dspv.cpp

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/**
 * @file
 * @ingroup ixlib
 * @brief Voice control.
 *
 * Originally `D:\rnd\prj\ix\win95\dsp\dspv.cpp`, address range
 * 4467a0-446f73: compiler-generated initializers, then the voice-control
 * functions. The separately assembled sample mixer, dspmix.asm, follows.
 *
 * Built /Od like the rest of ix: a full EBP frame, EBX, ESI and EDI saved
 * whether used or not, and one shared epilogue.
 */
#include <signal.h>
#include "ix.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>
 
IxVoice aVoices[34];             /* 0x005981A8 */
CRITICAL_SECTION csMixer;       /* 0x005985E8 */
int nVoiceCount;                /* 0x00598600 */
int nVoicesAllocated;           /* 0x00598604 */
 
/* Function start: 0x4467C5 */   /* source line 23 */
void ix_dspv_set_active(int voice)
{
    if (voice < 0 || voice >= nVoiceCount) {
        ix_log_printf("Fatal [%s - %d]:\n", IX_DSPV_FILE, 23);
        ix_log_printf("%d Invalid voice index!", voice);
        exit(-1);
    }
    aVoices[voice].flags |= IX_VOICE_ACTIVE;
}
 
/* Function start: 0x446829 */   /* source line 29 */
void ix_dspv_clear_active(int voice)
{
    if (voice < 0 || voice >= nVoiceCount) {
        ix_log_printf("Fatal [%s - %d]:\n", IX_DSPV_FILE, 29);
        ix_log_printf("%d Invalid voice index!", voice);
        exit(-1);
    }
    aVoices[voice].flags &= ~IX_VOICE_ACTIVE;
}
 
/* Function start: 0x44688E */   /* source line 35 */
void ix_dspv_clear_flag4(int voice)
{
    if (voice < 0 || voice >= nVoiceCount) {
        ix_log_printf("Fatal [%s - %d]:\n", IX_DSPV_FILE, 35);
        ix_log_printf("%d Invalid voice index!", voice);
        exit(-1);
    }
    aVoices[voice].flags &= ~IX_VOICE_FLAG4;
}
 
/* Function start: 0x4468F2 */   /* source line 41 */
unsigned int ix_dspv_get_flags(int voice)
{
    if (voice < 0 || voice >= nVoiceCount) {
        ix_log_printf("Fatal [%s - %d]:\n", IX_DSPV_FILE, 41);
        ix_log_printf("%d Invalid voice index!", voice);
        exit(-1);
    }
    return aVoices[voice].flags;
}
 
/* Function start: 0x446956 */
/* No bounds check in the original -- callers are internal. */
void ix_dspv_set_flag4(int voice, int on)
{
    if (on != 0)
        aVoices[voice].flags |= IX_VOICE_FLAG4;
    else
        aVoices[voice].flags &= ~IX_VOICE_FLAG4;
}
 
/* Function start: 0x44698F */   /* source line 55 */
void ix_dspv_set_buffer(int voice, unsigned char *p, int len)
{
    if (voice < 0 || voice >= nVoiceCount) {
        ix_log_printf("Fatal [%s - %d]:\n", IX_DSPV_FILE, 55);
        ix_log_printf("%d Invalid voice index!", voice);
        exit(-1);
    }
    IxVoice *v = &aVoices[voice];
 
    EnterCriticalSection(&csMixer);
    v->cursor = p;
    v->start = p;
    v->end = p + len;
    LeaveCriticalSection(&csMixer);
}
 
/* Function start: 0x446A2B */   /* source line 69 */
int ix_dspv_get_position(int voice)
{
    if (voice < 0 || voice >= nVoiceCount) {
        ix_log_printf("Fatal [%s - %d]:\n", IX_DSPV_FILE, 69);
        ix_log_printf("%d Invalid voice index!", voice);
        exit(-1);
    }
    IxVoice *v = &aVoices[voice];
 
    return (int)((unsigned long)v->cursor - (unsigned long)v->start);
}
 
/* Function start: 0x446AA0 */   /* source line 77 */
void ix_dspv_set_position(int voice, int off)
{
    if (voice < 0 || voice >= nVoiceCount) {
        ix_log_printf("Fatal [%s - %d]:\n", IX_DSPV_FILE, 77);
        ix_log_printf("%d Invalid voice index!", voice);
        exit(-1);
    }
    IxVoice *v = &aVoices[voice];
 
    v->cursor = v->start + off;
}
 
/* Function start: 0x446B18 */   /* source line 85 */
void ix_dspv_set_volume(int voice, short vol)
{
    if (voice < 0 || voice >= nVoiceCount) {
        ix_log_printf("Fatal [%s - %d]:\n", IX_DSPV_FILE, 85);
        ix_log_printf("%d Invalid voice index!", voice);
        exit(-1);
    }
    aVoices[voice].volume = vol;
    ix_dspv_recalc_mix(voice);
}
 
/* Function start: 0x446B8C */   /* source line 93 */
void ix_dspv_set_pan(int voice, unsigned short angle)
{
    short pos;
    {
        IxVoice *state;
        {
            short delta;
            {
                short step;
 
                if (voice < 0 || nVoiceCount <= voice) {
                    ix_log_printf("Fatal [%s - %d]:\n", IX_DSPV_FILE, 93);
                    ix_log_printf("%d Invalid voice index!", voice);
                    exit(-1);
                }
                state = &aVoices[voice];
                step = (short)((unsigned short)angle >> 9);
                delta = step - state->panAngle;
                if (delta > 0x40)
                    delta = delta - 0x80;
                if (delta < -0x40)
                    delta = delta + 0x80;
                pos = state->panPos + delta;
                if (pos < 0)
                    pos = pos + 0x100;
                if (pos >= 0x100)
                    pos = pos - 0x100;
                state->panAngle = step;
                state->panPos = pos;
                ix_dspv_recalc_mix(voice);
            }
        }
    }
}
 
/* Function start: 0x446CB1 */   /* source line 131 */
void ix_dspv_set_frequency(int voice, unsigned int hz)
{
    if (voice < 0 || nVoiceCount <= voice) {
        ix_log_printf("Fatal [%s - %d]:\n", IX_DSPV_FILE, 131);
        ix_log_printf("%d Invalid voice index!", voice);
        exit(-1);
    }
    aVoices[voice].rate =
        (short)(((int)(hz & 0xffff) << 8) / IX_MIXER_BASE_RATE);
}
 
/* Function start: 0x446D2C */   /* source lines 137, 138 */
void ix_dspv_set_bits_per_sample(int voice, int bps)
{
    if (voice < 0 || voice >= nVoiceCount) {
        ix_log_printf("Fatal [%s - %d]:\n", IX_DSPV_FILE, 137);
        ix_log_printf("%d Invalid voice index!", voice);
        exit(-1);
    }
    if (bps != 8 && bps != 16) {
        ix_log_printf("Fatal [%s - %d]:\n", IX_DSPV_FILE, 138);
        ix_log_printf("%d is an unsupported bps!", bps);
        exit(-1);
    }
    if (bps == 16)
        aVoices[voice].flags |= IX_VOICE_16BIT;
    else
        aVoices[voice].flags &= ~IX_VOICE_16BIT;
}
 
/* Function start: 0x446DF5 */   /* source lines 148, 149 */
void ix_dspv_set_channels(int voice, int channels)
{
    if (voice < 0 || voice >= nVoiceCount) {
        ix_log_printf("Fatal [%s - %d]:\n", IX_DSPV_FILE, 148);
        ix_log_printf("%d Invalid voice index!", voice);
        exit(-1);
    }
    if (channels != 1 && channels != 2) {
        ix_log_printf("Fatal [%s - %d]:\n", IX_DSPV_FILE, 149);
        ix_log_printf("%d is an unsupported number of channels!", channels);
        exit(-1);
    }
    if (channels == 2)
        aVoices[voice].flags |= IX_VOICE_STEREO;
    else
        aVoices[voice].flags &= ~IX_VOICE_STEREO;
}
 
/* Function start: 0x446EBF */
void ix_dspv_recalc_mix(int voice)
{
    IxVoice *voiceState;
    short panPosition;
    int scaledVolume;
 
    voiceState = &aVoices[voice];
    panPosition = voiceState->panPos;
    scaledVolume = ((unsigned int)voiceState->volume
                    * (unsigned int)nMasterVolume) / 0xffff;
    EnterCriticalSection(&csMixer);
    voiceState->leftGain =
        (short)((int)asPanGains[panPosition * 2] * scaledVolume >> 0x10);
    voiceState->rightGain =
        (short)((int)asPanGains[panPosition * 2 + 1] * scaledVolume >> 0x10);
    voiceState->leftGainHi = (unsigned char)(voiceState->leftGain >> 8);
    voiceState->rightGainHi = (unsigned char)(voiceState->rightGain >> 8);
    LeaveCriticalSection(&csMixer);
}
 
/* Portable counterpart of the assembled sample mixer in dspmix.asm. */