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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 2
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#ifndef COMMON_SYSTEM_H
#define COMMON_SYSTEM_H
#include "common/scummsys.h"
#include "common/noncopyable.h"
#include "common/list.h" // For OSystem::getSupportedFormats()
#include "graphics/pixelformat.h"
namespace Audio {
class Mixer;
}
namespace Graphics {
struct Surface;
}
namespace Common {
class EventManager;
struct Rect;
class SaveFileManager;
class SearchSet;
class String;
#if defined(USE_TASKBAR)
class TaskbarManager;
#endif
#if defined(USE_UPDATES)
class UpdateManager;
#endif
class TimerManager;
class SeekableReadStream;
class WriteStream;
#ifdef ENABLE_KEYMAPPER
class HardwareInputSet;
class Keymap;
class KeymapperDefaultBindings;
#endif
}
class AudioCDManager;
class FilesystemFactory;
class PaletteManager;
/**
* A structure describing time and date. This is a clone of struct tm
* from time.h. We roll our own since not all systems provide time.h.
* We also do not imitate all files of struct tm, only those we
* actually need.
*
* @note For now, the members are named exactly as in struct 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 {
enum Type {
kInfo,
kError,
kWarning,
kDebug
};
} // End of namespace LogMessageType
/**
* Interface for ScummVM backends. If you want to port ScummVM to a system
* which 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, to handle user input events,
* control audio CD playback, and sound output.
*/
class OSystem : Common::NonCopyable {
protected:
OSystem();
virtual ~OSystem();
protected:
/**
* @name Module slots
*
* 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, please look at the documentation of
* each slot.
*
* A backend may setup slot values in its initBackend() method,
* its constructor or somewhere in between. But it must a slot's value
* no later than in its initBackend() implementation, because
* OSystem::initBackend() will create any default instances if
* none has 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, BaseBackend::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 _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;
//@}
public:
/**
* The following method is called once, from main.cpp, after all
* config data (including command line params etc.) are 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();
/**
* Allows the backend to perform engine specific init.
* Called just before the engine is run.
*/
virtual void engineInit() { }
/**
* Allows the backend to perform engine specific de-init.
* Called after the engine finishes.
*/
virtual void engineDone() { }
/** @name Feature flags */
//@{
/**
* 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
* - a virtual keyboard for text entry (on PDAs)
*
* One has to distinguish between the *availability* of a feature,
* which 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 via getFeatureState(). Finally, to
* switch between fullscreen and windowed mode, use setFeatureState().
*/
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 to
* correct 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 (that is, the original graphics used non-square
* pixels). When the backend support 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
* which can be used to implement aspect ratio correction. In
* stretch200To240() can stretch a rect, including (very fast)
* particular, interpolation, and works in-place.
*/
kFeatureAspectRatioCorrection,
/**
* Determine whether a virtual keyboard is too be shown or not.
* This would mostly be implemented by backends for hand held 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 via 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,
/**
* A backend have 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,
/**
* Setting the state of this feature to true tells the backend to disable
* all key filtering/mapping, in cases where it would be beneficial to do so.
* As an example case, this is used in the AGI engine's predictive dialog.
* When the dialog is displayed this feature is set so that backends with
* phone-like keypad temporarily unmap all user actions which leads to
* comfortable word entry. Conversely, when the dialog exits the feature
* is set to false.
*
* TODO: The word 'beneficial' above is very unclear. Beneficial to
* whom and for what??? Just giving an example is not enough.
*
* TODO: Fingolfin suggests that the way the feature is used can be
* generalized in this sense: Have a keyboard mapping feature, which the
* engine queries for to assign keys to actions ("Here's my default key
* map for these actions, what do you want them set to?").
*/
kFeatureDisableKeyFiltering,
/**
* 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 hasTextInClipboard()
* and getTextFromClipboard() calls are supported.
*
* 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
};
/**
* Determine whether the backend supports the specified feature.
*/
virtual bool hasFeature(Feature f) { return false; }
/**
* En-/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; }
//@}
/**
* @name Graphics
*
* The way graphics work in the class OSystem are meant to make
* it possible for game frontends to implement all 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 in 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, the may be scaled to better
* fit on 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. We define p_w and p_h to be
* the width resp. height of a game pixel on the screen.
*
* In addition, there is a vertical "shake offset" (as defined by
* setShakePos) which is 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. We denote the shake offset
* by S.
*
* 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, p_hw * (y + S)) 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 when 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.
* Nowadays 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 16bpp mode right now.
*
* Finally, there is the mouse layer. This layer doesn't have to
* actually exist within the backend -- it all depends on how a
* backend chooses to implement mouse cursors, but 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.
*
* On a note for OSystem users here. We do not require our graphics
* 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 via the command line, or via 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 completely up to the
* backend. This value will be passed to the setGraphicsMode(int)
* method by 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 a list of supported graphics modes
*/
virtual const GraphicsMode *getSupportedGraphicsModes() const = 0;
/**
* 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 via
* the command line or a config file).
*
* @return the ID of the 'default' graphics mode
*/
virtual int getDefaultGraphicsMode() const = 0;
/**
* Switch to the specified graphics mode. If switching to the new mode
* failed, this method returns false.
*
* @param mode the ID of the new graphics mode
* @return true if the switch was successful, false otherwise
*/
virtual bool setGraphicsMode(int mode) = 0;
/**
* Switch to the graphics mode with the given name. If 'name' is unknown,
* or if switching to the new mode failed, this method returns false.
*
* @param name the name of the new graphics mode
* @return true if the switch was successful, false otherwise
* @note This is implemented via 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 the ID of the active graphics mode
*/
virtual int getGraphicsMode() const = 0;
/**
* Sets the graphics scale factor to x1. Games with large screen sizes
* reset the scale to x1 so the screen will not be too big when starting
* the game.
*/
virtual void resetGraphicsScale() {}
#ifdef USE_RGB_COLOR
/**
* Determine the pixel format currently in use for screen rendering.
* @return the active screen pixel format.
* @see Graphics::PixelFormat
*/
virtual Graphics::PixelFormat getScreenFormat() const = 0;
/**
* Returns 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 should be placed in order of descending preference for the
* backend to use.
*
* EG: 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
* 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
/**
* 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 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;
* this 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 the new virtual screen width
* @param height the new virtual screen height
* @param format the new virtual screen pixel format
*/
virtual void initSize(uint width, uint height, const Graphics::PixelFormat *format = NULL) = 0;
/**
* Return an int value which is changed whenever any screen
* parameters (like the resolution) change. That is, whenever a
* EVENT_SCREEN_CHANGED would be 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 an integer which can be used to track screen changes
*
* @note Backends which 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, some ugliness may result.
* E.g. 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 is able to save the different errors which can happen while
* changing GFX config values inside GFX transactions.
*
* endGFXTransaction returns a ORed combination of the '*Failed' values
* if any problem occures, on success 0.
*
* @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 */
};
/**
* End (and thereby commit) the current GFX transaction.
* @see beginGFXTransaction
* @see kTransactionError
* @return returns a ORed combination of TransactionError values or 0 on success
*/
virtual TransactionError endGFXTransaction() { return kTransactionSuccess; }
/**
* Returns the currently set virtual screen height.
* @see initSize
* @return the currently set virtual screen height
*/
virtual int16 getHeight() = 0;
/**
* Returns the currently set virtual screen width.
* @see initSize
* @return the currently set virtual screen width
*/
virtual int16 getWidth() = 0;
/**
* Return the palette manager singleton. For more information, refer
* to the PaletteManager documentation.
*/
virtual PaletteManager *getPaletteManager() = 0;
/**
* Blit a bitmap to the virtual screen.
* The real screen will not immediately be updated to reflect the changes.
* Client code has to to 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 the buffer containing the graphics data source
* @param pitch the pitch of the buffer (number of bytes in a scanline)
* @param x the x coordinate of the destination rectangle
* @param y the y coordinate of the destination rectangle
* @param w the width of the destination rectangle
* @param h the 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 matching call to unlockScreen(). Calling code
* should make sure to only lock the framebuffer for the briefest
* periods of time possible, as the whole system is potentially stalled
* while the lock is active.
* Returns 0 if an error occurred. 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;
/**
* Fills the screen with a given color value.
*
* @note We are using uint32 here even though currently
* we only support 8bpp indexed mode. Thus the value should
* be always inside [0, 255] for now.
*/
virtual void fillScreen(uint32 col) = 0;
/**
* Flush the whole screen, that is render the current content of the screen
* framebuffer to the display.
*
* This method could be called very often by engines. Backends are hence
* supposed to only perform any redrawing if it is necessary, and otherwise
* return immediately. See
* <http://wiki.scummvm.org/index.php/HOWTO-Backends#updateScreen.28.29_method>
*/
virtual void updateScreen() = 0;
/**
* Set current shake position, a feature needed for some SCUMM screen
* effects. The effect causes the displayed graphics to be shifted upwards
* by the specified (always positive) offset. The area at the bottom of the
* screen which is moved into view by this is filled with black. This does
* not cause any graphic data to be lost - that is, 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 shakeOffset the shake offset
*
* @note This is currently used in the SCUMM, QUEEN and KYRA engines.
*/
virtual void setShakePos(int shakeOffset) = 0;
/**
* Sets the area of the screen that has the focus. For example, when a character
* is speaking, they will have the focus. Allows for pan-and-scan style views
* where the backend could 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 A rectangle on the screen to be focused on
* @see clearFocusRectangle
*/
virtual void setFocusRectangle(const Common::Rect& rect) {}
/**
* Clears the focus set by a call to setFocusRectangle(). This allows the engine
* to clear the focus during times when no particular area of the screen has the
* focus.
* @see setFocusRectangle
*/
virtual void clearFocusRectangle() {}
//@}
/**
* @name Overlay
* In order to be able 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 which is blended over
* the game graphics. On backends which 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,
* 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.
*/
//@{
/** Activate the overlay mode. */
virtual void showOverlay() = 0;
/** Deactivate the overlay mode. */
virtual void hideOverlay() = 0;
/**
* Returns 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. Either it 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 buffer provided by the caller.
* This is only used to implement fake alpha blending.
*/
virtual void grabOverlay(void *buf, int pitch) = 0;
/**
* Blit a graphics buffer to the overlay.
* In a sense, this is the reverse of grabOverlay.
*
* @param buf the buffer containing the graphics data source
* @param pitch the pitch of the buffer (number of bytes in a scanline)
* @param x the x coordinate of the destination rectangle
* @param y the y coordinate of the destination rectangle
* @param w the width of the destination rectangle
* @param h the 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;
//@}
/** @name Mouse
* This is the lower level implementation as provided by the
* backends. The engines should use the Graphics::CursorManager
* class instead of using it 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;
/**
* Move ("warp") the mouse cursor to the specified position in virtual
* screen coordinates.
* @param x the new x position of the mouse
* @param y the new y position of the mouse
*/
virtual void warpMouse(int x, int y) = 0;
/**
* Set the bitmap used for drawing the cursor.
*
* @param buf the 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).
* @param dontScale Whether the cursor should never be scaled. An exception are high ppi displays, where the cursor
* would be too small to notice otherwise, these are allowed to scale the cursor anyway.
* @param format pointer to the pixel format which cursor graphic uses (0 means CLUT8)
*/
virtual void setMouseCursor(const void *buf, uint w, uint h, int hotspotX, int hotspotY, uint32 keycolor, bool dontScale = false, const Graphics::PixelFormat *format = NULL) = 0;
/**
* Replace the specified range of cursor the 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 it should have kFeatureCursorPalette flag set
*
* @see setPalette
* @see kFeatureCursorPalette
*/
virtual void setCursorPalette(const byte *colors, uint start, uint num) {}
//@}
/** @name Events and Time */
//@{
/** Get the number of milliseconds since the program was started.
@param skipRecord Skip recording of this value by event recorder.
This could be needed particularly when we are in
an on-screen GUI loop where 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.
* Corresponds on many systems to the combination of time()
* and localtime().
*/
virtual void getTimeAndDate(TimeDate &t) const = 0;
/**
* Return the timer manager singleton. For more information, refer
* to the TimerManager documentation.
*/
virtual Common::TimerManager *getTimerManager();
/**
* Return the event manager singleton. For more information, refer
* to the EventManager documentation.
*/
inline Common::EventManager *getEventManager() {
return _eventManager;
}
#ifdef ENABLE_KEYMAPPER
/**
* Register hardware inputs with keymapper
* IMPORTANT NOTE: This is part of the WIP Keymapper. If you plan to use
* this, please talk to tsoliman and/or LordHoto.
*
* @return HardwareInputSet with all keys and recommended mappings
*
* See keymapper documentation for further reference.
*/
virtual Common::HardwareInputSet *getHardwareInputSet() { return 0; }
/**
* Return a platform-specific global keymap
* IMPORTANT NOTE: This is part of the WIP Keymapper. If you plan to use
* this, please talk to tsoliman and/or LordHoto.
*
* @return Keymap with actions appropriate for the platform
*
* The caller will use and delete the return object.
*
* See keymapper documentation for further reference.
*/
virtual Common::Keymap *getGlobalKeymap() { return 0; }
/**
* Return platform-specific default keybindings
* IMPORTANT NOTE: This is part of the WIP Keymapper. If you plan to use
* this, please talk to tsoliman and/or LordHoto.
*
* @return KeymapperDefaultBindings populated with keybindings
*
* See keymapper documentation for further reference.
*/
virtual Common::KeymapperDefaultBindings *getKeymapperDefaultBindings() { return 0; }
#endif
//@}
/**
* @name Mutex handling
* Historically, the OSystem API used to have a method which allowed
* creating threads. Hence mutex support was needed for thread syncing.
* To ease portability, though, we decided to remove the threading API.
* Instead, we now use timers (see setTimerCallback() and Common::Timer).
* But since those may be implemented using threads (and in fact, that's
* how our primary backend, the SDL one, does it on many systems), we
* still have to 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 e.g. the SDL backend does).
*
* Hence backends which do not use threads to implement the timers simply
* can use dummy implementations for these methods.
*/
//@{
typedef struct OpaqueMutex *MutexRef;
/**
* Create a new mutex.
* @return the newly created mutex, or 0 if an error occurred.
*/
virtual MutexRef createMutex() = 0;
/**
* Lock the given mutex.
*
* @note ScummVM code assumes that the mutex implementation supports
* recursive locking. That is, a thread may lock a mutex twice w/o
* deadlocking. In case of a multilock, the mutex has to be unlocked
* as many times as it was locked befored it really becomes unlocked.
*
* @param mutex the mutex to lock.
*/
virtual void lockMutex(MutexRef mutex) = 0;
/**
* Unlock the given mutex.
* @param mutex the mutex to unlock.
*/
virtual void unlockMutex(MutexRef mutex) = 0;
/**
* Delete the given mutex. Make sure the mutex is unlocked before you delete it.
* If you delete a locked mutex, the behavior is undefined, in particular, your
* program may crash.
* @param mutex the mutex to delete.
*/
virtual void deleteMutex(MutexRef mutex) = 0;
//@}
/** @name Sound */
//@{
/**
* Return the audio mixer. For more information, refer to the
* Audio::Mixer documentation.
*/
virtual Audio::Mixer *getMixer() = 0;
//@}
/** @name Audio CD */
//@{
/**
* Return the audio cd manager. For more information, refer to the
* AudioCDManager documentation.
*/
inline AudioCDManager *getAudioCDManager() {
return _audiocdManager;
}
//@}
/** @name Miscellaneous */
//@{
/** Quit (exit) the application. */
virtual void quit() = 0;
/**
* Signals that a fatal error inside the client code has happened.
*
* This should quit the application.
*/
virtual void fatalError();
/**
* Set a window caption or any other comparable status display to the
* given value. The caption must be a pure ISO LATIN 1 string. Passing a
* string with a different encoding may lead to unexpected behavior,
* even crashes.
*
* @param caption the window caption to use, as an ISO LATIN 1 string
*/
virtual void setWindowCaption(const char *caption) {}
/**
* Display a message in an 'on screen display'. That is, display it in a
* fashion where it is visible on or near the screen (e.g. in a transparent
* rectangle over the regular screen content; or in a message box beneath
* it; etc.).
*
* The message is expected to be provided in the current TranslationManager
* charset.
*
* @note There is a default implementation in BaseBackend which uses a
* TimedMessageDialog to display the message. Hence implementing
* this is optional.
*
* @param msg the message to display on screen
*/
virtual void displayMessageOnOSD(const char *msg) = 0;
/**
* Display an icon indicating 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 screen
*/
virtual void displayActivityIconOnOSD(const Graphics::Surface *icon) = 0;
/**
* Blit a bitmap to the 'on screen display'.
*
* 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 the buffer containing the graphics data source
* @param pitch the pitch of the buffer (number of bytes in a scanline)
* @param x the x coordinate of the destination rectangle
* @param y the y coordinate of the destination rectangle
* @param w the width of the destination rectangle
* @param h the 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
* @see copyRectToScreen
*/
virtual void copyRectToOSD(const void *buf, int pitch, int x, int y, int w, int h) = 0;
/**
* Clears 'on screen display' from everything drawn on it.
*/
virtual void clearOSD() = 0;
/**
* Returns 'on screen display' pixel format.
*/
virtual Graphics::PixelFormat getOSDFormat() = 0;
/**
* Return the SaveFileManager, used to store and load savestates
* and other modifiable persistent game data. For more information,
* refer to the SaveFileManager documentation.
*/
virtual Common::SaveFileManager *getSavefileManager();
#if defined(USE_TASKBAR)
/**
* Returns the TaskbarManager, 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)
/**
* Returns the UpdateManager, 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
/**
* Returns the FilesystemFactory object, depending on the current architecture.
*
* @return the FSNode factory for the current architecture
*/
virtual FilesystemFactory *getFilesystemFactory();
/**
* Add system specific Common::Archive objects to the given SearchSet.
* E.g. on Unix the dir corresponding to DATA_PATH (if set), or on
* Mac OS X the 'Resource' dir in the app bundle.
*
* @todo Come up with a better name. This one sucks.
*
* @param s the SearchSet to which the system specific dirs, if any, are added
* @param priority the 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 callers 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 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 may use this.
*/
virtual Common::String getDefaultConfigFileName();
/**
* Logs a 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 the type of the message
* @param message the message itself
*/
virtual void logMessage(LogMessageType::Type type, const char *message) = 0;
/**
* 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,
* e.g. as part of a bug report.
*
* On a desktop operating system, this would typically launch
* some kind of (external) text editor / viewer.
* On a phone, it might also cause a context switch to another
* application. Finally, on some ports, it might not be supported
* at all, and so do nothing.
*
* The kFeatureDisplayLogFile feature flag can be used to
* test whether this call has been implemented by the active
* backend.
*
* @return true if all seems to have gone fine, false if an error occurred
*
* @note An error could mean that the log file did not exist,
* or the editor could not launch. However, a return value of true does
* not guarantee that the user actually will 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; }
/**
* Returns 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 false; }
/**
* Returns 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::String getTextFromClipboard() { return ""; }
/**
* 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.
*
* @parem url the URL to open
*/
virtual bool openUrl(const Common::String &url) {return false; }
/**
* Returns the locale of the system.
*
* This returns the currently set up locale of the system, on which
* ScummVM is run.
*
* The format of the locale is language_country. These should match
* the POSIX locale values.
*
* For information about POSIX locales read here:
* http://en.wikipedia.org/wiki/Locale#POSIX-type_platforms
*
* The default implementation returns "en_US".
*
* @return locale of the system
*/
virtual Common::String getSystemLanguage() const;
//@}
};
/** The global OSystem instance. Initialized in main(). */
extern OSystem *g_system;
#endif
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