/* * SID_linux.h - 6581 emulation, Linux specific stuff * * Frodo (C) 1994-1997,2002-2005 Christian Bauer * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ //#include //#include //#include //#include #include #include "VIC.h" SDL_AudioSpec *sdl_audio_desired, *sdl_audio; int16 *sdl_buffer ATTRIBUTE_ALIGN(32); DigitalRenderer* p; bool paused = false; void fill_audio(void *udata, Uint8 *stream, int len) { if(paused == true) { memset(stream, 0x0, len); } else { // memcpy(stream, sbuffer, len); p->calc_buffer((int16*)stream, len); } } /* * Initialization */ void DigitalRenderer::init_sound(void) { int arg; unsigned long format; ready = false; p = this; sndbufsize=0x138*4; sdl_audio_desired = (SDL_AudioSpec *)malloc(sizeof(SDL_AudioSpec)); sdl_audio = (SDL_AudioSpec *)malloc(sizeof(SDL_AudioSpec)); sdl_audio_desired->freq=32000; sdl_audio_desired->format=AUDIO_S16MSB; sdl_audio_desired->channels=2; sdl_audio_desired->samples=sndbufsize/2; sdl_audio_desired->callback=fill_audio; sdl_audio_desired->userdata=NULL; if (SDL_OpenAudio(sdl_audio_desired, sdl_audio) < 0) { fprintf(stderr, "Couldn't open audio: %s\n", SDL_GetError()); } free(sdl_audio_desired); SDL_PauseAudio(0); /*devfd = open("/dev/dsp", O_WRONLY); if (devfd < 0) return; ioctl(devfd, SNDCTL_DSP_GETFMTS, &format); if (!(format & AFMT_S16_LE)) return; format = AFMT_S16_LE; ioctl(devfd, SNDCTL_DSP_SETFMT, &format);*/ // Buffer size: 2^9 == 512 bytes. Note that too large buffers will not work // very well: The speed of the C64 is slowed down to an average speed of // 100% by the blocking write() call in EmulateLine(). If you use a buffer // of, say 4096 bytes, that will happen only about every 4 frames, which // means that the emulation runs much faster in some frames, and much // slower in others. // On really fast machines, it might make sense to use an even smaller // buffer size. /*arg = 0x00100009; ioctl(devfd, SNDCTL_DSP_SETFRAGMENT, &arg); arg = 0; ioctl(devfd, SNDCTL_DSP_STEREO, &arg); arg = 44100; ioctl(devfd, SNDCTL_DSP_SPEED, &arg); ioctl(devfd, SOUND_PCM_READ_RATE, &arg); if (arg < 43000 || arg > 45000) return;*/ /*ioctl(devfd, SNDCTL_DSP_GETBLKSIZE, &sndbufsize);*/ sound_buffer = new int16[sndbufsize]; sdl_buffer=sound_buffer; ready = true; } /* * Destructor */ DigitalRenderer::~DigitalRenderer() { free(sdl_audio); SDL_CloseAudio(); /*if (devfd >= 0) close(devfd);*/ } /* * Pause sound output */ void DigitalRenderer::Pause(void) { SDL_PauseAudio(1); paused = true; } /* * Resume sound output */ void DigitalRenderer::Resume(void) { SDL_PauseAudio(0); paused = false; } /* * Fill buffer, sample volume (for sampled voice) */ void DigitalRenderer::EmulateLine(void) { static int divisor = 0; static int to_output = 0; static int buffer_pos = 0; if (!ready) return; sample_buf[sample_in_ptr] = volume; sample_in_ptr = (sample_in_ptr + 1) % SAMPLE_BUF_SIZE; /* // Now see how many samples have to be added for this line divisor += SAMPLE_FREQ; while (divisor >= 0) divisor -= TOTAL_RASTERS*SCREEN_FREQ, to_output++; // Calculate the sound data only when we have enough to fill // the buffer entirely if ((buffer_pos + to_output) >= sndbufsize) { int datalen = sndbufsize - buffer_pos; to_output -= datalen; calc_buffer(sound_buffer + buffer_pos, datalen*2); //write(devfd, sound_buffer, sndbufsize*2); buffer_pos = 0; } */ }