Allow specifying a frequency of zero for silence.

src/xpdev/xpbeep.c

@@ -190,60 +190,65 @@ void makewave(double freq, unsigned char *wave, int samples, enum WAVE_SHAPE sha
 	double pos;
 	BOOL endhigh;
 
-	midpoint=samples/2;
-	inc=8.0*atan(1.0);
-	inc *= ((double)freq / (double)S_RATE);
-
-	for(i=0;i<samples;i++) {
-		pos=(inc*(double)i);
-		pos -= (int)(pos/WAVE_TPI)*WAVE_TPI;
-		switch(shape) {
-			case WAVE_SHAPE_SINE:
-				wave[i]=(sin (pos))*127+128;
-				break;
-			case WAVE_SHAPE_SINE_HARM:
-				wave[i]=(sin (pos))*64+128;
-				wave[i]=(sin ((inc*2)*(double)i))*24;
-				wave[i]=(sin ((inc*3)*(double)i))*16;
-				break;
-			case WAVE_SHAPE_SAWTOOTH:
-				wave[i]=(WAVE_TPI-pos)*40.5;
-				break;
-			case WAVE_SHAPE_SQUARE:
-				wave[i]=(pos<WAVE_PI)?255:0;
-				break;
-			case WAVE_SHAPE_SINE_SAW:
-				wave[i]=(((sin (pos))*127+128)+((WAVE_TPI-pos)*40.5))/2;
-				break;
-			case WAVE_SHAPE_SINE_SAW_CHORD:
-				wave[i]=(((sin (pos))*64+128)+((WAVE_TPI-pos)*6.2))/2;
-				wave[i]+=(sin ((inc/2)*(double)i))*24;
-				wave[i]+=(sin ((inc/3)*(double)i))*16;
-				break;
-			case WAVE_SHAPE_SINE_SAW_HARM:
-				wave[i]=(((sin (pos))*64+128)+((WAVE_TPI-pos)*6.2))/2;
-				wave[i]+=(sin ((inc*2)*(double)i))*24;
-				wave[i]+=(sin ((inc*3)*(double)i))*16;
-				break;
-		}
+	if(freq==0) {
+		memset(wave, 128, samples);
 	}
+	else {
+		midpoint=samples/2;
+		inc=8.0*atan(1.0);
+		inc *= ((double)freq / (double)S_RATE);
+
+		for(i=0;i<samples;i++) {
+			pos=(inc*(double)i);
+			pos -= (int)(pos/WAVE_TPI)*WAVE_TPI;
+			switch(shape) {
+				case WAVE_SHAPE_SINE:
+					wave[i]=(sin (pos))*127+128;
+					break;
+				case WAVE_SHAPE_SINE_HARM:
+					wave[i]=(sin (pos))*64+128;
+					wave[i]=(sin ((inc*2)*(double)i))*24;
+					wave[i]=(sin ((inc*3)*(double)i))*16;
+					break;
+				case WAVE_SHAPE_SAWTOOTH:
+					wave[i]=(WAVE_TPI-pos)*40.5;
+					break;
+				case WAVE_SHAPE_SQUARE:
+					wave[i]=(pos<WAVE_PI)?255:0;
+					break;
+				case WAVE_SHAPE_SINE_SAW:
+					wave[i]=(((sin (pos))*127+128)+((WAVE_TPI-pos)*40.5))/2;
+					break;
+				case WAVE_SHAPE_SINE_SAW_CHORD:
+					wave[i]=(((sin (pos))*64+128)+((WAVE_TPI-pos)*6.2))/2;
+					wave[i]+=(sin ((inc/2)*(double)i))*24;
+					wave[i]+=(sin ((inc/3)*(double)i))*16;
+					break;
+				case WAVE_SHAPE_SINE_SAW_HARM:
+					wave[i]=(((sin (pos))*64+128)+((WAVE_TPI-pos)*6.2))/2;
+					wave[i]+=(sin ((inc*2)*(double)i))*24;
+					wave[i]+=(sin ((inc*3)*(double)i))*16;
+					break;
+			}
+		}
 
-	/* Now we have a "perfect" wave... 
-	 * we must clean it up now to avoid click/pop
-	 */
-	if(wave[samples-1]>128)
-		endhigh=TRUE;
-	else
-		endhigh=FALSE;
-	/* Completely remove the last wave fragment */
-	i=samples-1;
-	if(wave[i]!=128) {
-		for(;i>midpoint;i--) {
-			if(endhigh && wave[i]<128)
-				break;
-			if(!endhigh && wave[i]>128)
-				break;
-			wave[i]=128;
+		/* Now we have a "perfect" wave... 
+		 * we must clean it up now to avoid click/pop
+		 */
+		if(wave[samples-1]>128)
+			endhigh=TRUE;
+		else
+			endhigh=FALSE;
+		/* Completely remove the last wave fragment */
+		i=samples-1;
+		if(wave[i]!=128) {
+			for(;i>midpoint;i--) {
+				if(endhigh && wave[i]<128)
+					break;
+				if(!endhigh && wave[i]>128)
+					break;
+				wave[i]=128;
+			}
 		}
 	}
 }
@@ -842,12 +847,14 @@ BOOL DLLCALL xptone(double freq, DWORD duration, enum WAVE_SHAPE shape)
 	unsigned char	wave[S_RATE*15/2+1];
 	int samples;
 
-	if(freq<17)
+	if(freq<17 && freq != 0)
 		freq=17;
 	samples=S_RATE*duration/1000;
-	if(samples<=S_RATE/freq*2)
-		samples=S_RATE/freq*2;
-	if(samples > S_RATE/freq*2) {
+	if(freq) {
+		if(samples<=S_RATE/freq*2)
+			samples=S_RATE/freq*2;
+	}
+	if(freq==0 || samples > S_RATE/freq*2) {
 		int sample_len;
 
 		makewave(freq,wave,S_RATE*15/2,shape);