pjs/gfx/public/nsIDrawingSurface.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape Public License
* Version 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
#ifndef nsIDrawingSurface_h___
#define nsIDrawingSurface_h___
#include "nscore.h"
#include "nsISupports.h"
#include "nsRect.h"
// a memory area that can be rendered to
typedef struct
{
PRUint32 mRedZeroMask; //red color mask in zero position
PRUint32 mGreenZeroMask; //green color mask in zero position
PRUint32 mBlueZeroMask; //blue color mask in zero position
PRUint32 mAlphaZeroMask; //alpha data mask in zero position
PRUint32 mRedMask; //red color mask
PRUint32 mGreenMask; //green color mask
PRUint32 mBlueMask; //blue color mask
PRUint32 mAlphaMask; //alpha data mask
PRUint8 mRedCount; //number of red color bits
PRUint8 mGreenCount; //number of green color bits
PRUint8 mBlueCount; //number of blue color bits
PRUint8 mAlphaCount; //number of alpha data bits
PRUint8 mRedShift; //number to shift value into red position
PRUint8 mGreenShift; //number to shift value into green position
PRUint8 mBlueShift; //number to shift value into blue position
PRUint8 mAlphaShift; //number to shift value into alpha position
} nsPixelFormat;
#define RASWIDTH(width, bpp) ((((width) * (bpp) + 31) >> 5) << 2)
#define NS_IDRAWING_SURFACE_IID \
{ 0x61cc77e0, 0xcaac, 0x11d2, \
{ 0xa8, 0x49, 0x00, 0x40, 0x95, 0x9a, 0x28, 0xc9 } }
class nsIDrawingSurface : public nsISupports
{
public:
NS_DEFINE_STATIC_IID_ACCESSOR(NS_IDRAWING_SURFACE_IID)
/**
* Lock a rect of a drawing surface and return a
* pointer to the upper left hand corner of the
* bitmap.
* @param aX x position of subrect of bitmap
* @param aY y position of subrect of bitmap
* @param aWidth width of subrect of bitmap
* @param aHeight height of subrect of bitmap
* @param aBits out parameter for upper left hand
* corner of bitmap
* @param aStride out parameter for number of bytes
* to add to aBits to go from scanline to scanline
* @param aWidthBytes out parameter for number of
* bytes per line in aBits to process aWidth pixels
* @return error status
*
**/
NS_IMETHOD Lock(PRInt32 aX, PRInt32 aY, PRUint32 aWidth, PRUint32 aHeight,
void **aBits, PRInt32 *aStride, PRInt32 *aWidthBytes,
PRUint32 aFlags) = 0;
/**
* Unlock a rect of a drawing surface. must be preceded
* by a call to Lock(). Lock()/Unlock() pairs do not nest.
* @return error status
*
**/
NS_IMETHOD Unlock(void) = 0;
/**
* Get the dimensions of a drawing surface
* @param aWidth out parameter for width of drawing surface
* @param aHeight out parameter for height of drawing surface
* @return error status
*
**/
NS_IMETHOD GetDimensions(PRUint32 *aWidth, PRUint32 *aHeight) = 0;
/**
* Get the offscreen status of the drawing surface
* @param aOffscreen out parameter for offscreen status of
* drawing surface. if PR_TRUE, then modifying the
* drawing surface does not immediately reflect the
* changes on the output device
* @return error status
*
**/
NS_IMETHOD IsOffscreen(PRBool *aOffScreen) = 0;
/**
* Get the pixel addressability status of the drawing surface
* @param aAddressable out parameter for pixel addressability
* status of drawing surface. if PR_TRUE, then the
* drawing surface is optimized for pixel addressability
* (i.e. the Lock() method has very low overhead). All
* drawing surfaces support Lock()ing, but doing so on
* drawing surfaces that do not return PR_TRUE here may
* impose significant overhead.
* @return error status
*
**/
NS_IMETHOD IsPixelAddressable(PRBool *aAddressable) = 0;
/**
* Get the pixel format of a drawing surface
* @param aOffscreen out parameter filled in with pixel
* format information.
* @return error status
*
**/
NS_IMETHOD GetPixelFormat(nsPixelFormat *aFormat) = 0;
};
//when creating a drawing surface, you can use this
//to tell the drawing surface that you anticipate
//the need to get to the actual bits of the drawing
//surface at some point during it's lifetime. typically
//used when creating bitmaps to be operated on by the
//nsIBlender implementations.
#define NS_CREATEDRAWINGSURFACE_FOR_PIXEL_ACCESS 0x0001
//when locking a drawing surface, use these flags to
//control how the data in the surface should be accessed
#define NS_LOCK_SURFACE_READ_ONLY 0x0001
#define NS_LOCK_SURFACE_WRITE_ONLY 0x0002
#endif // nsIDrawingSurface_h___