Make negative step sizes work on output in data mode, and also with pb in key mode.

midizap.c

@@ -67,6 +67,16 @@ static int16_t pbvalue[16] =
   {8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
    8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192};
 
+static int dataval(int val, int min, int max)
+{
+  if (!val || val > max)
+    return max;
+  else if (val < min)
+    return min;
+  else
+    return val;
+}
+
 void
 send_midi(uint8_t portno, int status, int data, int step, int incr, int index, int dir)
 {
@@ -78,8 +88,7 @@ send_midi(uint8_t portno, int status, int data, int step, int incr, int index, i
   switch (status & 0xf0) {
   case 0x90:
     if (!index) {
-      msg[2] = step?step:127;
+      msg[2] = dataval(step, 0, 127);
-      if (msg[2] > 127) msg[2] = 127;
     } else {
       msg[2] = 0;
     }
@@ -110,8 +119,7 @@ send_midi(uint8_t portno, int status, int data, int step, int incr, int index, i
 	msg[2] = ccvalue[chan][data];
       }
     } else if (!index) {
-      msg[2] = step?step:127;
+      msg[2] = dataval(step, 0, 127);
-      if (msg[2] > 127) msg[2] = 127;
     } else {
       msg[2] = 0;
     }
@@ -133,8 +141,7 @@ send_midi(uint8_t portno, int status, int data, int step, int incr, int index, i
       }
       msg[2] = kpvalue[chan][data];
     } else if (!index) {
-      msg[2] = step?step:127;
+      msg[2] = dataval(step, 0, 127);
-      if (msg[2] > 127) msg[2] = 127;
     } else {
       msg[2] = 0;
     }
@@ -156,8 +163,7 @@ send_midi(uint8_t portno, int status, int data, int step, int incr, int index, i
       }
       msg[1] = cpvalue[chan];
     } else if (!index) {
-      msg[1] = step?step:127;
+      msg[1] = dataval(step, 0, 127);
-      if (msg[1] > 127) msg[1] = 127;
     } else {
       msg[1] = 0;
     }
@@ -180,8 +186,7 @@ send_midi(uint8_t portno, int status, int data, int step, int incr, int index, i
       }
       pbval = pbvalue[chan];
     } else if (!index) {
-      pbval = 8192+(step?step:8191);
+      pbval = 8192+dataval(step, -8192, 8191);
-      if (pbval > 16383) pbval = 16383;
     } else {
       // we use 8192 (center) as the "home" (a.k.a. "off") value, so the pitch
       // will only bend up, never down below the center value

readconfig.c

@@ -826,7 +826,7 @@ parse_midi(char *tok, char *s, int lhs, int mode,
   // step size
   if (*p == '[') {
     if (sscanf(++p, "%d%n", &l, &n) == 1) {
-      if (l <= 0) return 0; // must be positive
+      if (!l || (lhs && l<0)) return 0; // must be nonzero / positive on lhs
       p += n;
       if (*p != ']') return 0;
       p++;
@@ -892,6 +892,7 @@ parse_midi(char *tok, char *s, int lhs, int mode,
   } else if (strcmp(s, "pb") == 0) {
     // pitch bend, no data byte
     *status = 0xe0 | k; *data = 0;
+    // negative step size is always permitted on rhs here, even in key mode
     // step size only permitted on lhs if incremental
     if (lhs && *step && !*incr) return 0;
     if (lhs && !*step) *step = 1; // default
@@ -899,6 +900,8 @@ parse_midi(char *tok, char *s, int lhs, int mode,
   } else if (strcmp(s, "cp") == 0) {
     // channel pressure, no data byte
     *status = 0xd0 | k; *data = 0;
+    // negative step size not permitted on rhs in key mode
+    if (!lhs && *step < 0 && !mode) return 0;
     // step size only permitted on lhs if incremental
     if (lhs && *step && !*incr) return 0;
     if (lhs && !*step) *step = 1; // default
@@ -913,6 +916,8 @@ parse_midi(char *tok, char *s, int lhs, int mode,
     // control change
     if (m < 0 || m > 127) return 0;
     *status = 0xb0 | k; *data = m;
+    // negative step size not permitted on rhs in key mode
+    if (!lhs && *step < 0 && !mode) return 0;
     // step size only permitted on lhs if incremental
     if (lhs && *step && !*incr) return 0;
     if (lhs && !*step) *step = 1; // default
@@ -921,12 +926,17 @@ parse_midi(char *tok, char *s, int lhs, int mode,
     // key pressure
     if (m < 0 || m > 127) return 0;
     *status = 0xa0 | k; *data = m;
+    // negative step size not permitted on rhs in key mode
+    if (!lhs && *step < 0 && !mode) return 0;
     // step size only permitted on lhs if incremental
     if (lhs && *step && !*incr) return 0;
     if (lhs && !*step) *step = 1; // default
     return 1;
   } else {
-    if (lhs && *step) return 0; // step size not permitted on lhs
+    // negative step size not permitted on rhs
+    if (!lhs && *step < 0) return 0;
+    // step size not permitted on lhs
+    if (lhs && *step) return 0;
     // we must be looking at a MIDI note here, with m denoting the
     // octave number; first character is the note name (must be a..g);
     // optionally, the second character may denote an accidental (# or b)