Windows PowerShell command on Get-command Tk

Manual Pages for UNIX Operating System command usage for man Tk_PhotoSetSize

Tk Library Procedures Tk_FindPhoto(3TK)

_________________________________________________________________

NAME

Tk_FindPhoto, Tk_PhotoPutBlock, Tk_PhotoPutZoomedBlock,

Tk_PhotoGetImage, Tk_PhotoBlank, Tk_PhotoExpand,

Tk_PhotoGetSize, Tk_PhotoSetSize - manipulate the image data

stored in a photo image.

SYNOPSIS

#include

Tk_PhotoHandle

Tk_FindPhoto(interp, imageName) |

void

Tk_PhotoPutBlock(handle, blockPtr, x, y, width, height, compRule)

void

Tk_PhotoPutZoomedBlock(handle, blockPtr, x, y, width, height,zoomX, zoomY, subsampleX, subsampleY, compRule)

int

Tk_PhotoGetImage(handle, blockPtr)

void

Tk_PhotoBlank(handle)

void

Tk_PhotoExpand(handle, width, height)

void

Tk_PhotoGetSize(handle, widthPtr, heightPtr)

void

Tk_PhotoSetSize(handle, width, height)

ARGUMENTS

Tcl_Interp *interp (in) Interpreter in |

which image was | created. CONST char *imageName (in) Name of the photo image.

Tk_PhotoHandle handle (in) Opaque handle

identifying the photo image to be affected.

Tk_PhotoImageBlock *blockPtr (in) Specifies the

address and storage layout Tk Last change: 8.0 1

Tk Library Procedures Tk_FindPhoto(3TK)

of image data. int x (in) Specifies the X coordinate

where the top-

left corner of the block is to be placed within the image. int y (in) Specifies the Y coordinate

where the top-

left corner of the block is to be placed within the image. int width (in) Specifies the width of the image area to be affected (for

Tk_PhotoPutBlock)

or the desired image width (for

Tk_PhotoExpand

and

Tk_PhotoSetSize).

int compRule (in) || Specifies the | compositing | rule used when |

combining tran- |

TK_PHOTO_COMPOSITE_OVERLAY|

with the previ- |

ous contents | showing through | Tk Last change: 8.0 2

Tk Library Procedures Tk_FindPhoto(3TK)

in the tran- |

sparent bits) | or |

TK_PHOTO_COMPOSITE_SET|

Tk_PhotoPutBlock)

or the desired image height (for

Tk_PhotoExpand

and

Tk_PhotoSetSize).

int *widthPtr (out) Pointer to location in which to store the image width. int *heightPtr (out) Pointer to location in which to store the image height. int subsampleX (in) Specifies the subsampling factor in the X direction for input image data. int subsampleY (in) Specifies the subsampling factor in the Y direction for input image data. int zoomX (in) Specifies the Tk Last change: 8.0 3

Tk Library Procedures Tk_FindPhoto(3TK)

zoom factor to be applied in the X direction to pixels being written to the photo image. int zoomY (in) Specifies the zoom factor to be applied in the Y direction to pixels being written to the photo image.

_________________________________________________________________

DESCRIPTION

Tk_FindPhoto returns an opaque handle that is used to iden-

tify a particular photo image to the other procedures. The

parameter is the name of the image, that is, the name speci-

fied to the image create photo command, or assigned by that command if no name was specified.

Tk_PhotoPutBlock is used to supply blocks of image data to

be displayed. The call affects an area of the image of size

width x height pixels, with its top-left corner at coordi-

nates (x,y). All of width, height, x, and y must be non-

negative. If part of this area lies outside the current bounds of the image, the image will be expanded to include the area, unless the user has specified an explicit image

size with the -width and/or -height widget configuration

options (see photo(1T)); in that case the area is silently clipped to the image boundaries.

The block parameter is a pointer to a Tk_PhotoImageBlock

structure, defined as follows: typedef struct { unsigned char *pixelPtr; int width; int height; int pitch; int pixelSize; int offset[4];

} Tk_PhotoImageBlock;

The pixelPtr field points to the first pixel, that is, the

top-left pixel in the block. The width and height fields

specify the dimensions of the block of pixels. The pixel-

Size field specifies the address difference between two hor-

izontally adjacent pixels. Often it is 3 or 4, but it can have any value. The pitch field specifies the address difference between two vertically adjacent pixels. The Tk Last change: 8.0 4

Tk Library Procedures Tk_FindPhoto(3TK)

offset array contains the offsets from the address of a pixel to the addresses of the bytes containing the red, green, blue and alpha (transparency) components. These are normally 0, 1, 2 and 3, but can have other values, e.g., for images that are stored as separate red, green and blue planes.

The compRule parameter to Tk_PhotoPutBlock specifies a com- |

positing rule that says what to do with transparent pixels. |

The value TK_PHOTO_COMPOSITE_OVERLAY says that the previous |

contents of the photo image should show through, and the |

value TK_PHOTO_COMPOSITE_SET says that the previous contents |

of the photo image should be completely ignored, and the | values from the block be copied directly across. The | behavior in Tk8.3 and earlier was equivalent to having |

TK_PHOTO_COMPOSITE_OVERLAY as a compositing rule.

The value given for the width and height parameters to

Tk_PhotoPutBlock do not have to correspond to the values

specified in block. If they are smaller, Tk_PhotoPutBlock

extracts a sub-block from the image data supplied. If they

are larger, the data given are replicated (in a tiled fashion) to fill the specified area. These rules operate independently in the horizontal and vertical directions.

Tk_PhotoPutZoomedBlock works like Tk_PhotoPutBlock except

that the image can be reduced or enlarged for display. The subsampleX and subsampleY parameters allow the size of the

image to be reduced by subsampling. Tk_PhotoPutZoomedBlock

will use only pixels from the input image whose X coordi-

nates are multiples of subsampleX, and whose Y coordinates are multiples of subsampleY. For example, an image of

512x512 pixels can be reduced to 256x256 by setting subsam-

pleX and subsampleY to 2. The zoomX and zoomY parameters allow the image to be enlarged by pixel replication. Each pixel of the (possibly subsampled) input image will be written to a block zoomX pixels wide and zoomY pixels high of the displayed image. Subsampling and zooming can be used together for special effects.

Tk_PhotoGetImage can be used to retrieve image data from a

photo image. Tk_PhotoGetImage fills in the structure

pointed to by the blockPtr parameter with values that describe the address and layout of the image data that the photo image has stored internally. The values are valid until the image is destroyed or its size is changed.

Tk_PhotoGetImage returns 1 for compatibility with the

corresponding procedure in the old photo widget. Tk Last change: 8.0 5

Tk Library Procedures Tk_FindPhoto(3TK)

Tk_PhotoBlank blanks the entire area of the photo image.

Blank areas of a photo image are transparent.

Tk_PhotoExpand requests that the widget's image be expanded

to be at least width x height pixels in size. The width and/or height are unchanged if the user has specified an

explicit image width or height with the -width and/or

-height configuration options, respectively. If the image

data are being supplied in many small blocks, it is more

efficient to use Tk_PhotoExpand or Tk_PhotoSetSize at the

beginning rather than allowing the image to expand in many small increments as image blocks are supplied.

Tk_PhotoSetSize specifies the size of the image, as if the

user had specified the given width and height values to the

-width and -height configuration options. A value of zero

for width or height does not change the image's width or

height, but allows the width or height to be changed by sub-

sequent calls to Tk_PhotoPutBlock, Tk_PhotoPutZoomedBlock or

Tk_PhotoExpand.

Tk_PhotoGetSize returns the dimensions of the image in

*widthPtr and *heightPtr. PORTABILITY

In Tk 8.3 and earlier, Tk_PhotoPutBlock and |

Tk_PhotoPutZoomedBlock had different signatures. If you want |

to compile code that uses the old interface against 8.4 | without updating your code, compile it with the flag |

-DUSE_COMPOSITELESS_PHOTO_PUT_BLOCK. Code linked using |

Stubs against older versions of Tk will continue to work. CREDITS The code for the photo image type was developed by Paul Mackerras, based on his earlier photo widget code. KEYWORDS photo, image

ATTRIBUTES

See attributes(5) for descriptions of the following attri-

butes: Tk Last change: 8.0 6

Tk Library Procedures Tk_FindPhoto(3TK)

_______________________________________

| ATTRIBUTE TYPE | ATTRIBUTE VALUE|

|____________________|__________________|_

| Availability | runtime/tk-8 |

|____________________|__________________|_

| Interface Stability| Uncommitted |

|____________________|_________________|

NOTES Source for Tk is available on http://opensolaris.org. Tk Last change: 8.0 7