本篇接下来介绍离屏服务内容。

三、离屏服务

        该服务主要提供处理离屏的功能。结构体定义如下：

typedef struct _TriglavPlugInOffscreenService {TriglavPlugInOffscreenCreatePlaneProc            createPlaneProc;TriglavPlugInOffscreenRetainProc                 retainProc;TriglavPlugInOffscreenReleaseProc                releaseProc;TriglavPlugInOffscreenGetWidthProc               getWidthProc;TriglavPlugInOffscreenGetHeightProc              getHeightProc;TriglavPlugInOffscreenGetRectProc                getRectProc;TriglavPlugInOffscreenGetExtentRectProc          getExtentRectProc;TriglavPlugInOffscreenGetChannelOrderProc        getChannelOrderProc;TriglavPlugInOffscreenGetRGBChannelIndexProc     getRGBChannelIndexProc;TriglavPlugInOffscreenGetCMYKChannelIndexProc    getCMYKChannelIndexProc;TriglavPlugInOffscreenGetBlockRectCountProc      getBlockRectCountProc;TriglavPlugInOffscreenGetBlockRectProc           getBlockRectProc;TriglavPlugInOffscreenGetBlockImageProc          getBlockImageProc;TriglavPlugInOffscreenGetBlockAlphaProc          getBlockAlphaProc;TriglavPlugInOffscreenGetBlockSelectAreaProc     getBlockSelectAreaProc;TriglavPlugInOffscreenGetBlockPlaneProc          getBlockPlaneProc;TriglavPlugInOffscreenGetTileWidthProc           getTileWidthProc;TriglavPlugInOffscreenGetTileHeightProc          getTileHeightProc;TriglavPlugInOffscreenGetBitmapProc              getBitmapProc;TriglavPlugInOffscreenSetBitmapProc              setBitmapProc;
} TriglavPlugInOffscreenService;

        1. 为指定的离屏对象创建一个空的离屏，不需要时需手动调用函数 releaceProc() 销毁。

/*** offscreenObject: 离屏对象* width: 宽度（像素）* height: 高度（像素）* depth: 颜色深度（字节）
**/
TRIGLAV_PLUGIN_API *createPlaneProc( TriglavPlugInOffscreenObject* offscreenObject, const TriglavPlugInInt width, const TriglavPlugInInt height, const TriglavPlugInInt depth );

        2. 销毁指定的离屏对象

/*** offscreenObject: 离屏对象
**/
TRIGLAV_PLUGIN_API *releaseProc( TriglavPlugInOffscreenObject offscreenObject );

        3. 获取指定离屏对象的宽度

/*** offscreenObject: 离屏对象* width: 宽度（像素）
**/
TRIGLAV_PLUGIN_API *getWidthProc( TriglavPlugInOffscreenObject offscreenObject, TriglavPlugInInt* width );

        4. 获取指定离屏对象的高度

/*** offscreenObject: 离屏对象* height: 高度（像素）
**/
TRIGLAV_PLUGIN_API *getHeightProc( TriglavPlugInOffscreenObject offscreenObject, TriglavPlugInInt* height );

        5. 获取指定离屏对象的大小

/*** offscreenObject: 离屏对象* rect: 离屏尺寸（像素）
**/
TRIGLAV_PLUGIN_API *getRectProc( TriglavPlugInOffscreenObject offscreenObject, TriglavPlugInRect* rect );

        6. 获取指定离屏对象的绘制区域的外接矩形

/*** offscreenObject: 离屏对象* rect: 绘制区域的外接矩形（像素）
**/
TRIGLAV_PLUGIN_API *getExtentRectProc( TriglavPlugInOffscreenObject offscreenObject, TriglavPlugInRect* rect );

        7. 获取指定离屏对象的通道对齐信息

/*** offscreenObject: 离屏对象* channelOrder: 通道对齐信息
**/
TRIGLAV_PLUGIN_API *getChannelOrderProc( TriglavPlugInOffscreenObject offscreenObject, TriglavPlugInInt* channelOrder );

        获取的 channel order 为下述常量之一：

#define    kTriglavPlugInOffscreenChannelOrderAlpha                     (0x01)
#define    kTriglavPlugInOffscreenChannelOrderGrayAlpha                 (0x02)
#define    kTriglavPlugInOffscreenChannelOrderRGBAlpha                  (0x03)
#define    kTriglavPlugInOffscreenChannelOrderCMYKAlpha                 (0x04)
#define    kTriglavPlugInOffscreenChannelOrderBinarizationAlpha         (0x05)
#define    kTriglavPlugInOffscreenChannelOrderBinarizationGrayAlpha     (0x06)
#define    kTriglavPlugInOffscreenChannelOrderSelectArea                (0x10)
#define    kTriglavPlugInOffscreenChannelOrderPlane                     (0x20)

        8. 获取指定离屏对象的 RGB channel index

/*** offscreenObject: 离屏对象* redChannelIndex: 红色 channel index* blueChannelIndex: 蓝色 channel index* greenChannelIndex: 绿色 channel index
**/
TRIGLAV_PLUGIN_API *getRGBChannelIndexProc( TriglavPlugInOffscreenObject offscreenObject, TriglavPlugInInt* redChannelIndex, TriglavPlugInInt* blueChannelIndex, TriglavPlugInInt* greenChannelIndex );

        9. 获取指定离屏对象的 CMYK channel index

/*** offscreenObject: 离屏对象* cyanChannelIndex: 青色 channel index* magentaChannelIndex: 品红色 channel index* yellowChannelIndex: 黄色 channel index* keytoneChannelIndex: 基调 channel index
**/
TRIGLAV_PLUGIN_API *getCMYKChannelIndexProc( TriglavPlugInOffscreenObject offscreenObject, TriglavPlugInInt* cyanChannelIndex, TriglavPlugInInt* magentaChannelIndex, TriglavPlugInInt* yellowChannelIndex, TriglavPlugInInt* keytoneChannelIndex );

        10. 获取指定区域的指定离屏对象的块数

/*** offscreenObject: 离屏对象* bounds: 搜索区域* blockRectCount: 块数
**/
TRIGLAV_PLUGIN_API *getBlockRectCountProc( TriglavPlugInOffscreenObject offscreenObject, TriglavPlugInRect* bounds, TriglavPlugInInt* blockRectCount);

        11. 在指定区域中获取指定离屏对象块的区域

/*** offscreenObject: 离屏对象* bounds: 搜索区域* blockIndex: 块索引* blockRect: 块所在区域
**/
TRIGLAV_PLUGIN_API *getBlockRectProc( TriglavPlugInOffscreenObject offscreenObject, TriglavPlugInRect* bounds, TriglavPlugInInt blockIndex, TriglavPlugInRect* blockRect);

        12. 在指定的离屏对象中根据指定坐标获取图像地址、到下一列像素的字节数、到下一行像素的字节数以及块的大小

/*** offscreenObject: 离屏对象* pos: 坐标* address: 地址* rowBytes: 到下一列像素的字节数* pixelBytes: 到下一行像素的字节数* blockRect: 块所在区域
**/
TRIGLAV_PLUGIN_API *getBlockImageProc( TriglavPlugInOffscreenObject offscreenObject, TriglavPlugInPoint* pos, TriglavPlugInPtr* address, TriglavPlugInInt* rowBytes, TriglavPlugInInt* pixelBytes, TriglavPlugInRect* blockRect);

        13. 在指定的离屏对象中根据指定坐标获取 alpha 地址、到下一列像素的字节数、到下一行像素的字节数以及块的大小

/*** offscreenObject: 离屏对象* pos: 坐标* address: 地址* rowBytes: 到下一列像素的字节数* pixelBytes: 到下一行像素的字节数* blockRect: 块所在区域
**/
TRIGLAV_PLUGIN_API *getBlockAlphaProc( TriglavPlugInOffscreenObject offscreenObject, TriglavPlugInPoint* pos, TriglavPlugInPtr* address, TriglavPlugInInt* rowBytes, TriglavPlugInInt* pixelBytes, TriglavPlugInRect* blockRect);

        14. 在指定的离屏对象中根据指定坐标获取选择区域地址、到下一列像素的字节数、到下一行像素的字节数以及块的大小

/*** offscreenObject: 离屏对象* pos: 坐标* address: 地址* rowBytes: 到下一列像素的字节数* pixelBytes: 到下一行像素的字节数* blockRect: 块所在区域
**/
TRIGLAV_PLUGIN_API *getBlockSelectAreaProc( TriglavPlugInOffscreenObject offscreenObject, TriglavPlugInPoint* pos, TriglavPlugInPtr* address, TriglavPlugInInt* rowBytes, TriglavPlugInInt* pixelBytes, TriglavPlugInRect* blockRect);

        15. 在指定的离屏对象中根据指定坐标获取屏幕地址、到下一列像素的字节数、到下一行像素的字节数以及块的大小

/*** offscreenObject: 离屏对象* pos: 坐标* address: 地址* rowBytes: 到下一列像素的字节数* pixelBytes: 到下一行像素的字节数* blockRect: 块所在区域
**/
TRIGLAV_PLUGIN_API *getBlockPlaneProc(TriglavPlugInOffscreenObject offscreenObject, TriglavPlugInPoint* pos, TriglavPlugInPtr* address, TriglavPlugInInt* rowBytes, TriglavPlugInInt* pixelBytes, TriglavPlugInRect* blockRect);

        16. 获取指定离屏对象的主机设置平铺宽度

/*** offscreenObject: 离屏对象* tileWidth: 平铺宽度
**/
TRIGLAV_PLUGIN_API *getTileWidthProc(TriglavPlugInOffscreenObject offscreenObject, TriglavPlugInInt* tileWidth);

        17. 获取指定离屏对象的主机设置平铺高度

/*** offscreenObject: 离屏对象* tileHeight: 平铺高度
**/
TRIGLAV_PLUGIN_API *getTileHeightProc(TriglavPlugInOffscreenObject offscreenObject, TriglavPlugInInt* tileHeight);

        18. 从指定的离屏对象创建并获取位图对象

/*** offscreenObject: 离屏对象* offscreenPos: 离屏左上角坐标* bitmapPos: 位图左上角坐标* copyWidth: 复制宽度* copyHeight: 复制高度* copyMode: 复制模式* bitmapObject: 位图对象
**/
TRIGLAV_PLUGIN_API *getBitmapProc(TriglavPlugInOffscreenObject offscreenObject, const TriglavPlugInPoint* offscreenPos, const TriglavPlugInPoint* bitmapPos, const TriglavPlugInInt copyWidth, const TriglavPlugInInt copyHeight, const TriglavPlugInInt copyMode, TriglavPlugInBitmapObject bitmapObject);

        复制模式取下列常量之一：

#define    kTriglavPlugInOffscreenCopyModeNormal                 (0x01)
#define    kTriglavPlugInOffscreenCopyModeImage                  (0x02)
#define    kTriglavPlugInOffscreenCopyModeGray                   (0x03)
#define    kTriglavPlugInOffscreenCopyModeRed                    (0x04)
#define    kTriglavPlugInOffscreenCopyModeGreen                  (0x05)
#define    kTriglavPlugInOffscreenCopyModeBlue                   (0x06)
#define    kTriglavPlugInOffscreenCopyModeCyan                   (0x07)
#define    kTriglavPlugInOffscreenCopyModeMagenta                (0x08)
#define    kTriglavPlugInOffscreenCopyModeYellow                 (0x09)
#define    kTriglavPlugInOffscreenCopyModeKeyPlate               (0x10)
#define    kTriglavPlugInOffscreenCopyModeAlpha                  (0x11)

        19. 根据指定的位图对象设置离屏对象

/*** bitmapObject: 位图对象* bitmapPos: 位图左上角坐标* copyWidth: 复制宽度* copyHeight: 复制高度* copyMode: 复制模式* offscreenObject: 离屏对象* offscreenPos: 离屏左上角坐标
**/
TRIGLAV_PLUGIN_API *setBitmapProc(TriglavPlugInBitmapObject bitmapObject, const TriglavPlugInPoint* bitmapPos, const TriglavPlugInInt copyWidth, const TriglavPlugInInt copyHeight, const TriglavPlugInInt copyMode, TriglavPlugInOffscreenObject offscreenObject, TriglavPlugInPoint* offscreenPos);

四、离屏服务2

        该服务主要提供处理离屏的功能，结构体定义如下：

typedef struct _TriglavPlugInOffscreenService2 {TriglavPlugInOffscreenGetBitmapNormalAlphaChannelIndexProc   getBitmapNormalAlphaChannelIndexProc;
} TriglavPlugInOffscreenService2;

        1. 获取复制模式为 kTriglavPlugInOffscreenCopyModeNormal 时的 channel index

/*** offscreenObject: 离屏对象* alphaChannelIndex: alpha channel index
**/
TRIGLAV_PLUGIN_API *getBitmapNormalAlphaChannelIndexProc(TriglavPlugInOffscreenObject offscreenObject, TriglavPlugInInt* alphaChannelIndex);

        以上就是离屏服务的 api，下篇将介绍属性服务相关内容。