atari-pendingscreenchanges.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef BACKENDS_GRAPHICS_ATARI_PENDINGSCREENCHANGES_H
#define BACKENDS_GRAPHICS_ATARI_PENDINGSCREENCHANGES_H

#include <utility>

class AtariGraphicsManager;
class AtariSurface;
class Screen;

class PendingScreenChanges {
public:
    PendingScreenChanges(const AtariGraphicsManager *manager)
        : _manager(manager) {
    }

    void clearTransaction() {
        _changes &= ~kTransaction;
    }

    void setScreenSurface(AtariSurface *surface) {
        _surface = surface;
    }

    void queueVideoMode() {
        _changes |= kVideoMode;
    }
    void queueAspectRatioCorrection() {
        _changes |= kAspectRatioCorrection;
    }
    void queuePalette() {
        _changes |= kPalette;
    }
    void queueShakeScreen() {
        _changes |= kShakeScreen;
    }
    void queueAll();

    int get() const {
        return _changes;
    }
    bool empty() const {
        return _changes == kNone;
    }

    AtariSurface *screenSurface() const {
        return _surface;
    }
    const std::pair<int, bool>& aspectRatioCorrectionYOffset() const {
        return _aspectRatioCorrectionYOffset;
    }
    const std::pair<bool, bool>& screenOffsets() const {
        return _setScreenOffsets;
    }
    const std::pair<bool, bool>& shrinkVidelVisibleArea() const {
        return _shrinkVidelVisibleArea;
    }

    void applyBeforeVblLock(const Screen &screen);
    void applyAfterVblLock(const Screen &screen);

private:
    void processAspectRatioCorrection(const Screen &screen);
    void processVideoMode(const Screen &screen);

    enum Change {
        kNone                  = 0,
        kVideoMode             = 1<<0,
        kAspectRatioCorrection = 1<<1,
        kPalette               = 1<<2,
        kShakeScreen           = 1<<3,
        kTransaction           = kVideoMode | kAspectRatioCorrection,
        kAll                   = kTransaction | kPalette | kShakeScreen
    };
    int _changes = kNone;

    const AtariGraphicsManager *_manager;

    AtariSurface *_surface = nullptr;

    int _mode;
    bool _resetSuperVidel;
    bool _switchToBlackPalette;

    // <value, set> ... std::optional would be so much better!
    std::pair<int, bool> _aspectRatioCorrectionYOffset;
    std::pair<bool, bool> _setScreenOffsets;
    std::pair<bool, bool> _shrinkVidelVisibleArea;
};

#endif // ATARI-PENDINGSCREENCHANGES_H