/* VU.C VU Meter for the Sampler (c) 1987 Todor Fay AZTEC C version */ #include "exec/exec.h" #include "exec/types.h" #include "soundscape.h" #include "intuition/intuition.h" /* Images for the LEDs. A red LED for lighting, a blue LED for turning it back off (the background color.) */ UWORD redleddata[] = { /* 16 x 3 */ 65535, 65535, 65535, 65535, 65535, 65535, }; struct Image redledimage = { 0,0,16,3,2,redleddata,3,0,0 }; UWORD blueleddata[] = { /* 16 x 3 */ 0, 0, 0, 0, 0, 0, }; struct Image blueledimage = { 0,0,16,3,2,blueleddata,3,0,0 }; /* We don't need any Intuition Gadgets, just a window to display the LEDs in. This was designed with Power Windows. */ struct NewWindow NewWindowStructure = { 0,0, 250,20, 0,1, NULL, WINDOWDRAG+WINDOWDEPTH, NULL, NULL, "VU Meter", NULL, NULL, 5,5, 0,0, WBENCHSCREEN }; short thisport; /* This port's id. */ long SoundScapeBase; /* SoundScape library. */ long IntuitionBase; /* We need a place to store the Sampler's output routine address, since we are replacing the code pointer in its port structure with our own. */ void (*sampleroutcode) (); struct Window *vuwindow; /* Display window. */ /* We need an array of velocity values for each note that is being played. These are zeroed for no note. If you add up all the velocities in this array, you should get totalvolume, which is used to determine the number of LEDs to light. */ unsigned char velocity[128]; unsigned short totalvolume; insertoutcode(note) /* This output routine is not given to the Patch Panel in the AddMidiPort call. Instead, this routine replaces the Sampler output code, and then calls it. So, this is inserted there by the open routine. Check the note status. If it is NOTEON or NOTEOFF, we want to use it for the display. Start by decrementing the totalvolume by velocity[note->value]. If this is a NOTEOFF event, this reduces totalvolume appropriately. If this is a NOTEON event, this clears any previous NOTEON that was stored. This is neccessary because we aren't supporting multiple playing of the same note (for simplicity.) If this is a NOTEON event, increment totalvolume by the velocity of this note. Store this velocity in the velocity array. Else, for a NOTEOFF event, simply put zero in the velocity array - there is no note being played. Compute how many LEDs should be on from totalvolume. Each additional LED represents a doubling in volume, so figure what the most significant bit of totalvolume is. If the new top LED position (newvupos) is greater than the currently displayed one (vupos), draw in the extra LEDs. Else, if newvupos is less than vupos, erase LEDs down to newvupos. Finally, forward the note event to the Sampler by calling its output routine. */ struct Note *note; { unsigned char status = note->status & 0xF0; static short vupos = 0; short newvupos, index; if (sampleroutcode) { if ((status == NOTEON) || (status == NOTEOFF)) { totalvolume -= velocity[note->value]; if ((status == NOTEON) && note->velocity) { totalvolume += note->velocity; velocity[note->value] = note->velocity; } else velocity[note->value] = 0; newvupos = 0; index = 4; for (;index < totalvolume; index = index << 1) newvupos++; if (newvupos < vupos) { for (;vupos > newvupos; vupos--) DrawImage(vuwindow->RPort, &blueledimage,-10 + vupos * 20,13); } else if (newvupos > vupos) { vupos++; for (;vupos <= newvupos; vupos++) DrawImage(vuwindow->RPort, &redledimage,-10 + vupos * 20,13); } vupos = newvupos; } (*sampleroutcode) (note); } else FreeNode(note); } outcode(note) /* This, the outcode for this module, does nothing. */ struct Note *note; { enteraztec(); FreeNode(note); leaveaztec(); } opencode(direction) /* This installs the VU meter. If this is to install the output routine: Get the Port structure for the Sampler. If the Sampler already has its output code stolen, (samplerport->show has somebody's port id) do nothing. Else, open the window, give samplerport->outcode insertoutcode and put the Sampler's output code in samplercode. Set samplerport->show to this port's id, so no other module will monkey with it. */ char direction; { short i; struct Port *samplerport; enteraztec(); if (!direction) { samplerport = (struct Port *) MidiPort(FindMidiPort("sampler")); if (samplerport) { if (samplerport->show) { CloseMidiPort(samplerport->show,0); } if (!samplerport->show) { vuwindow = (struct Window *) OpenWindow(&NewWindowStructure); if (vuwindow) { totalvolume = 0; for (i=0; i < 128; i++) velocity[i] = 0; sampleroutcode = samplerport->outcode; samplerport->outcode = insertoutcode; samplerport->show = thisport; leaveaztec(); return(1); } } } } leaveaztec(); return(0); } closecode(direction) /* This deactivates the VU Meter. Simply return the Sampler's output routine to its Port structure and clear samplerport->show. Close the display window. */ { struct Port *samplerport; enteraztec(); if (!direction) { samplerport = (struct Port *) MidiPort(FindMidiPort("sampler")); if (samplerport && sampleroutcode) { samplerport->outcode = sampleroutcode; samplerport->show = 0; } if (vuwindow) CloseWindow(vuwindow); vuwindow = 0; } leaveaztec(); return(1); } /* The main program is standard with one addition: After installing this port, call OpenMidiPort to activate it. This is needed because there is no icon for the user to click on. We could have added that icon, but it would be one more item on the Patch Panel, cluttering it and causing some confusion since nothing can be sent directly to it. There is a chance OpenMidiPort will fail. This is because the Sampler's output routine was already stolen. If so, there is no need to stick around, so call RemoveMidiPort and leave. Normally, RemoveMidiPort is done by SoundScape when it closes down, but this time we'll do it ourselves to get out early. */ main() { IntuitionBase = OpenLibrary("intuition.library",0); SoundScapeBase = OpenLibrary("soundscape.library",0); if (SoundScapeBase) { CloseLibrary(SoundScapeBase); thisport = AddMidiPort(opencode,closecode,0, outcode,0,0,-1,"vu meter"); if (OpenMidiPort(thisport,0)) { SetTaskPri(FindTask(0),-20); while (MidiPort(thisport)) Delay(100); } else RemoveMidiPort(thisport); } CloseLibrary(IntuitionBase); }