libretro-graphics.h

/* Copyright (C) 2024 Giovanni Cascione <ing.cascione@gmail.com>
 *
 * 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_LIBRETRO_GRAPHICS_H
#define BACKENDS_LIBRETRO_GRAPHICS_H

#include "common/system.h"
#include "graphics/paletteman.h"
#include "graphics/surface.h"
#include "backends/graphics/graphics.h"

#ifdef USE_OPENGL
#include "backends/graphics/opengl/opengl-graphics.h"
#endif

class LibretroPalette {
public:
    const byte *_prevColorsSource;
    unsigned char _colors[256 * 3];
    LibretroPalette(void);
    ~LibretroPalette(void) {};
    void set(const byte *colors, uint start, uint num);
    void get(byte *colors, uint start, uint num) const;
    unsigned char *getColor(uint aIndex) const;
    void reset(void) {
        _prevColorsSource = NULL;
    }
};

class LibretroGraphics : public GraphicsManager {

public:
    Graphics::Surface _screen;
    Graphics::Surface _gameScreen;
    Graphics::Surface _overlay;
    Graphics::Surface _mouseImage;
    LibretroPalette _mousePalette;
    LibretroPalette _gamePalette;

private:
    bool _overlayInGUI;
    bool _overlayVisible;
    bool _mouseDontScale;
    bool _mousePaletteEnabled;
    bool _mouseVisible;
    bool _screenUpdatePending;
    int _mouseHotspotX;
    int _mouseHotspotY;
    int _mouseKeyColor;

public:
    LibretroGraphics();
    ~LibretroGraphics();
    Common::List<Graphics::PixelFormat> getSupportedFormats() const override;
    const OSystem::GraphicsMode *getSupportedGraphicsModes(void) const override;
    void initSize(uint width, uint height, const Graphics::PixelFormat *format) override;
    int16 getHeight(void) const override;
    int16 getWidth(void) const override;
    Graphics::PixelFormat getScreenFormat(void) const override;
    void copyRectToScreen(const void *buf, int pitch, int x, int y, int w, int h) override;
    void updateScreen(void) override;
    void showOverlay(bool inGUI) override;
    void hideOverlay(void) override;
    void clearOverlay(void) override;
    void grabOverlay(Graphics::Surface &surface) const override;
    void copyRectToOverlay(const void *buf, int pitch, int x, int y, int w, int h) override;
    int16 getOverlayHeight(void) const override;
    int16 getOverlayWidth(void) const override;
    Graphics::PixelFormat getOverlayFormat() const override;
    const Graphics::Surface *getScreen(void);
    bool showMouse(bool visible) override;
    void warpMouse(int x, int y) override;
    void setMouseCursor(const void *buf, uint w, uint h, int hotspotX, int hotspotY, uint32 keycolor = 255, bool dontScale = false, const Graphics::PixelFormat *format = NULL, const byte *mask = nullptr) override;
    void setCursorPalette(const byte *colors, uint start, uint num) override;
    bool isOverlayInGUI(void);

    bool hasFeature(OSystem::Feature f) const override;
    void setFeatureState(OSystem::Feature f, bool enable) override;
    bool getFeatureState(OSystem::Feature f) const override;
    
    int getDefaultGraphicsMode() const override {
        return 0;
    }
    bool isOverlayVisible() const override {
        return _overlayVisible;
    }
    bool setGraphicsMode(int mode, uint flags = OSystem::kGfxModeNoFlags) override {
        return true;
    }
    int getGraphicsMode() const override {
        return 0;
    }
    Graphics::Surface *lockScreen() override {
        return &_gameScreen;
    }
    void unlockScreen() override {}

    void setShakePos(int shakeXOffset, int shakeYOffset) override {}
    int getScreenChangeID() const override {
        return 0;
    }
    void beginGFXTransaction() override {}
    OSystem::TransactionError endGFXTransaction() override {
        return OSystem::kTransactionSuccess;
    }
    void fillScreen(uint32 col) override {}
    void fillScreen(const Common::Rect &r, uint32 col) override {}
    void setFocusRectangle(const Common::Rect &rect) override {}
    void clearFocusRectangle() override {}
    void displayMessageOnOSD(const Common::U32String &msg) override;
    void displayActivityIconOnOSD(const Graphics::Surface *icon) override {}

    void realUpdateScreen(void);

protected:
    void setPalette(const byte *colors, uint start, uint num) override;
    void grabPalette(byte *colors, uint start, uint num) const override;
};

#ifdef USE_OPENGL
class LibretroOpenGLGraphics : public OpenGL::OpenGLGraphicsManager {
public:
    LibretroOpenGLGraphics(OpenGL::ContextType contextType);
    bool loadVideoMode(uint requestedWidth, uint requestedHeight, const Graphics::PixelFormat &format) override { return true; };
    void refreshScreen() override;
    void setSystemMousePosition(const int x, const int y) override {};

    bool isOverlayInGUI(void){ return _overlayInGUI; }
    void setMousePosition(int x, int y);
    Common::Point convertWindowToVirtual(int x, int y) const;
};

class LibretroHWFramebuffer : public OpenGL::Backbuffer {

protected:
    void activateInternal() override;
};
#endif
#endif //BACKENDS_LIBRETRO_GRAPHICS_H