CameraMovementLogic.h

/*
 * Copyright (C) 2014 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef CAMERAMOVEMENTLOGIC_H
#define CAMERAMOVEMENTLOGIC_H

#include <Engine/Logic.h>
#include <QMap>

class Camera;
class QRectF;

class CameraMovementLogic : public Logic {
    Q_OBJECT

    Q_PROPERTY(float minFov READ getMinFov WRITE setMinFov NOTIFY minFovChanged)
    Q_PROPERTY(float xPullFactor READ getXPullFactor WRITE setXPullFactor NOTIFY xPullFactorChanged)
    Q_PROPERTY(float yPullFactor READ getYPullFactor WRITE setYPullFactor NOTIFY yPullFactorChanged)
    Q_PROPERTY(float towedXPullFactor READ getTowedXPullFactor WRITE setTowedXPullFactor NOTIFY
               towedXPullFactorChanged)
    Q_PROPERTY(float towedYPullFactor READ getTowedYPullFactor WRITE setTowedYPullFactor NOTIFY
               towedYPullFactorChanged)
    Q_PROPERTY(float lookaheadScale READ getLookaheadScale WRITE setLookaheadScale NOTIFY
               lookaheadScaleChanged)
    Q_PROPERTY(float fovPullFactor READ getFovPullFactor WRITE setFovPullFactor NOTIFY
               fovPullFactorChanged)
    Q_PROPERTY(float xFovBorder READ getXFovBorder WRITE setXFovBorder NOTIFY xFovBorderChanged)
    Q_PROPERTY(float yFovBorder READ getYFovBorder WRITE setYFovBorder NOTIFY yFovBorderChanged)

public:
    float getMinFov() const { return mMinFov; }
    void setMinFov(float value);
    float getXPullFactor() const { return mXPullFactor; }
    void setXPullFactor(float value);
    float getYPullFactor() const { return mYPullFactor; }
    void setYPullFactor(float value);
    float getTowedXPullFactor() const { return mTowedXPullFactor; }
    void setTowedXPullFactor(float value);
    float getTowedYPullFactor() const { return mTowedYPullFactor; }
    void setTowedYPullFactor(float value);
    float getLookaheadScale() const { return mLookaheadScale; }
    void setLookaheadScale(float value);
    float getFovPullFactor() const { return mFovPullFactor; }
    void setFovPullFactor(float value);
    float getXFovBorder() const { return mXFovBorder; }
    void setXFovBorder(float value);
    float getYFovBorder() const { return mYFovBorder; }
    void setYFovBorder(float value);
    virtual void init() override;
    virtual void update() override;

signals:
    void minFovChanged();
    void xPullFactorChanged();
    void yPullFactorChanged();
    void towedXPullFactorChanged();
    void towedYPullFactorChanged();
    void lookaheadScaleChanged();
    void fovPullFactorChanged();
    void xFovBorderChanged();
    void yFovBorderChanged();

private:
    QRectF getExpandedBBoxOfPlayerActors() const;
    QPointF getExtrapolatedPosition(Actor* actor) const;
    QPointF computeLookAt(const QRectF& actorsBBox) const;
    float computeFov(const QRectF& actorsBBox) const;
    void boundCameraViewport(QPointF* lookAt, float* fov) const;
    void fillCameraViewport(QPointF* lookAt, float* fov) const;

    // Camera whose fov and lookAt is controlled by this logic
    Camera* mCamera = nullptr;
    float mMinFov = 16.0f;
    float mXPullFactor = 0.08f;
    float mYPullFactor = 0.08f;
    float mTowedXPullFactor = 0.04f;
    float mTowedYPullFactor = 0.04f;
    float mLookaheadScale = 1.0f;
    float mFovPullFactor = 1.0f;
    float mXFovBorder = 0.1f;
    float mYFovBorder = 0.1f;
    // Map of points which trail behind camera tracked actors
    QMap<Actor*, QPointF> mTowedControlPoints;
};
Q_DECLARE_METATYPE(CameraMovementLogic*)

#endif // CAMERAMOVEMENTLOGIC_H