d[a + 1] = r;
#endif
		echpos++;
		if (echpos == ECHBUFLEN) echpos = 0;
	}
}

// "flanger"
HDSP fladsp = 0;	// DSP handle
#define FLABUFLEN 350	// buffer length
float flabuf[FLABUFLEN][2];	// buffer
int flapos;	// cur.pos
float flas, flasinc;	// sweep pos/increment
void CALLBACK Flange(HDSP handle, DWORD channel, void *buffer, DWORD length, void *user)
{
	float *d = (float*)buffer;
	DWORD a;

	for (a = 0; a < length / 4; a += 2) {
		int p1 = (flapos + (int)flas) % FLABUFLEN;
		int p2 = (p1 + 1) % FLABUFLEN;
		float f = flas - (int)flas;
		float s;

		s = (d[a] + ((flabuf[p1][0] * (1 - f)) + (flabuf[p2][0] * f))) * 0.7;
		flabuf[flapos][0] = d[a];
		d[a] = s;

		s = (d[a + 1] + ((flabuf[p1][1] * (1 - f)) + (flabuf[p2][1] * f))) * 0.7;
		flabuf[flapos][1] = d[a + 1];
		d[a + 1] = s;

		flapos++;
		if (flapos == FLABUFLEN) flapos = 0;
		flas += flasinc;
		if (flas<0 || flas>FLABUFLEN - 1) {
			flasinc = -flasinc;
			flas += flasinc;
		}
	}
}

#define GetWidget(id) glade_xml_get_widget(glade,id)

void WindowDestroy(GtkObject *obj, gpointer data)
{
	gtk_main_quit();
}

void RotateToggled(GtkToggleButton *obj, gpointer data)
{ // toggle "rotate"
	if (obj->active) {
		rotpos = M_PI / 4;
		rotdsp = BASS_ChannelSetDSP(chan, &Rotate, 0, 2);
	} else
		BASS_ChannelRemoveDSP(chan, rotdsp);
}

void EchoToggled(GtkToggleButton *obj, gpointer data)
{ // toggle "echo"
	if (obj->active) {
		memset(echbuf, 0, sizeof(echbuf));
		echpos = 0;
		echdsp = BASS_ChannelSetDSP(chan, &Echo, 0, 1);
	} else
		BASS_ChannelRemoveDSP(chan, echdsp);
}

void FlangerToggled(GtkToggleButton *obj, gpointer data)
{ // toggle "flanger"
	if (obj->active) {
		memset(flabuf, 0, sizeof(flabuf));
		flapos = 0;
		flas = FLABUFLEN / 2;
		flasinc = 0.002f;
		fladsp = BASS_ChannelSetDSP(chan, &Flange, 0, 0);
	} else
		BASS_ChannelRemoveDSP(chan, fladsp);
}

gboolean FileExtensionFilter(const GtkFileFilterInfo *info, gpointer data)
{
	return !regexec((regex_t*)data, info->filename, 0, NULL, 0);
}

void OpenClicked(GtkButton *obj, gpointer data)
{
	int resp = gtk_dialog_run(GTK_DIALOG(filesel));
	gtk_widget_hide(filesel);
	if (resp == GTK_RESPONSE_ACCEPT) {
		char *file = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(filesel));
		// free both MOD and stream, it must be one of them! :)
		BASS_MusicFree(chan);
		BASS_StreamFree(chan);
		if (!(chan = BASS_StreamCreateFile(FALSE, file, 0, 0, BASS_SAMPLE_LOOP | BASS_SAMPLE_FLOAT))
			&& !(chan = BASS_MusicLoad(FALSE, file, 0, 0, BASS_MUSIC_RAMPS | BASS_SAMPLE_LOOP | BASS_SAMPLE_FLOAT, 1))) {
			// whatever it is, it ain't playable
			gtk_button_set_label(obj, "click here to open a file...");
			Error("Can't play the file");
		} else {
			BASS_CHANNELINFO info;
			BASS_ChannelGetInfo(chan, &info);
			if (info.chans != 2) { // the DSP expects stereo
				gtk_button_set_label(obj, "click here to open a file...");
				BASS_MusicFree(chan);
				BASS_StreamFree(chan);
				Error("only stereo sources are supported");
			} else {
				gtk_button_set_label(obj, file);
				// setup DSPs on new channel and play it
				RotateToggled(GTK_TOGGLE_BUTTON(GetWidget("rotate")), 0);
				EchoToggled(GTK_TOGGLE_BUTTON(GetWidget("echo")), 0);
				FlangerToggled(GTK_TOGGLE_BUTTON(GetWidget("flanger")), 0);
				BASS_ChannelPlay(chan, FALSE);
			}
		}
		g_free(file);
	}
}

int main(int argc, char* argv[])
{
	regex_t fregex;

	gtk_init(&argc, &argv);

	// check the correct BASS was loaded
	if (HIWORD(BASS_GetVersion()) != BASSVERSION) {
		Error("An incorrect version of BASS was loaded");
		return 0;
	}

	// check for floating-point capability
	if (!BASS_GetConfig(BASS_CONFIG_FLOAT)) {
		Error("This example requires floating-point support");
		return 0;
	}

	// enable floating-point DSP (not really necessary as the channels will be floating-point anyway)
	BASS_SetConfig(BASS_CONFIG_FLOATDSP, TRUE);

	// initialize default device
	if (!BASS_Init(-1, 44100, 0, NULL, NULL)) {
		Error("Can't initialize device");
		return 0;
	}

	// initialize GUI
	glade = glade_xml_new(GLADE_PATH"dsptest.glade", NULL, NULL);
	if (!glade) return 0;
	win = GetWidget("window1");
	if (!win) return 0;
	glade_xml_signal_autoconnect(glade);

	{ // initialize file selector
		GtkFileFilter *filter;
		filesel = gtk_file_chooser_dialog_new("Open File", GTK_WINDOW(win), GTK_FILE_CHOOSER_ACTION_OPEN,
			GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL, GTK_STOCK_OPEN, GTK_RESPONSE_ACCEPT, NULL);
		filter = gtk_file_filter_new();
		gtk_file_filter_set_name(filter, "Playable files");
		regcomp(&fregex, "\\.(mo3|xm|mod|s3m|it|umx|mp[1-3]|ogg|wav|aif)$", REG_ICASE | REG_NOSUB | REG_EXTENDED);
		gtk_file_filter_add_custom(filter, GTK_FILE_FILTER_FILENAME, FileExtensionFilter, &fregex, NULL);
		gtk_file_chooser_add_filter(GTK_FILE_CHOOSER(filesel), filter);
		filter = gtk_file_filter_new();
		gtk_file_filter_set_name(filter, "All files");
		gtk_file_filter_add_pattern(filter, "*");
		gtk_file_chooser_add_filter(GTK_FILE_CHOOSER(filesel), filter);
	}

	gtk_main();

	gtk_widget_destroy(filesel);
	regfree(&fregex);

	BASS_Free();

	return 0;
}