#include <juce_graphics.h>
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| Image () noexcept |
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| Image (PixelFormat format, int imageWidth, int imageHeight, bool clearImage) |
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| Image (PixelFormat format, int imageWidth, int imageHeight, bool clearImage, const ImageType &type) |
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| Image (const Image &) noexcept |
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Image & | operator= (const Image &) |
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| ~Image () |
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bool | operator== (const Image &other) const noexcept |
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bool | operator!= (const Image &other) const noexcept |
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bool | isValid () const noexcept |
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bool | isNull () const noexcept |
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int | getWidth () const noexcept |
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int | getHeight () const noexcept |
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Rectangle< int > | getBounds () const noexcept |
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PixelFormat | getFormat () const noexcept |
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bool | isARGB () const noexcept |
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bool | isRGB () const noexcept |
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bool | isSingleChannel () const noexcept |
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bool | hasAlphaChannel () const noexcept |
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void | clear (const Rectangle< int > &area, Colour colourToClearTo=Colour(0x00000000)) |
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Image | rescaled (int newWidth, int newHeight, Graphics::ResamplingQuality quality=Graphics::mediumResamplingQuality) const |
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Image | createCopy () const |
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Image | convertedToFormat (PixelFormat newFormat) const |
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void | duplicateIfShared () |
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Image | getClippedImage (const Rectangle< int > &area) const |
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Colour | getPixelAt (int x, int y) const |
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void | setPixelAt (int x, int y, Colour colour) |
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void | multiplyAlphaAt (int x, int y, float multiplier) |
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void | multiplyAllAlphas (float amountToMultiplyBy) |
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void | desaturate () |
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void | moveImageSection (int destX, int destY, int sourceX, int sourceY, int width, int height) |
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void | createSolidAreaMask (RectangleList< int > &result, float alphaThreshold) const |
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NamedValueSet * | getProperties () const |
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LowLevelGraphicsContext * | createLowLevelContext () const |
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int | getReferenceCount () const noexcept |
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ImagePixelData * | getPixelData () const noexcept |
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| Image (ImagePixelData *) noexcept |
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Holds a fixed-size bitmap.
The image is stored in either 24-bit RGB or 32-bit premultiplied-ARGB format.
To draw into an image, create a Graphics object for it. e.g.
g.fillEllipse (20, 20, 300, 200);
Other useful ways to create an image are with the ImageCache class, or the ImageFileFormat, which provides a way to load common image files.
- See also
- Graphics, ImageFileFormat, ImageCache, ImageConvolutionKernel
◆ PixelFormat
Enumerator |
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UnknownFormat | |
RGB | < each pixel is a 3-byte packed RGB colour value. For byte order, see the PixelRGB class.
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ARGB | < each pixel is a 4-byte ARGB premultiplied colour value. For byte order, see the PixelARGB class.
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SingleChannel | < each pixel is a 1-byte alpha channel value.
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◆ Image() [1/5]
◆ Image() [2/5]
Image::Image |
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PixelFormat |
format, |
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int |
imageWidth, |
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int |
imageHeight, |
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bool |
clearImage |
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) |
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Creates an image with a specified size and format.
The image's internal type will be of the NativeImageType class - to specify a different type, use the other constructor, which takes an ImageType to use.
- Parameters
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format | the number of colour channels in the image |
imageWidth | the desired width of the image, in pixels - this value must be greater than zero (otherwise a width of 1 will be used) |
imageHeight | the desired width of the image, in pixels - this value must be greater than zero (otherwise a height of 1 will be used) |
clearImage | if true, the image will initially be cleared to black (if it's RGB) or transparent black (if it's ARGB). If false, the image may contain junk initially, so you need to make sure you overwrite it thoroughly. |
◆ Image() [3/5]
Image::Image |
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PixelFormat |
format, |
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int |
imageWidth, |
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int |
imageHeight, |
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bool |
clearImage, |
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const ImageType & |
type |
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) |
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Creates an image with a specified size and format.
- Parameters
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format | the number of colour channels in the image |
imageWidth | the desired width of the image, in pixels - this value must be greater than zero (otherwise a width of 1 will be used) |
imageHeight | the desired width of the image, in pixels - this value must be greater than zero (otherwise a height of 1 will be used) |
clearImage | if true, the image will initially be cleared to black (if it's RGB) or transparent black (if it's ARGB). If false, the image may contain junk initially, so you need to make sure you overwrite it thoroughly. |
type | the type of image - this lets you specify the internal format that will be used to allocate and manage the image data. |
◆ Image() [4/5]
Image::Image |
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const Image & |
other | ) |
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noexcept |
Creates a shared reference to another image.
This won't create a duplicate of the image - when Image objects are copied, they simply point to the same shared image data. To make sure that an Image object has its own unique, unshared internal data, call duplicateIfShared().
◆ ~Image()
◆ Image() [5/5]
◆ clear()
Clears a section of the image with a given colour.
This won't do any alpha-blending - it just sets all pixels in the image to the given colour (which may be non-opaque if the image has an alpha channel).
◆ convertedToFormat()
Returns a version of this image with a different image format.
A new image is returned which has been converted to the specified format.
Note that if the new format is no different to the current one, this will just return a reference to the original image, and won't actually create a copy.
◆ createCopy()
Image Image::createCopy |
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const |
Creates a copy of this image. Note that it's usually more efficient to use duplicateIfShared(), because it may not be necessary to copy an image if nothing else is using it.
- See also
- getReferenceCount
◆ createLowLevelContext()
Creates a context suitable for drawing onto this image. Don't call this method directly! It's used internally by the Graphics class.
◆ createSolidAreaMask()
void Image::createSolidAreaMask |
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RectangleList< int > & |
result, |
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float |
alphaThreshold |
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Creates a RectangleList containing rectangles for all non-transparent pixels of the image.
- Parameters
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result | the list that will have the area added to it |
alphaThreshold | for a semi-transparent image, any pixels whose alpha is above this level will be considered opaque |
◆ desaturate()
void Image::desaturate |
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Changes all the colours to be shades of grey, based on their current luminosity.
◆ duplicateIfShared()
void Image::duplicateIfShared |
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Makes sure that no other Image objects share the same underlying data as this one.
If no other Image objects refer to the same shared data as this one, this method has no effect. But if there are other references to the data, this will create a new copy of the data internally.
Call this if you want to draw onto the image, but want to make sure that this doesn't affect any other code that may be sharing the same data.
- See also
- getReferenceCount
◆ getBounds()
Returns a rectangle with the same size as this image. The rectangle's origin is always (0, 0).
◆ getClippedImage()
Returns an image which refers to a subsection of this image.
This will not make a copy of the original - the new image will keep a reference to it, so that if the original image is changed, the contents of the subsection will also change. Likewise if you draw into the subimage, you'll also be drawing onto that area of the original image. Note that if you use operator= to make the original Image object refer to something else, the subsection image won't pick up this change, it'll remain pointing at the original.
The area passed-in will be clipped to the bounds of this image, so this may return a smaller image than the area you asked for, or even a null image if the area was out-of-bounds.
◆ getFormat()
Returns the image's pixel format.
◆ getHeight()
int Image::getHeight |
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const |
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noexcept |
Returns the image's height (in pixels).
◆ getPixelAt()
Colour Image::getPixelAt |
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int |
x, |
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int |
y |
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◆ getPixelData()
◆ getProperties()
Returns a NamedValueSet that is attached to the image and which can be used for associating custom values with it.
If this is a null image, this will return a null pointer.
◆ getReferenceCount()
int Image::getReferenceCount |
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const |
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noexcept |
Returns the number of Image objects which are currently referring to the same internal shared image data.
- See also
- duplicateIfShared
◆ getWidth()
int Image::getWidth |
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const |
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noexcept |
Returns the image's width (in pixels).
◆ hasAlphaChannel()
bool Image::hasAlphaChannel |
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const |
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noexcept |
True if the image contains an alpha-channel.
◆ isARGB()
bool Image::isARGB |
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const |
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noexcept |
True if the image's format is ARGB.
◆ isNull()
bool juce::Image::isNull |
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const |
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inlinenoexcept |
Returns true if this image is not valid. If you create an Image with the default constructor, it has no size or content, and is null until you reassign it to an Image which contains some actual data. The isNull() method is the opposite of isValid().
- See also
- isValid
◆ isRGB()
bool Image::isRGB |
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const |
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noexcept |
True if the image's format is RGB.
◆ isSingleChannel()
bool Image::isSingleChannel |
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const |
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noexcept |
True if the image's format is a single-channel alpha map.
◆ isValid()
bool juce::Image::isValid |
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const |
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inlinenoexcept |
Returns true if this image isn't null. If you create an Image with the default constructor, it has no size or content, and is null until you reassign it to an Image which contains some actual data. The isNull() method is the opposite of isValid().
- See also
- isNull
◆ moveImageSection()
void Image::moveImageSection |
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int |
destX, |
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int |
destY, |
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int |
sourceX, |
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int |
sourceY, |
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int |
width, |
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int |
height |
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) |
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Copies a section of the image to somewhere else within itself.
◆ multiplyAllAlphas()
void Image::multiplyAllAlphas |
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float |
amountToMultiplyBy | ) |
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Changes the overall opacity of the image.
This will multiply the alpha value of each pixel in the image by the given amount (limiting the resulting alpha values between 0 and 255). This allows you to make an image more or less transparent.
If the image doesn't have an alpha channel, this won't have any effect.
◆ multiplyAlphaAt()
void Image::multiplyAlphaAt |
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int |
x, |
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int |
y, |
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float |
multiplier |
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) |
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Changes the opacity of a pixel.
This only has an effect if the image has an alpha channel and if the given coordinates are inside the image's boundary.
The multiplier must be in the range 0 to 1.0, and the current alpha at the given coordinates will be multiplied by this value.
- See also
- setPixelAt
◆ operator!=()
bool juce::Image::operator!= |
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const Image & |
other | ) |
const |
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inlinenoexcept |
Returns true if the two images are not referring to the same internal, shared image.
◆ operator=()
Makes this image refer to the same underlying image as another object.
This won't create a duplicate of the image - when Image objects are copied, they simply point to the same shared image data. To make sure that an Image object has its own unique, unshared internal data, call duplicateIfShared().
◆ operator==()
bool juce::Image::operator== |
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const Image & |
other | ) |
const |
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inlinenoexcept |
Returns true if the two images are referring to the same internal, shared image.
◆ rescaled()
Returns a rescaled version of this image.
A new image is returned which is a copy of this one, rescaled to the given size.
Note that if the new size is identical to the existing image, this will just return a reference to the original image, and won't actually create a duplicate.
◆ setPixelAt()
void Image::setPixelAt |
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int |
x, |
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int |
y, |
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Colour |
colour |
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) |
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Sets the colour of one of the image's pixels.
If the coordinates are beyond the image's boundaries, then nothing will happen.
Note that this won't do any alpha-blending, it'll just replace the existing pixel with the given one. The colour's opacity will be ignored if this image doesn't have an alpha-channel.
- See also
- getPixelAt, Image::BitmapData::setPixelColour
◆ null
A null Image object that can be used when you need to return an invalid image. This object is the equivalient to an Image created with the default constructor.
The documentation for this class was generated from the following files: