VEX でカスタム COP 作成

sample_merge.vfl

#pragma opname sample_merge
#pragma oplabel "SampleMerge"
#pragma opmaxinputs 4
#pragma inputlabel 1 "R"
#pragma inputlabel 2 "G"
#pragma inputlabel 3 "B"
#pragma inputlabel 4 "A"
#pragma label useChannelOfR "Use channel of R"
#pragma choice useChannelOfR "0" "R"
#pragma choice useChannelOfR "1" "G"
#pragma choice useChannelOfR "2" "B"
#pragma choice useChannelOfR "3" "A"
#pragma label useChannelOfG "Use channel of G"
#pragma choice useChannelOfG "0" "R"
#pragma choice useChannelOfG "1" "G"
#pragma choice useChannelOfG "2" "B"
#pragma choice useChannelOfG "3" "A"
#pragma label useChannelOfB "Use channel of B"
#pragma choice useChannelOfB "0" "R"
#pragma choice useChannelOfB "1" "G"
#pragma choice useChannelOfB "2" "B"
#pragma choice useChannelOfB "3" "A"
#pragma label useChannelOfA "Use channel of A"
#pragma choice useChannelOfA "0" "R"
#pragma choice useChannelOfA "1" "G"
#pragma choice useChannelOfA "2" "B"
#pragma choice useChannelOfA "3" "A"

float sample(
  int opinput;
  int useChannel;
) {
  vector4 c;
  c = cinput(opinput, PL, IX, IY);
  if (useChannel == 0) {
    return c.x;
  }
  else if (useChannel == 1) {
    return c.y;
  }
  else if (useChannel == 2) {
    return c.z;
  }
  else {
    return c.w;
  }
}

cop2 sample_merge(
  int useChannelOfR=0;
  int useChannelOfG=0;
  int useChannelOfB=0;
  int useChannelOfA=0;
) {
  R = sample(0, useChannelOfR);
  G = sample(1, useChannelOfG);
  B = sample(2, useChannelOfB);
  A = sample(3, useChannelOfA);
}