adsr

source/engine/dsp.c

@@ -43,8 +43,6 @@ void dsp_filter_addin(struct dsp_filter filter, struct dsp_filter *in)
     }
 
     filter.in[filter.inputs++] = in;
-
-    return filter;
 }
 
 void am_mod(struct dsp_ammod *mod, short *c, int n)
@@ -52,10 +50,8 @@ void am_mod(struct dsp_ammod *mod, short *c, int n)
     dsp_run(mod->ina, mod->abuf, n);
     dsp_run(mod->inb, mod->bbuf, n);
 
-    for (int i = 0; i < n*2; i++) {
+    for (int i = 0; i < n*CHANNELS; i++)
         c[i] = (mod->abuf[i]*mod->bbuf[i])>>15;
-        //c[i] = mod->abuf[i];
-    }
 }
 
 static struct wav make_wav(float freq, int sr, int ch) {
@@ -334,11 +330,10 @@ struct dsp_filter lpf_make(int poles, float freq)
 
   free(ccof);
 
-  printf("LPF coefficients are:\n");
+  YughInfo("LPF coefficients are:", 0);
 
-  for (int i = 0; i < new->n; i++) {
+  for (int i = 0; i < new->n; i++)
-      YughInfo("%f, %f\n", new->ccof[i], new->dcof[i]);
+      YughInfo("%f, %f", new->ccof[i], new->dcof[i]);
-  }
 
   struct dsp_filter lpf;
   lpf.data = new;
@@ -361,9 +356,8 @@ struct dsp_filter hpf_make(int poles, float freq)
   for (int i = 0; i < new->n; i++)
       new->ccof[i] = ccof[i] * sf;
 
-    for (int i = 0; i < new->n; i++) {
+    for (int i = 0; i < new->n; i++)
-      printf("%f, %f\n", new->ccof[i], new->dcof[i]);
+      YughInfo("%f, %f", new->ccof[i], new->dcof[i]);
-  }
 
   free(ccof);
 
@@ -450,3 +444,77 @@ void dsp_delay_filbuf(struct dsp_delay *delay, short *buf, int n)
         buf[i] = cache[i] + cbuf_shift(&delay->buf);
     }
 }
+
+/* Get decay constant for a given pole */
+/* Samples to decay 1 time constant is exp(-1/timeconstant) */
+double tau2pole(double tau)
+{
+    return exp(-1/(tau*SAMPLERATE));
+}
+
+void dsp_adsr_fillbuf(struct dsp_adsr *adsr, short *out, int n)
+{
+    short val;
+
+    for (int i = 0; i < n; i++) {
+        if (adsr->time > adsr->rls) {
+            // Totally decayed
+            adsr->out = 0.f;
+
+            goto fin;
+        }
+
+        if (adsr->time > adsr->sus) {
+            // Release phase
+            adsr->out = adsr->rls_t * adsr->out;
+
+            goto fin;
+        }
+
+        if (adsr->time > adsr->dec) {
+            // Sustain phase
+            adsr->out = adsr->sus_pwr;
+
+            goto fin;
+        }
+
+        if (adsr->time > adsr->atk) {
+            // Decay phase
+            adsr->out = (1 - adsr->dec_t) * adsr->sus_pwr + adsr->dec_t * adsr->out;
+
+            goto fin;
+        }
+
+        // Attack phase
+        adsr->out = (1-adsr->atk_t) + adsr->atk_t * adsr->out;
+
+
+
+        fin:
+
+        val = SHRT_MAX * adsr->out;
+        out[i*CHANNELS] = out[i*CHANNELS+1] = val;
+        adsr->time += (double)(1000.f / SAMPLERATE);
+    }
+}
+
+
+
+struct dsp_filter make_adsr(unsigned int atk, unsigned int dec, unsigned int sus, unsigned int rls)
+{
+    struct dsp_adsr *adsr = calloc(sizeof(*adsr), 1);
+    adsr->atk = atk;
+    /* decay to 3 tau */
+    adsr->atk_t = tau2pole(atk / 3000.f);
+
+    adsr->dec = dec + adsr->atk;
+    adsr->dec_t = tau2pole(dec / 3000.f);
+
+    adsr->sus = sus + adsr->dec;
+    adsr->sus_pwr = 0.8f;
+
+    adsr->rls = rls + adsr->sus;
+    adsr->rls_t = tau2pole(rls / 3000.f);
+
+    return make_dsp(adsr, dsp_adsr_fillbuf);
+}

source/engine/dsp.h

@@ -18,7 +18,7 @@ struct dsp_filter {
     int inputs;
     struct dsp_filter *in[6];
 
-    short cache[CHANNELS*SAMPLERATE];
+    short cache[CHANNELS*BUF_FRAMES];
     int dirty;
 };
 
@@ -42,6 +42,24 @@ struct dsp_filter lpf_make(int poles, float freq);
 struct dsp_filter bpf_make(int poles, float freq1, float freq2);
 struct dsp_filter npf_make(int poles, float freq1, float freq2);
 
+/* atk, dec, sus, rls specify the time, in miliseconds, the phase begins */
+struct dsp_adsr {
+    unsigned int atk;
+    double atk_t;
+    unsigned int dec;
+    double dec_t;
+    unsigned int sus;
+    float sus_pwr; // Between 0 and 1
+    unsigned int rls;
+    double rls_t;
+
+    double time; /* Current time of the filter */
+    float out;
+};
+
+void dsp_adsr_fillbuf(struct dsp_adsr *adsr, short *out, int n);
+struct dsp_filter make_adsr(unsigned int atk, unsigned int dec, unsigned int sus, unsigned int rls);
+
 struct dsp_delay {
     unsigned int ms_delay;
     struct circbuf buf;
@@ -54,18 +72,23 @@ void dsp_delay_filbuf(struct dsp_delay *delay, short *buf, int n);
 struct dsp_ammod {
     struct dsp_filter ina;
     struct dsp_filter inb;
-    short abuf[BUF_FRAMES*2];
+    short abuf[BUF_FRAMES*CHANNELS];
-    short bbuf[BUF_FRAMES*2];
+    short bbuf[BUF_FRAMES*CHANNELS];
 };
 
 struct dsp_compressor {
 
 };
 
+struct dsp_filter dsp_make_compressor();
+void dsp_compressor_fillbuf(struct dsp_compressor *comp, short *out, int n);
+
 struct dsp_limiter {
 
 };
 
+struct dsp_filter dsp_make_limiter();
+void dsp_limiter_fillbuf(struct dsp_limiter *lim, short *out, int n);
 
 
 struct phasor {

source/engine/log.c

@@ -23,8 +23,8 @@ void mYughLog(int category, int priority, int line, const char *file, const char
 	va_end(args);
 
 	char buffer[ERROR_BUFFER] = { '\0' };
-	snprintf(buffer, ERROR_BUFFER, "LEVEL %d :: %s [ %s:%d ] %s\n",
+	snprintf(buffer, ERROR_BUFFER, "%s\n[ %s:%d ] %s\n",
-		 priority, msgbuffer, file, line, dt);
+		 msgbuffer, file, line, dt);
 
 	printf("%s", buffer);
 	fflush(stdout);

source/engine/music.c

@@ -58,7 +58,7 @@ void dsp_midi_fillbuf(struct dsp_midi_song *song, void *out, int n)
 
 void play_song(const char *midi, const char *sf)
 {
-    gsong.midi = tml_load_filename("sounds/stickerbrush.mid");
+    gsong.midi = tml_load_filename("sounds/littlewonder.mid");
     gsong.sf = tsf_load_filename("sounds/ff7.sf2");
     gsong.time = 0.f;
 

source/engine/sound.c

@@ -164,8 +164,7 @@ void sound_init()
     struct dsp_filter am_filter;
 
 
-    dspammod.ina = s600;
+
-    dspammod.inb = s20;
 
     am_filter.filter = am_mod;
     am_filter.data = &dspammod;
@@ -176,7 +175,12 @@ void sound_init()
     del_filter.filter = dsp_delay_filbuf;
     del_filter.data = &dspdel;
 
-    //first_free_bus(s600);
+    struct dsp_filter ad = make_adsr(50, 200, 500, 100);
+
+    dspammod.ina = s600;
+    dspammod.inb = ad;
+
+    first_free_bus(am_filter);
 
     struct dsp_filter wn;
     wn.filter = gen_pinknoise;