scummvm/graphics/scalerplugin.h
2023-02-12 09:44:51 +01:00

248 lines
7.0 KiB
C++

/* 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 GRAPHICS_SCALERPLUGIN_H
#define GRAPHICS_SCALERPLUGIN_H
#include "base/plugins.h"
#include "graphics/pixelformat.h"
#include "graphics/surface.h"
class Scaler {
public:
Scaler(const Graphics::PixelFormat &format) : _format(format) {}
virtual ~Scaler() {}
/**
* Scale a rect.
*
* @param srcPtr Pointer to the source buffer.
* @param srcPitch The number of bytes in a scanline of the source.
* @param dstPtr Pointer to the destination buffer.
* @param dstPitch The number of bytes in a scanline of the destination.
* @param width The width of the source rect to scale.
* @param height The height of the source rect to scale.
* @param x The x position of the source rect.
* @param y The y position of the source rect.
*/
void scale(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr,
uint32 dstPitch, int width, int height, int x, int y);
/**
* Increase the factor of scaling.
* @return The new factor
*/
virtual uint increaseFactor() = 0;
/**
* Decrease the factor of scaling.
* @return The new factor
*/
virtual uint decreaseFactor() = 0;
virtual uint getFactor() const { return _factor; }
/**
* Set the scaling factor.
* Intended to be used with GUI to set a known valid factor.
* Plugins should override if they require additional state changes.
* @param factor A valid scaling factor for the plugin
* @return The old factor.
*/
virtual uint setFactor(uint factor) {
uint oldFactor = _factor;
_factor = factor;
return oldFactor;
}
/**
* Set the source to be used when scaling and copying to the old buffer.
*
* @param padding The number of pixels on the border (Used to prevent memory access crashes)
* @param type The surface type. This source will only be used when calling oldSrcScale with the same type.
*/
virtual void setSource(const byte *src, uint pitch, int width, int height, int padding) {
// Should not be called unless overriden
assert(0);
}
/**
* Enable or disable the old Source functionality. It is initially
* disabled. When disabled, the old source data is preserved until re-enabled.
*
* Useful for scaling a different surface (e.g. the cursor).
*/
virtual void enableSource(bool enable) {
// Should not be called unless overriden
assert(0);
}
protected:
/**
* @see scale
*/
virtual void scaleIntern(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr,
uint32 dstPitch, int width, int height, int x, int y) = 0;
uint _factor;
Graphics::PixelFormat _format;
};
/**
* Convenience class that implements some bookkeeping for keeping track of
* old source images.
*/
class SourceScaler : public Scaler {
public:
SourceScaler(const Graphics::PixelFormat &format);
virtual ~SourceScaler();
virtual void setSource(const byte *src, uint pitch, int width, int height, int padding) final;
virtual void enableSource(bool enable) final { _enable = enable; }
virtual uint setFactor(uint factor) final;
protected:
virtual void scaleIntern(const uint8 *srcPtr, uint32 srcPitch, uint8 *dstPtr,
uint32 dstPitch, int width, int height, int x, int y) final;
/**
* Scalers must implement this function. It will be called by oldSrcScale.
* If by comparing the src and oldsrc images it is discovered that no change
* is necessary, do not write a pixel.
*
* If oldSrcPtr is NULL, do not read from it. Scale every pixel.
*/
virtual void internScale(const uint8 *srcPtr, uint32 srcPitch,
uint8 *dstPtr, uint32 dstPitch,
const uint8 *oldSrcPtr, uint32 oldSrcPitch,
int width, int height, const uint8 *buffer, uint32 bufferPitch) = 0;
private:
int _width, _height, _padding;
bool _enable;
byte *_oldSrc;
Graphics::Surface _bufferedOutput;
};
class ScalerPluginObject : public PluginObject {
public:
virtual ~ScalerPluginObject() {}
virtual Scaler *createInstance(const Graphics::PixelFormat &format) const = 0;
const Common::Array<uint> &getFactors() const { return _factors; }
bool hasFactor(uint factor) const {
const Common::Array<uint> &factors = getFactors();
for (Common::Array<uint>::const_iterator it = factors.begin(); it != factors.end(); it++) {
if ((*it) == factor)
return true;
}
return false;
}
/**
* Indicates how far outside the scaling region this scaler "looks"
* @return The number of pixels in any direction
*/
virtual uint extraPixels() const = 0;
/**
* Some scalers are not suitable for scaling the cursor.
* Blurring scalers should return false.
*/
virtual bool canDrawCursor() const = 0;
/**
* This value will be displayed on the GUI.
*/
virtual const char *getPrettyName() const = 0;
/**
* The default scale factor.
*/
virtual uint getDefaultFactor() const { return 2; }
/**
* Computationally intense scalers can benefit from comparing new and old
* source images and updating only the pixels necessary. If the function
* returns true, this scaler prefers this method and the backend can
* optionally use it.
*
* @see enableSource
* @see setSource
*/
virtual bool useOldSource() const { return false; }
protected:
Common::Array<uint> _factors;
};
/**
* Singleton class to manage scaler plugins
*/
class ScalerManager : public Common::Singleton<ScalerManager> {
private:
friend class Common::Singleton<SingletonBaseType>;
public:
const PluginList &getPlugins() const;
/**
* Queries all scaler plugins for the maximum number of pixels they
* can access out of bounds. Useful for adding extra rows and columns
* to surfaces.
*/
uint getMaxExtraPixels() const;
/**
* Search the scaler plugins for a special plugin based on its name.
*/
Plugin *findScalerPlugin(const char *name) const;
/**
* Search the scaler plugins for a special plugin based on its name.
*/
uint findScalerPluginIndex(const char *name) const;
/**
* Update scaler settings from older versions of ScummVM.
*/
void updateOldSettings();
/**
* Returns whether the supplied mode is one of the old gfx-modes.
*/
bool isOldGraphicsSetting(const Common::String &gfxMode);
};
/** Convenience shortcut for accessing singleton */
#define ScalerMan ScalerManager::instance()
#endif