File format

Adobe Texture Format files store image texture data ready to be used from Actionscript in Adobe Flash or Harman AIR applications with the Stage3D API.

Capabilities

• Compressed image data (PVRTC, ETC1, DXT1, DXT5)
• Uncompressed image data
• Builtin cubemaps
• Builtin mipmaps
• Texture streaming

Format

The file is made up of to primary sections: the header which provides information about the file and the image data blocks which store the file's image data.

Header

char signature[3] = "ATF";  // The signature is used to identify the file
int24 dataLength;
byte imageFlags;            // Image type and format stored in a bitmask
int8 imageWidth;            // The width of the image as a power of 2 (e.g. a value of 10 would be 2^10 = 1024 pixels)
int8 imageHeight;           // The height of the image as a power of 2 (e.g. a value of 10 would be 2^10 = 1024 pixels)
int8 mipmaps;               // Number of images stored in this file, the amount of images may be greater if the image is a cubemap

imageFlags bitmask

TFFFFFFF

Key	Value	Description
T	0	Normal image type
T	1	Cubemap image type
FFFFFFF	0	RGB888 image format
FFFFFFF	1	RGBA8888 image format
FFFFFFF	2	Compressed image format (DXT,PVRTC,ETC)

Image data blocks

The number of image blocks depends on the image count and wether the image is compressed and/or is a cubemap, cubemaps have 6 data blocks per image and compressed images have 8 data blocks per image.