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https://github.com/wavemotion-dave/A7800DS.git
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252 lines
9.4 KiB
C
252 lines
9.4 KiB
C
// ----------------------------------------------------------------------------
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// ___ ___ ___ ___ ___ ____ ___ _ _
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// /__/ /__/ / / /__ /__/ /__ / /_ / |/ /
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// / / \ /__/ ___/ ___/ ___/ / /__ / / emulator
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//
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// ----------------------------------------------------------------------------
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// Copyright 2005 Greg Stanton
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//
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// This program is free software; you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation; either version 2 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, write to the Free Software
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// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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// ----------------------------------------------------------------------------
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// TiaSound is Copyright(c) 1997 by Ron Fries
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//
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// This library is free software; you can redistribute it and/or modify it
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// under the terms of version 2 of the GNU Library General Public License
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// as published by the Free Software Foundation.
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//
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// This library is distributed in the hope that it will be useful, but
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// WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library
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// General Public License for more details.
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// To obtain a copy of the GNU Library General Public License, write to the
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// Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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//
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// Any permitted reproduction of these routines, in whole or in part, must
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// bear this legend.
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// ----------------------------------------------------------------------------
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// Tia.cpp
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// ----------------------------------------------------------------------------
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#include "Tia.h"
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#define TIA_POLY4_SIZE 15
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#define TIA_POLY5_SIZE 31
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#define TIA_POLY9_SIZE 511
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u32 tiaBufIdx __attribute__((section(".dtcm"))) = 0;
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u16 tia_buffer[SNDLENGTH] __attribute__((section(".dtcm"))) = {0};
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byte tia_volume[2] __attribute__((section(".dtcm"))) = {0};
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uint tia_counter[2] __attribute__((section(".dtcm"))) = {0};
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uint tia_counterMax[2] __attribute__((section(".dtcm"))) = {0};
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byte TIA_POLY4[ ] __attribute__((section(".dtcm"))) = {1,1,0,1,1,1,0,0,0,0,1,0,1,0,0};
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byte TIA_POLY5[ ] __attribute__((section(".dtcm"))) = {0,0,1,0,1,1,0,0,1,1,1,1,1,0,0,0,1,1,0,1,1,1,0,1,0,1,0,0,0,0,1};
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static byte TIA_POLY9[ ] __attribute__((section(".dtcm"))) = {0,0,1,0,1,0,0,0,1,0,0,0,0,0,0,0,1,0,1,1,1,0,0,1,0,1,0,0,1,1,1,1,1,0,0,1,1,0,1,1,0,1,0,1,1,1,0,1,1,0,0,1,0,0,1,1,1,1,0,1,0,0,0,0,1,1,0,1,1,0,0,0,1,0,0,0,1,1,1,1,0,1,0,1,1,0,1,0,1,0,0,0,0,1,1,0,1,0,1,0,0,0,1,0,1,0,0,0,1,1,1,0,0,1,1,0,1,1,0,0,1,1,1,1,1,0,0,1,1,0,0,0,1,1,0,1,0,0,0,1,1,0,0,1,1,1,1,0,0,1,0,0,0,1,1,1,0,0,1,1,0,1,0,1,1,0,1,1,0,1,0,0,1,0,0,1,1,1,1,1,1,0,1,1,1,1,0,1,1,0,0,0,0,1,1,1,1,1,0,0,0,1,0,0,0,0,1,0,0,0,1,0,1,0,1,1,0,0,0,0,1,0,1,1,1,1,0,1,0,0,0,1,1,0,0,0,1,1,1,0,1,1,1,0,1,0,0,0,0,0,0,0,0,1,0,1,0,0,1,0,0,0,0,1,1,1,0,0,0,1,1,1,0,0,1,1,0,0,1,0,0,1,0,1,1,0,0,0,0,1,0,0,0,1,0,0,0,1,0,1,1,1,1,0,0,0,1,1,1,0,0,0,1,0,0,1,1,1,1,0,1,1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,0,1,0,1,1,1,1,0,0,1,0,1,0,1,1,1,0,0,0,0,0,1,1,0,1,1,0,0,0,1,0,1,0,1,0,0,0,0,1,0,1,1,1,0,0,0,0,1,0,0,1,0,1,0,0,0,1,0,1,1,1,0,0,1,1,1,1,1,1,1,0,0,0,0,0,1,0,0,1,1,0,1,0,0,1,0,0,0,1,0,0,1,0,1,0,0,0,1,1,0,1,0,0,0,0,0,1,1,1,1,0,0,1,0,0,1,0,1,1,1,1,1,1,1,0,1,0,0,1,0,0,0,1,1,0,1,1,1,0,0,0,1,0,1,0,0,1,0,1,0,1,0,1,1,1,0,0,1,0,1,1,0,0,1,1,1,1,1,0,0,0,1,1,0};
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static byte TIA_DIV31[ ] __attribute__((section(".dtcm"))) = {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0};
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byte tia_audc[2] __attribute__((section(".dtcm"))) = {0};
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byte tia_audf[2] __attribute__((section(".dtcm"))) = {0};
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byte tia_audv[2] __attribute__((section(".dtcm"))) = {0};
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static byte tia_poly4Cntr[2] __attribute__((section(".dtcm"))) = {0};
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static byte tia_poly5Cntr[2] __attribute__((section(".dtcm"))) = {0};
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static u16 tia_poly9Cntr[2] __attribute__((section(".dtcm"))) = {0};
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u16 tia_wait __attribute__((section(".dtcm"))) = 0;
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// ----------------------------------------------------------------------------
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// ProcessChannel
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// ----------------------------------------------------------------------------
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static ITCM_CODE void tia_ProcessChannel0(void)
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{
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tia_poly5Cntr[0] = (tia_poly5Cntr[0] + 1) % TIA_POLY5_SIZE;
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if(((tia_audc[0] & 2) == 0) || (((tia_audc[0] & 1) == 0) && TIA_DIV31[tia_poly5Cntr[0]]) || (((tia_audc[0] & 1) == 1) && TIA_POLY5[tia_poly5Cntr[0]]))
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{
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if(tia_audc[0] & 4)
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{
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tia_volume[0] = (!tia_volume[0])? tia_audv[0]: 0;
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}
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else if(tia_audc[0] & 8)
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{
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if(tia_audc[0] == 8)
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{
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tia_poly9Cntr[0] = (tia_poly9Cntr[0]+1) % TIA_POLY9_SIZE;
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tia_volume[0] = (TIA_POLY9[tia_poly9Cntr[0]])? tia_audv[0]: 0;
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}
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else
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{
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tia_volume[0] = (TIA_POLY5[tia_poly5Cntr[0]])? tia_audv[0]: 0;
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}
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}
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else
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{
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tia_poly4Cntr[0] = (tia_poly4Cntr[0] + 1) % TIA_POLY4_SIZE;
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tia_volume[0] = (TIA_POLY4[tia_poly4Cntr[0]])? tia_audv[0]: 0;
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}
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}
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}
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static ITCM_CODE void tia_ProcessChannel1(void)
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{
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tia_poly5Cntr[1] = (tia_poly5Cntr[1] + 1) % TIA_POLY5_SIZE;
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if(((tia_audc[1] & 2) == 0) || (((tia_audc[1] & 1) == 0) && TIA_DIV31[tia_poly5Cntr[1]]) || (((tia_audc[1] & 1) == 1) && TIA_POLY5[tia_poly5Cntr[1]]))
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{
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if(tia_audc[1] & 4)
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{
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tia_volume[1] = (!tia_volume[1])? tia_audv[1]: 0;
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}
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else if(tia_audc[1] & 8)
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{
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if(tia_audc[1] == 8)
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{
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tia_poly9Cntr[1] = (tia_poly9Cntr[1]+1) % TIA_POLY9_SIZE;
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tia_volume[1] = (TIA_POLY9[tia_poly9Cntr[1]])? tia_audv[1]: 0;
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}
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else
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{
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tia_volume[1] = (TIA_POLY5[tia_poly5Cntr[1]])? tia_audv[1]: 0;
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}
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}
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else
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{
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tia_poly4Cntr[1] = (tia_poly4Cntr[1] + 1) % TIA_POLY4_SIZE;
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tia_volume[1] = (TIA_POLY4[tia_poly4Cntr[1]])? tia_audv[1]: 0;
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}
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}
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}
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// ----------------------------------------------------------------------------
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// Reset
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// ----------------------------------------------------------------------------
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void tia_Reset( ) {
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uint index;
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tiaBufIdx = 0;
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for(index = 0; index < 2; index++) {
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tia_volume[index] = 0;
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tia_counterMax[index] = 0;
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tia_counter[index] = 0;
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tia_audc[index] = 0;
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tia_audf[index] = 0;
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tia_audv[index] = 0;
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tia_poly4Cntr[index] = 0;
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tia_poly5Cntr[index] = 0;
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tia_poly9Cntr[index] = 0;
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}
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tia_Clear( );
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tia_wait = 0;
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}
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// ----------------------------------------------------------------------------
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// Clear
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// ----------------------------------------------------------------------------
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void tia_Clear( ) {
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uint index;
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for(index = 0; index < SNDLENGTH; index++) {
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tia_buffer[index] = 0;
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}
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}
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// Same as TIA_Process but designed for Pokey integration...
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ITCM_CODE int TIA_Sample(void)
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{
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if(tia_counter[0] > 1)
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{
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tia_counter[0]--;
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}
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else if(tia_counter[0] == 1)
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{
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tia_counter[0] = tia_counterMax[0];
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tia_ProcessChannel0();
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}
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if(tia_counter[1] > 1)
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{
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tia_counter[1]--;
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}
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else if(tia_counter[1] == 1)
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{
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tia_counter[1] = tia_counterMax[1];
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tia_ProcessChannel1();
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}
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return ((int)tia_volume[0] + (int)tia_volume[1]);
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}
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// --------------------------------------------------------------------------------------
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// Process
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// --------------------------------------------------------------------------------------
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ITCM_CODE void tia_Process(void)
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{
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u32 samp[2];
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if (tia_wait) return;
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for(u8 index = 0; index < 2; index++)
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{
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if(tia_counter[0] > 1)
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{
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tia_counter[0]--;
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}
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else if(tia_counter[0] == 1)
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{
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tia_counter[0] = tia_counterMax[0];
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tia_ProcessChannel0();
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}
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if(tia_counter[1] > 1)
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{
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tia_counter[1]--;
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}
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else if(tia_counter[1] == 1)
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{
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tia_counter[1] = tia_counterMax[1];
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tia_ProcessChannel1();
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}
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samp[index] = ((tia_volume[0] + tia_volume[1]));
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}
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// We have filled the buffer... let the buffer drain a bit
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if (((tiaBufIdx+1) & (SNDLENGTH-1)) == myTiaBufIdx)
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{
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tia_wait = (SNDLENGTH >> 2);
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}
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else
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{
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tia_buffer[tiaBufIdx++] = (samp[1] << 8) | (samp[0]);
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tiaBufIdx &= (SNDLENGTH-1);
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}
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}
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ITCM_CODE u16 tia_ProcessNow(void)
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{
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u32 samp[2];
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for(u8 index = 0; index < 2; index++)
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{
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if(tia_counter[0] > 1)
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{
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tia_counter[0]--;
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}
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else if(tia_counter[0] == 1)
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{
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tia_counter[0] = tia_counterMax[0];
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tia_ProcessChannel0();
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}
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if(tia_counter[1] > 1)
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{
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tia_counter[1]--;
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}
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else if(tia_counter[1] == 1)
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{
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tia_counter[1] = tia_counterMax[1];
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tia_ProcessChannel1();
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}
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samp[index] = ((tia_volume[0] + tia_volume[1]));
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}
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return (u16)((samp[1] << 8) | (samp[0]));
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}
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