1 Syntax  General
1 (EN googletranslate)
1 (PL googletranslate)


Formulas are differentiated whether they give their result to a normal variable or to an instrument. In the latter case, a selective division is performed at the end of the formula to determine a pitch.
Each number appearing in a line can also be parameterized by a variable, if this variable was defined before.
Syntax  The six line types
1) Blank lines are simply skipped.
2) Line COMMENTS #
Line COMMENTS are introduced with # at the beginning of the respective line.
3) PULSE !
PULSE Count up from an initial value t0 in steps measured in milliseconds dt.
The syntax is: t0 dt ! x
The exclamation mark is the characteristic on the basis which a line which represents a pulse is identified. x is an arbitrary variable name over which the pulse can be processed then at other place further down in a formula. Valid variables consist of one or two characters from {abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789}.

8000 100 ! t 0 8000 ! tm
Code 11: Beispiele zu PULSE !
4) INSTRUMENTS
In the instrument line, the base number for each possible instrument is defined, the amplification and stereo direction is defined, the transposition, the range the type of instrument and finally the variable name, under which it can be addressed further down.
The special character that allows a line to be recognized as an instrument definition is the colon :
An instrument line always consists of exactly 14 elements separated by spaces:
In AOGdogmaWEB there are only 11, because CHANNEL, GAINLEFT and GAINRIGHT are not implemented there. The first instrument there is always the xylophone, the second the vibraphone and the third the marimba.
p q r s REST FACTOR TRANSPOSITION MIDIMIN MIDIMAX CHANNEL GAINLEFT GAINRIGHT : x
BASISZAHL = 2^p * 3^q * 5^r * 7^s * REST
Before converting a frequency into a midi value, it is multiplied by FACTOR. The value is given in hundredths 100 corresponds to factor 1. Afterwards the TRANSPOSITION is executed in semitone steps. Here 24 is the neutral position and does not lead to a transposition. 12 would lead to a transposition one octave lower. The tonal range is defined by MIDIMIN and MIDIMAX inclusive. Due to the software, certain instrument sounds and several playing variants are available. At the moment these are xylophone, vibraphone and marimba, each in three velocities. CHANNEL==0 means that the xylophone is addressed 1==vibraphone, 2==marimba. Example lines for the definition of instruments:
3 2 1 1 NN 100 19 65 108 0 70 30 : xy 3 2 1 1 NN 100 19 53 89 2 50 50 : ma 3 2 1 1 NN 100 19 45 108 1 15 35 : vb
Code 12: Examples for INSTRUMENTS :

5) FORMULAS ~

tm /18 %3 ~ WW tm /24 +12 ~ XX tm /48 +1 *6 +66 ~ YY t *PP %72 /3 +4 ~ vb t +tm *QQ %XX ~ ma t +tm *RR %XX /2 ~ xy
Code 13: Examples for FORMULAS ~
In the upper three examples, the result of the calculation is stored in the ordinary variables WW, XX and YY. In the last three lines, the result is assigned to one instrument each. The latter has the effect that the result of the formula calculation is first taken as a divisor of the associated base number for the selective division. The result is then interpreted as frequency and multiplied by FACTOR, converted to a midi value and transposed. Finally, it is checked whether the result lies within the required tonal range of the instrument. If so, the tone is heard. If it is not, you may hear a tone that was determined for the instrument by another formula. The last result that can be played always applies.
Formulas that control instruments can create musical phrases and represent what AOG originally is. All other line types are used to automatically change these formulas over time.
How is a formula interpreted? This can be represented mathematically in a very compact way:
tm /48 +1 *6 +66 ~ YY corresponds as a mathematical formula: YY = (((tm/48)+1)*6)+66 Where tm is a time sequence defined above: 0 8000 ! tm This means: tm0 = 0ms tm1 = 8000ms tm2 = 16000ms usw.
Code 14: Second case: Interpretation of formulas whose result is transferred to an ordinary variable.
For formulas that deliver their result to an instrument, the evaluation is somewhat more complex:
t *PP %72 /3 +4 ~ vb means: Base number B is according to the definition of vb above: B=2*2*2*3*3*5*7*NN Divider z = (((t*PP)%72)/3)+4 If the result is zero for z, no tone is assigned to the instrument. The following operations will then not be performed. frequency f = B // z Where // corresponds to a selective division, which only removes the prime factors 2,3,5,7 from B in the same quantity as they appear in the divider z. As this is central, here is an implementation of // for understanding: f=B; while(f>=2 && f%2==0 && z>=2 && z%2==0) {f=f/2;z=z/2;} while(f>=3 && f%3==0 && z>=3 && z%3==0) {f=f/3;z=z/3;} while(f>=5 && f%5==0 && z>=5 && z%5==0) {f=f/5;z=z/5;} while(f>=7 && f%7==0 && z>=7 && z%7==0) {f=f/7;z=z/7;} After that, there is still to be done: f = f * FACTOR midi = frequency2midi(f) midi = midi + TRANSPOSITION if(midi>=MIDIMIN && midi<=MIDIMAX) { playTone(midi); ...Play the sound on the instrument vb }
Code 15: Interpretation of formulas whose result is transferred to an instrument.
Permitted operations are:
+ Addition  Subtraction * Multiplication / Division (returns result, if no remainder exists, otherwise zero) % Modulo, or rest division, examples: 6%3=0 7%3=1 8%3=2 (returns result if operand is positive, otherwise zero)  "divides", preserves the intermediate result, if it is divisible by the operand with no remaining rest, else returns zero.
Code 16: Permitted operations and their meaning
6) PLAYING TECHNIQUE §
The current version has three instruments, each available in samples with three velocities. When a technique formula sends a value of 0, 1, or 2 to an instrument, the instrument is assigned a low soft stroke selected at 0, a medium stroke at 1, or a hard loud stroke at 2.
The same operations can occur as in FORMULA.
Examples:
16 DD /2 +CC /4 %3 § xy 16 DD /2 +CC /4 %3 § ma 16 DD /2 +CC /4 %3 § vb
Code 17: Examples for PLAYING TECHNIQUE §

Restricted language coverage of the web application AOGdogmaWEB

Compared to the above, the language range of AOGdogmaWEB is limited in the following way: playing technique is not implemented and no variables are predefined, especially not dt, t0, t1, DD and CC, see below.
While AOGdogmaWEB ensures a quick start with AOGdogma, the Java processing sketch AOGdogma offers more extensive possibilities within the "Distributed Libraries" of Processing: There you can animate the performance on demand. Wavfiles can be created directly and scores in Lilypond format.
Predefined variables
Predefined variables are:
dt Minimum time step, typically 10 milliseconds. I.e. the script is evaluated every 10 milliseconds. The specifications for PULSE should be integer multiples thereof. t0 Start time in milliseconds. This value is added to t at 8000 100 ! t So if ts is the milliseconds since the start: t = t0 + 8000 + ts/dt t1 If a wavfile is modified, or if the boolean variable HAS_AN_END=true (only processing), then the piece ends at this point. (Has no meaning for AOGdogmaWEB) DD and CC result from the current midi value, so they are not fixed like the formulas for playing technique may suggest. DD Maximum pairwise determined dissonance value of the last 12 midi values (no matter in which voice) including the current Midi event. Usually the value is between 0 and 10. More information: See source code of the Gradus class in Library ComposingForEveryone CC Average dissonance value between the current midi event and all 12 previous midi events. Expresses how much the new event conflicts with the previous ones. More information: See source code of the Gradus class in Library ComposingForEveryone
Code 18: Predefined variables and their meaning.