Added in API level 8

Summary: Constants | Ctors | Methods | Inherited Methods

ETC1

Kotlin |Java

public class ETC1
extends Object

java.lang.Object
↳	android.opengl.ETC1

Methods for encoding and decoding ETC1 textures.

The standard for the ETC1 texture format can be found at http://www.khronos.org/registry/gles/extensions/OES/OES_compressed_ETC1_RGB8_texture.txt

The PKM file format is of a 16-byte header that describes the image bounds followed by the encoded ETC1 texture data.

See also:

ETC1Util

Summary

Constants
`int`	`DECODED_BLOCK_SIZE` Size in bytes of a decoded block.
`int`	`ENCODED_BLOCK_SIZE` Size in bytes of an encoded block.
`int`	`ETC1_RGB8_OES` Accepted by the internalformat parameter of glCompressedTexImage2D.
`int`	`ETC_PKM_HEADER_SIZE` Size of a PKM file header, in bytes.

Public constructors
`ETC1()`

Public methods
`static void`	`decodeBlock(Buffer in, Buffer out)` Decode a block of pixels.
`static void`	`decodeImage(Buffer in, Buffer out, int width, int height, int pixelSize, int stride)` Decode an entire image.
`static void`	`encodeBlock(Buffer in, int validPixelMask, Buffer out)` Encode a block of pixels.
`static void`	`encodeImage(Buffer in, int width, int height, int pixelSize, int stride, Buffer out)` Encode an entire image.
`static void`	`formatHeader(Buffer header, int width, int height)` Format a PKM header
`static int`	`getEncodedDataSize(int width, int height)` Return the size of the encoded image data (does not include size of PKM header).
`static int`	`getHeight(Buffer header)` Read the image height from a PKM header
`static int`	`getWidth(Buffer header)` Read the image width from a PKM header
`static boolean`	`isValid(Buffer header)` Check if a PKM header is correctly formatted.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Constants

DECODED_BLOCK_SIZE

Added in API level 8

public static final int DECODED_BLOCK_SIZE

Size in bytes of a decoded block.

Constant Value: 48 (0x00000030)

ENCODED_BLOCK_SIZE

Added in API level 8

public static final int ENCODED_BLOCK_SIZE

Size in bytes of an encoded block.

Constant Value: 8 (0x00000008)

ETC1_RGB8_OES

Added in API level 8

public static final int ETC1_RGB8_OES

Accepted by the internalformat parameter of glCompressedTexImage2D.

Constant Value: 36196 (0x00008d64)

ETC_PKM_HEADER_SIZE

Added in API level 8

public static final int ETC_PKM_HEADER_SIZE

Size of a PKM file header, in bytes.

Constant Value: 16 (0x00000010)

Public constructors

ETC1

public ETC1 ()

Public methods

decodeBlock

Added in API level 8

public static void decodeBlock (Buffer in, 
                Buffer out)

Decode a block of pixels.

Parameters
`in`	`Buffer`: a native order direct buffer of size ENCODED_BLOCK_SIZE that contains the ETC1 compressed version of the data.
`out`	`Buffer`: a native order direct buffer of size DECODED_BLOCK_SIZE that will receive the decoded data. The data represents a 4 x 4 square of 3-byte pixels in form R, G, B. Byte (3 * (x + 4 * y) is the R value of pixel (x, y).

decodeImage

Added in API level 8

public static void decodeImage (Buffer in, 
                Buffer out, 
                int width, 
                int height, 
                int pixelSize, 
                int stride)

Decode an entire image.

Parameters
`in`	`Buffer`: native order direct buffer of the encoded data.
`out`	`Buffer`: native order direct buffer of the image data. Will be written such that pixel (x,y) is at pIn + pixelSize * x + stride * y. Must be large enough to store entire image.
`width`	`int`
`height`	`int`
`pixelSize`	`int`: must be 2 or 3. 2 is an GL_UNSIGNED_SHORT_5_6_5 image, 3 is a GL_BYTE RGB image.
`stride`	`int`

encodeBlock

Added in API level 8

public static void encodeBlock (Buffer in, 
                int validPixelMask, 
                Buffer out)

Encode a block of pixels.

Parameters
`in`	`Buffer`: a native order direct buffer of size DECODED_BLOCK_SIZE that represent a 4 x 4 square of 3-byte pixels in form R, G, B. Byte (3 * (x + 4 * y) is the R value of pixel (x, y).
`validPixelMask`	`int`: is a 16-bit mask where bit (1 << (x + y * 4)) indicates whether the corresponding (x,y) pixel is valid. Invalid pixel color values are ignored when compressing.
`out`	`Buffer`: a native order direct buffer of size ENCODED_BLOCK_SIZE that receives the ETC1 compressed version of the data.

encodeImage

Added in API level 8

public static void encodeImage (Buffer in, 
                int width, 
                int height, 
                int pixelSize, 
                int stride, 
                Buffer out)

Encode an entire image.

Parameters
`in`	`Buffer`: a native order direct buffer of the image data. Formatted such that pixel (x,y) is at pIn + pixelSize * x + stride * y;
`width`	`int`
`height`	`int`
`pixelSize`	`int`: must be 2 or 3. 2 is an GL_UNSIGNED_SHORT_5_6_5 image, 3 is a GL_BYTE RGB image.
`stride`	`int`
`out`	`Buffer`: a native order direct buffer of the encoded data. Must be large enough to store entire encoded image.

formatHeader

Added in API level 8

public static void formatHeader (Buffer header, 
                int width, 
                int height)

Format a PKM header

Parameters
`header`	`Buffer`: native order direct buffer of the header.
`width`	`int`: the width of the image in pixels.
`height`	`int`: the height of the image in pixels.

getEncodedDataSize

Added in API level 8

public static int getEncodedDataSize (int width, 
                int height)

Return the size of the encoded image data (does not include size of PKM header).

Parameters
`width`	`int`
`height`	`int`

Returns
`int`

getHeight

Added in API level 8

public static int getHeight (Buffer header)

Read the image height from a PKM header

Parameters
`header`	`Buffer`: native order direct buffer of the header.

Returns
`int`

getWidth

Added in API level 8

public static int getWidth (Buffer header)

Read the image width from a PKM header

Parameters
`header`	`Buffer`: native order direct buffer of the header.

Returns
`int`

isValid

Added in API level 8

public static boolean isValid (Buffer header)

Check if a PKM header is correctly formatted.

Parameters
`header`	`Buffer`: native order direct buffer of the header.

Returns
`boolean`