/*
 * Copyright 2000, 2001, 2002
 *         Dan Potter. All rights reserved.
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of Cryptic Allusion nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/* 2005-11-09 Modified by Walter van Niftrik. */

#include "aica_cmd_iface.h"
#include "aica.h"

extern volatile aica_channel_t *chans;

void aica_init() {
	int i, j;
	
	/* Initialize AICA channels */	
	SNDREG32(0x2800) = 0x0000;
	
	for (i=0; i<64; i++) {
		CHNREG32(i,0) = 0x8000;
		for (j=4; j<0x80; j+=4)
			CHNREG32(i, j) = 0;
		CHNREG32(i,20) = 0x1f;
	}

	SNDREG32(0x2800) = 0x000f;
}

/* Translates a volume from linear form to logarithmic form (required by
   the AICA chip */
static int logs[] = {
	0, 15, 22, 27, 31, 35, 39, 42, 45, 47, 50, 52, 55, 57, 59, 61,
	63, 65, 67, 69, 71, 73, 74, 76, 78, 79, 81, 82, 84, 85, 87, 88,
	90, 91, 92, 94, 95, 96, 98, 99, 100, 102, 103, 104, 105, 106,
	108, 109, 110, 111, 112, 113, 114, 116, 117, 118, 119, 120, 121,
	122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134,
	135, 136, 137, 138, 138, 139, 140, 141, 142, 143, 144, 145, 146,
	146, 147, 148, 149, 150, 151, 152, 152, 153, 154, 155, 156, 156,
	157, 158, 159, 160, 160, 161, 162, 163, 164, 164, 165, 166, 167,
	167, 168, 169, 170, 170, 171, 172, 173, 173, 174, 175, 176, 176,
	177, 178, 178, 179, 180, 181, 181, 182, 183, 183, 184, 185, 185,
	186, 187, 187, 188, 189, 189, 190, 191, 191, 192, 193, 193, 194,
	195, 195, 196, 197, 197, 198, 199, 199, 200, 200, 201, 202, 202,
	203, 204, 204, 205, 205, 206, 207, 207, 208, 209, 209, 210, 210,
	211, 212, 212, 213, 213, 214, 215, 215, 216, 216, 217, 217, 218,
	219, 219, 220, 220, 221, 221, 222, 223, 223, 224, 224, 225, 225,
	226, 227, 227, 228, 228, 229, 229, 230, 230, 231, 232, 232, 233,
	233, 234, 234, 235, 235, 236, 236, 237, 237, 238, 239, 239, 240,
	240, 241, 241, 242, 242, 243, 243, 244, 244, 245, 245, 246, 246,
	247, 247, 248, 248, 249, 249, 250, 250, 251, 251, 252, 252, 253, 254, 255
};

static inline int calc_aica_vol(int x) {
	return 0xff - logs[x & 0xff];
}

static inline int calc_aica_pan(int x) {
	if (x == 0x80)
		return 0;
	else if (x < 0x80) {
		return 0x10 | ((0x7f - x) >> 3);
	} else {
		return (x - 0x80) >> 3;
	}
}

/* Sets up a sound channel completely. This is generally good if you want
   a quick and dirty way to play notes. If you want a more comprehensive
   set of routines (more like PC wavetable cards) see below.
   
   ch is the channel to play on (0 - 63)
   smpptr is the pointer to the sound data; if you're running off the
     SH4, then this ought to be (ptr - 0xa0800000); otherwise it's just
     ptr. Basically, it's an offset into sound ram.
   mode is one of the mode constants (16 bit, 8 bit, ADPCM)
   nsamp is the number of samples to play (not number of bytes!)
   freq is the sampling rate of the sound
   vol is the volume, 0 to 0xff (0xff is louder)
   pan is a panning constant -- 0 is left, 128 is center, 255 is right.

   This routine (and the similar ones) owe a lot to Marcus' sound example -- 
   I hadn't gotten quite this far into dissecting the individual regs yet. */
void aica_play(int ch, int delay) {
	unsigned long smpptr	= chans[ch].base;
	int mode		= chans[ch].type;
	int loopst		= chans[ch].loopstart;
	int loopend		= chans[ch].loopend;
	int freq		= chans[ch].freq;
	int vol			= chans[ch].vol;
	int pan			= chans[ch].pan;
	int loopflag		= chans[ch].loop;
	unsigned long freq_lo, freq_base = 5644800;
	int freq_hi = 7;
	int i;
	uint32 playCont;

	/* Stop the channel (if it's already playing) */
	aica_stop(ch);
	
	/* Need to convert frequency to floating point format
	   (freq_hi is exponent, freq_lo is mantissa)
	   Formula is freq = 44100*2^freq_hi*(1+freq_lo/1024) */
	while (freq < freq_base && freq_hi > -8) {
		freq_base >>= 1;
		--freq_hi;
	}
	freq_lo = (freq<<10) / freq_base;
	
	/* Envelope setup. The first of these is the loop point,
	   e.g., where the sample starts over when it loops. The second
	   is the loop end. This is the full length of the sample when
	   you are not looping, or the loop end point when you are (though
	   storing more than that is a waste of memory if you're not doing
	   volume enveloping). */
	CHNREG32(ch, 8) = loopst & 0xffff;
	CHNREG32(ch, 12) = loopend & 0xffff;
	
	/* Write resulting values */
	CHNREG32(ch, 24) = (freq_hi << 11) | (freq_lo & 1023);
	
	/* Set volume, pan */
	CHNREG8(ch, 36) = calc_aica_pan(pan);
	CHNREG8(ch, 37) = 0xf;
	/* turn off Low Pass Filter (LPF) */
	CHNREG8(ch, 40) = 0x24;
	/* Convert the incoming volume and pan into hardware values */
	/* Vol starts at zero so we can ramp */
	CHNREG8(ch, 41) = 0xff;

	/* If we supported volume envelopes (which we don't yet) then
	   this value would set that up. The top 4 bits determine the
	   envelope speed. f is the fastest, 1 is the slowest, and 0
	   seems to be an invalid value and does weird things). The
	   default (below) sets it into normal mode (play and terminate/loop).
	CHNREG32(ch, 16) = 0xf010;
	*/
	CHNREG32(ch, 16) = 0x1f;	/* No volume envelope */
	
	
	/* Set sample format, buffer address, and looping control. If
	   0x0200 mask is set on reg 0, the sample loops infinitely. If
	   it's not set, the sample plays once and terminates. We'll
	   also set the bits to start playback here. */
	CHNREG32(ch, 4) = smpptr & 0xffff;
	playCont = (mode<<7) | (smpptr >> 16);
	vol = calc_aica_vol(vol);
	
	if (loopflag)
		playCont |= 0x0200;

	if (delay) {
		CHNREG32(ch, 0) = playCont; 		/* key off */
		CHNREG8(ch, 41) = vol;
	} else {
		CHNREG32(ch, 0) = 0xc000 | playCont;	/* key on */
	
		/* ramp up the volume */
		for (i=0xff; i>=vol; i--)
			CHNREG8(ch, 41) = i;
	}
}

/* Start sound on all channels specified by chmap bitmap */
void aica_sync_play(uint32 chmap) {
	int i = 0;
	while (chmap) {
		if (chmap & 0x1)
			CHNREG32(i, 0) = CHNREG32(i, 0) | 0xc000;
		i++;
		chmap >>= 1;
	}
}

/* Stop the sound on a given channel */
void aica_stop(int ch) {
	CHNREG32(ch, 0) = (CHNREG32(ch, 0) & ~0x4000) | 0x8000;
}


/* The rest of these routines can change the channel in mid-stride so you
   can do things like vibrato and panning effects. */
   
/* Set channel volume */
void aica_vol(int ch) {
	CHNREG8(ch, 41) = calc_aica_vol(chans[ch].vol);
}

/* Set channel pan */
void aica_pan(int ch) {
	CHNREG8(ch, 36) = calc_aica_pan(chans[ch].pan);
}

/* Set channel frequency */
void aica_freq(int ch) {
	int freq = chans[ch].freq;
	unsigned long freq_lo, freq_base = 5644800;
	int freq_hi = 7;

	while (freq < freq_base && freq_hi > -8) {
		freq_base >>= 1;
		freq_hi--;
	}
	freq_lo = (freq<<10) / freq_base;
	CHNREG32(ch, 24) = (freq_hi << 11) | (freq_lo & 1023);
}

/* Get channel position */
int aica_get_pos(int ch) {
	int i;

	/* Observe channel ch */
	SNDREG8(0x280d) = ch;

	/* Wait a while */
	for (i = 0; i < 20; i++);

	/* Update position counters */
	chans[ch].pos = SNDREG32(0x2814) & 0xffff;

	return chans[ch].pos;
}