openglsdl-graphics3d.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_GRAPHICS3D_OPENGLSDL_GRAPHICS3D_H
#define BACKENDS_GRAPHICS3D_OPENGLSDL_GRAPHICS3D_H

#include "backends/graphics/sdl/sdl-graphics.h"

#include "math/rect2d.h"

#if defined(USE_OPENGL_GAME) || defined(USE_OPENGL_SHADERS)

#include "graphics/opengl/context.h"

namespace OpenGL {
    class FrameBuffer;
    class SurfaceRenderer;
    class TiledSurface;
}

class OpenGLSdlGraphics3dManager : public SdlGraphicsManager {
public:
    OpenGLSdlGraphics3dManager(SdlEventSource *eventSource, SdlWindow *window, bool supportsFrameBuffer);
    virtual ~OpenGLSdlGraphics3dManager();

    // GraphicsManager API - Features
    bool hasFeature(OSystem::Feature f) const override;
    bool getFeatureState(OSystem::Feature f) const override;
    void setFeatureState(OSystem::Feature f, bool enable) override;

    const OSystem::GraphicsMode *getSupportedGraphicsModes() const override;
    int getDefaultGraphicsMode() const override;
    bool setGraphicsMode(int mode, uint flags = OSystem::kGfxModeNoFlags) override;
    int getGraphicsMode() const override;

    const OSystem::GraphicsMode *getSupportedStretchModes() const override;
    int getDefaultStretchMode() const override;
    bool setStretchMode(int mode) override;
    int getStretchMode() const override;

    void beginGFXTransaction() override;
    OSystem::TransactionError endGFXTransaction() override;

    // GraphicsManager API - Graphics mode
#ifdef USE_RGB_COLOR
    Graphics::PixelFormat getScreenFormat() const override { return _overlayFormat; }
    Common::List<Graphics::PixelFormat> getSupportedFormats() const override {
        Common::List<Graphics::PixelFormat> supportedFormats;
        return supportedFormats;
    }
#endif
    int getScreenChangeID() const override { return _screenChangeCount; }
    void initSize(uint w, uint h, const Graphics::PixelFormat *format) override;
    int16 getHeight() const override;
    int16 getWidth() const override;

    // GraphicsManager API - Draw methods
    void updateScreen() override;
    // Following methods are not used by 3D graphics managers
    void setPalette(const byte *colors, uint start, uint num) override {}
    void grabPalette(byte *colors, uint start, uint num) const override {}
    void copyRectToScreen(const void *buf, int pitch, int x, int y, int w, int h) override {}
    Graphics::Surface *lockScreen() override { return nullptr; }
    void unlockScreen() override {}
    void fillScreen(uint32 col) override {}
    void fillScreen(const Common::Rect &r, uint32 col) override {}
    void setShakePos(int shakeXOffset, int shakeYOffset) override {};
    void setFocusRectangle(const Common::Rect& rect) override {}
    void clearFocusRectangle() override {}

    // GraphicsManager API - Overlay
    void showOverlay(bool inGUI) override;
    void hideOverlay() override;
    Graphics::PixelFormat getOverlayFormat() const override { return _overlayFormat; }
    void clearOverlay() 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 getOverlayWidth() const override;
    int16 getOverlayHeight() const override;

    // GraphicsManager API - Mouse
    bool showMouse(bool visible) override;
    void setMouseCursor(const void *buf, uint w, uint h, int hotspotX, int hotspotY, uint32 keycolor, bool dontScale = false, const Graphics::PixelFormat *format = NULL, const byte *mask = NULL) override {}
    void setCursorPalette(const byte *colors, uint start, uint num) override {}

    // SdlGraphicsManager API
    void notifyVideoExpose() override {};
    void notifyResize(const int width, const int height) override;

    bool gameNeedsAspectRatioCorrection() const override;

    void showSystemMouseCursor(bool visible) override;

#if defined(USE_IMGUI) && SDL_VERSION_ATLEAST(2, 0, 0)
    void *getImGuiTexture(const Graphics::Surface &image, const byte *palette, int palCount) override;
    void freeImGuiTexture(void *texture) override;
#endif

protected:
#if SDL_VERSION_ATLEAST(2, 0, 0)
    int _glContextProfileMask, _glContextMajor, _glContextMinor;
    SDL_GLContext _glContext;
    void deinitializeRenderer();
#endif

    OpenGL::ContextType _glContextType;

    bool _supportsFrameBuffer;

    struct OpenGLPixelFormat {
        uint bytesPerPixel;
        uint redSize;
        uint blueSize;
        uint greenSize;
        uint alphaSize;
        int multisampleSamples;

        OpenGLPixelFormat(uint screenBytesPerPixel, uint red, uint blue, uint green, uint alpha, int samples);
    };

    bool createOrUpdateGLContext(uint gameWidth, uint gameHeight, uint effectiveWidth, uint effectiveHeight,
                                 bool renderToFramebuffer, bool engineSupportsArbitraryResolutions);

    void createOrUpdateScreen();
    void setupScreen();

    void handleResizeImpl(const int width, const int height) override;

#ifdef EMSCRIPTEN

    bool _queuedScreenshot = false;
    void saveScreenshot() override;
#endif

    bool saveScreenshot(const Common::Path &filename) const override;

    uint _engineRequestedWidth, _engineRequestedHeight;

    int _screenChangeCount;
    int _antialiasing;
    int _stretchMode;
    bool _vsync;
    bool _fullscreen;
    bool _lockAspectRatio;

    OpenGL::TiledSurface *_overlayScreen;
    OpenGL::TiledSurface *_overlayBackground;
    OpenGL::SurfaceRenderer *_surfaceRenderer;

    Graphics::PixelFormat _overlayFormat;

    void initializeOpenGLContext() const;
    void drawOverlay();
    void closeOverlay();

    OpenGL::FrameBuffer *_frameBuffer;
    OpenGL::FrameBuffer *createFramebuffer(uint width, uint height);
    bool shouldRenderToFramebuffer() const;

protected:

    enum TransactionMode {
        kTransactionNone = 0,
        kTransactionActive = 1,
        kTransactionRollback = 2
    };

    TransactionMode _transactionMode;
};

#endif // defined(USE_OPENGL_GAME) || defined(USE_OPENGL_SHADERS)

#endif