| 1 | /***************************************************************************\r |
| 2 | reverb.c - description\r |
| 3 | -------------------\r |
| 4 | begin : Wed May 15 2002\r |
| 5 | copyright : (C) 2002 by Pete Bernert\r |
| 6 | email : BlackDove@addcom.de\r |
| 7 | \r |
| 8 | Portions (C) GraÅžvydas "notaz" Ignotas, 2010-2011\r |
| 9 | Portions (C) SPU2-X, gigaherz, Pcsx2 Development Team\r |
| 10 | \r |
| 11 | ***************************************************************************/\r |
| 12 | /***************************************************************************\r |
| 13 | * *\r |
| 14 | * This program is free software; you can redistribute it and/or modify *\r |
| 15 | * it under the terms of the GNU General Public License as published by *\r |
| 16 | * the Free Software Foundation; either version 2 of the License, or *\r |
| 17 | * (at your option) any later version. See also the license.txt file for *\r |
| 18 | * additional informations. *\r |
| 19 | * *\r |
| 20 | ***************************************************************************/\r |
| 21 | \r |
| 22 | #include "stdafx.h"\r |
| 23 | \r |
| 24 | #define _IN_REVERB\r |
| 25 | \r |
| 26 | // will be included from spu.c\r |
| 27 | #ifdef _IN_SPU\r |
| 28 | \r |
| 29 | ////////////////////////////////////////////////////////////////////////\r |
| 30 | // globals\r |
| 31 | ////////////////////////////////////////////////////////////////////////\r |
| 32 | \r |
| 33 | // REVERB info and timing vars...\r |
| 34 | \r |
| 35 | int * sRVBPlay = 0;\r |
| 36 | int * sRVBEnd = 0;\r |
| 37 | int * sRVBStart = 0;\r |
| 38 | \r |
| 39 | ////////////////////////////////////////////////////////////////////////\r |
| 40 | // START REVERB\r |
| 41 | ////////////////////////////////////////////////////////////////////////\r |
| 42 | \r |
| 43 | INLINE void StartREVERB(int ch)\r |
| 44 | {\r |
| 45 | if(s_chan[ch].bReverb && (spuCtrl&0x80)) // reverb possible?\r |
| 46 | {\r |
| 47 | s_chan[ch].bRVBActive=!!iUseReverb;\r |
| 48 | }\r |
| 49 | else s_chan[ch].bRVBActive=0; // else -> no reverb\r |
| 50 | }\r |
| 51 | \r |
| 52 | ////////////////////////////////////////////////////////////////////////\r |
| 53 | // HELPER FOR NEILL'S REVERB: re-inits our reverb mixing buf\r |
| 54 | ////////////////////////////////////////////////////////////////////////\r |
| 55 | \r |
| 56 | INLINE void InitREVERB(void)\r |
| 57 | {\r |
| 58 | memset(sRVBStart,0,NSSIZE*2*4);\r |
| 59 | }\r |
| 60 | \r |
| 61 | ////////////////////////////////////////////////////////////////////////\r |
| 62 | // STORE REVERB\r |
| 63 | ////////////////////////////////////////////////////////////////////////\r |
| 64 | \r |
| 65 | INLINE void StoreREVERB(int ch,int ns,int l,int r)\r |
| 66 | {\r |
| 67 | ns<<=1;\r |
| 68 | \r |
| 69 | sRVBStart[ns] +=l; // -> we mix all active reverb channels into an extra buffer\r |
| 70 | sRVBStart[ns+1]+=r;\r |
| 71 | }\r |
| 72 | \r |
| 73 | ////////////////////////////////////////////////////////////////////////\r |
| 74 | \r |
| 75 | INLINE int rvb2ram_offs(int curr, int space, int iOff)\r |
| 76 | {\r |
| 77 | iOff += curr;\r |
| 78 | if (iOff >= 0x40000) iOff -= space;\r |
| 79 | return iOff;\r |
| 80 | }\r |
| 81 | \r |
| 82 | // get_buffer content helper: takes care about wraps\r |
| 83 | #define g_buffer(var) \\r |
| 84 | ((int)(signed short)spuMem[rvb2ram_offs(curr_addr, space, rvb.n##var)])\r |
| 85 | \r |
| 86 | // saturate iVal and store it as var\r |
| 87 | #define s_buffer(var, iVal) \\r |
| 88 | ssat32_to_16(iVal); \\r |
| 89 | spuMem[rvb2ram_offs(curr_addr, space, rvb.n##var)] = iVal\r |
| 90 | \r |
| 91 | #define s_buffer1(var, iVal) \\r |
| 92 | ssat32_to_16(iVal); \\r |
| 93 | spuMem[rvb2ram_offs(curr_addr, space, rvb.n##var + 1)] = iVal\r |
| 94 | \r |
| 95 | ////////////////////////////////////////////////////////////////////////\r |
| 96 | \r |
| 97 | // portions based on spu2-x from PCSX2\r |
| 98 | static void MixREVERB(void)\r |
| 99 | {\r |
| 100 | int l_old = rvb.iRVBLeft;\r |
| 101 | int r_old = rvb.iRVBRight;\r |
| 102 | int curr_addr = rvb.CurrAddr;\r |
| 103 | int space = 0x40000 - rvb.StartAddr;\r |
| 104 | int l, r, ns;\r |
| 105 | \r |
| 106 | for (ns = 0; ns < NSSIZE*2; )\r |
| 107 | {\r |
| 108 | int IIR_ALPHA = rvb.IIR_ALPHA;\r |
| 109 | int ACC0, ACC1, FB_A0, FB_A1, FB_B0, FB_B1;\r |
| 110 | int mix_dest_a0, mix_dest_a1, mix_dest_b0, mix_dest_b1;\r |
| 111 | \r |
| 112 | int input_L = sRVBStart[ns] * rvb.IN_COEF_L;\r |
| 113 | int input_R = sRVBStart[ns+1] * rvb.IN_COEF_R;\r |
| 114 | \r |
| 115 | int IIR_INPUT_A0 = ((g_buffer(IIR_SRC_A0) * rvb.IIR_COEF) + input_L) >> 15;\r |
| 116 | int IIR_INPUT_A1 = ((g_buffer(IIR_SRC_A1) * rvb.IIR_COEF) + input_R) >> 15;\r |
| 117 | int IIR_INPUT_B0 = ((g_buffer(IIR_SRC_B0) * rvb.IIR_COEF) + input_L) >> 15;\r |
| 118 | int IIR_INPUT_B1 = ((g_buffer(IIR_SRC_B1) * rvb.IIR_COEF) + input_R) >> 15;\r |
| 119 | \r |
| 120 | int iir_dest_a0 = g_buffer(IIR_DEST_A0);\r |
| 121 | int iir_dest_a1 = g_buffer(IIR_DEST_A1);\r |
| 122 | int iir_dest_b0 = g_buffer(IIR_DEST_B0);\r |
| 123 | int iir_dest_b1 = g_buffer(IIR_DEST_B1);\r |
| 124 | \r |
| 125 | int IIR_A0 = iir_dest_a0 + ((IIR_INPUT_A0 - iir_dest_a0) * IIR_ALPHA >> 15);\r |
| 126 | int IIR_A1 = iir_dest_a1 + ((IIR_INPUT_A1 - iir_dest_a1) * IIR_ALPHA >> 15);\r |
| 127 | int IIR_B0 = iir_dest_b0 + ((IIR_INPUT_B0 - iir_dest_b0) * IIR_ALPHA >> 15);\r |
| 128 | int IIR_B1 = iir_dest_b1 + ((IIR_INPUT_B1 - iir_dest_b1) * IIR_ALPHA >> 15);\r |
| 129 | \r |
| 130 | s_buffer1(IIR_DEST_A0, IIR_A0);\r |
| 131 | s_buffer1(IIR_DEST_A1, IIR_A1);\r |
| 132 | s_buffer1(IIR_DEST_B0, IIR_B0);\r |
| 133 | s_buffer1(IIR_DEST_B1, IIR_B1);\r |
| 134 | \r |
| 135 | ACC0 = (g_buffer(ACC_SRC_A0) * rvb.ACC_COEF_A +\r |
| 136 | g_buffer(ACC_SRC_B0) * rvb.ACC_COEF_B +\r |
| 137 | g_buffer(ACC_SRC_C0) * rvb.ACC_COEF_C +\r |
| 138 | g_buffer(ACC_SRC_D0) * rvb.ACC_COEF_D) >> 15;\r |
| 139 | ACC1 = (g_buffer(ACC_SRC_A1) * rvb.ACC_COEF_A +\r |
| 140 | g_buffer(ACC_SRC_B1) * rvb.ACC_COEF_B +\r |
| 141 | g_buffer(ACC_SRC_C1) * rvb.ACC_COEF_C +\r |
| 142 | g_buffer(ACC_SRC_D1) * rvb.ACC_COEF_D) >> 15;\r |
| 143 | \r |
| 144 | FB_A0 = g_buffer(FB_SRC_A0);\r |
| 145 | FB_A1 = g_buffer(FB_SRC_A1);\r |
| 146 | FB_B0 = g_buffer(FB_SRC_B0);\r |
| 147 | FB_B1 = g_buffer(FB_SRC_B1);\r |
| 148 | \r |
| 149 | mix_dest_a0 = ACC0 - ((FB_A0 * rvb.FB_ALPHA) >> 15);\r |
| 150 | mix_dest_a1 = ACC1 - ((FB_A1 * rvb.FB_ALPHA) >> 15);\r |
| 151 | \r |
| 152 | mix_dest_b0 = FB_A0 + (((ACC0 - FB_A0) * rvb.FB_ALPHA - FB_B0 * rvb.FB_X) >> 15);\r |
| 153 | mix_dest_b1 = FB_A1 + (((ACC1 - FB_A1) * rvb.FB_ALPHA - FB_B1 * rvb.FB_X) >> 15);\r |
| 154 | \r |
| 155 | s_buffer(MIX_DEST_A0, mix_dest_a0);\r |
| 156 | s_buffer(MIX_DEST_A1, mix_dest_a1);\r |
| 157 | s_buffer(MIX_DEST_B0, mix_dest_b0);\r |
| 158 | s_buffer(MIX_DEST_B1, mix_dest_b1);\r |
| 159 | \r |
| 160 | l = (mix_dest_a0 + mix_dest_b0) / 3;\r |
| 161 | r = (mix_dest_a1 + mix_dest_b1) / 3;\r |
| 162 | \r |
| 163 | l = (l * rvb.VolLeft) >> 14;\r |
| 164 | r = (r * rvb.VolRight) >> 14;\r |
| 165 | \r |
| 166 | SSumLR[ns++] += (l + l_old) / 2;\r |
| 167 | SSumLR[ns++] += (r + r_old) / 2;\r |
| 168 | SSumLR[ns++] += l;\r |
| 169 | SSumLR[ns++] += r;\r |
| 170 | \r |
| 171 | l_old = l;\r |
| 172 | r_old = r;\r |
| 173 | \r |
| 174 | curr_addr++;\r |
| 175 | if (curr_addr >= 0x40000) curr_addr = rvb.StartAddr;\r |
| 176 | }\r |
| 177 | \r |
| 178 | rvb.iRVBLeft = l;\r |
| 179 | rvb.iRVBRight = r;\r |
| 180 | rvb.CurrAddr = curr_addr;\r |
| 181 | }\r |
| 182 | \r |
| 183 | static void prepare_offsets(void)\r |
| 184 | {\r |
| 185 | int space = 0x40000 - rvb.StartAddr;\r |
| 186 | int t;\r |
| 187 | #define prep_offs(v) \\r |
| 188 | t = rvb.v; \\r |
| 189 | while (t >= space) \\r |
| 190 | t -= space; \\r |
| 191 | rvb.n##v = t\r |
| 192 | #define prep_offs2(d, v1, v2) \\r |
| 193 | t = rvb.v1 - rvb.v2; \\r |
| 194 | while (t >= space) \\r |
| 195 | t -= space; \\r |
| 196 | rvb.n##d = t\r |
| 197 | \r |
| 198 | prep_offs(IIR_SRC_A0);\r |
| 199 | prep_offs(IIR_SRC_A1);\r |
| 200 | prep_offs(IIR_SRC_B0);\r |
| 201 | prep_offs(IIR_SRC_B1);\r |
| 202 | prep_offs(IIR_DEST_A0);\r |
| 203 | prep_offs(IIR_DEST_A1);\r |
| 204 | prep_offs(IIR_DEST_B0);\r |
| 205 | prep_offs(IIR_DEST_B1);\r |
| 206 | prep_offs(ACC_SRC_A0);\r |
| 207 | prep_offs(ACC_SRC_A1);\r |
| 208 | prep_offs(ACC_SRC_B0);\r |
| 209 | prep_offs(ACC_SRC_B1);\r |
| 210 | prep_offs(ACC_SRC_C0);\r |
| 211 | prep_offs(ACC_SRC_C1);\r |
| 212 | prep_offs(ACC_SRC_D0);\r |
| 213 | prep_offs(ACC_SRC_D1);\r |
| 214 | prep_offs(MIX_DEST_A0);\r |
| 215 | prep_offs(MIX_DEST_A1);\r |
| 216 | prep_offs(MIX_DEST_B0);\r |
| 217 | prep_offs(MIX_DEST_B1);\r |
| 218 | prep_offs2(FB_SRC_A0, MIX_DEST_A0, FB_SRC_A);\r |
| 219 | prep_offs2(FB_SRC_A1, MIX_DEST_A1, FB_SRC_A);\r |
| 220 | prep_offs2(FB_SRC_B0, MIX_DEST_B0, FB_SRC_B);\r |
| 221 | prep_offs2(FB_SRC_B1, MIX_DEST_B1, FB_SRC_B);\r |
| 222 | \r |
| 223 | #undef prep_offs\r |
| 224 | #undef prep_offs2\r |
| 225 | rvb.dirty = 0;\r |
| 226 | }\r |
| 227 | \r |
| 228 | INLINE void REVERBDo(void)\r |
| 229 | {\r |
| 230 | if (!rvb.StartAddr) // reverb is off\r |
| 231 | {\r |
| 232 | rvb.iRVBLeft = rvb.iRVBRight = 0;\r |
| 233 | return;\r |
| 234 | }\r |
| 235 | \r |
| 236 | if (spuCtrl & 0x80) // -> reverb on? oki\r |
| 237 | {\r |
| 238 | if (rvb.dirty)\r |
| 239 | prepare_offsets();\r |
| 240 | \r |
| 241 | MixREVERB();\r |
| 242 | }\r |
| 243 | else // -> reverb off\r |
| 244 | {\r |
| 245 | // supposedly runs anyway?\r |
| 246 | rvb.CurrAddr += NSSIZE/2;\r |
| 247 | while (rvb.CurrAddr >= 0x40000)\r |
| 248 | rvb.CurrAddr -= 0x40000 - rvb.StartAddr;\r |
| 249 | }\r |
| 250 | }\r |
| 251 | \r |
| 252 | ////////////////////////////////////////////////////////////////////////\r |
| 253 | \r |
| 254 | #endif\r |
| 255 | \r |
| 256 | /*\r |
| 257 | -----------------------------------------------------------------------------\r |
| 258 | PSX reverb hardware notes\r |
| 259 | by Neill Corlett\r |
| 260 | -----------------------------------------------------------------------------\r |
| 261 | \r |
| 262 | Yadda yadda disclaimer yadda probably not perfect yadda well it's okay anyway\r |
| 263 | yadda yadda.\r |
| 264 | \r |
| 265 | -----------------------------------------------------------------------------\r |
| 266 | \r |
| 267 | Basics\r |
| 268 | ------\r |
| 269 | \r |
| 270 | - The reverb buffer is 22khz 16-bit mono PCM.\r |
| 271 | - It starts at the reverb address given by 1DA2, extends to\r |
| 272 | the end of sound RAM, and wraps back to the 1DA2 address.\r |
| 273 | \r |
| 274 | Setting the address at 1DA2 resets the current reverb work address.\r |
| 275 | \r |
| 276 | This work address ALWAYS increments every 1/22050 sec., regardless of\r |
| 277 | whether reverb is enabled (bit 7 of 1DAA set).\r |
| 278 | \r |
| 279 | And the contents of the reverb buffer ALWAYS play, scaled by the\r |
| 280 | "reverberation depth left/right" volumes (1D84/1D86).\r |
| 281 | (which, by the way, appear to be scaled so 3FFF=approx. 1.0, 4000=-1.0)\r |
| 282 | \r |
| 283 | -----------------------------------------------------------------------------\r |
| 284 | \r |
| 285 | Register names\r |
| 286 | --------------\r |
| 287 | \r |
| 288 | These are probably not their real names.\r |
| 289 | These are probably not even correct names.\r |
| 290 | We will use them anyway, because we can.\r |
| 291 | \r |
| 292 | 1DC0: FB_SRC_A (offset)\r |
| 293 | 1DC2: FB_SRC_B (offset)\r |
| 294 | 1DC4: IIR_ALPHA (coef.)\r |
| 295 | 1DC6: ACC_COEF_A (coef.)\r |
| 296 | 1DC8: ACC_COEF_B (coef.)\r |
| 297 | 1DCA: ACC_COEF_C (coef.)\r |
| 298 | 1DCC: ACC_COEF_D (coef.)\r |
| 299 | 1DCE: IIR_COEF (coef.)\r |
| 300 | 1DD0: FB_ALPHA (coef.)\r |
| 301 | 1DD2: FB_X (coef.)\r |
| 302 | 1DD4: IIR_DEST_A0 (offset)\r |
| 303 | 1DD6: IIR_DEST_A1 (offset)\r |
| 304 | 1DD8: ACC_SRC_A0 (offset)\r |
| 305 | 1DDA: ACC_SRC_A1 (offset)\r |
| 306 | 1DDC: ACC_SRC_B0 (offset)\r |
| 307 | 1DDE: ACC_SRC_B1 (offset)\r |
| 308 | 1DE0: IIR_SRC_A0 (offset)\r |
| 309 | 1DE2: IIR_SRC_A1 (offset)\r |
| 310 | 1DE4: IIR_DEST_B0 (offset)\r |
| 311 | 1DE6: IIR_DEST_B1 (offset)\r |
| 312 | 1DE8: ACC_SRC_C0 (offset)\r |
| 313 | 1DEA: ACC_SRC_C1 (offset)\r |
| 314 | 1DEC: ACC_SRC_D0 (offset)\r |
| 315 | 1DEE: ACC_SRC_D1 (offset)\r |
| 316 | 1DF0: IIR_SRC_B1 (offset)\r |
| 317 | 1DF2: IIR_SRC_B0 (offset)\r |
| 318 | 1DF4: MIX_DEST_A0 (offset)\r |
| 319 | 1DF6: MIX_DEST_A1 (offset)\r |
| 320 | 1DF8: MIX_DEST_B0 (offset)\r |
| 321 | 1DFA: MIX_DEST_B1 (offset)\r |
| 322 | 1DFC: IN_COEF_L (coef.)\r |
| 323 | 1DFE: IN_COEF_R (coef.)\r |
| 324 | \r |
| 325 | The coefficients are signed fractional values.\r |
| 326 | -32768 would be -1.0\r |
| 327 | 32768 would be 1.0 (if it were possible... the highest is of course 32767)\r |
| 328 | \r |
| 329 | The offsets are (byte/8) offsets into the reverb buffer.\r |
| 330 | i.e. you multiply them by 8, you get byte offsets.\r |
| 331 | You can also think of them as (samples/4) offsets.\r |
| 332 | They appear to be signed. They can be negative.\r |
| 333 | None of the documented presets make them negative, though.\r |
| 334 | \r |
| 335 | Yes, 1DF0 and 1DF2 appear to be backwards. Not a typo.\r |
| 336 | \r |
| 337 | -----------------------------------------------------------------------------\r |
| 338 | \r |
| 339 | What it does\r |
| 340 | ------------\r |
| 341 | \r |
| 342 | We take all reverb sources:\r |
| 343 | - regular channels that have the reverb bit on\r |
| 344 | - cd and external sources, if their reverb bits are on\r |
| 345 | and mix them into one stereo 44100hz signal.\r |
| 346 | \r |
| 347 | Lowpass/downsample that to 22050hz. The PSX uses a proper bandlimiting\r |
| 348 | algorithm here, but I haven't figured out the hysterically exact specifics.\r |
| 349 | I use an 8-tap filter with these coefficients, which are nice but probably\r |
| 350 | not the real ones:\r |
| 351 | \r |
| 352 | 0.037828187894\r |
| 353 | 0.157538631280\r |
| 354 | 0.321159685278\r |
| 355 | 0.449322115345\r |
| 356 | 0.449322115345\r |
| 357 | 0.321159685278\r |
| 358 | 0.157538631280\r |
| 359 | 0.037828187894\r |
| 360 | \r |
| 361 | So we have two input samples (INPUT_SAMPLE_L, INPUT_SAMPLE_R) every 22050hz.\r |
| 362 | \r |
| 363 | * IN MY EMULATION, I divide these by 2 to make it clip less.\r |
| 364 | (and of course the L/R output coefficients are adjusted to compensate)\r |
| 365 | The real thing appears to not do this.\r |
| 366 | \r |
| 367 | At every 22050hz tick:\r |
| 368 | - If the reverb bit is enabled (bit 7 of 1DAA), execute the reverb\r |
| 369 | steady-state algorithm described below\r |
| 370 | - AFTERWARDS, retrieve the "wet out" L and R samples from the reverb buffer\r |
| 371 | (This part may not be exactly right and I guessed at the coefs. TODO: check later.)\r |
| 372 | L is: 0.333 * (buffer[MIX_DEST_A0] + buffer[MIX_DEST_B0])\r |
| 373 | R is: 0.333 * (buffer[MIX_DEST_A1] + buffer[MIX_DEST_B1])\r |
| 374 | - Advance the current buffer position by 1 sample\r |
| 375 | \r |
| 376 | The wet out L and R are then upsampled to 44100hz and played at the\r |
| 377 | "reverberation depth left/right" (1D84/1D86) volume, independent of the main\r |
| 378 | volume.\r |
| 379 | \r |
| 380 | -----------------------------------------------------------------------------\r |
| 381 | \r |
| 382 | Reverb steady-state\r |
| 383 | -------------------\r |
| 384 | \r |
| 385 | The reverb steady-state algorithm is fairly clever, and of course by\r |
| 386 | "clever" I mean "batshit insane".\r |
| 387 | \r |
| 388 | buffer[x] is relative to the current buffer position, not the beginning of\r |
| 389 | the buffer. Note that all buffer offsets must wrap around so they're\r |
| 390 | contained within the reverb work area.\r |
| 391 | \r |
| 392 | Clipping is performed at the end... maybe also sooner, but definitely at\r |
| 393 | the end.\r |
| 394 | \r |
| 395 | IIR_INPUT_A0 = buffer[IIR_SRC_A0] * IIR_COEF + INPUT_SAMPLE_L * IN_COEF_L;\r |
| 396 | IIR_INPUT_A1 = buffer[IIR_SRC_A1] * IIR_COEF + INPUT_SAMPLE_R * IN_COEF_R;\r |
| 397 | IIR_INPUT_B0 = buffer[IIR_SRC_B0] * IIR_COEF + INPUT_SAMPLE_L * IN_COEF_L;\r |
| 398 | IIR_INPUT_B1 = buffer[IIR_SRC_B1] * IIR_COEF + INPUT_SAMPLE_R * IN_COEF_R;\r |
| 399 | \r |
| 400 | IIR_A0 = IIR_INPUT_A0 * IIR_ALPHA + buffer[IIR_DEST_A0] * (1.0 - IIR_ALPHA);\r |
| 401 | IIR_A1 = IIR_INPUT_A1 * IIR_ALPHA + buffer[IIR_DEST_A1] * (1.0 - IIR_ALPHA);\r |
| 402 | IIR_B0 = IIR_INPUT_B0 * IIR_ALPHA + buffer[IIR_DEST_B0] * (1.0 - IIR_ALPHA);\r |
| 403 | IIR_B1 = IIR_INPUT_B1 * IIR_ALPHA + buffer[IIR_DEST_B1] * (1.0 - IIR_ALPHA);\r |
| 404 | \r |
| 405 | buffer[IIR_DEST_A0 + 1sample] = IIR_A0;\r |
| 406 | buffer[IIR_DEST_A1 + 1sample] = IIR_A1;\r |
| 407 | buffer[IIR_DEST_B0 + 1sample] = IIR_B0;\r |
| 408 | buffer[IIR_DEST_B1 + 1sample] = IIR_B1;\r |
| 409 | \r |
| 410 | ACC0 = buffer[ACC_SRC_A0] * ACC_COEF_A +\r |
| 411 | buffer[ACC_SRC_B0] * ACC_COEF_B +\r |
| 412 | buffer[ACC_SRC_C0] * ACC_COEF_C +\r |
| 413 | buffer[ACC_SRC_D0] * ACC_COEF_D;\r |
| 414 | ACC1 = buffer[ACC_SRC_A1] * ACC_COEF_A +\r |
| 415 | buffer[ACC_SRC_B1] * ACC_COEF_B +\r |
| 416 | buffer[ACC_SRC_C1] * ACC_COEF_C +\r |
| 417 | buffer[ACC_SRC_D1] * ACC_COEF_D;\r |
| 418 | \r |
| 419 | FB_A0 = buffer[MIX_DEST_A0 - FB_SRC_A];\r |
| 420 | FB_A1 = buffer[MIX_DEST_A1 - FB_SRC_A];\r |
| 421 | FB_B0 = buffer[MIX_DEST_B0 - FB_SRC_B];\r |
| 422 | FB_B1 = buffer[MIX_DEST_B1 - FB_SRC_B];\r |
| 423 | \r |
| 424 | buffer[MIX_DEST_A0] = ACC0 - FB_A0 * FB_ALPHA;\r |
| 425 | buffer[MIX_DEST_A1] = ACC1 - FB_A1 * FB_ALPHA;\r |
| 426 | buffer[MIX_DEST_B0] = (FB_ALPHA * ACC0) - FB_A0 * (FB_ALPHA^0x8000) - FB_B0 * FB_X;\r |
| 427 | buffer[MIX_DEST_B1] = (FB_ALPHA * ACC1) - FB_A1 * (FB_ALPHA^0x8000) - FB_B1 * FB_X;\r |
| 428 | \r |
| 429 | -----------------------------------------------------------------------------\r |
| 430 | */\r |
| 431 | \r |
| 432 | // vim:shiftwidth=1:expandtab\r |