gd-3000.2.0: A Haskell binding to a subset of the GD graphics library Source code Contents Index

Graphics.GD

Contents Types Creating and copying images Memory management Loading images JPEG PNG GIF Saving images JPEG PNG GIF Getting image information Manipulating images Drawing Colors

Synopsis

data Image type Size = (Int, Int) type Point = (Int, Int) type Color = CInt newImage :: Size -> IO Image copyImage :: Image -> IO Image withImage :: IO Image -> Image -> IO b -> IO b loadJpegFile :: FilePath -> IO Image loadJpegData :: Int -> Ptr a -> IO Image loadPngFile :: FilePath -> IO Image loadPngData :: Int -> Ptr a -> IO Image loadGifFile :: FilePath -> IO Image loadGifData :: Int -> Ptr a -> IO Image saveJpegFile :: Int -> FilePath -> Image -> IO () savePngFile :: FilePath -> Image -> IO () saveGifFile :: FilePath -> Image -> IO () imageSize :: Image -> IO (Int, Int) resizeImage :: Int -> Int -> Image -> IO Image rotateImage :: Int -> Image -> IO Image fillImage :: Color -> Image -> IO () drawFilledRectangle :: Point -> Point -> Color -> Image -> IO () drawFilledEllipse :: Point -> Size -> Color -> Image -> IO () drawLine :: Point -> Point -> Color -> Image -> IO () drawArc :: Point -> Size -> Int -> Int -> Color -> Image -> IO () antiAliased :: (Color -> Image -> IO a) -> Color -> Image -> IO a setPixel :: Point -> Color -> Image -> IO () rgb :: Int -> Int -> Int -> Color rgba :: Int -> Int -> Int -> Int -> Color

Types

data Image Source

type Size = (Int, Int) Source

type Point = (Int, Int) Source

type Color = CInt Source

Creating and copying images

newImage :: Size -> IO Image Source

Create a new empty image.

copyImage :: Image -> IO Image Source

Make a copy of an image.

Memory management

withImage Source

:: => IO Image Image creation action. -> Image -> IO b Some operation on the image. The result should not reference the Image. -> IO b Creates an image, performs an operation on the image, and frees it. This function allows block scoped management of Image objects. If you are handling large images, the delay before the finalizer which frees the image runs may cause significant temporary extra memory use. Use this function to force the image to be freed as soons as you are done with it. Note that it is unsafe to hold on to the Image after the function is done.

Loading images

JPEG

loadJpegFile :: FilePath -> IO Image Source

Load a JPEG image from a file.

loadJpegData Source

:: => Int Buffer size. -> Ptr a Buffer with image data. -> IO Image Load a JPEG image from a buffer.

PNG

loadPngFile :: FilePath -> IO Image Source

Load a PNG image from a file.

loadPngData Source

:: => Int Buffer size. -> Ptr a Buffer with image data. -> IO Image Load a PNG image from a buffer.

GIF

loadGifFile :: FilePath -> IO Image Source

Load a GIF image from a file.

loadGifData Source

:: => Int Buffer size. -> Ptr a Buffer with image data. -> IO Image Load a GIF image from a buffer.

Saving images

JPEG

saveJpegFile Source

:: Int quality: 0-95, or negative for default quality. -> FilePath -> Image -> IO () Save an image as a JPEG file.

PNG

savePngFile :: FilePath -> Image -> IO () Source

Save an image as a PNG file.

GIF

saveGifFile :: FilePath -> Image -> IO () Source

Save an image as a GIF file.

Getting image information

imageSize Source

:: Image -> IO (Int, Int) (width, height) Get the size of an image.

Manipulating images

resizeImage Source

:: Int width in pixels of output image -> Int height in pixels of output image -> Image -> IO Image Resize an image to a give size.

rotateImage Source

:: Int 1 for 90 degrees counter-clockwise, 2 for 180 degrees, etc. -> Image -> IO Image Rotate an image by a multiple of 90 degrees counter-clockwise.

Drawing

fillImage :: Color -> Image -> IO () Source

Fill the entire image with the given color.

drawFilledRectangle Source

:: Point Upper left corner -> Point Lower right corner -> Color -> Image -> IO ()

drawFilledEllipse Source

:: Point Center -> Size Width and height -> Color -> Image -> IO ()

drawLine Source

:: Point Start -> Point End -> Color -> Image -> IO ()

drawArc Source

:: Point Center -> Size Width and height -> Int Starting position (degrees) -> Int Ending position (degrees) -> Color -> Image -> IO ()

antiAliased :: (Color -> Image -> IO a) -> Color -> Image -> IO a Source

Use anti-aliasing when performing the given drawing function. This can cause a segault with some gd versions.

setPixel :: Point -> Color -> Image -> IO () Source

Colors

rgb Source

:: Int Red (0-255) -> Int Green (0-255) -> Int Blue (0-255) -> Color

rgba Source

:: Int Red (0-255) -> Int Green (0-255) -> Int Blue (0-255) -> Int Alpha (0-127), 0 is opaque, 127 is transparent -> Color

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