Adopted by | |
Framework | /System/Library/Frameworks/OpenGLES.framework |
Availability | Available in iOS 2.0 and later. |
Companion guide | |
Declared in | EAGLDrawable.h |
iOS objects that implement the EAGLDrawable
protocol can be used as a rendering surface and displayed to the screen by an EAGLContext
object. In iOS 2.0, this protocol is implemented only by the CAEAGLLayer
class, but in the future other classes may choose to implement the protocol. The EAGLDrawable
protocol is not intended to be implemented by objects outside of the iOS.
For more about Objective-C properties, see “Properties” in The Objective-C Programming Language.
A dictionary of values that specify the desired characteristics of the drawable surface. (required)
@property(copy) NSDictionary* drawableProperties;
The drawableProperties
dictionary specifies the properties that are used by this object when it is attached to an OpenGL ES renderbuffer. Your application should set these properties before passing this object into the EAGLContext
method renderbufferStorage:fromDrawable:
. If you change the drawableProperties
dictionary, your application must call renderbufferStorage:fromDrawable:
again on the context for the new values to take effect.
EAGLDrawable.h
Keys to specify in the drawableProperties
dictionary.
EAGL_EXTERN NSString * const kEAGLDrawablePropertyColorFormat; EAGL_EXTERN NSString * const kEAGLDrawablePropertyRetainedBacking;
kEAGLDrawablePropertyColorFormat
The key specifying the internal color buffer format for the drawable surface. The value for this key is an NSString
object that specifies a specific color buffer format. This color buffer format is used by the EAGLContext
object to create the storage for a renderbuffer. The default value is kEAGLColorFormatRGBA8
.
Available in iOS 2.0 and later.
Declared in EAGLDrawable.h
.
kEAGLDrawablePropertyRetainedBacking
The key specifying whether the drawable surface retains its contents after displaying them. The value for this key is an NSNumber
object containing a BOOL
data type. If NO
, you may not rely on the contents being the same after the contents are displayed. If YES
, then the contents will not change after being displayed. Setting the value to YES
is recommended only when you need the content to remain unchanged, as using it can result in both reduced performance and additional memory usage. The default value is NO
.
Available in iOS 2.0 and later.
Declared in EAGLDrawable.h
.
Color formats that can be specified under the kEAGLDrawablePropertyColorFormat
key.
EAGL_EXTERN NSString * const kEAGLColorFormatRGB565; EAGL_EXTERN NSString * const kEAGLColorFormatRGBA8;
kEAGLColorFormatRGB565
Specifies a 16-bit RGB format that corresponds to the OpenGL ES GL_RGB565
format.
Available in iOS 2.0 and later.
Declared in EAGLDrawable.h
.
kEAGLColorFormatRGBA8
Specifies a 32-bit RGBA format that corresponds to the OpenGL ES GL_RGBA8888
format.
Available in iOS 2.0 and later.
Declared in EAGLDrawable.h
.
Last updated: 2009-06-11