Advanced functions

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gflResize

The gflResize function allows to resize a picture.

GFL_ERROR gflResize(
  GFL_BITMAP* src,  
  GFL_BITMAP** dst,  
  GFL_INT32 width,  
  GFL_INT32 height,  
  GFL_UINT32 method,  
  GFL_UINT32 flags
);

Parameters

src

Pointer to a GFL_BITMAP structure.

dst

Address of a pointer to a GFL_BITMAP structure. NULL if on the same instance.

width

New width.

height

New height.

method

GFL_RESIZE_QUICK	Quick
GFL_RESIZE_BILINEAR	Bilinear

flags

Reserved, must be 0.

Return value

The function returns GFL_NO_ERROR if it is successful or a value of GFL_ERROR.

gflResizeCanvas

The gflResizeCanvas function allows to resize the canvas of a picture.

GFL_ERROR gflResizeCanvas(
  GFL_BITMAP* src,  
  GFL_BITMAP** dst,  
  GFL_INT32 width,  
  GFL_INT32 height,  
  GFL_CANVASRESIZE mode,  
  const GFL_COLOR* color
);

Parameters

src

Pointer to a GFL_BITMAP structure.

dst

Address of a pointer to a GFL_BITMAP structure. NULL if on the same instance.

width

New width.

height

New height.

mode

GFL_CANVASRESIZE_CENTER	Center
GFL_CANVASRESIZE_TOPLEFT	Top-Left
GFL_CANVASRESIZE_TOPRIGHT	Top-Right
GFL_CANVASRESIZE_BOTTOMLEFT	Bottom-Left
GFL_CANVASRESIZE_BOTTOMRIGHT	Bottom-Right

color

Pointer to a GFL_COLOR structure to receive the background color.

Return value

The function returns GFL_NO_ERROR if it is successful or a value of GFL_ERROR.

gflCrop

The gflCrop function crops a picture.

GFL_ERROR gflCrop(
  GFL_BITMAP* src,  
  GFL_BITMAP** dst,  
  const GFL_RECT* rect
);

Parameters

src

Pointer to a GFL_BITMAP structure.

dst

Address of a pointer to a GFL_BITMAP structure. NULL if on the same instance.

rect

Crop rectangle.

Return value

The function returns GFL_NO_ERROR if it is successful or a value of GFL_ERROR.

gflAutoCrop

The gflAutoCrop function performs a automatic crop on a picture.

GFL_ERROR gflAutoCrop(
  GFL_BITMAP* src,  
  GFL_BITMAP** dst,  
  const GFL_COLOR* color, 
  GFL_INT32 tolerance
);

Parameters

src

Pointer to a GFL_BITMAP structure.

dst

Address of a pointer to a GFL_BITMAP structure. NULL if on the same instance.

color

Pointer to a GFL_COLOR structure used to set the background color to search.

Can be NULL, the background color is the color at x=0, y=0.

tolerance

Color tolerance.

Return value

The function returns GFL_NO_ERROR if it is successful or a value of GFL_ERROR.

gflRotate

The gflRotate function applies a rotation on a picture.

GFL_ERROR gflRotate(
  GFL_BITMAP* src,  
  GFL_BITMAP** dst,  
  GFL_INT32 angle,  
  const GFL_COLOR* color
);

Parameters

src

Pointer to a GFL_BITMAP structure.

dst

Address of a pointer to a GFL_BITMAP structure. NULL if on the same instance.

angle

Angle of rotation in degrees.

color

Pointer to a GFL_COLOR structure used to set the background color.

Can be NULL, the background color is (0,0,0).

Return value

The function returns GFL_NO_ERROR if it is successful or a value of GFL_ERROR.

gflRotateFine

The gflRotateFine function applies a rotation on a picture.

GFL_ERROR gflRotateFine(
  GFL_BITMAP* src,  
  GFL_BITMAP** dst,  
  double angle,  
  const GFL_COLOR* color
);

Parameters

src

Pointer to a GFL_BITMAP structure.

dst

Address of a pointer to a GFL_BITMAP structure. NULL if on the same instance.

angle

Angle of rotation in degrees.

color

Pointer to a GFL_COLOR structure used to set the background color.

Can be NULL, the background color is (0,0,0).

Return value

The function returns GFL_NO_ERROR if it is successful or a value of GFL_ERROR.

gflFlipHorizontal

The gflFlipHorizontal function applies a horizontal flip on picture.

GFL_ERROR gflFlipHorizontal(
  GFL_BITMAP* src,  
  GFL_BITMAP** dst
);

Parameters

src

Pointer to a GFL_BITMAP structure.

dst

Address of a pointer to a GFL_BITMAP structure. NULL if on the same instance.

Return value

The function returns GFL_NO_ERROR if it is successful or a value of GFL_ERROR.

gflFlipVertical

The gflFlipVertical function applies a vertical flip on picture.

GFL_ERROR gflFlipVertical(
  GFL_BITMAP* src,  
  GFL_BITMAP** dst
);

Parameters

src

Pointer to a GFL_BITMAP structure.

dst

Address of a pointer to a GFL_BITMAP structure. NULL if on the same instance.

Return value

The function returns GFL_NO_ERROR if it is successful or a value of GFL_ERROR.

gflChangeColorDepth

The gflChangeColorDepth function changes the picture type.

GFL_ERROR gflChangeColorDepth(
  GFL_BITMAP* src,  
  GFL_BITMAP** dst,  
  GFL_MODE mode,  
  GFL_MODE_PARAMS params
);

Parameters

src

Pointer to a GFL_BITMAP structure.

dst

Address of a pointer to a GFL_BITMAP structure. NULL if on the same instance.

mode

GFL_MODE_TO_BINARY	Binary (8 bits)
GFL_MODE_TO_4GREY	4 Greyscale (8 bits)
GFL_MODE_TO_8GREY	8 Greyscale (8 bits)
GFL_MODE_TO_16GREY	16 Greyscale (8 bits)
GFL_MODE_TO_32GREY	32 Greyscale (8 bits)
GFL_MODE_TO_64GREY	64 Greyscale (8 bits)
GFL_MODE_TO_128GREY	128 Greyscale (8 bits)
GFL_MODE_TO_216GREY	216 Greyscale (8 bits)
GFL_MODE_TO_256GREY	256 Greyscale (8 bits)
GFL_MODE_TO_8COLORS	8 Colors (8 bits)
GFL_MODE_TO_16COLORS	16 Colors (8 bits)
GFL_MODE_TO_32COLORS	32 Colors (8 bits)
GFL_MODE_TO_64COLORS	64 Colors (8 bits)
GFL_MODE_TO_128GREY	128 Colors (8 bits)
GFL_MODE_TO_216COLORS	216 Colors (8 bits)
GFL_MODE_TO_256COLORS	256 Colors (8 bits)
GFL_MODE_TO_RGB	Red-Green-Blue (24 bits)
GFL_MODE_TO_RGBA	Red-Green-Blue-Alpha (32 bits)
GFL_MODE_TO_BGR	Blue-Green-Red (24 bits)
GFL_MODE_TO_ABGR	Alpha-Blue-Green-Red (32 bits)
GFL_MODE_TO_BGRA	Blue-Green-Red-Alpha (32 bits)

params

Indicates a dither to be used for colors, greyscale & binary.

GFL_MODE_NO_DITHER	No dithering
GFL_MODE_ADAPTIVE	Adaptive without dithering
GFL_MODE_PATTERN_DITHER	Pattern dithering
GFL_MODE_HALTONE45_DITHER	HalfTone 45 dithering
GFL_MODE_HALTONE90_DITHER	HalfTone 90 dithering
GFL_MODE_FLOYD_STEINBERG	Floyd-Steinberg dithering

Return value

The function returns GFL_NO_ERROR if it is successful or a value of GFL_ERROR.

gflMerge

The gflMerge function allows to merge a list of picture.

GFL_ERROR gflMerge(
  const GFL_BITMAP* src[],  
  const GFL_POINT origin[],  
  const GFL_UINT32 opacity[],  
  GFL_INT32  num_bitmap,  
  GFL_BITMAP** dst
);

Parameters

src

Address of an array of pointer to GFL_BITMAP structure.

origin

Address of an array of GFL_POINT structure, origin to insert for each picture.

If NULL, origin used is (0,0).

opacity

Address of an array of opacity, for each picture.

num_bitmap

Number of picture to merge.

dst

Address of a pointer to a GFL_BITMAP structure.

Remark

gflMerge works only in 24 or 32bits.

Return value

The function returns GFL_NO_ERROR if it is successful or a value of GFL_ERROR.

gflBitblt

The gflBitblt function performs a block transfert between two pictures.

GFL_ERROR gflBitblt(
  const GFL_BITMAP* src,  
  const GFL_RECT* rect,  
  const GFL_BITMAP* dst,  
  GFL_INT32 x_dest,  
  GFL_INT32 y_dest
);

Parameters

src

Pointer to a GFL_BITMAP structure, used as source.

rect

Pointer to a GFL_RECT structure. Area to copy.

dst

Pointer to a GFL_BITMAP structure, used as destination.

x_dest

X position in the destination picture.

y_dest

Y position in the destination picture.

Return value

The function returns GFL_NO_ERROR if it is successful or a value of GFL_ERROR.

gflBitbltEx

The gflBitbltEx function performs a block transfert between two pictures with alpha blending.

GFL_ERROR gflBitbltEx(
  const GFL_BITMAP* src,  
  const GFL_RECT* rect,  
  const GFL_BITMAP* dst,  
  GFL_INT32 x_dest,  
  GFL_INT32 y_dest
);

Parameters

src

Pointer to a GFL_BITMAP structure, used as source. Must be 32bits.

rect

Pointer to a GFL_RECT structure. Area to copy.

dst

Pointer to a GFL_BITMAP structure, used as destination.

x_dest

X position in the destination picture.

y_dest

Y position in the destination picture.

Return value

The function returns GFL_NO_ERROR if it is successful or a value of GFL_ERROR.

gflGetColorAt

The gflGetColorAt function gets the color at a position of the picture.

GFL_ERROR gflGetColorAt(
  GFL_BITMAP* src,  
  GFL_INT32 x,  
  GFL_INT32 y,  
  GFL_COLOR* color
);

Parameters

src

Pointer to a GFL_BITMAP structure.

x

X position.

y

Y position.

color

Pointer to a GFL_COLOR structure to obtain the result.

Return value

The function returns GFL_NO_ERROR if it is successful or a value of GFL_ERROR.

gflSetColorAt

The gflSetColorAt function allows to set a color at a position of the picture.

GFL_ERROR gflSetColorAt(
  GFL_BITMAP* src,  
  GFL_INT32 x,  
  GFL_INT32 y,  
  const GFL_COLOR* color
);

Parameters

src

Pointer to a GFL_BITMAP structure.

x

X position.

y

Y position.

color

Pointer to a GFL_COLOR structure.

Return value

The function returns GFL_NO_ERROR if it is successful or a value of GFL_ERROR.

Advanced functions

From XnView Wiki

Contents

gflResize

gflResizeCanvas

gflCrop

gflAutoCrop

gflRotate

gflRotateFine

gflFlipHorizontal

gflFlipVertical

gflChangeColorDepth

gflMerge

gflBitblt

gflBitbltEx

gflGetColorAt

gflSetColorAt