Info

Summary

Info is a Gadget in ViewMain (button “ Info ”). Clicking it dispatches into InfoDispatch, a self running demo of the graphics classes: one step at a time, each shown for Info.STEP_MILLIS (4000 ms; change the constant or start Java with -Dinfo.step.millis=2000). Every example is built in code when its step starts. Each step runs in its own nested Dispatch frame, so when the step ends Dispatch.begin() restores the Gob, Gadget, text and line lists and the example is gone.

Skip: Next gadget or Space / Enter / Right arrow / n. Leave: Exit gadget or Escape. After the last step ViewMain is shown again exactly as it was.

Source files: Info.java (the Gadget and STEP_MILLIS), InfoDispatch.java (step sequencer, skip gadgets, keyboard), InfoStep.java (abstract step), InfoSteps.java (the steps). This page is written by test/com/multiversesocial/hyperview/InfoDoc.java from the same step table the demo runs.

Hierarchy

Extends: Gadget → Gob

Implements: none (Gadget implements HyperConstants)

Helper classes: InfoDispatch extends Dispatch (its inner classes StepFrame, Skip extend Dispatch, InfoKeys extends Gadget); InfoStep (abstract); InfoSteps implements HyperConstants.

Demo steps, in order

Which step explains which class and methods. The caption text is what the step shows on screen.

Class coverage

Each class named by a step and the steps (see the table above) that explain it.

Graphics classes not demonstrated

Classes the demo has no step for, and why. Each has its own page.

Behavior notes (what the code really does)

• Splines (3.2). CURVE_LINEAR, CURVE_BEZIER and CURVE_CATMULL_ROM are real curves now. Before, the Gob moved on straight, octant snapped segments whatever the type (the Bezier control points were computed but never read); now Spline samples the curve into an arc length table and HyperView.run() calls Spline.step(gob), which moves the Gob speed pixels per frame along the curve in floating point (Gob.fx/fy; x,y are those rounded). Attach a Spline with Gob.attachSpline(), release it with detachSpline().
• COLLIDE_AT_END is a Spline end mode implemented with CollisionManager: the Gob stops exactly on its last point, the Spline stays attached and the Gob keeps taking part (combined with WRAP/BOUNCE it keeps moving). Every display frame HyperView.collisionPass() tests the participating Gobs of the current Dispatch frame against each other: bounding box, then point-in-polygon on the outline. The outline is, in this order, a polygon set with Gob.setOutline(), the polygon traced from the Gob's image if the Gob has the flag GOB_COLLISION_OUTLINE (Gob.setImageOutlineEnabled(true)), or the bounding box. The flag also makes a Gob a participant without any Spline; only flagged Gobs are ever traced (Gob.getOutlineComputeCount() proves it). Nothing is moved or stopped on contact; the Gobs get GOB_COLLIDED, collisionCount, collidedWith and a CollisionAnimGob impact animation at the contact point (the impact sprite is generated in code: the shipped media has none).
• Two thin outlines crossing like a plus sign have no vertex inside each other, so after the vertex tests CollisionManager also tests edge crossings (CollisionManager.edgeTest, default true). Points exactly on an edge count as inside.
• createCircle/createEllipse (closed, WRAP_AT_END | SP_ZBUFFER_ENA by default, z swings 10 -/+ 4 as a double), createSpiral (open, BOUNCE_AT_END) and createHeart (closed, WRAP_AT_END) now set their end logic; each has an overload with explicit flags that replaces the default. Before 3.2 the circle and ellipse set the z flag but no end logic, so the Gob stopped at the end unless the caller set one.
• STOP_AT_END (or no END_LOGIC flag) still detaches the Spline when the Gob reaches the end (the Gob stays on the end point); direct edits of the old int arrays Spline.x[] no longer move the Gob (use setPoints/translate/scale/addPoint); a Spline whose points are all the same never moves its Gob; one Spline belongs to one Gob.
• new Circle(view,r,n) only builds HyperLine objects; they are drawn once passed to HyperView.addLine().
• new Gob(...) does not add itself to the view (call view.addGob(gob)); an AnimGob constructor does add itself.
• DBVectorDraw() stores a target line and a speed; the renderer has a Todo for moving lines, so only the start line is drawn.
• Gob, Gadget and AnimGob images are loaded from new URL(getCodeBase(),name); -Dcodebase=<url> changes the base. Objects themselves are not loaded by URL.
• Dispatch.begin() also backs up and restores the line list (INHERIT_LINES flag, new in this version); before that fix a dispatched frame inherited and left behind lines.

Declaration & members

public class Info extends Gadget

Fields (1)

Constructors (1)

InfoDispatch (constants used by steps)

Running and testing

Compile with compile27 or this single plain line (javac on the PATH, no environment variables) : javac -encoding US-ASCII -d build/classes -cp lib/comm.jar -sourcepath src src/com/multiversesocial/hyperview/*.java. Run ViewMain and click “ Info ”. The test test/com/multiversesocial/hyperview/InfoRunTest.java starts ViewMain, clicks Info, saves a screenshot of every step, checks no step threw, the dispatch stack step reports all lists restored, and that Next, Space and Escape work (run it on a display, for example under Xvfb). It also checks the spline steps (the three curve types have three different lengths, the STOP step lets go of the Spline), the attach/detach step (sub pixel fx while x is an int), the COLLIDE_AT_END step (the Gobs get flagged, collide, the impact animation is drawn) and the image outline step (3 traces for the 3 flagged Gobs, none for the Gob without the flag; the circle's box overlaps the L's box without a collision, then it hits the plus sign). test/com/multiversesocial/hyperview/CollisionTest.java tests CollisionManager.pointInPoly and the collision pass itself (flags, counters, the CollisionAnimGob, no spurious or recursive collisions, nested Dispatch frames). SplineTest.java tests the curve math (Bezier and Catmull-Rom at known t, arc length, constant speed, the four end modes with fractional speeds), attach/detach and the movement in the real display loop. OutlineTest.java tests OutlineTracer on known shapes, the flag gating (the compute counter), and collisions between outlined Gobs whose boxes overlap but whose shapes do not.