Image and ImageBuffer

Image represents an immutable image value. Image can be directly painted to Draw. To create or change Image, use ImageBuffer.

Image has low-cost constant time deep copy. It is moveable and Rich-Value compatible type.

U++ expects pixels to be in premultiplied alpha format.

operator const RGBA*() const

Returns a pointer to Image pixels.

Returns a pointer to the first pixel in the line i.

Returns the dimension of Image.

Same as GetSize().cx.

Same as GetSize().cy.

Number of pixels in Image - GetWidth() * GetHeight().

Returns the reference point.

Gets the physical size of Image. If physical size is not set, returns Size(0, 0).

Returns the kind of image. See ImageBuffer for detail.

Returns the unique, per application run, identifier of Image. All Images with the same serial id can be considered equal (this is useful for caching images).

bool IsSame(const Image& img) const

Same as GetSerialId() == img.GetSerialId().

bool operator==(const Image& img) const

bool operator!=(const Image& img) const

Tests whether two Images are equal (or not equal). Dimensions, hot-spot, dots and all pixels are compared. Note that the comparison can be slow.

Returns the hash-value for image. All pixels combined into hash value (potentially slow).

Returns the basic Image informations as String.

Serializes Image.

Assigns an empty Image.

Image& operator=(const Image& img)

Assigns another Image.

Image& operator=(ImageBuffer& img)

Assigns Image created in ImageBuffer. ImageBuffer is emptied by this operation.

Test whether Image has nonzero dimension.

Same as IsNullInstance.

Converts Image to Value.

Image(const Nuller&)

Constructs empty Image.

Converts Image from Value.

Copy constructor.

This function allow Image to be directly constructed from pointer to function returning the Image. This allows omitting parenthesis when passing Iml image constants as arguments.

Image(ImageBuffer& b)

Uses Image created in ImageBuffer. ImageBuffer is emptied by this operation.

Destructor.

Standard cursors

Image class contains several standard mouse cursor Images as static member methods:

ImageBuffer represents a writable Image - an array of RGBA pixels. ImageBuffer can be converted to Image in low-const constant time while loosing its content and vice versa, Image can be converted to ImageBuffer again loosing its content.

Content of Image / ImageBuffer can be classified to optimize drawing. Possible classifications are

Note that is the kind of image is unknown, painting routine determines it automatically by scanning pixels and stores the result.

Pixels of image are organized in simple continual POD array, first pixel being top-left.

U++ expects pixels to be in premultiplied alpha format.

Sets the kind of image. You can use this to avoid automatic detection.

Returns the kind of image set by SetKind.

Scans all RGBA pixels to determine Image kind.

If kind set by SetKind is other than IMAGE_UNKNOWN, returns it, otherwise calls ScanKind().

Sets the reference point. This point is e.g. used as hot-spot when Image is used as mouse pointer.

Returns the reference point.

Sets the optional physical size in dots.

Returns the optional physical size. Default value is Size(0, 0).

Returns the dimensions of image.

Same as GetSize().cx.

Same as GetSize().cy.

Returns the number of pixels in the image. Same as GetSize().cx * GetSize().cy.

Returns a pointer to the first pixel in the line i.

Returns a pointer to the first pixel of the image.  

Creates a new image of specified size. Value of pixels is undefined. Previous content of ImageBuffer is lost.

Same as GetLength() == 0.

Clears the content, removing all pixels and setting the size of Image to Size(0, 0).

void operator=(Image& img)

void operator=(ImageBuffer& img)

Assigns pixels of img to ImageBuffer. img is cleared and empty after this operation, price paid for low-cost constant time operation.

Constructs empty ImageBuffer.

Constructs ImageBuffer of specified size. Value of pixels is undefined.

ImageBuffer(Image& img)

Assigns pixels of img to ImageBuffer. img is cleared and empty after this operation, price paid for low-cost constant time operation.

Creates ImageBuffer from ImageDraw. ImageDraw is cleared and empty after this operation, price paid for low-cost constant time operation.