PiGetPixel()

Retrieve the value of a pixel within an image

Synopsis:

int PiGetPixel( PhImage_t const *image,
                unsigned short x,
                unsigned short y,
                unsigned long *value );

Library:

ph

Description:

This function retrieves the value of a pixel within an image.

The image argument is a pointer to a PhImage_t structure that defines the image to be queried, while the x and y arguments specify the coordinates of the pixel to be examined.

The value argument points to an area of memory where the result of the query is stored. The meaning of this value depends on the type of the image, as follows:

Pg_IMAGE_DIRECT_1555
Pg_IMAGE_DIRECT_444
Pg_IMAGE_DIRECT_4444
Pg_IMAGE_DIRECT_565
Pg_IMAGE_DIRECT_888
Pg_IMAGE_DIRECT_8888

A PgColor_t representing the pixel's color.

Pg_IMAGE_PALETTE_BYTE
Pg_IMAGE_PALETTE_NIBBLE

An index into the image's palette (0 - 255 for BYTE palettes, 0 - 15 for NIBBLE palettes).

Pg_IMAGE_GRADIENT_BYTE
Pg_IMAGE_GRADIENT_NIBBLE

A number representing the pixel's intensity (0 - 255 for BYTE gradients, 0 - 15 for NIBBLE gradients).

Pg_BITMAP_BACKFILL
Pg_BITMAP_TRANSPARENT

0 or 1 representing the pixel's state.

Returns:

0

Success.

-1

An error occurred because the pixel was out of bounds or the image type wasn't recognized.

Classification:

Photon

See also:

PgColor_t, PhImage_t, PiGetPixelFromData(), PiGetPixelRGB(), PiSetPixel(), PiSetPixelInData()

“Images” in the Raw Drawing and Animation chapter of the Photon Programmer's Guide