[Gzz-commits] gzz/gzz/vob VobScene.java

[Tuomas J. Lukka]

CVSROOT:        /cvsroot/gzz
Module name:    gzz
Changes by:     Tuomas J. Lukka <address@hidden>        02/11/22 10:31:11

Modified files:
        gzz/vob        : VobScene.java 

Log message:
        more Vob tutorial

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/gzz/gzz/gzz/vob/VobScene.java.diff?tr1=1.17&tr2=1.18&r1=text&r2=text

Patches:
Index: gzz/gzz/vob/VobScene.java
diff -u gzz/gzz/vob/VobScene.java:1.17 gzz/gzz/vob/VobScene.java:1.18
--- gzz/gzz/vob/VobScene.java:1.17      Fri Nov 22 10:23:11 2002
+++ gzz/gzz/vob/VobScene.java   Fri Nov 22 10:31:11 2002
@@ -80,8 +80,34 @@
        // A translation RELATIVE to cs: the origin of cs_t is at (150, 125) on 
screen.
        int cs_t = vs.coords.translate(0, .5, .5, 0);
 
-
+       vs.matcher.add(cs, "V1");
+       // Sub key
+       vs.matcher.add(cs, cs_t, "X");
    </pre>
+    Now, cs_t will only be interpolated to a coordinate system whose parent is 
interpolated
+    to cs, and whose key is "X".
+    Here, both hierarchies were parallel, and indeed, usually they are. But 
sometimes
+    non-parallel hierarchies are useful. For example, if we are placing images 
next to a map
+    and markers on the map about where those images are, it's easier to do
+    <pre>
+       void placeImage(int imageCS, int mapCS, String param) {
+           // Place image into the image coordsys
+           // ...
+           int marker_cs = vs.coords.ortho(mapCS, 0, markx, marky, w, h);
+           vs.matcher.add(imageCS, marker_cs, "MARK");
+       }
+    </pre>
+    Here, the marker <i>transformation</i> is a child of the map 
transformation, but
+    as a <i>keyframe object,</i> for matching, its parent is imageCS.
+    This allows us to use the constant key "MARK" for all the marks.
+    <p>
+    However, you'll probably see this situation pretty rarely; most often the 
hierarchies
+    are indeed parallel, and for that case VobScene provides a shortcut:
+    <pre>
+       int cs = vs.orthoCS(0, "V1", 0, 100, 100, 100, 50);
+       int cs_t = vs.translateCS(cs, "X", .5, .5, 0);
+    </pre>
+    has the same effect as the earlier code.
  * <p>
  *
  */