PhImage_t

Data and characteristics of an image

Synopsis:

typedef struct PhImage
{
    int         type;
    ulong_t     image_tag;
    int         bpl;
    PhDim_t     size;
    ulong_t     palette_tag;
    int         colors;
    int         xscale;
    int         yscale;
    char        format;
    char        flags;
    char        ghost_bpl;
    char        spare1;
    char        *ghost_bitmap;
    int         mask_bpl;
    char        *mask_bm;
    PgColor_t   *palette;
    char        *image;
} PhImage_t;

Description:

The PhImage_t structure describes the data and characteristics of an image. When you give an image to a PtLabel subclass widget, this is the structure you must provide. To get a pointer to this structure, use PxLoadImage(). To free the allocated members of this structure, call PhReleaseImage().

The structure contains at least the following members:

int type

The graphic type. For more info, see the discussion on the type argument in PgDrawImage().

ulong_t image_tag

The image-data tag, a cyclic redundancy check (CRC) that's used extensively by phrelay to cache images.

This tag is filled in automatically for images created in PhAB or by PxLoadImage(). If you're creating an image in some other way, you should fill in the tag by calling PxCRC(), passing it the image pixel data and the size of that data.

int bpl

The number of bytes in each line of the image.

PhDim_t size

The size of the image.

ulong_t palette_tag

The palette-data tag.

int colors

The number of colors in the image.

int xscale

The x scale factor for the image.

int yscale

The y scale factor for the image.

char format

Not used.

char flags

The image flags. The valid bits are:

• Ph_RELEASE_IMAGE-free the image data.
• Ph_RELEASE_PALETTE-free the palette data.
• Ph_RELEASE_TRANSPARENCY_MASK-free the transparency mask bitmap.
• Ph_RELEASE_GHOST_BITMAP-free the bitmap used for ghosting.
• Ph_RELEASE_IMAGE_ALL-free all the above.

The freeing is done automatically by widgets if these bits are set. Calling PhReleaseImage() with an image frees any resources that have the corresponding bit set in the image flags.

char ghost_bpl

The number of bytes per line for the ghosting bitmap.

char *ghost_bitmap

A pointer to the transparency mask for ghosting an image. The leftmost pixel corresponds to the top bit of the first byte in the mask.

int mask_bpl

The number of bytes per line for the transparency mask.

char *mask_bm

A pointer to the transparency mask. The leftmost pixel corresponds to the top bit of the first byte in the mask.

PgColor_t *palette

The image palette.

char *image

The image pixel data.

Classification:

Photon

See also:

ApGetImageRes(), PgDrawPhImagemx(), PhMakeGhostBitmap(), PhMakeTransBitmap(), PhReleaseImage(), PmMemCreateMC(), PmMemFlush(), PxLoadImage()