D3DFORMAT

Defines the various types of surface formats.

Syntax

typedef enum _D3DFORMAT {
...  (values) 
} D3DFORMAT;

There are several types of formats:

• BackBuffer or Display Formats
• Buffer Formats
• DXTn Compressed Texture Formats
• Floating-Point Formats
• FOURCC Formats
• IEEE Formats
• Mixed Formats
• Signed Formats
• Unsigned Formats
• Other
• Constant Information

All formats are listed from left to right, most-significant bit to least-significant bit. For example, D3DFORMAT_ARGB is ordered from the most-significant bit channel A (alpha), to the least-significant bit channel B (blue). When traversing surface data, the data is stored in memory from least-significant bit to most-significant bit, which means that the channel order in memory is from least-significant bit (blue) to most-significant bit (alpha).

The default value for formats that contain undefined channels (G16R16, A8, and so on) is 1. The only exception is the A8 format, which is initialized to 000 for the three color channels.

The order of the bits is from the most significant byte first, so D3DFMT_A8L8 indicates that the high byte of this 2-byte format is alpha. D3DFMT_D16 indicates a 16-bit integer value and an application-lockable surface.

Pixel formats have been chosen to enable the expression of hardware-vendor-defined extension formats, as well as to include the well-established FOURCC method. The set of formats understood by the Direct3D runtime is defined by D3DFORMAT.

Note that formats are supplied by independent hardware vendors (IHVs) and many FOURCC codes are not listed. The formats in this enumeration are unique in that they are sanctioned by the runtime, meaning that the reference rasterizer will operate on all these types. IHV-supplied formats will be supported by the individual IHVs on a card-by-card basis.

BackBuffer or Display Formats

These formats are the only valid formats for a back buffer or a display.

Buffer Formats

Depth, stencil, vertex, and index buffers each have unique formats.

All depth-stencil formats except D3DFMT_D16_LOCKABLE indicate no particular bit ordering per pixel, and the driver is allowed to consume more than the indicated number of bits-per-depth channel (but not stencil channel).

DXTn Compressed Texture Formats

These flags are used for compressed textures:

The runtime will not allow an application to create a surface using a DXTn format unless the surface dimensions are multiples of 4. This applies to offscreen-plain surfaces, render targets, 2D textures, cube textures, and volume textures.

Floating-Point Formats

These flags are used for floating-point surface formats. These 16-bits-per-channel formats are also known as s10e5 formats.

FOURCC Formats

Data in a FOURCC format is compressed data.

MAKEFOURCC

A macro for generating four-character codes follows:

#define MAKEFOURCC(ch0, ch1, ch2, ch3)                              \
                ((DWORD)(BYTE)(ch0) | ((DWORD)(BYTE)(ch1) << 8) |   \
                ((DWORD)(BYTE)(ch2) << 16) | ((DWORD)(BYTE)(ch3) << 24 ))

Here are the defined FOURCC formats:

IEEE Formats

These flags are used for floating-point surface formats. These 32-bits-per-channel formats are also known as s23e8 formats.

Mixed Formats

Data in mixed formats can contain a combination of unsigned data and signed data.

Signed Formats

Data in a signed format can be both positive and negative. Signed formats use combinations of (U), (V), (W), and (Q) data.

Unsigned Formats

Data in an unsigned format must be positive. Unsigned formats use combinations of (R)ed, (G)reen, (B)lue, (A)lpha, (L)uminance, and (P)alette data. Palette data is also referred to as color indexed data because the data is used to index a color palette.

Other

This flag is used for undefined formats.

Constant Information