osys_n64.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 __OSYS_N64_H__
#define __OSYS_N64_H__

#include "common/rect.h"
#include "common/config-manager.h"
#include "common/events.h"

#include "backends/base-backend.h"

#include "base/main.h"

#include "graphics/surface.h"
#include "graphics/paletteman.h"
#include "graphics/pixelformat.h"

#include "audio/mixer_intern.h"

#include <libn64.h>
#include <n64utils.h>

#define DEFAULT_SOUND_SAMPLE_RATE 8000 // 8 kHz
//#define DEFAULT_SOUND_SAMPLE_RATE 11025 // 11 kHz

#define N64_PAL_FPS 25
#define N64_NTSC_FPS 30

typedef int (*TimerProc)(int interval);

// Interrupt callback functions
void vblCallback(void);
void sndCallback(void);
void refillAudioBuffers(void);

// External utility functions
void enableAudioPlayback(void);
void disableAudioPlayback(void);
void checkTimers(void);
int timer_handler(int t);

static volatile bool _audioEnabled = false; // Used by interrupt callbacks

/* Graphic mode identifiers */
enum GraphicModeID {
    OVERS_NTSC_340X240,
    NORM_NTSC_320X240,
    NORM_PAL_320X240,
    OVERS_PAL_340X240,
    NORM_MPAL_320X240,
    OVERS_MPAL_340X240
};

class OSystem_N64 : virtual public BaseBackend, public Common::EventSource, public PaletteManager {
protected:
    enum TransactionMode {
        kTransactionNone = 0,
        kTransactionActive = 1,
        kTransactionRollback = 2
    };

    TransactionMode _transactionMode;

    //
    // Transaction support
    //
    struct VideoState {
        constexpr VideoState() : width(0), height(0), format(),
            graphicsMode(OVERS_NTSC_340X240) {
        }

        uint width, height;
        Graphics::PixelFormat format;
        int graphicsMode;
    };

    VideoState _currentState;

    VideoState _oldState;

    int _screenChangeID;

    Audio::MixerImpl *_mixer;

    struct display_context * _dc; // Display context for N64 on screen buffer switching

    Graphics::Surface _framebuffer;

    uint16 *_offscreen_hic; // Offscreen converted to 16bit surface
    uint8  *_offscreen_pal; // Offscreen with palette indexes
    uint16 *_overlayBuffer; // Offscreen for the overlay (16 bit)

    uint16 *_screenPalette; // Array for palette entries (256 colors max)

#ifndef N64_EXTREME_MEMORY_SAVING
    uint8 *_screenExactPalette; // Array for palette entries, as received by setPalette(), no precision loss
#endif
    uint16 _cursorPalette[256]; // Palette entries for the cursor

    uint16 _screenWidth, _screenHeight;
    uint16 _frameBufferWidth; // Width of framebuffer in N64 memory
    uint8 _offscrPixels; // Pixels to skip on each line before start drawing, used to center image
    uint8 _maxFps; // Max frames-per-second which can be shown on screen

    int _shakeXOffset;
    int _shakeYOffset;

    uint8 *_cursor_pal; // Cursor buffer, palettized
    uint16 *_cursor_hic; // Cursor buffer, 16bit
    bool _cursorPaletteDisabled;
    bool _dirtyPalette;

    uint _cursorWidth, _cursorHeight;

    int _cursorKeycolor;

    uint16  _overlayHeight, _overlayWidth;
    bool    _overlayVisible;
    bool    _overlayInGUI;

    bool    _disableFpsLimit; // When this is enabled, the system doesn't limit screen updates

    bool _mouseVisible;
    volatile int _mouseX, _mouseY;
    volatile float _tempMouseX, _tempMouseY;
    volatile int _mouseMaxX, _mouseMaxY;
    int _mouseHotspotX, _mouseHotspotY;

    int8 _controllerPort;
    int8 _mousePort;
    bool _controllerHasRumble; // Gets enabled if rumble-pak is detected

    bool _dirtyOffscreen;

public:

    /* These have to be accessed by interrupt callbacks */
    uint16 _audioBufferSize;
    uint32 _viClockRate; // Clock rate of video system, depending on VI mode

    uint32 _timerCallbackNext;
    uint32 _timerCallbackTimer;
    TimerProc _timerCallback;
    /* *** */

    OSystem_N64();
    virtual ~OSystem_N64();

    virtual void initBackend();

    virtual bool hasFeature(Feature f);
    virtual void setFeatureState(Feature f, bool enable);
    virtual bool getFeatureState(Feature f);
    virtual const GraphicsMode *getSupportedGraphicsModes() const;
    virtual int getDefaultGraphicsMode() const;
    virtual bool setGraphicsMode(int mode, uint flags = OSystem::kGfxModeNoFlags);
    virtual int getGraphicsMode() const;
    virtual void beginGFXTransaction();
    virtual OSystem::TransactionError endGFXTransaction();
    virtual int getScreenChangeID() const;
    virtual void initSize(uint width, uint height, const Graphics::PixelFormat *format);
    virtual int16 getHeight();
    virtual int16 getWidth();

    virtual PaletteManager *getPaletteManager() { return this; }
protected:
    // PaletteManager API
    virtual void setPalette(const byte *colors, uint start, uint num);
    virtual void grabPalette(byte *colors, uint start, uint num) const;

public:
    virtual void copyRectToScreen(const void *buf, int pitch, int x, int y, int w, int h);
    virtual void updateScreen();
    virtual Graphics::Surface *lockScreen();
    virtual void unlockScreen();
    virtual void setShakePos(int shakeXOffset, int shakeYOffset);

    virtual void showOverlay(bool inGUI);
    virtual void hideOverlay();
    virtual bool isOverlayVisible() const { return _overlayVisible; }
    virtual void clearOverlay();
    virtual void grabOverlay(Graphics::Surface &surface);
    virtual void copyRectToOverlay(const void *buf, int pitch, int x, int y, int w, int h);
    virtual int16 getOverlayHeight() const;
    virtual int16 getOverlayWidth() const;
    virtual Graphics::PixelFormat getOverlayFormat() const {
        return Graphics::PixelFormat(2, 5, 5, 5, 0, 11, 6, 1, 0);
    }

    virtual bool showMouse(bool visible);

    virtual void warpMouse(int x, int y);
    virtual void setMouseCursor(const void *buf, uint w, uint h, int hotspotX, int hotspotY, uint32 keycolor, bool dontScale, const Graphics::PixelFormat *format, const byte *mask);
    virtual void setCursorPalette(const byte *colors, uint start, uint num);

    virtual bool pollEvent(Common::Event &event);
    virtual uint32 getMillis(bool skipRecord = false);
    virtual void delayMillis(uint msecs);

    virtual Common::MutexInternal *createMutex(void);

    virtual void quit();

    virtual Audio::Mixer *getMixer();
    virtual void getTimeAndDate(TimeDate &t, bool skipRecord = false) const;
    virtual void setTimerCallback(TimerProc callback, int interval);
    virtual void logMessage(LogMessageType::Type type, const char *message);

    void rebuildOffscreenGameBuffer(void);
    void rebuildOffscreenMouseBuffer(void);
    void switchGraphicModeId(int mode);

    void setupMixer(void);

    void detectControllers(void);
    void readControllerAnalogInput(void); // read controller analog nub position
};

#endif /* __OSYS_N64_H__ */