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scummvm/common/system.h
Le Philousophe 2f34975164 COMMON: Make shaders API use the Path class
2023-12-24 13:19:25 +01:00

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/* 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 COMMON_SYSTEM_H
#define COMMON_SYSTEM_H
#include "common/scummsys.h"
#include "common/noncopyable.h"
#include "common/array.h" // For OSystem::getGlobalKeymaps()
#include "common/list.h" // For OSystem::getSupportedFormats()
#include "common/ustr.h"
#include "common/str-array.h" // For OSystem::updateStartSettings()
#include "common/hash-str.h" // For OSystem::updateStartSettings()
#include "common/path.h"
#include "graphics/pixelformat.h"
#include "graphics/mode.h"
#include "graphics/opengl/context.h"
namespace Audio {
class Mixer;
}
namespace Graphics {
struct Surface;
}
namespace GUI {
class GuiObject;
class OptionsContainerWidget;
}
namespace DLC {
class Store;
}
namespace Common {
class EventManager;
class MutexInternal;
struct Rect;
class SaveFileManager;
class SearchSet;
class String;
#if defined(USE_TASKBAR)
class TaskbarManager;
#endif
#if defined(USE_UPDATES)
class UpdateManager;
#endif
class TextToSpeechManager;
#if defined(USE_SYSDIALOGS)
class DialogManager;
#endif
class TimerManager;
class SeekableReadStream;
class WriteStream;
class HardwareInputSet;
class Keymap;
class KeymapperDefaultBindings;
typedef Array<Keymap *> KeymapArray;
}
/**
* @defgroup common_system OSystem
* @ingroup common
*
* @brief API related to OSystem - the main interface for ScummVM backends.
*
* @{
*/
class AudioCDManager;
class FilesystemFactory;
class PaletteManager;
/**
* Structure describing time and date.
*
* This is a clone of struct @c tm from time.h.
* We implement our own since not all systems provide time.h.
* This is not a one-to-one replacement of the @c tm struct,
* as only the fields that we need were added.
*
* @note For now, the members are named exactly as in struct @c tm to ease
* the transition.
*/
struct TimeDate {
int tm_sec; /**< Seconds (0 - 60). */
int tm_min; /**< Minutes (0 - 59). */
int tm_hour; /**< Hours (0 - 23). */
int tm_mday; /**< Day of month (1 - 31). */
int tm_mon; /**< Month of year (0 - 11). */
int tm_year; /**< Year - 1900. */
int tm_wday; /**< Days since Sunday (0 - 6). */
};
namespace LogMessageType {
/**
* Enumeration for log message types.
* @ingroup common_system
*
*/
enum Type {
kInfo, /**< Info logs. */
kError, /**< Error logs. */
kWarning, /**< Warning logs. */
kDebug /**< Debug logs. */
};
} // End of namespace LogMessageType
/**
* Pixel mask modes for cursor graphics.
*/
enum CursorMaskValue {
/** Overlapped pixel is unchanged */
kCursorMaskTransparent = 0,
/** Overlapped pixel is replaced with the cursor pixel. */
kCursorMaskOpaque = 1,
/** Fully inverts the overlapped pixel regardless of the cursor color data.
* Backend must support kFeatureCursorMaskInvert for this mode. */
kCursorMaskInvert = 2,
/** Blends with mode (Destination AND Mask) XOR Color in palette modes, or
* (Destination AND Mask) XOR (NOT Color) in RGB modes, which is equivalent to
* Classic MacOS behavior for pixel colors other than black and white.
* Backend must support kFeatureCursorMaskPaletteXorColorXnor for this mode. */
kCursorMaskPaletteXorColorXnor = 3,
};
/**
* Interface for ScummVM backends.
*
* If you want to port ScummVM to a system that is not currently
* covered by any of our backends, this is the place to start.
* ScummVM will create an instance of a subclass of this interface
* and use it to interact with the system.
*
* In particular, a backend provides:
*
* - A video surface for ScummVM to draw in
* - Methods to create timers
* - Methods to handle user input events
* - Control audio CD playback
* - Sound output
*/
class OSystem : Common::NonCopyable {
protected:
OSystem();
virtual ~OSystem();
protected:
/**
* @defgroup common_system_module Subsystem modules
* @ingroup common_system
* @{
*
* For backend authors only, the following pointers (= "slots") to various
* subsystem managers / factories / etc. can and should be set to
* a suitable instance of the respective type.
*
* For some of the slots, a default instance is set if your backend
* does not do so. For details, refer to the documentation of
* each slot.
*
* A backend may set up slot values in its initBackend() method,
* its constructor, or somewhere in between. But it must set a slot's value
* no later than in its initBackend() implementation, because
* OSystem::initBackend() will create any default instances if
* none have been set yet (and for other slots, will verify that
* one has been set; if not, an error may be generated).
*/
/**
* No default value is provided for _audiocdManager by OSystem.
* However, BaseBackend::initBackend() does set a default value
* if none has been set before.
*
* @note _audiocdManager is deleted by the OSystem destructor.
*/
AudioCDManager *_audiocdManager;
/**
* No default value is provided for _eventManager by OSystem.
* However, EventsBaseBackend::initBackend() does set a default value
* if none has been set before.
*
* @note _eventManager is deleted by the OSystem destructor.
*/
Common::EventManager *_eventManager;
/**
* No default value is provided for _timerManager by OSystem.
*
* @note _timerManager is deleted by the OSystem destructor.
*/
Common::TimerManager *_timerManager;
/**
* No default value is provided for _savefileManager by OSystem.
*
* @note _savefileManager is deleted by the OSystem destructor.
*/
Common::SaveFileManager *_savefileManager;
#if defined(USE_TASKBAR)
/**
* No default value is provided for _taskbarManager by OSystem.
*
* @note _taskbarManager is deleted by the OSystem destructor.
*/
Common::TaskbarManager *_taskbarManager;
#endif
#if defined(USE_UPDATES)
/**
* No default value is provided for _updateManager by OSystem.
*
* @note _updateManager is deleted by the OSystem destructor.
*/
Common::UpdateManager *_updateManager;
#endif
/**
* No default value is provided for _textToSpeechManager by OSystem.
*
* @note _textToSpeechManager is deleted by the OSystem destructor.
*/
Common::TextToSpeechManager *_textToSpeechManager;
#if defined(USE_SYSDIALOGS)
/**
* No default value is provided for _dialogManager by OSystem.
*
* @note _dialogManager is deleted by the OSystem destructor.
*/
Common::DialogManager *_dialogManager;
#endif
/**
* No default value is provided for _fsFactory by OSystem.
*
* Note that _fsFactory is typically required very early on,
* so it usually should be set in the backends constructor or shortly
* thereafter, and before initBackend() is called.
*
* @note _fsFactory is deleted by the OSystem destructor.
*/
FilesystemFactory *_fsFactory;
/**
* Used by the DLC Manager implementation
*/
DLC::Store *_dlcStore;
/**
* Used by the default clipboard implementation, for backends that don't
* implement clipboard support.
*/
Common::U32String _clipboard;
/** Workaround for a bug in the osx_intel toolchain introduced by
* 014bef9eab9fb409cfb3ec66830e033e4aaa29a9. Adding this variable fixes it.
*/
bool _dummyUnused;
/** @} */
private:
/**
* Indicate if initBackend() has been called.
*/
bool _backendInitialized;
//@}
public:
/**
* Destoy this OSystem instance.
*/
void destroy();
/**
* Call this method once, after g_system is created.
*/
virtual void init() {}
/**
* The following method is called once, from main.cpp, after all
* config data (including command line params etc.) is fully loaded.
*
* @note Subclasses should always invoke the implementation of their
* parent class. They should do so near the end of their own
* implementation.
*/
virtual void initBackend();
/**
* Return false if initBackend() has not yet been called and true otherwise.
*
* Some functionalities such as mutexes cannot be used until the backend
* is initialized.
*/
bool backendInitialized() const { return _backendInitialized; }
/**
* Allow the backend to perform engine-specific initialization.
*
* Called just before the engine is run.
*/
virtual void engineInit() { }
/**
* Allow the backend to perform engine-specific deinitialization.
*
* Called after the engine finishes.
*/
virtual void engineDone() { }
/**
* Identify a task that ScummVM can perform.
*/
enum Task {
/**
* The local server is running, allowing connections from other devices to transfer files.
*/
kLocalServer,
/**
* ScummVM is downloading games or synchronizing savegames from the cloud.
*/
kCloudDownload,
/**
* ScummVM is downloading an icons or shaders pack.
*/
kDataPackDownload
};
/**
* Allow the backend to be notified when a task is started.
*/
virtual void taskStarted(Task) { }
/**
* Allow the backend to be notified when a task is finished.
*/
virtual void taskFinished(Task) { }
/**
* Allow the backend to customize the start settings, such as for example starting
* automatically a game under certain circumstances.
*
* This function is called after the command line parameters have been parsed,
* and thus the initial value of command and settings will reflect those.
*
* The default implementation checks if the executable name is "scummvm-auto"
* or if a file named "scummvm-autorun" sits next to it to enable autorun mode.
*/
virtual void updateStartSettings(const Common::String &executable, Common::String &command, Common::StringMap &startSettings, Common::StringArray& additionalArgs);
/**
* @defgroup common_system_flags Feature flags
* @ingroup common_system
* @{
*/
/**
* A feature in this context means an ability of the backend which can be
* either on or off.
*
* Examples include:
* - Fullscreen mode
* - Aspect ration correction
* - Virtual keyboard for text entry (on PDAs)
*
* There is a difference between the *availability* of a feature
* that can be checked using hasFeature(), and its *state*.
* For example, the SDL backend *has* the kFeatureFullscreenMode,
* so hasFeature returns true for it. On the other hand,
* fullscreen mode may be active or not. This can be determined
* by checking the state using getFeatureState(). Finally, to
* switch between fullscreen and windowed mode, use setFeatureState().
*
* Some features, for example kFeatureClipboardSupport and kFeatureOpenUrl
* have no state and can only be used to check if the corresponding feature
* is available or not. Calling getFeatureState() or setFeatureState()
* for them is pointless.
*/
enum Feature {
/**
* If supported, this feature flag can be used to switch between
* windowed and fullscreen mode.
*/
kFeatureFullscreenMode,
/**
* Control aspect ratio correction.
*
* Aspect ratio correction is used for correcting games running at 320x200
* (i.e with an aspect ratio of 8:5), but which on their original hardware
* were displayed with the standard 4:3 ratio
* (which means that the original graphics used non-square pixels).
* When the backend supports this, then games running at
* 320x200 pixels should be scaled up to 320x240 pixels.
* For all other resolutions, ignore this feature flag.
*
* @note Backend implementors can find utility functions in common/scaler.h.
* These functions can be used to implement aspect ratio correction.
* You can use stretch200To240() can stretch a rect, including (very fast)
* particular, interpolation, and works in-place.
*/
kFeatureAspectRatioCorrection,
/**
* If supported, this flag can be used to switch between unfiltered and
* filtered graphics modes.
*/
kFeatureFilteringMode,
/**
* Indicate if stretch modes are supported by the backend.
*/
kFeatureStretchMode,
/**
* Determine whether a virtual keyboard is to be shown or not.
* This would mostly be implemented by backends for handheld devices,
* like PocketPC, Palms, Symbian phones like the P800, Zaurus, etc.
*/
kFeatureVirtualKeyboard,
/**
* Backends supporting this feature allow specifying a custom palette
* for the cursor. The custom palette is used if the feature state
* is set to true by the client code using setFeatureState().
*
* It is currently used only by some Macintosh versions of Humongous
* Entertainment games. If the backend doesn't implement this feature
* then the engine switches to b/w versions of cursors.
* The GUI also relies on this feature for mouse cursors.
*/
kFeatureCursorPalette,
/**
* Backends supporting this feature allow cursors to contain an alpha
* channel.
*/
kFeatureCursorAlpha,
/**
* Backends supporting this feature allow specifying a mask for a
* cursor instead of a key color.
*/
kFeatureCursorMask,
/**
* Backends supporting this feature allow cursor masks to use mode kCursorMaskInvert in mask values,
* which inverts the destination pixel.
*/
kFeatureCursorMaskInvert,
/**
* Backends supporting this feature allow cursor masks to use mode kCursorMaskPaletteXorColorXnor in the mask values,
* which uses (Color XOR Destination) for CLUT8 blending and (Color XNOR Destination) for RGB blending. This is
* equivalent to Classic MacOS behavior for pixel colors other than black and white.
*/
kFeatureCursorMaskPaletteXorColorXnor,
/**
* A backend has this feature if its overlay pixel format has an alpha
* channel which offers at least 3-4 bits of accuracy (as opposed to
* just a single alpha bit).
*
* This feature has no associated state.
*/
kFeatureOverlaySupportsAlpha,
/**
* Client code can set the state of this feature to true in order to
* iconify the application window.
*/
kFeatureIconifyWindow,
/**
* This feature flag can be used to check if hardware-accelerated
* OpenGL is supported and can be used for 3D game rendering.
*/
kFeatureOpenGLForGame,
/**
* This feature flag can be used to check if shaders are supported
* and can be used for 3D game rendering.
*/
kFeatureShadersForGame,
/**
* If supported, this feature flag can be used to check if
* waiting for vertical sync before refreshing the screen to reduce
* tearing is enabled.
*/
kFeatureVSync,
/**
* When a backend supports this feature, it guarantees the graphics
* context is not destroyed when switching to and from fullscreen.
*
* For OpenGL, that means the context is kept with all of its content:
* texture, programs, etc.
*
* For TinyGL, that means the backbuffer surface is kept.
*/
kFeatureFullscreenToggleKeepsContext,
/**
* The presence of this feature indicates whether the displayLogFile()
* call is supported.
*
* This feature has no associated state.
*/
kFeatureDisplayLogFile,
/**
* The presence of this feature indicates whether the system clipboard is
* available.
*
* If this feature is not present, the hasTextInClipboard(),
* getTextFromClipboard(), and setTextInClipboard() calls can still be used,
* however it should not be used in scenarios where the user is expected to
* copy data outside of the application.
*
* This feature has no associated state.
*/
kFeatureClipboardSupport,
/**
* The presence of this feature indicates whether the openUrl()
* call is supported.
*
* This feature has no associated state.
*/
kFeatureOpenUrl,
/**
* Mouse emulation mode.
*/
kFeatureTouchpadMode,
/**
* Keyboard mouse and joystick mouse speed.
*/
kFeatureKbdMouseSpeed,
/**
* Change analog joystick deadzone.
*/
kFeatureJoystickDeadzone,
/**
* Scalers.
*/
kFeatureScalers,
/**
* Shaders.
*/
kFeatureShaders,
/**
* Support for downloading DLC packages.
*/
kFeatureDLC,
/**
* Support for using the native system file browser dialog
* through the DialogManager.
*/
kFeatureSystemBrowserDialog,
/**
* For platforms that should not have a Quit button.
*/
kFeatureNoQuit,
/**
* The presence of this feature indicates that the backend uses a touchscreen.
*
* This feature has no associated state.
*/
kFeatureTouchscreen,
/**
* Arm-v8 requires NEON extensions, but before that, NEON was just
* optional, so this signifies that the processor can use NEON.
*/
kFeatureCpuNEON,
/**
* For x86/x86_64 platforms that have SSE2 support
*/
kFeatureCpuSSE2,
/**
* For x86/x86_64 platforms that have SSE4.1 support
*/
kFeatureCpuSSE41,
/**
* For x86_64 platforms that have AVX2 support
*/
kFeatureCpuAVX2,
/**
* For PowerPC platforms that have the altivec standard as of 1999.
* Covers a wide range of platforms, Apple Macs, XBox 360, PS3, and more
*/
kFeatureCpuAltivec,
};
/**
* Determine whether the backend supports the specified feature.
*/
virtual bool hasFeature(Feature f) { return false; }
/**
* Enable or disable the specified feature.
*
* For example, this may be used to enable fullscreen mode
* or to deactivate aspect correction, etc.
*/
virtual void setFeatureState(Feature f, bool enable) {}
/**
* Query the state of the specified feature.
*
* For example, test whether fullscreen mode is active or not.
*/
virtual bool getFeatureState(Feature f) { return false; }
/** @} */
/**
* @defgroup common_system_graphics Graphics
* @ingroup common_system
* @{
*
* The way graphics work in the OSystem class is meant to make
* it possible for game frontends to implement everything they need in
* an efficient manner. The downside of this is that it may be
* rather complicated for backend authors to fully understand and
* implement the semantics of the OSystem interface.
*
* The graphics visible to the user in the end are actually
* composed of three layers: the game graphics, the overlay
* graphics, and the mouse.
*
* First, there are the game graphics. The methods in this section
* deal with them exclusively. In particular, the size of the game
* graphics is defined by a call to initSize(), and
* copyRectToScreen() blits the data in the current pixel format
* into the game layer. Let W and H denote the width and height of
* the game graphics.
*
* Before the user sees these graphics, the backend may apply some
* transformations to it. For example, they may be scaled to better
* fit the visible screen or aspect ratio correction may be
* performed (see kFeatureAspectRatioCorrection). As a result of
* this, a pixel of the game graphics may occupy a region bigger
* than a single pixel on the screen. p_w and p_h are defined to be
* the width and, respectively, height of a game pixel on the screen.
*
* In addition, there is a horizontal and vertical "shake offset" (as
* defined by setShakePos) that are used in some games to provide a
* shaking effect. Note that shaking is applied to all three layers,
* i.e. also to the overlay and the mouse. The shake offsets are
* denoted by XS and YS.
*
* Putting this together, a pixel (x,y) of the game graphics is
* transformed to a rectangle of height p_h and width p_w
* appearing at position (p_w * (x + XS), p_hw * (y + YS)) on the real
* screen. In addition, a backend may choose to offset
* everything, e.g. to center the graphics on the screen.
*
* The next layer is the overlay. It is composed over the game
* graphics. Historically, the overlay size had always been a
* multiple of the game resolution. For example, if the game
* resolution was 320x200 and the user selected a 2x scaler and did
* not enable aspect ratio correction, it had a size of 640x400.
* An exception was the aspect ratio correction, which did allow
* for non multiples of the vertical resolution of the game screen.
* Currently, the overlay size does not need to have any relation to
* the game resolution though, for example the overlay resolution
* might be the same as the physical screen resolution.
* The overlay is forced to a 16 bpp mode right now.
*
* Finally, there is the mouse layer. This layer does not have to
* actually exist within the backend -- it all depends on how a
* backend chooses to implement mouse cursors. However, in the default
* SDL backend, it really is a separate layer. The mouse can
* have a palette of its own, if the backend supports it.
*
* Graphics do not need to be thread-safe and in fact most/all backends
* using OpenGL are not. So do *not* try to call any of these functions
* from a timer and/or audio callback (like readBuffer of AudioStreams).
*/
/**
* Description of a graphics mode.
*/
struct GraphicsMode {
/**
* The name of the graphics mode.
*
* This name is matched when selecting a mode using the command line
* or using the config file. Examples: "1x", "advmame2x", "hq3x".
*/
const char *name;
/**
* Human-readable description of the scaler.
*
* Examples: "Normal (no scaling)", "AdvMAME2x", "HQ3x".
*/
const char *description;
/**
* ID of the graphics mode.
*
* How to use this is entirely up to the backend. This value is passed
* to the setGraphicsMode(int) method by the client code.
*/
int id;
};
/**
* Retrieve a list of all graphics modes supported by this backend.
*
* This can be both video modes as well as graphic filters/scalers.
* It is completely up to the backend maintainer to decide what is
* appropriate here and what not.
* The list is terminated by an all-zero entry.
*
* @return List of supported graphics modes.
*/
virtual const GraphicsMode *getSupportedGraphicsModes() const {
static const GraphicsMode noGraphicsModes[] = {{"NONE", "Normal", 0}, {nullptr, nullptr, 0 }};
return noGraphicsModes;
}
/**
* Return the ID of the 'default' graphics mode. What exactly this means
* is up to the backend. This mode is set by the client code when no user
* overrides are present (i.e. if no custom graphics mode is selected using
* the command line or a config file).
*
* @return ID of the 'default' graphics mode.
*/
virtual int getDefaultGraphicsMode() const { return 0; }
enum GfxModeFlags {
kGfxModeNoFlags = 0, /**< No flags. */
kGfxModeRender3d = (1 << 0) /**< Indicate 3D hardware-accelerated in-game GFX. */
};
/**
* Switch to the specified graphics mode.
*
* If switching to the new mode fails, this method returns false.
*
* The flag 'kGfxModeRender3d' is optional. It allows to switch to 3D-only rendering mode.
* In this mode, the game engine is allowed to use OpenGL(ES) directly.
*
* @param mode ID of the new graphics mode.
* @param flags Flags for the new graphics mode.
*
* @return True if the switch was successful, false otherwise.
*/
virtual bool setGraphicsMode(int mode, uint flags = kGfxModeNoFlags) { return (mode == 0); }
/**
* Switch to the graphics mode with the given name.
*
* If @p name is unknown, or if switching to the new mode fails, this method returns false.
*
* @param name Name of the new graphics mode.
*
* @return True if the switch was successful, false otherwise.
*
* @note This is implemented using the setGraphicsMode(int) method, as well
* as getSupportedGraphicsModes() and getDefaultGraphicsMode().
* In particular, backends do not have to overload this!
*/
bool setGraphicsMode(const char *name);
/**
* Determine which graphics mode is currently active.
*
* @return ID of the active graphics mode.
*/
virtual int getGraphicsMode() const { return 0; }
#ifdef USE_RGB_COLOR
/**
* Fetch the pixel format currently in use for screen rendering.
*
* This is not neccessarily the native format for the system - if unset
* it defaults toCLUT8. To set a different format, engines should set
* their preferred format using ::initGraphics().
*
* @return the active screen pixel format.
*
* @see Graphics::PixelFormat
*/
virtual Graphics::PixelFormat getScreenFormat() const = 0;
/**
* Return a list of all pixel formats supported by the backend.
*
* The first item in the list must be directly supported by hardware
* and provide the largest color space of those formats with direct
* hardware support. It is also strongly recommended that remaining
* formats are placed in the order of descending preference for the
* backend to use.
*
* Example: a backend that supports 32-bit ABGR and 16-bit 555 BGR in hardware
* and provides conversion from equivalent RGB(A) modes should order its list
* in the following way:
* 1) Graphics::PixelFormat(4, 0, 0, 0, 0, 0, 8, 16, 24)
* 2) Graphics::PixelFormat(2, 3, 3, 3, 8, 0, 5, 10, 0)
* 3) Graphics::PixelFormat(4, 0, 0, 0, 0, 24, 16, 8, 0)
* 4) Graphics::PixelFormat(2, 3, 3, 3, 8, 10, 5, 0, 0)
* 5) Graphics::PixelFormat::createFormatCLUT8()
*
* @see Graphics::PixelFormat
*
* @note Backends supporting RGB color should accept game data in RGB color
* order, even if hardware uses BGR or some other color order.
*/
virtual Common::List<Graphics::PixelFormat> getSupportedFormats() const = 0;
#else
inline Graphics::PixelFormat getScreenFormat() const {
return Graphics::PixelFormat::createFormatCLUT8();
}
inline Common::List<Graphics::PixelFormat> getSupportedFormats() const {
Common::List<Graphics::PixelFormat> list;
list.push_back(Graphics::PixelFormat::createFormatCLUT8());
return list;
}
#endif
/**
* Retrieve a list of supported levels of anti-aliasing.
*
* Anti-aliasing only works when using one of the hardware-accelerated
* renderers. An empty list means anti-aliasing is not supported.
*/
virtual Common::Array<uint> getSupportedAntiAliasingLevels() const {
return Common::Array<uint>();
}
/**
* Return the chosen OpenGL type.
*
* This function works even when a 2D graphical manager is active and
* let to select a proper renderer before changing mode.
* Implementation having feature kFeatureOpenGLForGame are expected to
* override this function.
*
* @return the OpenGL type of context which is supported.
*/
virtual OpenGL::ContextType getOpenGLType() const {
return OpenGL::kContextNone;
}
#if defined(USE_OPENGL) && defined(USE_GLAD)
/**
* Query the address of an OpenGL function by name.
*
* This can only be used after a context has been created.
* Please note that this function can return valid addresses even if the
* OpenGL context does not support the function.
*
* @param name The name of the OpenGL function.
* @return A function pointer for the requested OpenGL function or
* nullptr in case of failure.
*/
virtual void *getOpenGLProcAddress(const char *name) const { return nullptr; }
#endif
/**
* Load the specified shader.
*
* If loading the new shader fails, this method returns false.
*
* @param fileNode File node of the new shader.
*
* @return True if the switch was successful, false otherwise.
*/
virtual bool setShader(const Common::Path &fileName) { return false; }
/**
* Retrieve a list of all stretch modes supported by this backend.
*
* It is completely up to the backend maintainer to decide what is
* appropriate here and what not.
* The list is terminated by an all-zero entry.
*
* @return a list of supported stretch modes
*/
virtual const GraphicsMode *getSupportedStretchModes() const {
static const GraphicsMode noStretchModes[] = {{"NONE", "Normal", 0}, {nullptr, nullptr, 0 }};
return noStretchModes;
}
/**
* Return the ID of the 'default' stretch mode.
*
* What exactly this means is up to the backend. This mode is set
* by the client code when no user overrides are present
* (i.e. if no custom stretch mode is selected using the command line or a config file).
*
* @return ID of the 'default' graphics mode.
*/
virtual int getDefaultStretchMode() const { return 0; }
/**
* Switch to the specified stretch mode.
*
* If switching to the new mode fails, this method returns false.
*
* @param mode ID of the new graphics mode.
*
* @return True if the switch was successful, false otherwise.
*/
virtual bool setStretchMode(int mode) { return false; }
/**
* Switch to the stretch mode with the given name.
*
* If @p name is unknown, or if switching to the new mode fails,
* this method returns false.
*
* @param name Name of the new stretch mode.
*
* @return True if the switch was successful, false otherwise.
*
* @note This is implemented using the setStretchMode(int) method, as well
* as getSupportedStretchModes() and getDefaultStretchMode().
* In particular, backends do not have to overload this!
*/
bool setStretchMode(const char *name);
/**
* Determine which stretch mode is currently active.
*
* @return ID of the active stretch mode.
*/
virtual int getStretchMode() const { return 0; }
/**
* Return the ID of the 'default' scaler.
*
* This mode is set by the client code when no user overrides
* are present (i.e. if no custom scaler is selected using the
* command line or a config file).
*
* @return ID of the 'default' scaler.
*/
virtual uint getDefaultScaler() const { return 0; }
/**
* Return the 'default' scale factor.
*
* This mode is set by the client code when no user overrides
* are present (i.e. if no custom scaler is selected using the
* command line or a config file).
*
* @return The 'default' scale factor.
*/
virtual uint getDefaultScaleFactor() const { return 1; }
/**
* Switch to the specified scaler.
*
* If switching to the new mode fails, this method returns false.
*
* @param mode ID of the new scaler.
* @param factor The scale factor to use
*
* @return True if the switch was successful, false otherwise.
*/
virtual bool setScaler(uint mode, int factor) { return false; }
/**
* Switch to the scaler with the given name.
*
* If @p name is unknown, or if switching to the new mode fails,
* this method returns false.
*
* @param name Name of the new scaler.
* @param factor The scale factor to use
*
* @return True if the switch was successful, false otherwise.
*/
virtual bool setScaler(const char *name, int factor) { return false; }
/**
* Determine which scaler is currently active.
*
* @return ID of the active stretch mode.
*/
virtual uint getScaler() const { return 0; }
/**
* Determine which scale factor is currently active.
*
* @return The active scale factor.
*/
virtual uint getScaleFactor() const { return 1; }
/**
* Set the size and color format of the virtual screen.
*
* Typical sizes include:
* - 320x200 (e.g. for most SCUMM games, and Simon)
* - 320x240 (e.g. for FM-TOWN SCUMM games)
* - 640x480 (e.g. for Curse of Monkey Island)
*
* This is the resolution for which the client code generates data.
* This is not necessarily equal to the actual display size. For example,
* a backend may magnify the graphics to fit on the screen (see also the
* GraphicsMode), stretch the data to perform aspect ratio correction,
* or shrink it to fit on small screens (in cell phones).
*
* Typical formats include:
* - CLUT8 (e.g. 256 color, for most games)
* - RGB555 (e.g. 16-bit color, for later SCUMM HE games)
* - RGB565 (e.g. 16-bit color, for Urban Runner)
*
* This is the pixel format for which the client code generates data.
* It is not necessarily equal to the hardware pixel format. For example,
* a backend may perform color lookup of 8-bit graphics before pushing
* a screen to hardware, or correct the ARGB color order.
*
* @param width New virtual screen width.
* @param height New virtual screen height.
* @param format New virtual screen pixel format.
*/
virtual void initSize(uint width, uint height, const Graphics::PixelFormat *format = nullptr) = 0;
/**
* Send a list of graphics modes to the backend so it can make a decision
* about the best way to set up the display hardware.
*
* Engines that switch between different virtual screen sizes during a game
* should call this function prior to any call to initSize. Engines that use
* only a single screen size do not need to call this function.
*
* @param modes List of graphics modes the engine will probably use.
*/
virtual void initSizeHint(const Graphics::ModeList &modes) {}
/**
* Return an int value that is changed whenever any screen
* parameters (like the resolution) change, i.e. whenever
* EVENT_SCREEN_CHANGED is sent.
*
* You can track this value in your code to detect screen changes in case
* you do not have full control over the event loop(s)
* being used (like the GUI code).
*
* @return Integer that can be used to track screen changes.
*
* @note Backends that generate EVENT_SCREEN_CHANGED events must
* overload this method appropriately.
*/
virtual int getScreenChangeID() const { return 0; }
/**
* Begin a new GFX transaction, which is a sequence of GFX mode changes.
*
* The idea behind GFX transactions is to make it possible to activate
* several different GFX changes at once as a "batch" operation. For
* example, assume we are running in 320x200 with a 2x scaler (thus using
* 640x400 pixels in total). Now, we want to switch to 640x400 with the 1x
* scaler. Without transactions, we have to choose whether we want to first
* switch the scaler mode, or first to 640x400 mode. In either case,
* depending on the backend implementation, problems may occur.
* For example, the window might briefly switch to 320x200 or 1280x800.
* Using transactions, this can be avoided.
*
* @note Transaction support is optional, and the default implementations
* of the relevant methods simply do nothing.
*
* @see endGFXTransaction
*/
virtual void beginGFXTransaction() {}
/**
* This type can save the different errors which can happen while
* changing GFX config values inside GFX transactions.
*
* endGFXTransaction returns an ORed combination of the '*Failed' values
* if any problem occurs. It returns '0' on success.
*
* @see endGFXTransaction
*/
enum TransactionError {
kTransactionSuccess = 0, /**< Everything fine (use EQUAL check for this one!) */
kTransactionAspectRatioFailed = (1 << 0), /**< Failed switching aspect ratio correction mode */
kTransactionFullscreenFailed = (1 << 1), /**< Failed switching fullscreen mode */
kTransactionModeSwitchFailed = (1 << 2), /**< Failed switching the GFX graphics mode (setGraphicsMode) */
kTransactionSizeChangeFailed = (1 << 3), /**< Failed switching the screen dimensions (initSize) */
kTransactionFormatNotSupported = (1 << 4), /**< Failed setting the color format */
kTransactionFilteringFailed = (1 << 5), /**< Failed setting the filtering mode */
kTransactionStretchModeSwitchFailed = (1 << 6), /**< Failed setting the stretch mode */
kTransactionShaderChangeFailed = (1 << 7), /**< Failed setting the shader */
kTransactionVSyncFailed = (1 << 8), /**< Failed switching vsync mode */
};
/**
* End (and thereby commit) the current GFX transaction.
*
* @see beginGFXTransaction
* @see kTransactionError
*
* @return ORed combination of TransactionError values or 0 on success.
*/
virtual TransactionError endGFXTransaction() { return kTransactionSuccess; }
/**
* Return the currently set virtual screen height.
*
* @see initSize
*
* @return Currently set virtual screen height.
*/
virtual int16 getHeight() = 0;
/**
* Return the currently set virtual screen width.
*
* @see initSize
*
* @return Currently set virtual screen width.
*/
virtual int16 getWidth() = 0;
/**
* Return the palette manager singleton.
*
* For more information, see @ref PaletteManager.
*/
virtual PaletteManager *getPaletteManager() = 0;
/**
* Return the scale factor for HiDPI screens.
* Returns 1 for non-HiDPI screens, or if HiDPI display is not supported by the backend.
*/
virtual float getHiDPIScreenFactor() const { return 1.0f; }
/**
* Blit a bitmap to the virtual screen.
*
* The real screen will not immediately be updated to reflect the changes.
* Client code must call updateScreen to ensure any changes are visible
* to the user. This can be used to optimize drawing and reduce flicker.
*
* If the current pixel format has one byte per pixel, the graphics data
* uses 8 bits per pixel, using the palette specified via setPalette.
* If more than one byte per pixel is in use, the graphics data uses the
* pixel format returned by getScreenFormat.
*
* @param buf Buffer containing the graphics data source.
* @param pitch Pitch of the buffer (number of bytes in a scanline).
* @param x x coordinate of the destination rectangle.
* @param y y coordinate of the destination rectangle.
* @param w Width of the destination rectangle.
* @param h Height of the destination rectangle.
*
* @note The specified destination rectangle must be completly contained
* in the visible screen space, and must be non-empty. If not, a
* backend may or may not perform clipping, trigger an assert, or
* silently corrupt memory.
*
* @see updateScreen
* @see getScreenFormat
*/
virtual void copyRectToScreen(const void *buf, int pitch, int x, int y, int w, int h) = 0;
/**
* Lock the active screen framebuffer and return a Graphics::Surface
* representing it.
*
* The caller can then perform arbitrary graphics transformations
* on the framebuffer (blitting, scrolling, etc.).
* Must be followed by a matching call to unlockScreen().
* Code that is calling this should make sure to only lock the framebuffer
* for the shortest time possible, as the whole system is potentially stalled
* while the lock is active.
*
* @return 0 if an error occurs. Otherwise, a surface with the pixel
* format described by getScreenFormat is returned.
*
* The returned surface must *not* be deleted by the client code.
*
* @see getScreenFormat
*/
virtual Graphics::Surface *lockScreen() = 0;
/**
* Unlock the screen framebuffer, and mark it as dirty, i.e. during the
* next updateScreen() call, the whole screen will be updated.
*/
virtual void unlockScreen() = 0;
/**
* Fill the screen with the given color value.
*/
virtual void fillScreen(uint32 col) = 0;
/**
* Fill the specified area of the screen with the given color value.
*/
virtual void fillScreen(const Common::Rect &r, uint32 col) = 0;
/**
* Flush the whole screen, i.e. render the current content of the screen
* framebuffer to the display.
*
* This method may be called very often by engines. Backends are hence
* supposed to only perform any redrawing if it is necessary and otherwise
* return immediately. See
* <https://wiki.scummvm.org/index.php/HOWTO-Backends#updateScreen.28.29_method>
*/
virtual void updateScreen() = 0;
/**
* Set current shake position, a feature needed for screen effects in some
* engines.
*
* The effect causes the displayed graphics to be shifted downwards and
* rightwards by the specified offsets (the offsets can be negative to shift
* upwards or leftwards). The area at the border of the screen which is
* moved into view by this (for example at the bottom when moving
* upward) is filled with black. This does not cause any graphic data to
* be lost. To restore the original view, the game engine only has to call
* this method again with offset equal to zero. No calls to
* copyRectToScreen are necessary.
*
* @param shakeXOffset Shake x offset.
* @param shakeYOffset Shake y offset.
*
* @note This is currently used in the SCUMM, QUEEN, KYRA, SCI, DREAMWEB,
* SUPERNOVA, TEENAGENT, TOLTECS, ULTIMA, and PETKA engines.
*/
virtual void setShakePos(int shakeXOffset, int shakeYOffset) = 0;
/**
* Set the area of the screen that has the focus.
*
* For example, when a character is speaking, they will have the focus.
* This allows for pan-and-scan style views where the backend
* can follow the speaking character or area of interest on the screen.
*
* The backend is responsible for clipping the rectangle and deciding how best to
* zoom the screen to show any shape and size rectangle the engine provides.
*
* @param rect Rectangle on the screen to be focused on.
*
* @see clearFocusRectangle
*/
virtual void setFocusRectangle(const Common::Rect& rect) {}
/**
* Clear the focus set by a call to setFocusRectangle().
*
* This allows the engine to clear the focus when no particular area
* of the screen has the focus.
*
* @see setFocusRectangle
*/
virtual void clearFocusRectangle() {}
/**
* Instruct the backend to capture a screenshot of the current screen.
*
* The backend can persist it the way it considers appropriate.
*/
virtual void saveScreenshot() {}
/** @} */
/**
* @defgroup common_system_overlay Overlay
* @ingroup common_system
* @{
*
* To display dialogs atop the game graphics, backends
* must provide an overlay mode.
*
* The overlay is currently forced at 16 bpp.
*
* For 'coolness' we usually want to have an overlay that is blended over
* the game graphics. On backends that support alpha blending, this is
* no issue but on other systems this needs some trickery.
*
* Essentially, we fake (alpha) blending on these systems by copying the
* current game graphics into the overlay buffer when activating the overlay,
* and then manually compose whatever graphics we want to show in the overlay.
* This works because we assume the game to be "paused" whenever an overlay
* is active.
*
* @param inGame Whether the overlay is used to display GUI or in game images
*
*/
/** Activate the overlay mode. */
virtual void showOverlay(bool inGUI = true) = 0;
/** Deactivate the overlay mode. */
virtual void hideOverlay() = 0;
/** Return true if the overlay mode is activated, false otherwise. */
virtual bool isOverlayVisible() const = 0;
/**
* Return the pixel format description of the overlay.
*
* @see Graphics::PixelFormat
*/
virtual Graphics::PixelFormat getOverlayFormat() const = 0;
/**
* Reset the overlay.
*
* After calling this method while the overlay mode is active, the user
* should be seeing only the game graphics. How this is achieved depends
* on how the backend implements the overlay. It either sets all pixels of
* the overlay to be transparent (when alpha blending is used) or,
* in case of fake alpha blending, it might just put a copy of the
* current game graphics screen into the overlay.
*/
virtual void clearOverlay() = 0;
/**
* Copy the content of the overlay into a surface provided by the
* caller.
*
* This is only used to implement fake alpha blending.
*/
virtual void grabOverlay(Graphics::Surface &surface) = 0;
/**
* Blit a graphics buffer to the overlay.
*
* In a sense, this is the reverse of grabOverlay.
*
* @param buf Buffer containing the graphics data source.
* @param pitch Pitch of the buffer (number of bytes in a scanline).
* @param x x coordinate of the destination rectangle.
* @param y y coordinate of the destination rectangle.
* @param w Width of the destination rectangle.
* @param h Height of the destination rectangle.
*
* @see copyRectToScreen
* @see grabOverlay
*/
virtual void copyRectToOverlay(const void *buf, int pitch, int x, int y, int w, int h) = 0;
/**
* Return the height of the overlay.
*
* @see getHeight
*/
virtual int16 getOverlayHeight() = 0;
/**
* Return the width of the overlay.
*
* @see getWidth
*/
virtual int16 getOverlayWidth() = 0;
/** @} */
/** @defgroup common_system_mouse Mouse
* @ingroup common_system
* @{
*
* This is the lower level implementation as provided by the
* backends. The engines should use the Graphics::CursorManager
* class instead of using this directly.
*/
/**
* Show or hide the mouse cursor.
*
* Currently, the backend is not required to immediately draw the
* mouse cursor on showMouse(true).
*
* @todo We might want to reconsider this fact,
* check Graphics::CursorManager::showMouse for some details about
* this.
*
* @see Graphics::CursorManager::showMouse
*/
virtual bool showMouse(bool visible) = 0;
/**
* Lock or unlock the mouse cursor within the window.
*
*/
virtual bool lockMouse(bool lock) { return false; }
/**
* Move ("warp") the mouse cursor to the specified position in virtual
* screen coordinates.
*
* @param x New x position of the mouse.
* @param y New y position of the mouse.
*/
virtual void warpMouse(int x, int y) = 0;
/**
* Set the bitmap used for drawing the cursor.
*
* @param buf Pixmap data to be used.
* @param w Width of the mouse cursor.
* @param h Height of the mouse cursor.
* @param hotspotX Horizontal offset from the left side to the hotspot.
* @param hotspotY Vertical offset from the top side to the hotspot.
* @param keycolor Transparency color value. This should not exceed the maximum color value of the specified format.
* In case it does, the behavior is undefined. The backend might just error out or simply ignore the
* value. (The SDL backend will just assert to prevent abuse of this).
* This parameter does nothing if a mask is provided.
* @param dontScale Whether the cursor should never be scaled. An exception is high ppi displays, where the cursor
* might be too small to notice otherwise, these are allowed to scale the cursor anyway.
* @param format Pointer to the pixel format that the cursor graphic uses (0 means CLUT8).
* @param mask A mask containing values from the CursorMaskValue enum for each cursor pixel.
*/
virtual void setMouseCursor(const void *buf, uint w, uint h, int hotspotX, int hotspotY, uint32 keycolor, bool dontScale = false, const Graphics::PixelFormat *format = nullptr, const byte *mask = nullptr) = 0;
/**
* Replace the specified range of cursor palette with new colors.
*
* The palette entries from 'start' till (start+num-1) will be replaced - so
* a full palette update is accomplished via start=0, num=256.
*
* Backends which implement this should have the kFeatureCursorPalette flag set.
*
* @see setPalette
* @see kFeatureCursorPalette
*/
virtual void setCursorPalette(const byte *colors, uint start, uint num) {}
/**
* Get the system-configured double-click time interval.
* If the system doesn't support configuring double-click time, returns 0.
*/
virtual uint32 getDoubleClickTime() const { return 0; }
/** @} */
/** @defgroup common_system_event_time Events and Time
* @ingroup common_system
* @{
*/
/** Get the number of milliseconds since the program was started.
*
* @param skipRecord Skip recording of this value by the event recorder.
* This might be needed particularly when we are in
* an on-screen GUI loop where the player can pause
* the recording.
*/
virtual uint32 getMillis(bool skipRecord = false) = 0;
/** Delay/sleep for the specified amount of milliseconds. */
virtual void delayMillis(uint msecs) = 0;
/**
* Get the current time and date, in the local timezone.
*
* On many systems, this corresponds to the combination of time()
* and localtime().
*/
virtual void getTimeAndDate(TimeDate &td, bool skipRecord = false) const = 0;
/**
* Return the timer manager singleton.
*
* For more information, see @ref TimerManager.
*/
virtual Common::TimerManager *getTimerManager();
/**
* Return the event manager singleton.
*
* For more information, see @ref EventManager.
*/
inline Common::EventManager *getEventManager() {
return _eventManager;
}
/**
* Register hardware inputs with keymapper.
*
* @return HardwareInputSet with all keys and recommended mappings.
*
* For more information, see @ref keymapper.
*/
virtual Common::HardwareInputSet *getHardwareInputSet() { return nullptr; }
/**
* Return a platform-specific global keymap.
*
* @return Keymap with actions appropriate for the platform.
*
* The caller will use and delete the return object.
*
* For more information, see @ref keymapper.
*/
virtual Common::KeymapArray getGlobalKeymaps() { return Common::KeymapArray(); }
/**
* Return platform-specific default keybindings.
*
* @return KeymapperDefaultBindings populated with keybindings.
*
* For more information, see @ref keymapper.
*/
virtual Common::KeymapperDefaultBindings *getKeymapperDefaultBindings() { return nullptr; }
/** @} */
/**
* @defgroup common_system_mutex Mutex handling
* @ingroup common_system
* @{
*
* Historically, the OSystem API used to have a method that allowed
* creating threads. Hence, mutex support was needed for thread syncing.
* To ease portability, we decided to remove the threading API.
* Instead, we now use timers (see setTimerCallback() and Common::Timer).
* But since those can be implemented using threads (and in fact, that is
* how our primary backend, the SDL one, does it on many systems), we
* still must do mutex syncing in our timer callbacks.
* In addition, the sound mixer uses a mutex in case the backend runs it
* from a dedicated thread (as the SDL backend does).
*
* Hence, backends that do not use threads to implement the timers can simply
* use dummy implementations for these methods.
*/
/**
* Create a new mutex.
*
* @return The newly created mutex, or 0 if an error occurred.
*/
virtual Common::MutexInternal *createMutex() = 0;
/** @} */
/** @defgroup common_system_sound Sound
* @ingroup common_system
* @{
*/
/**
* Return the audio mixer.
*
* For more information, see @ref Audio::Mixer.
*/
virtual Audio::Mixer *getMixer() = 0;
/** @} */
/** @defgroup common_system_audio Audio CD
* @ingroup common_system
* @{
*/
/**
* Return the audio CD manager.
*
* For more information, see @ref AudioCDManager.
*/
inline AudioCDManager *getAudioCDManager() {
return _audiocdManager;
}
/** @} */
/** @defgroup common_system_misc Miscellaneous
* @ingroup common_system
* @{
*/
/** Quit (exit) the application. */
virtual void quit() = 0;
/**
* Signal that a fatal error inside the client code has occurred.
*
* This should quit the application.
*/
virtual void fatalError();
/**
* Set a window caption or any other comparable status display to the
* given value.
*
* @param caption The window caption to use.
*/
virtual void setWindowCaption(const Common::U32String &caption) {}
/**
* Display a message in an 'on-screen display'.
*
* Displays a message in such a way that it is visible on or near the screen,
* for example in a transparent rectangle over the regular screen content,
* or in a message box beneath it.
*
* The message is expected to be provided in the current TranslationManager
* charset.
*
* @note There is a default implementation in BaseBackend that uses a
* TimedMessageDialog to display the message. Hence, implementing
* this is optional.
*
* @param msg The message to display on the screen.
*/
virtual void displayMessageOnOSD(const Common::U32String &msg) = 0;
/**
* Display an icon that indicates background activity.
*
* The icon is displayed in an 'on-screen display'. It is visible above
* the regular screen content or near it.
*
* The caller keeps ownership of the icon. It is acceptable to free
* the surface just after the call.
*
* There is no preferred pixel format for the icon. The backend should
* convert its copy of the icon to an appropriate format.
*
* The caller must call this method again with a null pointer
* as a parameter to indicate the icon should no longer be displayed.
*
* @param icon The icon to display on the screen.
*/
virtual void displayActivityIconOnOSD(const Graphics::Surface *icon) = 0;
/** @} */
/**
* @addtogroup common_system_module
* @{
*/
/**
* Return the SaveFileManager, which is used to store and load savestates
* and other modifiable persistent game data.
*
* For more information, see @ref SaveFileManager.
*/
virtual Common::SaveFileManager *getSavefileManager();
#if defined(USE_TASKBAR)
/**
* Return the TaskbarManager, which is used to handle progress bars,
* icon overlay, tasks, and recent items list on the taskbar.
*
* @return The TaskbarManager for the current architecture.
*/
virtual Common::TaskbarManager *getTaskbarManager() {
return _taskbarManager;
}
#endif
#if defined(USE_UPDATES)
/**
* Return the UpdateManager, which is used to handle auto-updating
* and updating of ScummVM in general.
*
* @return The UpdateManager for the current architecture.
*/
virtual Common::UpdateManager *getUpdateManager() {
return _updateManager;
}
#endif
/**
* Return the TextToSpeechManager, used to handle text-to-speech features.
*
* @return The TextToSpeechManager for the current architecture.
*/
virtual Common::TextToSpeechManager *getTextToSpeechManager() {
return _textToSpeechManager;
}
#if defined(USE_SYSDIALOGS)
/**
* Return the DialogManager, which is used to handle system dialogs.
*
* @return The DialogManager for the current architecture.
*/
virtual Common::DialogManager *getDialogManager() {
return _dialogManager;
}
#endif
/**
* Return the DLC Store, used to implement DLC manager functions.
*
* @return The Store for the current architecture/distribution platform.
*/
virtual DLC::Store *getDLCStore() {
return _dlcStore;
}
/**
* Return the FilesystemFactory object, depending on the current architecture.
*
* @return The FSNode factory for the current architecture.
*/
virtual FilesystemFactory *getFilesystemFactory();
/** @} */
/**
* @addtogroup common_system_misc
* @{
*/
/** Add system-specific Common::Archive objects to the given SearchSet.
* For example, on Unix, the directory corresponding to DATA_PATH (if set), or, on
* macOS, the 'Resource' dir in the app bundle.
*
* @todo Come up with a better name.
*
* @param s SearchSet to which the system-specific dirs, if any, are added.
* @param priority Priority with which those dirs are added.
*/
virtual void addSysArchivesToSearchSet(Common::SearchSet &s, int priority = 0) {}
/**
* Open the default config file for reading by returning a suitable
* ReadStream instance.
*
* It is the caller's responsiblity to delete the stream after use.
*/
virtual Common::SeekableReadStream *createConfigReadStream();
/**
* Open the default config file for writing by returning a suitable
* WriteStream instance.
*
* It is the callers responsiblity to delete the stream after use.
*
* May return 0 to indicate that writing to the config file is not possible.
*/
virtual Common::WriteStream *createConfigWriteStream();
/**
* Get the default file name (or even path) where the user configuration
* of ScummVM will be saved.
*
* Note that not all ports can use this.
*/
virtual Common::Path getDefaultConfigFileName();
/**
* Get the default file name (or even path) where the scummvm.log
* will be saved.
*
* Note that not all ports can use this.
*/
virtual Common::Path getDefaultLogFileName() { return Common::Path(); }
/**
* Register the default values for the settings the backend uses into the
* configuration manager.
*
* @param target name of a config manager target
*/
virtual void registerDefaultSettings(const Common::String &target) const {}
/**
* Return a GUI widget container for configuring the specified target options.
*
* The returned widget is shown in the Backend tab in the options dialog.
* Backends can build custom options dialogs.
*
* Backends that don't want to have a Backend tab in the options dialog
* can return nullptr.
*
* @param boss the widget / dialog the returned widget is a child of
* @param name the name the returned widget must use
* @param target name of a config manager target
*/
virtual GUI::OptionsContainerWidget *buildBackendOptionsWidget(GUI::GuiObject *boss, const Common::String &name, const Common::String &target) const { return nullptr; }
/**
* Return list of strings used for building help dialog
*
* The strings represented in triplets:
* - Name of a tab (will be translated)
* - ZIP pack name with images (optional)
* - Text of the tab with Markdown formatting (also be translated)
*
* The string list is null-terminated.
*/
virtual const char * const *buildHelpDialogData() { return nullptr; }
/**
* Notify the backend that the settings editable from the game tab in the
* options dialog may have changed and that they need to be applied if
* necessary.
*/
virtual void applyBackendSettings() {}
/**
* Log the given message.
*
* It is up to the backend where to log the different messages.
* The backend should aim at using a non-buffered output for it,
* so that no log data is lost in case of a crash.
*
* The default implementation outputs them on stdout/stderr.
*
* @param type Type of the message.
* @param message The message itself.
*/
virtual void logMessage(LogMessageType::Type type, const char *message) = 0;
/**
* Display a dialog box containing the given message.
*
* @param type Type of the message.
* @param message The message itself.
*/
virtual void messageBox(LogMessageType::Type type, const char *message) {}
/**
* Open the log file in a way that allows the user to review it,
* and possibly email it (or parts of it) to the ScummVM team,
* for example as part of a bug report.
*
* On a desktop operating system, this would typically launch
* some kind of an (external) text editor / viewer.
* On a phone, it can also cause a context switch to another
* application. Finally, on some ports, it might not be supported
* at all, and do nothing.
*
* The kFeatureDisplayLogFile feature flag can be used to
* test whether this call has been implemented by the active
* backend.
*
* @return True on success, false if an error occurred.
*
* @note An error might mean that the log file did not exist,
* or that the editor could not launch. However, a return value of true does
* not guarantee that the user will actually see the log file.
*
* @note It is up to the backend to ensure that the system is in a state
* that allows the user to actually see the displayed log files. This
* might for example require leaving fullscreen mode.
*/
virtual bool displayLogFile() { return false; }
/**
* Check whether there is text available in the clipboard.
*
* The kFeatureClipboardSupport feature flag can be used to
* test whether this call has been implemented by the active
* backend.
*
* @return True if there is text in the clipboard, false otherwise.
*/
virtual bool hasTextInClipboard() { return !_clipboard.empty(); }
/**
* Return clipboard contents as a string.
*
* The kFeatureClipboardSupport feature flag can be used to
* test whether this call has been implemented by the active
* backend.
*
* @return clipboard contents ("" if hasTextInClipboard() == false).
*/
virtual Common::U32String getTextFromClipboard() { return _clipboard; }
/**
* Set the content of the clipboard to the given string.
*
* The kFeatureClipboardSupport feature flag can be used to
* test whether this call has been implemented by the active
* backend.
*
* @return True if the text has been properly set in the clipboard, false otherwise.
*/
virtual bool setTextInClipboard(const Common::U32String &text) { _clipboard = text; return true; }
/**
* Open the given URL in the default browser (if available on the target
* system).
*
* @return True on success, false otherwise.
*
* @note It is up to the backend to ensure that the system is in a state
* that allows the user to actually see the web page. This might for
* example require leaving fullscreen mode.
*
* @param url The URL to open.
*/
virtual bool openUrl(const Common::String &url) {return false; }
/**
* Return the language of the system.
*
* This returns the currently set language of the system on which
* ScummVM is run.
*
* The format is an ISO 639 language code, optionally followed by an ISO 3166-1 country code
* in the form language_country.
*
* For information about POSIX locales, see the following link:
* https://en.wikipedia.org/wiki/ISO_639
* https://en.wikipedia.org/wiki/ISO_3166-1
*
* The default implementation returns "en_US".
*
* @return Locale of the system.
*/
virtual Common::String getSystemLanguage() const;
/**
* Return whether the connection is limited (if available on the target system).
*
* @return True if the connection is limited.
*/
virtual bool isConnectionLimited();
//@}
};
/** The global OSystem instance. Initialized in main(). */
extern OSystem *g_system;
/** @} */
#endif
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