b8d70d26fa
This update uses upstream commit f88ef828a600ce66d1f730c8fb2a7f580f6f6165. This update switches to use the new Munt C++ interface, which will allow ScummVM to link to an external Munt library instead of requiring it to be built-in in the future. For the moment, the emulator is still built-in, since it is not available from most package repositories. The Munt driver in ScummVM now uses writeSysex instead of the (now-private) playSysexWithoutFraming, per recommendation from the Munt team <https://github.com/munt/munt/pull/30>. This changeset also removes direct modifications that used to be made to Munt code, to ease future updates. To update Munt code in the future: 1. Replace all source files in the `softsynth/mt32` directory with new files from the upstream `mt32emu/src` directory; 2. Update `config.h` with the correct version number for the new version of Munt; 3. Update `module.mk` to add any new source files that need to be built.
97 lines
3.7 KiB
C++
Executable file
97 lines
3.7 KiB
C++
Executable file
/* Copyright (C) 2003, 2004, 2005, 2006, 2008, 2009 Dean Beeler, Jerome Fisher
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* Copyright (C) 2011-2016 Dean Beeler, Jerome Fisher, Sergey V. Mikayev
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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 Lesser General Public License as published by
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* the Free Software Foundation, either version 2.1 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 Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "internals.h"
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#include "Tables.h"
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#include "mmath.h"
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namespace MT32Emu {
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// UNUSED: const int MIDDLEC = 60;
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const Tables &Tables::getInstance() {
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static const Tables instance;
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return instance;
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}
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Tables::Tables() {
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for (int lf = 0; lf <= 100; lf++) {
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// CONFIRMED:KG: This matches a ROM table found by Mok
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float fVal = (2.0f - LOG10F(float(lf) + 1.0f)) * 128.0f;
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int val = int(fVal + 1.0);
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if (val > 255) {
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val = 255;
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}
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levelToAmpSubtraction[lf] = Bit8u(val);
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}
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envLogarithmicTime[0] = 64;
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for (int lf = 1; lf <= 255; lf++) {
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// CONFIRMED:KG: This matches a ROM table found by Mok
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envLogarithmicTime[lf] = Bit8u(ceil(64.0f + LOG2F(float(lf)) * 8.0f));
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}
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#if 0
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// The table below is to be used in conjunction with emulation of VCA of newer generation units which is currently missing.
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// These relatively small values are rather intended to fine-tune the overall amplification of the VCA.
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// CONFIRMED: Based on a table found by Mok in the LAPC-I control ROM
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// Note that this matches the MT-32 table, but with the values clamped to a maximum of 8.
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memset(masterVolToAmpSubtraction, 8, 71);
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memset(masterVolToAmpSubtraction + 71, 7, 3);
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memset(masterVolToAmpSubtraction + 74, 6, 4);
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memset(masterVolToAmpSubtraction + 78, 5, 3);
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memset(masterVolToAmpSubtraction + 81, 4, 4);
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memset(masterVolToAmpSubtraction + 85, 3, 3);
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memset(masterVolToAmpSubtraction + 88, 2, 4);
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memset(masterVolToAmpSubtraction + 92, 1, 4);
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memset(masterVolToAmpSubtraction + 96, 0, 5);
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#else
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// CONFIRMED: Based on a table found by Mok in the MT-32 control ROM
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masterVolToAmpSubtraction[0] = 255;
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for (int masterVol = 1; masterVol <= 100; masterVol++) {
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masterVolToAmpSubtraction[masterVol] = Bit8u(106.31 - 16.0f * LOG2F(float(masterVol)));
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}
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#endif
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for (int i = 0; i <= 100; i++) {
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pulseWidth100To255[i] = Bit8u(i * 255 / 100.0f + 0.5f);
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//synth->printDebug("%d: %d", i, pulseWidth100To255[i]);
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}
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// The LA32 chip contains an exponent table inside. The table contains 12-bit integer values.
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// The actual table size is 512 rows. The 9 higher bits of the fractional part of the argument are used as a lookup address.
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// To improve the precision of computations, the lower bits are supposed to be used for interpolation as the LA32 chip also
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// contains another 512-row table with inverted differences between the main table values.
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for (int i = 0; i < 512; i++) {
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exp9[i] = Bit16u(8191.5f - EXP2F(13.0f + ~i / 512.0f));
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}
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// There is a logarithmic sine table inside the LA32 chip. The table contains 13-bit integer values.
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for (int i = 1; i < 512; i++) {
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logsin9[i] = Bit16u(0.5f - LOG2F(sin((i + 0.5f) / 1024.0f * FLOAT_PI)) * 1024.0f);
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}
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// The very first value is clamped to the maximum possible 13-bit integer
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logsin9[0] = 8191;
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// found from sample analysis
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static const Bit8u resAmpDecayFactorTable[] = {31, 16, 12, 8, 5, 3, 2, 1};
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resAmpDecayFactor = resAmpDecayFactorTable;
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}
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} // namespace MT32Emu
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