BITMAPCOREINFO
The BITMAPCOREINFO
structure defines the dimensions and color information for a device-independent
bitmap (DIB).
typedef struct _BITMAPCOREINFO { // bmci
BITMAPCOREHEADER bmciHeader;
RGBTRIPLE bmciColors[1];
} BITMAPCOREINFO;
Members
bmciHeader
Specifies a BITMAPCOREHEADER structure that contains
information about the dimensions and color format of a DIB.
bmciColors
Specifies an
array of RGBTRIPLE
structures that define the colors in the bitmap.
Remarks
A DIB
consists of two parts: a BITMAPCOREINFO structure describing the
dimensions and colors of the bitmap, and an array of bytes defining the pixels
of the bitmap. The bits in the array are packed together, but each scan line
must be padded with zeroes to end on a LONG boundary. The origin of the
bitmap is the lower left corner.
The bcBitCount
member of the BITMAPCOREHEADER structure determines the number of bits
that define each pixel and the maximum number of colors in the bitmap. This
member can be one of the following values:
|
Value |
Meaning |
|
1 |
The bitmap
is monochrome, and the bmciColors member contains two entries. Each
bit in the bitmap array represents a pixel. If the bit is clear, the pixel is
displayed with the color of the first entry in the bmciColors table;
if the bit is set, the pixel has the color of the second entry in the table. |
|
4 |
The bitmap
has a maximum of 16 colors, and the bmciColors member contains up to
16 entries. Each pixel in the bitmap is represented by a 4-bit index into the
color table. For example, if the first byte in the bitmap is 0x1F, the byte
represents two pixels. The first pixel contains the color in the second table
entry, and the second pixel contains the color in the sixteenth table entry. |
|
8 |
The bitmap
has a maximum of 256 colors, and the bmciColors member contains up to
256 entries. In this case, each byte in the array represents a single pixel. |
|
24 |
The bitmap
has a maximum of 2 (24) colors, and
the bmciColors member is NULL. Each three-byte triplet in the bitmap
array represents the relative intensities of red, green, and blue,
respectively, for a pixel. |
The colors in
the bmciColors table should appear in order of importance.
Alternatively,
for functions that use DIBs, the bmciColors member can be an array of
16-bit unsigned integers that specify indices into the currently realized
logical palette, instead of explicit RGB values. In this case, an application
using the bitmap must call the DIB functions (CreateDIBitmap, CreateDIBPatternBrush,
and CreateDIBSection) with the iUsage parameter set to
DIB_PAL_COLORS.
Note The bmciColors
member should not contain palette indices if the bitmap is to be stored in a
file or transferred to another application. Unless the application has
exclusive use and control of the bitmap, the bitmap color table should contain
explicit RGB values.
See Also