How to manipulate Canvas elements: Difference between revisions

How to manipulate Canvas elements (view source)

529 bytes added , 7 December 2017

229

edits

@@ Line 285: / Line 285: @@
 <syntaxhighlight>
 arrow.setTranslation(0,0);
-arrow.setScale(1.5,2);
+arrow.setScale(2,4);
 arrow.getScale();
-</syntaxhighlight> you get ''[9.5,19.5, 120.5,40.5]'' which are the values for [Sx, Sy].<br />
+</syntaxhighlight> you get ''[2,4]'' which are the values for [Sx, Sy].<br />[[File:Scaled.png|none|Scaled arrow]]
 Again, the BoundingBox and the intrinsic coordenate system remains unchanged.<br />
+=== Fundamental Equations ===
+Now the general case, applying both Translation and Scaling:
+<syntaxhighlight>
+arrow.setTranslation(150,80);
+arrow.setScale(2,4);
+</syntaxhighlight>
+The Fundamental Equations:
+ <big>'''''u = T<sub>x</sub> + x * Sx'''''</big>
+ <big>'''''v = T<sub>y</sub> + y * Sy'''''</big>
+                                 and his reciprocals:
+ <big>'''''T<sub>x</sub> =  u - x * Sx'''''</big>
+ <big>'''''T<sub>y</sub> =  v - y * Sy'''''</big>
+'''Plot2D''' makes extensive use of these equations.