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math [2019/07/04 17:43] – [AnglesToVector] korshunmath [2019/08/26 18:26] (current) – [Length] korshun
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 ''int ipow(int x, int y)'' ''int ipow(int x, int y)''
  
-Returns x^y. Uses a simple multiplication loop.+Returns x<sup>y</sup>. Uses a simple multiplication loop.
  
 ==== fpow ==== ==== fpow ====
 ''fixed fpow(fixed x, fixed y)'' ''fixed fpow(fixed x, fixed y)''
  
-returns x^y. Supports powers below ''1.0''. Uses a simple loop with ''FixedMul'' or ''FixedDiv'', depending on whether the power is below ''1.0''.+returns x<sup>y</sup>. Supports powers below ''1.0''. Uses a simple loop with ''FixedMul'' or ''FixedDiv'', depending on whether the power is below ''1.0''.
  
  
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 ===== Vector math ===== ===== Vector math =====
  
-==== VectorLength3D ==== +Vector math functions come in 2D and 3D versions. All vector math functions operate only on fixed-point vectors. No integer versions are available.
-''fixed VectorLength3D(fixed x, fixed y, fixed z)''+
  
-A 3D version of [[zdoom>VectorLength]]. Returns the length of the 3D vector.+Vectors are passed as arguments named ''x'', ''y'', ''z''. 
 + 
 +If a function returns a vector, it uses [[multiple return values]], returning vector components in the same XYZ order, so ''r1'' is X, ''r2'' is Y and ''r3'' is Z. 
 + 
 +If a function accepts more than one vector, the first vector is passed as ''x1'', ''y1'', ''z1'', and the second one as ''x2'', ''y2'', ''z2''. 
 + 
 + 
 +==== Length ==== 
 + 
 +  * 2D: [[zdoom>VectorLength]] -- already built into ZDoom. 
 +  * 3D: ''fixed VectorLength3D(fixed x, fixed y, fixed Z)'' 
 + 
 +These functions return the length of the input vector. ''VectorLength3D'' is implemented efficiently as ''VectorLength(VectorLength(x, y), z)''. 
 + 
 +==== Dot product ====
  
-==== dot ==== 
   * 2D: ''fixed dot2(fixed x1, fixed y1, fixed x2, fixed y2)''   * 2D: ''fixed dot2(fixed x1, fixed y1, fixed x2, fixed y2)''
   * 3D: ''fixed dot3(fixed x1, fixed y1, fixed z1, fixed x2, fixed y2, fixed z2)''   * 3D: ''fixed dot3(fixed x1, fixed y1, fixed z1, fixed x2, fixed y2, fixed z2)''
  
-Returns the [[wp>dot product]] of two vectors. Shorthand for writing out ''FixedMul(x1, x2) + FixedMul(y1, y2) + ...''.+These functions return the sum of components of a vector obtained by componentwise multiplication of the two input vectors, also known as the [[wp>dot product]]. They are shorthands for writing out ''FixedMul(x1, x2) + FixedMul(y1, y2) + ...''. 
 + 
 +==== Normalization ====
  
-==== normalize ==== 
   * 2D: ''fixed, fixed normalize2d(fixed x, fixed y)''   * 2D: ''fixed, fixed normalize2d(fixed x, fixed y)''
   * 3D: ''fixed, fixed, fixed normalize3d(fixed x, fixed y, fixed z)''   * 3D: ''fixed, fixed, fixed normalize3d(fixed x, fixed y, fixed z)''
  
-[[wp>Normalized vector|Normalizes]] the vector and returns the result using [[multiple return values]].+These functions return the input vector scaled to have length ''1.0'', also known as [[wp>Normalized vector|normalizing]] the input vector, and return the result using [[multiple return values]].
  
-=== Example usage ===+=== Examples ===
 <code> <code>
 normalize3d(x, y, z); normalize3d(x, y, z);
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 Converts the vector's direction to a pair of angles (angle, pitch) and returns them using [[multiple return values]]. Converts the vector's direction to a pair of angles (angle, pitch) and returns them using [[multiple return values]].
  
-<note important>Remember that ZDoom uses inverted pitch angles on actors. ACSUtils functions don't invert pitches.</note>+<note important>Remember that ZDoom uses negated pitch angles on actors. ACSUtils functions don't use negated pitches. </note>
  
 === Example usage === === Example usage ===
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     int pitch = r2;     int pitch = r2;
     SetActorAngle(tid, angle);     SetActorAngle(tid, angle);
-    SetActorPitch(tid, -pitch); // SetActorPitch expects inverted pitch.+    SetActorPitch(tid, -pitch); // SetActorPitch expects negated pitch.
 } }
 </code> </code>
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 Converts a pair of angles (angle, pitch) to a 3D vector of length ''1.0'', which points in the same direction, and returns it using [[multiple return values]]. Converts a pair of angles (angle, pitch) to a 3D vector of length ''1.0'', which points in the same direction, and returns it using [[multiple return values]].
  
-<note important>Remember that ZDoom uses inverted pitches on actors. ACSUtils functions don't invert pitches.</note>+<note important>Remember that ZDoom uses negated pitch angles on actors. ACSUtils functions don't use negated pitches.</note>
  
 === Example usage === === Example usage ===
  
 <code> <code>
-AnglesToVector(GetActorAngle(0), -GetActorPitch(0));+AnglesToVector(GetActorAngle(0), -GetActorPitch(0)); // Un-negate actor pitch
 int dirX = r1; int dirX = r1;
 int dirY = r2; int dirY = r2;
math.1562262189.txt.gz · Last modified: 2019/07/04 17:43 by korshun

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