/**
* Sets a binding for a special dynamic variable in this Environment. This is not for end-users,
* and will throw an AssertionError in case of conflict.
*
* @param varname the name of the dynamic variable to be bound
* @param value a value to bind to the variable
* @return this Environment, in fluid style
*/
public Environment setupDynamic(String varname, Object value) {
if (dynamicFrame.get(varname) != null) {
throw new AssertionError(
String.format("Trying to bind dynamic variable '%s' but it is already bound", varname));
}
if (lexicalFrame != null && lexicalFrame.get(varname) != null) {
throw new AssertionError(
String.format(
"Trying to bind dynamic variable '%s' but it is already bound lexically", varname));
}
if (globalFrame.get(varname) != null) {
throw new AssertionError(
String.format(
"Trying to bind dynamic variable '%s' but it is already bound globally", varname));
}
try {
dynamicFrame.put(this, varname, value);
} catch (MutabilityException e) {
// End users don't have access to setupDynamic, and it is an implementation error
// if we encounter a mutability exception.
throw new AssertionError(
Printer.format(
"Trying to bind dynamic variable '%s' in frozen environment %r", varname, this),
e);
}
return this;
}
/**
* Gets a binding from the current frame or if not found its parent.
*
* @param varname the name of the variable to be bound
* @return the value bound to variable
*/
public Object get(String varname) {
if (bindings.containsKey(varname)) {
return bindings.get(varname);
}
if (parent != null) {
return parent.get(varname);
}
return null;
}
protected boolean sameForm(RBTerm other, Frame lr, Frame rl) {
if (!(other.getClass() == this.getClass())) return false;
else {
RBVariable binding = (RBVariable) lr.get(this);
if (binding == null) {
lr.put(this, other);
} else if (!binding.equals(other)) {
return false;
}
binding = (RBVariable) rl.get(other);
if (binding == null) {
rl.put(other, this);
return true;
} else {
return this.equals(binding);
}
}
}
/**
* @return the value from the environment whose name is "varname".
* @throws NoSuchVariableException if the variable is not defined in the Environment.
*/
public Object lookup(String varname) throws NoSuchVariableException {
// Which Frame to lookup first doesn't matter because update prevents clashes.
if (lexicalFrame != null) {
Object lexicalValue = lexicalFrame.get(varname);
if (lexicalValue != null) {
return lexicalValue;
}
}
Object globalValue = globalFrame.get(varname);
Object dynamicValue = dynamicFrame.get(varname);
if (globalValue == null && dynamicValue == null) {
throw new NoSuchVariableException(varname);
}
if (knownGlobalVariables != null) {
knownGlobalVariables.add(varname);
}
if (globalValue != null) {
return globalValue;
}
return dynamicValue;
}
public Frame unify(RBTerm other, Frame f) {
// System.err.println("** entering unify " + this + " to: " + other);
if (other instanceof RBIgnoredVariable) return f;
RBTerm val = f.get(this);
if (val == null) {
other = other.substitute(f);
if (equals(other)) return f;
else if (other.freefor(this)) {
return bind(other, f);
} else return null;
} else return val.unify(other, f);
}
/**
* Modifies a binding in the current Frame of this Environment, as would an {@link
* AssignmentStatement}. Does not try to modify an inherited binding. This will shadow any
* inherited binding, which may be an error that you want to guard against before calling this
* function.
*
* @param varname the name of the variable to be bound
* @param value the value to bind to the variable
* @return this Environment, in fluid style
*/
public Environment update(String varname, Object value) throws EvalException {
Preconditions.checkNotNull(value, "update(value == null)");
// prevents clashes between static and dynamic variables.
if (dynamicFrame.get(varname) != null) {
throw new EvalException(
null, String.format("Trying to update special read-only global variable '%s'", varname));
}
if (isKnownGlobalVariable(varname)) {
throw new EvalException(
null, String.format("Trying to update read-only global variable '%s'", varname));
}
try {
currentFrame().put(this, varname, Preconditions.checkNotNull(value));
} catch (MutabilityException e) {
// Note that since at this time we don't accept the global keyword, and don't have closures,
// end users should never be able to mutate a frozen Environment, and a MutabilityException
// is therefore a failed assertion for Bazel. However, it is possible to shadow a binding
// imported from a parent Environment by updating the current Environment, which will not
// trigger a MutabilityException.
throw new AssertionError(
Printer.format("Can't update %s to %r in frozen environment", varname, value), e);
}
return this;
}
/** Intenal use. Call {@link #checkValidity()} and if path is not valid recomputes it. */
protected void updatePath() {
checkValidity();
if (!pathIsValid) {
path.clear();
int nbSteps = 30;
if (keyFrameList.isEmpty()) return;
if (!valuesAreValid) updateModifiedFrameValues();
if (keyFrameList.get(0) == keyFrameList.get(keyFrameList.size() - 1))
// TODO experimenting really
path.add(
new Frame(
keyFrameList.get(0).position(),
keyFrameList.get(0).orientation(),
keyFrameList.get(0).magnitude()));
else {
KeyFrame[] kf = new KeyFrame[4];
kf[0] = keyFrameList.get(0);
kf[1] = kf[0];
int index = 1;
kf[2] = (index < keyFrameList.size()) ? keyFrameList.get(index) : null;
index++;
kf[3] = (index < keyFrameList.size()) ? keyFrameList.get(index) : null;
while (kf[2] != null) {
Vec pdiff = Vec.subtract(kf[2].position(), kf[1].position());
Vec pvec1 = Vec.add(Vec.multiply(pdiff, 3.0f), Vec.multiply(kf[1].tgP(), (-2.0f)));
pvec1 = Vec.subtract(pvec1, kf[2].tgP());
Vec pvec2 = Vec.add(Vec.multiply(pdiff, (-2.0f)), kf[1].tgP());
pvec2 = Vec.add(pvec2, kf[2].tgP());
for (int step = 0; step < nbSteps; ++step) {
Frame frame = new Frame();
float alpha = step / (float) nbSteps;
frame.setPosition(
Vec.add(
kf[1].position(),
Vec.multiply(
Vec.add(
kf[1].tgP(),
Vec.multiply(Vec.add(pvec1, Vec.multiply(pvec2, alpha)), alpha)),
alpha)));
if (gScene.is3D()) {
frame.setOrientation(
Quat.squad(
(Quat) kf[1].orientation(),
((KeyFrame3D) kf[1]).tgQ(),
((KeyFrame3D) kf[2]).tgQ(),
(Quat) kf[2].orientation(),
alpha));
} else {
// linear interpolation
float start = kf[1].orientation().angle();
float stop = kf[2].orientation().angle();
frame.setOrientation(new Rot(start + (stop - start) * alpha));
}
frame.setMagnitude(Util.lerp(kf[1].magnitude(), kf[2].magnitude(), alpha));
path.add(frame.get());
}
// Shift
kf[0] = kf[1];
kf[1] = kf[2];
kf[2] = kf[3];
index++;
kf[3] = (index < keyFrameList.size()) ? keyFrameList.get(index) : null;
}
// Add last KeyFrame
path.add(new Frame(kf[1].position(), kf[1].orientation(), kf[1].magnitude()));
}
pathIsValid = true;
}
}