The BITMAPCOREINFO structure fully defines the dimensions and color information for a device-independent bitmap that is compatible with Microsoft OS/2 Presentation Manager versions 1.1 and 1.2 bitmaps.
typedef struct _BITMAPCOREINFO {
BITMAPCOREHEADER bmciHeader;
RGBTRIPLE bmciColors[];
} BITMAPCOREINFO;
The BITMAPCOREINFO structure contains the following fields:
| Field | Description |
| bmciHeader | Specifies a BITMAPCOREHEADER data structure that contains information about the dimensions and color format of a device-independent bitmap. | |
| bmciColors | Specifies an array of RGBTRIPLE data structures that define the colors in the bitmap. |
An OS/2 Presentation Manager device-independent bitmap consists of two distinct parts: a BITMAPCOREINFO data structure that describes the dimensions and colors of the bitmap, and an array of bytes which define the pixels of the bitmap. The bits in the array are packed together, but each scan line must be zero-padded to end on a LONG boundary. Segment boundaries can appear anywhere in the bitmap, however. The origin of the bitmap is the lower-left corner.
The bcBitCount field of the BITMAPCOREHEADER structure determines the number of bits which define each pixel and the maximum number of colors in the bitmap. This field may be set to any of the following values:
| Value | Meaning |
| 1 | The bitmap is monochrome, and the bmciColors field must contain 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 field contains 16 entries. Each pixel in the bitmap is represented by a four-bit index into the color table. |
| For example, if the first byte in the bitmap is 0x1F, then 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 16th table entry. | |
| 8 | The bitmap has a maximum of 256 colors, and the bmciColors field contains 256 entries. In this case, each byte in the array represents a single pixel. |
| 24 | The bitmap has a maximum of 224 colors. The bmciColors field is NULL, and each three bytes in the bitmap array represents the relative intensities of red, green, and blue, respectively, of a pixel. |
The colors in the bmciColors table should appear in order of importance.
Alternatively, for functions that use device-independent bitmaps, the bmciColors field can be an array of 16-bit unsigned integers that specify an index into the currently realized logical palette instead of explicit RGB values. In this case, an application using the bitmap must call device-independent bitmap functions with the wUsage parameter set to DIB_PAL_COLORS.
Note:
The bmciColors field should not contain palette indexes if the bitmap is to be stored in a file or transferred to another application. Unless the application uses the bitmap exclusively and under its complete control, the bitmap color table should contain explicit RGB values.