Merge pull request #6660 from hyperlogic/tony/anim-expressions

AnimExpression: boolean expression parser and evaluator

libraries/animation/src/AnimExpression.cpp

@@ -0,0 +1,676 @@
+//
+//  AnimExpression.cpp
+//
+//  Created by Anthony J. Thibault on 11/1/15.
+//  Copyright (c) 2015 High Fidelity, Inc. All rights reserved.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include <StreamUtils.h>
+#include <QRegExp>
+
+#include "AnimExpression.h"
+#include "AnimationLogging.h"
+
+AnimExpression::AnimExpression(const QString& str) :
+    _expression(str) {
+    auto iter = str.begin();
+    parseExpr(_expression, iter);
+    while(!_tokenStack.empty()) {
+        _tokenStack.pop();
+    }
+}
+
+//
+// Tokenizer
+//
+
+void AnimExpression::unconsumeToken(const Token& token) {
+    _tokenStack.push(token);
+}
+
+AnimExpression::Token AnimExpression::consumeToken(const QString& str, QString::const_iterator& iter) const {
+    if (!_tokenStack.empty()) {
+        Token top = _tokenStack.top();
+        _tokenStack.pop();
+        return top;
+    } else {
+        while (iter != str.end()) {
+            if (iter->isSpace()) {
+                ++iter;
+            } else if (iter->isLetter()) {
+                return consumeIdentifier(str, iter);
+            } else if (iter->isDigit()) {
+                return consumeNumber(str, iter);
+            } else {
+                switch (iter->unicode()) {
+                case '&': return consumeAnd(str, iter);
+                case '|': return consumeOr(str, iter);
+                case '>': return consumeGreaterThan(str, iter);
+                case '<': return consumeLessThan(str, iter);
+                case '(': ++iter; return Token(Token::LeftParen);
+                case ')': ++iter; return Token(Token::RightParen);
+                case '!': return consumeNot(str, iter);
+                case '-': ++iter; return Token(Token::Minus);
+                case '+': ++iter; return Token(Token::Plus);
+                case '*': ++iter; return Token(Token::Multiply);
+                case '/': ++iter; return Token(Token::Divide);
+                case '%': ++iter; return Token(Token::Modulus);
+                case ',': ++iter; return Token(Token::Comma);
+                default:
+                    qCCritical(animation) << "AnimExpression: unexpected char" << *iter << "at index " << (int)(iter - str.begin());
+                    return Token(Token::Error);
+                }
+            }
+        }
+        return Token(Token::End);
+    }
+}
+
+AnimExpression::Token AnimExpression::consumeIdentifier(const QString& str, QString::const_iterator& iter) const {
+    assert(iter != str.end());
+    assert(iter->isLetter());
+    auto begin = iter;
+    while ((iter->isLetter() || iter->isDigit()) && iter != str.end()) {
+        ++iter;
+    }
+    int pos = (int)(begin - str.begin());
+    int len = (int)(iter - begin);
+
+    QStringRef stringRef(const_cast<const QString*>(&str), pos, len);
+    if (stringRef == "true") {
+        return Token(true);
+    } else if (stringRef == "false") {
+        return Token(false);
+    } else {
+        return Token(stringRef);
+    }
+}
+
+// TODO: not very efficient or accruate, but it's close enough for now.
+static float computeFractionalPart(int fractionalPart)
+{
+    float frac = (float)fractionalPart;
+    while (fractionalPart) {
+        fractionalPart /= 10;
+        frac /= 10.0f;
+    }
+    return frac;
+}
+
+static float computeFloat(int whole, int fraction) {
+    return (float)whole + computeFractionalPart(fraction);
+}
+
+AnimExpression::Token AnimExpression::consumeNumber(const QString& str, QString::const_iterator& iter) const {
+    assert(iter != str.end());
+    assert(iter->isDigit());
+    auto begin = iter;
+    while (iter->isDigit() && iter != str.end()) {
+        ++iter;
+    }
+
+    // parse whole integer part
+    int pos = (int)(begin - str.begin());
+    int len = (int)(iter - begin);
+    QString sub = QStringRef(const_cast<const QString*>(&str), pos, len).toString();
+    int whole = sub.toInt();
+
+    // parse optional fractional part
+    if (iter->unicode() == '.') {
+        iter++;
+        auto begin = iter;
+        while (iter->isDigit() && iter != str.end()) {
+            ++iter;
+        }
+
+        int pos = (int)(begin - str.begin());
+        int len = (int)(iter - begin);
+        QString sub = QStringRef(const_cast<const QString*>(&str), pos, len).toString();
+        int fraction = sub.toInt();
+
+        return Token(computeFloat(whole, fraction));
+
+    } else {
+        return Token(whole);
+    }
+}
+
+AnimExpression::Token AnimExpression::consumeAnd(const QString& str, QString::const_iterator& iter) const {
+    assert(iter != str.end());
+    assert(iter->unicode() == '&');
+    iter++;
+    if (iter->unicode() == '&') {
+        iter++;
+        return Token(Token::And);
+    } else {
+        qCCritical(animation) << "AnimExpression: unexpected char" << *iter << "at index " << (int)(iter - str.begin());
+        return Token(Token::Error);
+    }
+}
+
+AnimExpression::Token AnimExpression::consumeOr(const QString& str, QString::const_iterator& iter) const {
+    assert(iter != str.end());
+    assert(iter->unicode() == '|');
+    iter++;
+    if (iter->unicode() == '|') {
+        iter++;
+        return Token(Token::Or);
+    } else {
+        qCCritical(animation) << "AnimExpression: unexpected char" << *iter << "at index " << (int)(iter - str.begin());
+        return Token(Token::Error);
+    }
+}
+
+AnimExpression::Token AnimExpression::consumeGreaterThan(const QString& str, QString::const_iterator& iter) const {
+    assert(iter != str.end());
+    assert(iter->unicode() == '>');
+    iter++;
+    if (iter->unicode() == '=') {
+        iter++;
+        return Token(Token::GreaterThanEqual);
+    } else {
+        return Token(Token::GreaterThan);
+    }
+}
+
+AnimExpression::Token AnimExpression::consumeLessThan(const QString& str, QString::const_iterator& iter) const {
+    assert(iter != str.end());
+    assert(iter->unicode() == '<');
+    iter++;
+    if (iter->unicode() == '=') {
+        iter++;
+        return Token(Token::LessThanEqual);
+    } else {
+        return Token(Token::LessThan);
+    }
+}
+
+AnimExpression::Token AnimExpression::consumeNot(const QString& str, QString::const_iterator& iter) const {
+    assert(iter != str.end());
+    assert(iter->unicode() == '!');
+    iter++;
+    if (iter->unicode() == '=') {
+        iter++;
+        return Token(Token::NotEqual);
+    } else {
+        return Token(Token::Not);
+    }
+}
+
+//
+// Parser
+//
+
+/*
+Expr   → Term Expr'
+Expr'  → '||' Term Expr'
+       | ε
+Term   → Unary Term'
+Term'  → '&&' Unary Term'
+       | ε
+Unary  → '!' Unary
+       | Factor
+Factor → INT
+       | BOOL
+       | FLOAT
+       | IDENTIFIER
+       | '(' Expr ')'
+*/
+
+// Expr → Term Expr'
+bool AnimExpression::parseExpr(const QString& str, QString::const_iterator& iter) {
+    if (!parseTerm(str, iter)) {
+        return false;
+    }
+    if (!parseExprPrime(str, iter)) {
+        return false;
+    }
+    return true;
+}
+
+// Expr' → '||' Term Expr' | ε
+bool AnimExpression::parseExprPrime(const QString& str, QString::const_iterator& iter) {
+    auto token = consumeToken(str, iter);
+    if (token.type == Token::Or) {
+        if (!parseTerm(str, iter)) {
+            unconsumeToken(token);
+            return false;
+        }
+        if (!parseExprPrime(str, iter)) {
+            unconsumeToken(token);
+            return false;
+        }
+        _opCodes.push_back(OpCode {OpCode::Or});
+        return true;
+    } else {
+        unconsumeToken(token);
+        return true;
+    }
+}
+
+// Term → Unary Term'
+bool AnimExpression::parseTerm(const QString& str, QString::const_iterator& iter) {
+    if (!parseUnary(str, iter)) {
+        return false;
+    }
+    if (!parseTermPrime(str, iter)) {
+        return false;
+    }
+    return true;
+}
+
+// Term' → '&&' Unary Term' | ε
+bool AnimExpression::parseTermPrime(const QString& str, QString::const_iterator& iter) {
+    auto token = consumeToken(str, iter);
+    if (token.type == Token::And) {
+        if (!parseUnary(str, iter)) {
+            unconsumeToken(token);
+            return false;
+        }
+        if (!parseTermPrime(str, iter)) {
+            unconsumeToken(token);
+            return false;
+        }
+        _opCodes.push_back(OpCode {OpCode::And});
+        return true;
+    } else {
+        unconsumeToken(token);
+        return true;
+    }
+}
+
+// Unary → '!' Unary | Factor
+bool AnimExpression::parseUnary(const QString& str, QString::const_iterator& iter) {
+
+    auto token = consumeToken(str, iter);
+    if (token.type == Token::Not) {
+        if (!parseUnary(str, iter)) {
+            unconsumeToken(token);
+            return false;
+        }
+        _opCodes.push_back(OpCode {OpCode::Not});
+        return true;
+    }
+    unconsumeToken(token);
+
+    return parseFactor(str, iter);
+}
+
+
+// Factor → INT | BOOL | FLOAT | IDENTIFIER | '(' Expr ')'
+bool AnimExpression::parseFactor(const QString& str, QString::const_iterator& iter) {
+    auto token = consumeToken(str, iter);
+    if (token.type == Token::Int) {
+        _opCodes.push_back(OpCode {token.intVal});
+        return true;
+    } else if (token.type == Token::Bool) {
+        _opCodes.push_back(OpCode {(bool)token.intVal});
+        return true;
+    } else if (token.type == Token::Float) {
+        _opCodes.push_back(OpCode {token.floatVal});
+        return true;
+    } else if (token.type == Token::Identifier) {
+        _opCodes.push_back(OpCode {token.strVal});
+        return true;
+    } else if (token.type == Token::LeftParen) {
+        if (!parseExpr(str, iter)) {
+            unconsumeToken(token);
+            return false;
+        }
+        auto nextToken = consumeToken(str, iter);
+        if (nextToken.type != Token::RightParen) {
+            unconsumeToken(nextToken);
+            unconsumeToken(token);
+            return false;
+        }
+        return true;
+    } else {
+        unconsumeToken(token);
+        return false;
+    }
+}
+
+//
+// Evaluator
+//
+
+AnimExpression::OpCode AnimExpression::evaluate(const AnimVariantMap& map) const {
+    std::stack<OpCode> stack;
+    for (auto& opCode : _opCodes) {
+        switch (opCode.type) {
+        case OpCode::Identifier:
+        case OpCode::Int:
+        case OpCode::Float:
+        case OpCode::Bool:
+            stack.push(opCode);
+            break;
+        case OpCode::And: evalAnd(map, stack); break;
+        case OpCode::Or: evalOr(map, stack); break;
+        case OpCode::GreaterThan: evalGreaterThan(map, stack); break;
+        case OpCode::GreaterThanEqual: evalGreaterThanEqual(map, stack); break;
+        case OpCode::LessThan: evalLessThan(map, stack); break;
+        case OpCode::LessThanEqual: evalLessThanEqual(map, stack); break;
+        case OpCode::Equal: evalEqual(map, stack); break;
+        case OpCode::NotEqual: evalNotEqual(map, stack); break;
+        case OpCode::Not: evalNot(map, stack); break;
+        case OpCode::Subtract: evalSubtract(map, stack); break;
+        case OpCode::Add: evalAdd(map, stack); break;
+        case OpCode::Multiply: evalMultiply(map, stack); break;
+        case OpCode::Divide: evalDivide(map, stack); break;
+        case OpCode::Modulus: evalModulus(map, stack); break;
+        case OpCode::UnaryMinus: evalUnaryMinus(map, stack); break;
+        }
+    }
+    return coerseToValue(map, stack.top());
+}
+
+#define POP_BOOL(NAME)                           \
+    const OpCode& NAME##_temp = stack.top();     \
+    bool NAME = NAME##_temp.coerceBool(map);     \
+    stack.pop()
+
+#define PUSH(EXPR)                              \
+    stack.push(OpCode {(EXPR)})
+
+void AnimExpression::evalAnd(const AnimVariantMap& map, std::stack<OpCode>& stack) const {
+    POP_BOOL(lhs);
+    POP_BOOL(rhs);
+    PUSH(lhs && rhs);
+}
+
+void AnimExpression::evalOr(const AnimVariantMap& map, std::stack<OpCode>& stack) const {
+    POP_BOOL(lhs);
+    POP_BOOL(rhs);
+    PUSH(lhs || rhs);
+}
+
+void AnimExpression::evalGreaterThan(const AnimVariantMap& map, std::stack<OpCode>& stack) const {
+    OpCode lhs = stack.top(); stack.pop();
+    OpCode rhs = stack.top(); stack.pop();
+
+    // TODO:
+    PUSH(false);
+}
+
+void AnimExpression::evalGreaterThanEqual(const AnimVariantMap& map, std::stack<OpCode>& stack) const {
+    OpCode lhs = stack.top(); stack.pop();
+    OpCode rhs = stack.top(); stack.pop();
+
+    // TODO:
+    PUSH(false);
+}
+
+void AnimExpression::evalLessThan(const AnimVariantMap& map, std::stack<OpCode>& stack) const {
+    OpCode lhs = stack.top(); stack.pop();
+    OpCode rhs = stack.top(); stack.pop();
+
+    // TODO:
+    PUSH(false);
+}
+
+void AnimExpression::evalLessThanEqual(const AnimVariantMap& map, std::stack<OpCode>& stack) const {
+    OpCode lhs = stack.top(); stack.pop();
+    OpCode rhs = stack.top(); stack.pop();
+
+    // TODO:
+    PUSH(false);
+}
+
+void AnimExpression::evalEqual(const AnimVariantMap& map, std::stack<OpCode>& stack) const {
+    OpCode lhs = stack.top(); stack.pop();
+    OpCode rhs = stack.top(); stack.pop();
+
+    // TODO:
+    PUSH(false);
+}
+
+void AnimExpression::evalNotEqual(const AnimVariantMap& map, std::stack<OpCode>& stack) const {
+    OpCode lhs = stack.top(); stack.pop();
+    OpCode rhs = stack.top(); stack.pop();
+
+    // TODO:
+    PUSH(false);
+}
+
+void AnimExpression::evalNot(const AnimVariantMap& map, std::stack<OpCode>& stack) const {
+    POP_BOOL(rhs);
+    PUSH(!rhs);
+}
+
+void AnimExpression::evalSubtract(const AnimVariantMap& map, std::stack<OpCode>& stack) const {
+    OpCode lhs = stack.top(); stack.pop();
+    OpCode rhs = stack.top(); stack.pop();
+
+    // TODO:
+    PUSH(0.0f);
+}
+
+void AnimExpression::add(int lhs, const OpCode& rhs, std::stack<OpCode>& stack) const {
+    switch (rhs.type) {
+    case OpCode::Bool:
+    case OpCode::Int:
+        PUSH(lhs + rhs.intVal);
+        break;
+    case OpCode::Float:
+        PUSH((float)lhs + rhs.floatVal);
+        break;
+    default:
+        PUSH(lhs);
+    }
+}
+
+void AnimExpression::add(float lhs, const OpCode& rhs, std::stack<OpCode>& stack) const {
+    switch (rhs.type) {
+    case OpCode::Bool:
+    case OpCode::Int:
+        PUSH(lhs + (float)rhs.intVal);
+        break;
+    case OpCode::Float:
+        PUSH(lhs + rhs.floatVal);
+        break;
+    default:
+        PUSH(lhs);
+    }
+}
+
+void AnimExpression::evalAdd(const AnimVariantMap& map, std::stack<OpCode>& stack) const {
+    OpCode lhs = coerseToValue(map, stack.top());
+    stack.pop();
+    OpCode rhs = coerseToValue(map, stack.top());
+    stack.pop();
+
+    switch (lhs.type) {
+    case OpCode::Bool:
+        add(lhs.intVal, rhs, stack);
+        break;
+    case OpCode::Int:
+        add(lhs.intVal, rhs, stack);
+        break;
+    case OpCode::Float:
+        add(lhs.floatVal, rhs, stack);
+        break;
+    default:
+        add(0, rhs, stack);
+        break;
+    }
+}
+
+void AnimExpression::evalMultiply(const AnimVariantMap& map, std::stack<OpCode>& stack) const {
+    OpCode lhs = coerseToValue(map, stack.top());
+    stack.pop();
+    OpCode rhs = coerseToValue(map, stack.top());
+    stack.pop();
+
+    switch(lhs.type) {
+    case OpCode::Bool:
+        mul(lhs.intVal, rhs, stack);
+        break;
+    case OpCode::Int:
+        mul(lhs.intVal, rhs, stack);
+        break;
+    case OpCode::Float:
+        mul(lhs.floatVal, rhs, stack);
+        break;
+    default:
+        mul(0, rhs, stack);
+        break;
+    }
+}
+
+void AnimExpression::mul(int lhs, const OpCode& rhs, std::stack<OpCode>& stack) const {
+    switch (rhs.type) {
+    case OpCode::Bool:
+    case OpCode::Int:
+        PUSH(lhs * rhs.intVal);
+        break;
+    case OpCode::Float:
+        PUSH((float)lhs * rhs.floatVal);
+        break;
+    default:
+        PUSH(lhs);
+    }
+}
+
+void AnimExpression::mul(float lhs, const OpCode& rhs, std::stack<OpCode>& stack) const {
+    switch (rhs.type) {
+    case OpCode::Bool:
+    case OpCode::Int:
+        PUSH(lhs * (float)rhs.intVal);
+        break;
+    case OpCode::Float:
+        PUSH(lhs * rhs.floatVal);
+        break;
+    default:
+        PUSH(lhs);
+    }
+}
+
+void AnimExpression::evalDivide(const AnimVariantMap& map, std::stack<OpCode>& stack) const {
+    OpCode lhs = stack.top(); stack.pop();
+    OpCode rhs = stack.top(); stack.pop();
+
+    // TODO:
+    PUSH(0.0f);
+}
+
+void AnimExpression::evalModulus(const AnimVariantMap& map, std::stack<OpCode>& stack) const {
+    OpCode lhs = stack.top(); stack.pop();
+    OpCode rhs = stack.top(); stack.pop();
+
+    // TODO:
+    PUSH((int)0);
+}
+
+void AnimExpression::evalUnaryMinus(const AnimVariantMap& map, std::stack<OpCode>& stack) const {
+    OpCode rhs = stack.top(); stack.pop();
+
+    switch (rhs.type) {
+    case OpCode::Identifier: {
+        const AnimVariant& var = map.get(rhs.strVal);
+        switch (var.getType()) {
+        case AnimVariant::Type::Bool:
+            qCWarning(animation) << "AnimExpression: type missmatch for unary minus, expected a number not a bool";
+            // interpret this as boolean not.
+            PUSH(!var.getBool());
+            break;
+        case AnimVariant::Type::Int:
+            PUSH(-var.getInt());
+            break;
+        case AnimVariant::Type::Float:
+            PUSH(-var.getFloat());
+            break;
+        default:
+            // TODO: Vec3, Quat are unsupported
+            assert(false);
+            PUSH(false);
+            break;
+        }
+    }
+    case OpCode::Int:
+        PUSH(-rhs.intVal);
+        break;
+    case OpCode::Float:
+        PUSH(-rhs.floatVal);
+        break;
+    case OpCode::Bool:
+        qCWarning(animation) << "AnimExpression: type missmatch for unary minus, expected a number not a bool";
+        // interpret this as boolean not.
+        PUSH(!rhs.coerceBool(map));
+        break;
+    default:
+        qCCritical(animation) << "AnimExpression: ERRROR for unary minus, expected a number, type = " << rhs.type;
+        assert(false);
+        PUSH(false);
+        break;
+    }
+}
+
+AnimExpression::OpCode AnimExpression::coerseToValue(const AnimVariantMap& map, const OpCode& opCode) const {
+    switch (opCode.type) {
+    case OpCode::Identifier:
+        {
+            const AnimVariant& var = map.get(opCode.strVal);
+            switch (var.getType()) {
+            case AnimVariant::Type::Bool:
+                return OpCode((bool)var.getBool());
+                break;
+            case AnimVariant::Type::Int:
+                return OpCode(var.getInt());
+                break;
+            case AnimVariant::Type::Float:
+                return OpCode(var.getFloat());
+                break;
+            default:
+                // TODO: Vec3, Quat are unsupported
+                assert(false);
+                return OpCode(0);
+                break;
+            }
+        }
+        break;
+    case OpCode::Bool:
+    case OpCode::Int:
+    case OpCode::Float:
+        return opCode;
+    default:
+        qCCritical(animation) << "AnimExpression: ERROR expected a number, type = " << opCode.type;
+        assert(false);
+        return OpCode(0);
+        break;
+    }
+}
+
+#ifndef NDEBUG
+void AnimExpression::dumpOpCodes() const {
+    QString tmp;
+    for (auto& op : _opCodes) {
+        switch (op.type) {
+        case OpCode::Identifier: tmp += QString(" %1").arg(op.strVal); break;
+        case OpCode::Bool: tmp += QString(" %1").arg(op.intVal ? "true" : "false"); break;
+        case OpCode::Int: tmp += QString(" %1").arg(op.intVal); break;
+        case OpCode::Float: tmp += QString(" %1").arg(op.floatVal); break;
+        case OpCode::And: tmp += " &&"; break;
+        case OpCode::Or: tmp += " ||"; break;
+        case OpCode::GreaterThan: tmp += " >"; break;
+        case OpCode::GreaterThanEqual: tmp += " >="; break;
+        case OpCode::LessThan: tmp += " <"; break;
+        case OpCode::LessThanEqual: tmp += " <="; break;
+        case OpCode::Equal: tmp += " =="; break;
+        case OpCode::NotEqual: tmp += " !="; break;
+        case OpCode::Not: tmp += " !"; break;
+        case OpCode::Subtract: tmp += " -"; break;
+        case OpCode::Add: tmp += " +"; break;
+        case OpCode::Multiply: tmp += " *"; break;
+        case OpCode::Divide: tmp += " /"; break;
+        case OpCode::Modulus: tmp += " %"; break;
+        case OpCode::UnaryMinus: tmp += " unary-"; break;
+        default: tmp += " ???"; break;
+        }
+    }
+    qCDebug(animation).nospace().noquote() << "opCodes =" << tmp;
+    qCDebug(animation).resetFormat();
+}
+#endif

libraries/animation/src/AnimExpression.h

@@ -0,0 +1,158 @@
+//
+//  AnimExpression.h
+//
+//  Created by Anthony J. Thibault on 11/1/15.
+//  Copyright (c) 2015 High Fidelity, Inc. All rights reserved.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#ifndef hifi_AnimExpression
+#define hifi_AnimExpression
+
+#include <QString>
+#include <glm/glm.hpp>
+#include <glm/gtc/quaternion.hpp>
+#include <stack>
+#include <vector>
+#include "AnimVariant.h"
+
+class AnimExpression {
+public:
+    friend class AnimTests;
+    AnimExpression(const QString& str);
+protected:
+    struct Token {
+        enum Type {
+            End = 0,
+            Identifier,
+            Bool,
+            Int,
+            Float,
+            And,
+            Or,
+            GreaterThan,
+            GreaterThanEqual,
+            LessThan,
+            LessThanEqual,
+            Equal,
+            NotEqual,
+            LeftParen,
+            RightParen,
+            Not,
+            Minus,
+            Plus,
+            Multiply,
+            Divide,
+            Modulus,
+            Comma,
+            Error
+        };
+        Token(Type type) : type {type} {}
+        Token(const QStringRef& strRef) : type {Type::Identifier}, strVal {strRef.toString()} {}
+        explicit Token(int val) : type {Type::Int}, intVal {val} {}
+        explicit Token(bool val) : type {Type::Bool}, intVal {val} {}
+        explicit Token(float val) : type {Type::Float}, floatVal {val} {}
+        Type type {End};
+        QString strVal;
+        int intVal {0};
+        float floatVal {0.0f};
+    };
+
+    struct OpCode {
+        enum Type {
+            Identifier,
+            Bool,
+            Int,
+            Float,
+            And,
+            Or,
+            GreaterThan,
+            GreaterThanEqual,
+            LessThan,
+            LessThanEqual,
+            Equal,
+            NotEqual,
+            Not,
+            Subtract,
+            Add,
+            Multiply,
+            Divide,
+            Modulus,
+            UnaryMinus
+        };
+        OpCode(Type type) : type {type} {}
+        explicit OpCode(const QStringRef& strRef) : type {Type::Identifier}, strVal {strRef.toString()} {}
+        explicit OpCode(const QString& str) : type {Type::Identifier}, strVal {str} {}
+        explicit OpCode(int val) : type {Type::Int}, intVal {val} {}
+        explicit OpCode(bool val) : type {Type::Bool}, intVal {(int)val} {}
+        explicit OpCode(float val) : type {Type::Float}, floatVal {val} {}
+
+        bool coerceBool(const AnimVariantMap& map) const {
+            if (type == Int || type == Bool) {
+                return intVal != 0;
+            } else if (type == Identifier) {
+                return map.lookup(strVal, false);
+            } else {
+                return true;
+            }
+        }
+
+        Type type {Int};
+        QString strVal;
+        int intVal {0};
+        float floatVal {0.0f};
+    };
+
+    void unconsumeToken(const Token& token);
+    Token consumeToken(const QString& str, QString::const_iterator& iter) const;
+    Token consumeIdentifier(const QString& str, QString::const_iterator& iter) const;
+    Token consumeNumber(const QString& str, QString::const_iterator& iter) const;
+    Token consumeAnd(const QString& str, QString::const_iterator& iter) const;
+    Token consumeOr(const QString& str, QString::const_iterator& iter) const;
+    Token consumeGreaterThan(const QString& str, QString::const_iterator& iter) const;
+    Token consumeLessThan(const QString& str, QString::const_iterator& iter) const;
+    Token consumeNot(const QString& str, QString::const_iterator& iter) const;
+
+    bool parseExpr(const QString& str, QString::const_iterator& iter);
+    bool parseExprPrime(const QString& str, QString::const_iterator& iter);
+    bool parseTerm(const QString& str, QString::const_iterator& iter);
+    bool parseTermPrime(const QString& str, QString::const_iterator& iter);
+    bool parseUnary(const QString& str, QString::const_iterator& iter);
+    bool parseFactor(const QString& str, QString::const_iterator& iter);
+
+    OpCode evaluate(const AnimVariantMap& map) const;
+    void evalAnd(const AnimVariantMap& map, std::stack<OpCode>& stack) const;
+    void evalOr(const AnimVariantMap& map, std::stack<OpCode>& stack) const;
+    void evalGreaterThan(const AnimVariantMap& map, std::stack<OpCode>& stack) const;
+    void evalGreaterThanEqual(const AnimVariantMap& map, std::stack<OpCode>& stack) const;
+    void evalLessThan(const AnimVariantMap& map, std::stack<OpCode>& stack) const;
+    void evalLessThanEqual(const AnimVariantMap& map, std::stack<OpCode>& stack) const;
+    void evalEqual(const AnimVariantMap& map, std::stack<OpCode>& stack) const;
+    void evalNotEqual(const AnimVariantMap& map, std::stack<OpCode>& stack) const;
+    void evalNot(const AnimVariantMap& map, std::stack<OpCode>& stack) const;
+    void evalSubtract(const AnimVariantMap& map, std::stack<OpCode>& stack) const;
+    void evalAdd(const AnimVariantMap& map, std::stack<OpCode>& stack) const;
+    void add(int lhs, const OpCode& rhs, std::stack<OpCode>& stack) const;
+    void add(float lhs, const OpCode& rhs, std::stack<OpCode>& stack) const;
+    void evalMultiply(const AnimVariantMap& map, std::stack<OpCode>& stack) const;
+    void mul(int lhs, const OpCode& rhs, std::stack<OpCode>& stack) const;
+    void mul(float lhs, const OpCode& rhs, std::stack<OpCode>& stack) const;
+    void evalDivide(const AnimVariantMap& map, std::stack<OpCode>& stack) const;
+    void evalModulus(const AnimVariantMap& map, std::stack<OpCode>& stack) const;
+    void evalUnaryMinus(const AnimVariantMap& map, std::stack<OpCode>& stack) const;
+
+    OpCode coerseToValue(const AnimVariantMap& map, const OpCode& opCode) const;
+
+    QString _expression;
+    mutable std::stack<Token> _tokenStack;    // TODO: remove, only needed during parsing
+    std::vector<OpCode> _opCodes;
+
+#ifndef NDEBUG
+    void dumpOpCodes() const;
+#endif
+};
+
+#endif
+

libraries/animation/src/AnimVariant.cpp

@@ -15,6 +15,8 @@
 #include <RegisteredMetaTypes.h>
 #include "AnimVariant.h" // which has AnimVariant/AnimVariantMap
 
+const AnimVariant AnimVariant::False = AnimVariant();
+
 QScriptValue AnimVariantMap::animVariantMapToScriptValue(QScriptEngine* engine, const QStringList& names, bool useNames) const {
     if (QThread::currentThread() != engine->thread()) {
         qCWarning(animation) << "Cannot create Javacript object from non-script thread" << QThread::currentThread();

libraries/animation/src/AnimVariant.h

@@ -34,6 +34,8 @@ public:
         NumTypes
     };
 
+    static const AnimVariant False;
+
     AnimVariant() : _type(Type::Bool) { memset(&_val, 0, sizeof(_val)); }
     AnimVariant(bool value) : _type(Type::Bool) { _val.boolVal = value; }
     AnimVariant(int value) : _type(Type::Int) { _val.intVal = value; }
@@ -57,13 +59,50 @@ public:
     void setQuat(const glm::quat& value) { assert(_type == Type::Quat); *reinterpret_cast<glm::quat*>(&_val) = value; }
     void setString(const QString& value) { assert(_type == Type::String); _stringVal = value; }
 
-    bool getBool() const { assert(_type == Type::Bool); return _val.boolVal; }
-    int getInt() const { assert(_type == Type::Int || _type == Type::Float); return _type == Type::Float ? (int)_val.floats[0] : _val.intVal; }
-    float getFloat() const { assert(_type == Type::Float || _type == Type::Int); return _type == Type::Int ? (float)_val.intVal : _val.floats[0]; }
-
-    const glm::vec3& getVec3() const { assert(_type == Type::Vec3); return *reinterpret_cast<const glm::vec3*>(&_val); }
-    const glm::quat& getQuat() const { assert(_type == Type::Quat); return *reinterpret_cast<const glm::quat*>(&_val); }
-    const QString& getString() const { assert(_type == Type::String); return _stringVal; }
+    bool getBool() const {
+        if (_type == Type::Bool) {
+            return _val.boolVal;
+        } else if (_type == Type::Int) {
+            return _val.intVal != 0;
+        } else {
+            return false;
+        }
+    }
+    int getInt() const {
+        if (_type == Type::Int) {
+            return _val.intVal;
+        } else if (_type == Type::Float) {
+            return (int)_val.floats[0];
+        } else {
+            return 0;
+        }
+    }
+    float getFloat() const {
+        if (_type == Type::Float) {
+            return _val.floats[0];
+        } else if (_type == Type::Int) {
+            return (float)_val.intVal;
+        } else {
+            return 0.0f;
+        }
+    }
+    const glm::vec3& getVec3() const {
+        if (_type == Type::Vec3) {
+            return *reinterpret_cast<const glm::vec3*>(&_val);
+        } else {
+            return Vectors::ZERO;
+        }
+    }
+    const glm::quat& getQuat() const {
+        if (_type == Type::Quat) {
+            return *reinterpret_cast<const glm::quat*>(&_val);
+        } else {
+            return Quaternions::IDENTITY;
+        }
+    }
+    const QString& getString() const {
+        return _stringVal;
+    }
 
 protected:
     Type _type;
@@ -71,7 +110,7 @@ protected:
     union {
         bool boolVal;
         int intVal;
-        float floats[16];
+        float floats[4];
     } _val;
 };
 
@@ -172,6 +211,15 @@ public:
     void clearMap() { _map.clear(); }
     bool hasKey(const QString& key) const { return _map.find(key) != _map.end(); }
 
+    const AnimVariant& get(const QString& key) const {
+        auto iter = _map.find(key);
+        if (iter != _map.end()) {
+            return iter->second;
+        } else {
+            return AnimVariant::False;
+        }
+    }
+
     // Answer a Plain Old Javascript Object (for the given engine) all of our values set as properties.
     QScriptValue animVariantMapToScriptValue(QScriptEngine* engine, const QStringList& names, bool useNames) const;
     // Side-effect us with the value of object's own properties. (No inherited properties.)

libraries/shared/src/GLMHelpers.h

@@ -82,6 +82,7 @@ public:
     static const vec3& RIGHT;
     static const vec3& UP;
     static const vec3& FRONT;
+    static const vec3 ZERO4;
 };
 
 // These pack/unpack functions are designed to start specific known types in as efficient a manner

tests/QTestExtensions.h

@@ -274,7 +274,7 @@ struct ByteData {
 
 QTextStream & operator << (QTextStream& stream, const ByteData & wrapper) {
     // Print bytes as hex
-    stream << QByteArray::fromRawData(wrapper.data, wrapper.length).toHex();
+    stream << QByteArray::fromRawData(wrapper.data, (int)wrapper.length).toHex();
 
     return stream;
 }

tests/animation/src/AnimTests.cpp

@@ -8,12 +8,13 @@
 //
 
 #include "AnimTests.h"
-#include "AnimNodeLoader.h"
-#include "AnimClip.h"
-#include "AnimBlendLinear.h"
-#include "AnimationLogging.h"
-#include "AnimVariant.h"
-#include "AnimUtil.h"
+#include <AnimNodeLoader.h>
+#include <AnimClip.h>
+#include <AnimBlendLinear.h>
+#include <AnimationLogging.h>
+#include <AnimVariant.h>
+#include <AnimExpression.h>
+#include <AnimUtil.h>
 
 #include <../QTestExtensions.h>
 
@@ -315,7 +316,6 @@ void AnimTests::testAccumulateTimeWithParameters(float startFrame, float endFram
     triggers.clear();
 }
 
-
 void AnimTests::testAnimPose() {
     const float PI = (float)M_PI;
     const glm::quat ROT_X_90 = glm::angleAxis(PI / 2.0f, glm::vec3(1.0f, 0.0f, 0.0f));
@@ -394,3 +394,234 @@ void AnimTests::testAnimPose() {
         }
     }
 }
+
+void AnimTests::testExpressionTokenizer() {
+    QString str = "(10 +  x) >= 20.1 && (y != !z)";
+    AnimExpression e("x");
+    auto iter = str.cbegin();
+    AnimExpression::Token token = e.consumeToken(str, iter);
+    QVERIFY(token.type == AnimExpression::Token::LeftParen);
+    token = e.consumeToken(str, iter);
+    QVERIFY(token.type == AnimExpression::Token::Int);
+    QVERIFY(token.intVal == 10);
+    token = e.consumeToken(str, iter);
+    QVERIFY(token.type == AnimExpression::Token::Plus);
+    token = e.consumeToken(str, iter);
+    QVERIFY(token.type == AnimExpression::Token::Identifier);
+    QVERIFY(token.strVal == "x");
+    token = e.consumeToken(str, iter);
+    QVERIFY(token.type == AnimExpression::Token::RightParen);
+    token = e.consumeToken(str, iter);
+    QVERIFY(token.type == AnimExpression::Token::GreaterThanEqual);
+    token = e.consumeToken(str, iter);
+    QVERIFY(token.type == AnimExpression::Token::Float);
+    QVERIFY(fabsf(token.floatVal - 20.1f) < 0.0001f);
+    token = e.consumeToken(str, iter);
+    QVERIFY(token.type == AnimExpression::Token::And);
+    token = e.consumeToken(str, iter);
+    QVERIFY(token.type == AnimExpression::Token::LeftParen);
+    token = e.consumeToken(str, iter);
+    QVERIFY(token.type == AnimExpression::Token::Identifier);
+    QVERIFY(token.strVal == "y");
+    token = e.consumeToken(str, iter);
+    QVERIFY(token.type == AnimExpression::Token::NotEqual);
+    token = e.consumeToken(str, iter);
+    QVERIFY(token.type == AnimExpression::Token::Not);
+    token = e.consumeToken(str, iter);
+    QVERIFY(token.type == AnimExpression::Token::Identifier);
+    QVERIFY(token.strVal == "z");
+    token = e.consumeToken(str, iter);
+    QVERIFY(token.type == AnimExpression::Token::RightParen);
+    token = e.consumeToken(str, iter);
+
+    str = "true";
+    iter = str.cbegin();
+    token = e.consumeToken(str, iter);
+    QVERIFY(token.type == AnimExpression::Token::Bool);
+    QVERIFY(token.intVal == (int)true);
+}
+
+void AnimTests::testExpressionParser() {
+
+    auto vars = AnimVariantMap();
+    vars.set("f", false);
+    vars.set("t", true);
+    vars.set("ten", (int)10);
+    vars.set("twenty", (int)20);
+    vars.set("five", (float)5.0f);
+    vars.set("forty", (float)40.0f);
+
+    AnimExpression e("10");
+    QVERIFY(e._opCodes.size() == 1);
+    if (e._opCodes.size() == 1) {
+        QVERIFY(e._opCodes[0].type == AnimExpression::OpCode::Int);
+        QVERIFY(e._opCodes[0].intVal == 10);
+    }
+
+    e = AnimExpression("(10)");
+    QVERIFY(e._opCodes.size() == 1);
+    if (e._opCodes.size() == 1) {
+        QVERIFY(e._opCodes[0].type == AnimExpression::OpCode::Int);
+        QVERIFY(e._opCodes[0].intVal == 10);
+    }
+
+    e = AnimExpression("((10))");
+    QVERIFY(e._opCodes.size() == 1);
+    if (e._opCodes.size() == 1) {
+        QVERIFY(e._opCodes[0].type == AnimExpression::OpCode::Int);
+        QVERIFY(e._opCodes[0].intVal == 10);
+    }
+
+    e = AnimExpression("12.5");
+    QVERIFY(e._opCodes.size() == 1);
+    if (e._opCodes.size() == 1) {
+        QVERIFY(e._opCodes[0].type == AnimExpression::OpCode::Float);
+        QVERIFY(e._opCodes[0].floatVal == 12.5f);
+    }
+
+    e = AnimExpression("twenty");
+    QVERIFY(e._opCodes.size() == 1);
+    if (e._opCodes.size() == 1) {
+        QVERIFY(e._opCodes[0].type == AnimExpression::OpCode::Identifier);
+        QVERIFY(e._opCodes[0].strVal == "twenty");
+    }
+
+    e = AnimExpression("true || false");
+    QVERIFY(e._opCodes.size() == 3);
+    if (e._opCodes.size() == 3) {
+        QVERIFY(e._opCodes[0].type == AnimExpression::OpCode::Bool);
+        QVERIFY(e._opCodes[0].intVal == (int)true);
+        QVERIFY(e._opCodes[1].type == AnimExpression::OpCode::Bool);
+        QVERIFY(e._opCodes[1].intVal == (int)false);
+        QVERIFY(e._opCodes[2].type == AnimExpression::OpCode::Or);
+    }
+
+    e = AnimExpression("true || false && true");
+    QVERIFY(e._opCodes.size() == 5);
+    if (e._opCodes.size() == 5) {
+        QVERIFY(e._opCodes[0].type == AnimExpression::OpCode::Bool);
+        QVERIFY(e._opCodes[0].intVal == (int)true);
+        QVERIFY(e._opCodes[1].type == AnimExpression::OpCode::Bool);
+        QVERIFY(e._opCodes[1].intVal == (int)false);
+        QVERIFY(e._opCodes[2].type == AnimExpression::OpCode::Bool);
+        QVERIFY(e._opCodes[2].intVal == (int)true);
+        QVERIFY(e._opCodes[3].type == AnimExpression::OpCode::And);
+        QVERIFY(e._opCodes[4].type == AnimExpression::OpCode::Or);
+    }
+
+    e = AnimExpression("(true || false) && true");
+    QVERIFY(e._opCodes.size() == 5);
+    if (e._opCodes.size() == 5) {
+        QVERIFY(e._opCodes[0].type == AnimExpression::OpCode::Bool);
+        QVERIFY(e._opCodes[0].intVal == (int)true);
+        QVERIFY(e._opCodes[1].type == AnimExpression::OpCode::Bool);
+        QVERIFY(e._opCodes[1].intVal == (int)false);
+        QVERIFY(e._opCodes[2].type == AnimExpression::OpCode::Or);
+        QVERIFY(e._opCodes[3].type == AnimExpression::OpCode::Bool);
+        QVERIFY(e._opCodes[3].intVal == (int)true);
+        QVERIFY(e._opCodes[4].type == AnimExpression::OpCode::And);
+    }
+
+    e = AnimExpression("!(true || false) && true");
+    QVERIFY(e._opCodes.size() == 6);
+    if (e._opCodes.size() == 6) {
+        QVERIFY(e._opCodes[0].type == AnimExpression::OpCode::Bool);
+        QVERIFY(e._opCodes[0].intVal == (int)true);
+        QVERIFY(e._opCodes[1].type == AnimExpression::OpCode::Bool);
+        QVERIFY(e._opCodes[1].intVal == (int)false);
+        QVERIFY(e._opCodes[2].type == AnimExpression::OpCode::Or);
+        QVERIFY(e._opCodes[3].type == AnimExpression::OpCode::Not);
+        QVERIFY(e._opCodes[4].type == AnimExpression::OpCode::Bool);
+        QVERIFY(e._opCodes[4].intVal == (int)true);
+        QVERIFY(e._opCodes[5].type == AnimExpression::OpCode::And);
+    }
+}
+
+#define TEST_BOOL_EXPR(EXPR)                                \
+    result = AnimExpression( #EXPR ).evaluate(vars);        \
+    QVERIFY(result.type == AnimExpression::OpCode::Bool);   \
+    QVERIFY(result.intVal == (int)(EXPR))
+
+void AnimTests::testExpressionEvaluator() {
+    auto vars = AnimVariantMap();
+
+    bool f = false;
+    bool t = true;
+    int ten = 10;
+    int twenty = 20;
+    float five = 5.0f;
+    float fourty = 40.0f;
+    vars.set("f", f);
+    vars.set("t", t);
+    vars.set("ten", ten);
+    vars.set("twenty", twenty);
+    vars.set("five", five);
+    vars.set("forty", fourty);
+
+    AnimExpression::OpCode result(AnimExpression::OpCode::Int);
+
+    result = AnimExpression("10").evaluate(vars);
+    QVERIFY(result.type == AnimExpression::OpCode::Int);
+    QVERIFY(result.intVal == 10);
+
+    result = AnimExpression("(10)").evaluate(vars);
+    QVERIFY(result.type == AnimExpression::OpCode::Int);
+    QVERIFY(result.intVal == 10);
+
+    TEST_BOOL_EXPR(true);
+    TEST_BOOL_EXPR(false);
+    TEST_BOOL_EXPR(t);
+    TEST_BOOL_EXPR(f);
+
+    TEST_BOOL_EXPR(true || false);
+    TEST_BOOL_EXPR(true || true);
+    TEST_BOOL_EXPR(false || false);
+    TEST_BOOL_EXPR(false || true);
+
+    TEST_BOOL_EXPR(true && false);
+    TEST_BOOL_EXPR(true && true);
+    TEST_BOOL_EXPR(false && false);
+    TEST_BOOL_EXPR(false && true);
+
+    TEST_BOOL_EXPR(true || false && true);
+    TEST_BOOL_EXPR(true || false && false);
+    TEST_BOOL_EXPR(true || true && true);
+    TEST_BOOL_EXPR(true || true && false);
+    TEST_BOOL_EXPR(false || false && true);
+    TEST_BOOL_EXPR(false || false && false);
+    TEST_BOOL_EXPR(false || true && true);
+    TEST_BOOL_EXPR(false || true && false);
+
+    TEST_BOOL_EXPR(true && false || true);
+    TEST_BOOL_EXPR(true && false || false);
+    TEST_BOOL_EXPR(true && true || true);
+    TEST_BOOL_EXPR(true && true || false);
+    TEST_BOOL_EXPR(false && false || true);
+    TEST_BOOL_EXPR(false && false || false);
+    TEST_BOOL_EXPR(false && true || true);
+    TEST_BOOL_EXPR(false && true || false);
+
+    TEST_BOOL_EXPR(t || false);
+    TEST_BOOL_EXPR(t || true);
+    TEST_BOOL_EXPR(f || false);
+    TEST_BOOL_EXPR(f || true);
+
+    TEST_BOOL_EXPR(!true);
+    TEST_BOOL_EXPR(!false);
+    TEST_BOOL_EXPR(!true || true);
+
+    TEST_BOOL_EXPR(!true && !false || !true);
+    TEST_BOOL_EXPR(!true && !false || true);
+    TEST_BOOL_EXPR(!true && false || !true);
+    TEST_BOOL_EXPR(!true && false || true);
+    TEST_BOOL_EXPR(true && !false || !true);
+    TEST_BOOL_EXPR(true && !false || true);
+    TEST_BOOL_EXPR(true && false || !true);
+    TEST_BOOL_EXPR(true && false || true);
+
+    TEST_BOOL_EXPR(!(true && f) || !t);
+    TEST_BOOL_EXPR(!!!(t) && (!!f || true));
+    TEST_BOOL_EXPR(!(true && f) && true);
+}
+
+

tests/animation/src/AnimTests.h

@@ -27,6 +27,9 @@ private slots:
     void testVariant();
     void testAccumulateTime();
     void testAnimPose();
+    void testExpressionTokenizer();
+    void testExpressionParser();
+    void testExpressionEvaluator();
 };
 
 #endif // hifi_AnimTests_h