/* sendvirtual.c -- test for creating a virtual device and sending to it */ /* * Roger B. Dannenberg * Sep 2021 */ #include "portmidi.h" #include "porttime.h" #include "stdlib.h" #include "stdio.h" #include "string.h" #include "assert.h" #define OUTPUT_BUFFER_SIZE 0 #define DEVICE_INFO NULL #define DRIVER_INFO NULL #define TIME_PROC ((PmTimeProcPtr) Pt_Time) #define TIME_INFO NULL #define TIME_START Pt_Start(1, 0, 0) /* timer started w/millisecond accuracy */ int latency = 0; static void prompt_and_exit(void) { printf("type ENTER..."); while (getchar() != '\n') ; /* this will clean up open ports: */ exit(-1); } static PmError checkerror(PmError err) { if (err == pmHostError) { /* it seems pointless to allocate memory and copy the string, * so I will do the work of Pm_GetHostErrorText directly */ char errmsg[80]; Pm_GetHostErrorText(errmsg, 80); printf("PortMidi found host error...\n %s\n", errmsg); prompt_and_exit(); } else if (err < 0) { printf("PortMidi call failed...\n %s\n", Pm_GetErrorText(err)); prompt_and_exit(); } return err; } void wait_until(PmTimestamp when) { PtTimestamp now = Pt_Time(); if (when > now) { Pt_Sleep(when - now); } } void main_test_output(int num) { PmStream *midi; int32_t next_time; PmEvent buffer[1]; PmTimestamp timestamp; int pitch = 60; int id; /* It is recommended to start timer before Midi; otherwise, PortMidi may start the timer with its (default) parameters */ TIME_START; /* create a virtual output device */ id = checkerror(Pm_CreateVirtualOutput("portmidi", NULL, DEVICE_INFO)); checkerror(Pm_OpenOutput(&midi, id, DRIVER_INFO, OUTPUT_BUFFER_SIZE, TIME_PROC, TIME_INFO, latency)); printf("Midi Output Virtual Device \"portmidi\" created.\n"); printf("Type ENTER to send messages: "); while (getchar() != '\n') ; buffer[0].timestamp = Pt_Time(); #define PROGRAM 0 buffer[0].message = Pm_Message(0xC0, PROGRAM, 0); Pm_Write(midi, buffer, 1); next_time = Pt_Time() + 1000; /* wait 1s */ while (num > 0) { wait_until(next_time); Pm_WriteShort(midi, next_time, Pm_Message(0x90, pitch, 100)); printf("Note On pitch %d\n", pitch); num--; next_time += 500; wait_until(next_time); Pm_WriteShort(midi, next_time, Pm_Message(0x90, pitch, 0)); printf("Note Off pitch %d\n", pitch); num--; pitch = (pitch + 1) % 12 + 60; next_time += 500; } /* close device (this not explicitly needed in most implementations) */ printf("ready to close..."); Pm_Close(midi); printf("done closing.\nNow delete the virtual device..."); checkerror(Pm_DeleteVirtualDevice(id)); printf("done deleting.\n"); } void show_usage() { printf("Usage: sendvirtual [-h] [-l latency-in-ms] [n]\n" " -h for this message,\n" " -l ms designates latency for precise timing (default 0),\n" " n is number of message to send.\n" "sends change program to 1, then one note per second with 0.5s on,\n" "0.5s off, for n/2 seconds. Latency >0 uses the device driver for \n" "precise timing (see PortMidi documentation).\n"); exit(0); } int main(int argc, char *argv[]) { int num = 10; int i; for (i = 1; i < argc; i++) { if (strcmp(argv[i], "-h") == 0) { show_usage(); } else if (strcmp(argv[i], "-l") == 0 && (i + 1 < argc)) { i = i + 1; latency = atoi(argv[i]); printf("Latency will be %d\n", latency); } else { num = atoi(argv[1]); if (num <= 0) { show_usage(); } printf("Sending %d messages.\n", num); } } main_test_output(num); printf("finished sendvirtual test...type ENTER to quit..."); while (getchar() != '\n') ; return 0; }