GDI+ Structures

Structures used by the GDI+ Flat API functions. Some of them have been prefixed with “Gp” to avoid name conflicts with other structures with the same name.

BitmapData

Stores attributes of a Bitmap objec. The BitmapData structure is used by the GdpiBitmapLockBits and GdpiBitmapUnlockBits functions.

BlurParams

A BlurParams structure contains members that specify the nature of a Gaussian blur.

You can apply a Gaussian blur effect to a bitmap by following these steps.

1. Create and initialize a BlurParams structure.
2. Pass the address of the BlurParams structure to the GdipSetEffectParameters function.

Remarks: Minimum availability: GDI+ 1.1

BrightnessContrastParams

A BrightnessContrastParams structure contains members that specify a the nature of a brightness or contrast adjustment.

You can change the brightness or contrast (or both) of a bitmap by following these steps.

1. Create and initialize a BrightnessContrastParams structure.
2. Pass the address of the BrightnessContrastParams structure to the GdipSetEffectParameters function.

Remarks: Minimum availability: GDI+ 1.1

ColorBalanceParams

A ColorBalanceParams structure contains members that specify the nature of a color balance adjustment.

You can change the color balance of a bitmap by following these steps.

1. Create and initialize a ColorBalanceParams structure.
2. Pass the address of the ColorBalanceParams structure to the GdipSetEffectParameters function.

ColorLUTParams

A ColorLUTParams structure contains members (color lookup tables) that specify color adjustments to a bitmap.

You can apply a custom adjustment to a bitmap by following these steps.

1. Create a ColorLUTParams structure.
2. Each member of the ColorLUTParams structure is a color lookup table (array of 256 bytes) for a particular color channel, alpha, red, green, or blue. Assign values of your choice to the four lookup tables.
3. Pass the address of the ColorLUTParams structure to the ColorLUT::SetParameters method of a ColorLUT object.
4. Pass the address of the ColorLUT object to the Graphics::DrawImage method or to the Bitmap::ApplyEffect method.

Remarks

A lookup table specifies how existing color channel values should be replaced by new values. A color channel value of j is replaced by the jth entry in the lookup table for that channel. For example, an existing blue channel value of 25 would be replaced by the value of lutB(25).

ColorMatrix

The ColorMatrix structure contains a 5x5 matrix of real numbers. Several of the ImageAttributes functions adjust image colors by using a color matrix. Alias: GpColorMatrix.

m(0 to 4, 0 to 4) as REAL

Use an array (0 TO 4, 0 TO 4) AS SINGLE, and pass @array(0, 0)

Remarks

A 5x5 color matrix is a homogeneous matrix for a 4-space transformation. The element in the fifth row and fifth column of a 5x5 homogeneous matrix must be 1, and all of the other elements in the fifth column must be 0. Color matrices are used to transform color vectors. The first four components of a color vector hold the red, green, blue, and alpha components (in that order) of a color. The fifth component of a color vector is always 1.

ColorPalette

The ColorPalette structure defines an array of colors that make up a color palette. The colors are 32-bit ARGB colors.

To ease the use of this structure, GpColorPalette defines Entries as an array (2 TO 255) of ARGB colors.

EncoderParameter

An EncoderParameter structure holds a parameter that can be passed to an image encoder. An EncoderParameter structure can also be used to receive a list of possible values supported by a particular parameter of a particular image encoder.

' // Encoder parameter GUIDs
Dim Shared EncoderChrominanceTable AS GUID = Type(&hF2E455DC, &h09B3, &h4316, {&h82, &h60, &h67, &h6A, &hDA, &h32, &h48, &h1C})
Dim Shared EncoderColorDepth       AS GUID = Type(&h66087055, &hAD66, &h4C7C, {&h9A, &h18, &h38, &hA2, &h31, &h0B, &h83, &h37})
Dim Shared EncoderColorSpace       AS GUID = Type(&hAE7A62A0, &hEE2C, &h49D8, {&h9D, &h07, &h16, &hAF, &h4E, &h4D, &hBD, &h1E})
Dim Shared EncoderCompression      AS GUID = Type(&hECCBFEFF, &h4F77, &h4D61, {&h8A, &hB9, &h6A, &h51, &hF6, &hD3, &h8E, &h8B})
Dim Shared EncoderImageItems       AS GUID = Type(&h63875E13, &h1F1D, &h45AB, {&h91, &h95, &hCF, &h0F, &h5A, &h0C, &hBE, &h1B})
Dim Shared EncoderLuminanceTable   AS GUID = Type(&hEDB33BCE, &h0266, &h4A77, {&hB9, &h04, &h27, &h21, &h60, &h99, &hE7, &h17})
Dim Shared EncoderQuality          AS GUID = Type(&h1D5BE4B5, &hFA4A, &h452D, {&h9C, &hDD, &h5D, &hB3, &h51, &h05, &hE7, &hEB})
Dim Shared EncoderRenderMethod     AS GUID = Type(&h6DB9FCAA, &h0E84, &h485E, {&h9A, &h8D, &h1E, &h8B, &h12, &h1F, &h0C, &hC1})
Dim Shared EncoderSaveAsCMYK       AS GUID = Type(&hC617F8E1, &h1E5F, &h4B1F, {&hA6, &hD3, &h5E, &h1D, &h73, &h6C, &h6A, &h1D})
Dim Shared EncoderSaveFlag         AS GUID = Type(&h292266FC, &hAC40, &h47BF, {&h8C, &hFC, &hA8, &h5B, &h89, &hA6, &h55, &hDE})
Dim Shared EncoderScanMethod       AS GUID = Type(&h3A4E2661, &h3109, &h4E56, {&h85, &h1E, &h9F, &h7E, &h42, &h9F, &h1A, &h22})
Dim Shared EncoderTransformation   AS GUID = Type(&h8D0EB2D1, &h6A48, &h4A94, {&hAC, &h61, &h52, &h95, &hC7, &h2E, &h8E, &h33})
Dim Shared EncoderVersion          AS GUID = Type(&h24D18C76, &h814A, &h41A4, {&hBF, &h53, &h1C, &h21, &h9C, &hCC, &hF7, &h97})

EncoderParameters

An EncoderParameters structure is an array of EncoderParameter structures along with a data member that specifies the number of EncoderParameter structures in the array.

ENHMETAHEADER

The ENHMETAHEADER structure contains enhanced-metafile data such as the dimensions of the picture stored in the enhanced metafile, the count of records in the enhanced metafile, the resolution of the device on which the picture was created, and so on.

This structure is always the first record in an enhanced metafile.

[ENHMETAHEADER structure] (https://learn.microsoft.com/en-us/windows/win32/api/wingdi/ns-wingdi-enhmetaheader)

GdiplusStartupInput

The GdiplusStartupInput structure holds a block of arguments that are required by the GdiplusStartup function.

Remarks

The GdiplusStartupInput structure provides a constructor that sets the GdiplusVersion member to 1 and allows you to specify values for the other three members. All of the constructor parameters are optional, so you can declare a variable of type GdiplusStartupInput without passing any arguments to the constructor, and all of the members will be initialized with appropriate default values.

If you set the SuppressBackgroundThread member of the GdiplusStartupinput parameter to TRUE, you must call the hook and unhook functions returned in the output parameter. Call those functions before and after the application’s main message loop; that is, a message loop that is active for the lifetime of GDI+. Call the hook function before the loop starts, and call the unhook function after the loop ends.

GdiplusStartupOutput

The GdiplusStartup function uses the GdiplusStartupOutput structure to return (in its output parameter) a pointer to a hook function and a pointer to an unhook function. If you set the SuppressBackgroundThread member of the input parameter to TRUE, then you are responsible for calling those functions to replace the Microsoft Windows GDI+ background thread.

Call the hook and unhook functions before and after the application’s main message loop; that is, a message loop that is active for the lifetime of GDI+. Call the hook function before the loop starts, and call the unhook function after the loop ends. The token parameter of the hook function receives an identifier that you should later pass to the unhook function. If you do not pass the proper identifier (the one returned by the hook function) to the unhook function, there will be resource leaks that won’t be cleaned up until the process exits.

If you do not want to be responsible for calling the hook and unhook functions, set the SuppressBackgroundThread member of the input parameter (passed to GdiplusStartup) to FALSE.

GpCharacterRange

A CharacterRange structure specifies a range of character positions within a string.

Remarks

A character range is a range of character positions within a string of text. The area of the display that is occupied by a group of characters that are specified by the character range is the bounding region. A character range is set by GdipSetStringFormatMeasurableCharacterRanges. The number of ranges that are currently set can be determined by calling GdipGetStringFormatMeasurableCharacterRangeCount. This number is also the number of regions expected to be obtained by the GdipMeasureCharacterRanges function.

GpColorMap

The ColorMap structure contains two COLORREF values. Several of the ImageAttributes functions adjust image colors by using a color remap table, which is an array of ColorMap structures.

Renamed as GpColorMp because there is a GDI ColorMap structure with different member names.

GpPathData

The PathData structure is used by the GdipGetPathData function. It has an array of points and an array of types. Each element in the array of types is a byte that specifies the point type and a set of flags for the corresponding element in the array of points. You can use a PathData structure to get or set the data points (and their types) of a path.

GpPointF

Encapsulates a point in a 2-D coordinate system.

GpRectF

Stores the upper-left corner, width, and height of a rectangle.

GpSizeF

The GpSizeF structure encapsulates a Width and Height dimension in a 2-D coordinate system.

HueSaturationLightnessParams

The HueSaturationLightnessParams structure contains members that specify hue, saturation and lightness adjustments to a bitmap.

You can adjust the hue, saturation, and lightness of a bitmap by following these steps.

1. Create and initialize a HueSaturationLightnessParams structure.
2. Pass the address of the HueSaturationLightnessParams structure to the GdipSetEffectParameters function.

Remarks: Minimum availability: GDI+ 1.1

ImageCodecInfo

An ImageCodecInfo structure stores information about an image codec (encoder/decoder). GDI+ provides several built-in image codecs. You can obtain information about those codecs by calling the GetImageEncoders function and the GetImageDecoders function. Each of those functions returns an array of ImageCodecInfo structures, one for each available encoder or decoder.

LevelParams

The LevelsParams structure contains members that specify adjustments to the light, midtone, or dark areas of a bitmap.

You can adjust the light, midtone, or dark areas of a bitmap by following these steps.

1. Create and initialize a LevelsParams structure.
2. Pass the address of the LevelsParams structure to the GdipSetEffectParameters function.

Remarks: Minimum availability: GDI+ 1.1

MetafileHeader

A MetafileHeader object stores properties of an associated metafile.

Metafile type

Remarks

Metafiles provide a device-independent and application-independent way to share pictures. They contain records that describe a sequence of graphics application programming interfaces (APIs) to invoke in a particular order with their associated graphics data. Metafiles can be recorded by an application and later played back by that application or by another one to reproduce a particular picture. They can also be used to send content to a print spooler. Enhanced metafiles support the ability to provide both Microsoft Windows GDI+ and Windows Graphics Device Interface (GDI) descriptions of the same picture so that both GDI+ and down-level GDI applications can render it.

PropertyItem

A PropertyItem structure holds one piece of image metadata.

PWMFRect16

The PWMFRect16 structure defines a rectangle that bounds a placeable metafile. The rectangle defines the size and position of the metafile.

RedEyeCorrectionParams

A RedEyeCorrectionParams structure contains members that specify the areas of a bitmap to which a red-eye correction is applied.

You can can correct red eyes in a bitmap by following these steps.

1. Create and initialize a RedEyeCorrectionParams structure.
2. Pass the address of the RedEyeCorrectionParams structure to the GdipSetEffectParameters function.

Remarks: Minimum availability: GDI+ 1.1

SharpenParams

The SharpenParams structure contains members that specify the nature of a sharpening adjustment to a bitmap.

You can adjust the sharpness of a bitmap by following these steps.

1. Create and initialize a SharpenParams structure.
2. Pass the address of the SharpenParams structure to the GdipSetEffectParameters function.

Remarks: Minimum availability: GDI+ 1.1

TintParams

A TintParams structure contains members that specify the nature of a tint adjustment to a bitmap.

You can adjust the tint of a bitmap by following these steps.

1. Create and initialize a TintParams structure.

2. Pass the address of the TintParams structure to the GdipSetEffectParameters function.

Remarks: Minimum availability: GDI+ 1.1

WmfPlaceableFileHeader

The WmfPlaceableFileHeader structure defines the fields of a placeable metafile header. Placeable metafiles were created as a way of specifying how a metafile is mapped and scaled on a display device.

Remarks

Although placeable metafiles are quite common, they are not directly supported by the Microsoft Windows application programming interface (API). To display a placeable metafile using the Windows API, you must first strip the placeable metafile header from the file. This is typically performed by copying the metafile to a temporary file starting at file offset 22 (0x16). This is because each placeable metafile begins with a 22-byte header that is followed by a standard metafile.