ImageAttributes::GetAdjustedPalette method (gdiplusimageattributes.h)

Article
10/13/2021

The ImageAttributes::GetAdjustedPalette method adjusts the colors in a palette according to the adjustment settings of a specified category.

Syntax

Status GetAdjustedPalette(
  [in, out] ColorPalette    *colorPalette,
  [in]      ColorAdjustType colorAdjustType
);

Parameters

[in, out] colorPalette

Type: ColorPalette*

Pointer to a ColorPalette structure that on input, contains the palette to be adjusted and, on output, receives the adjusted palette.

[in] colorAdjustType

Type: ColorPalette

Element of the ColorAdjustType enumeration that specifies the category whose adjustment settings will be applied to the palette.

Return value

Type: Status

If the method succeeds, it returns Ok, which is an element of the Status enumeration.

If the method fails, it returns one of the other elements of the Status enumeration.

Remarks

An ImageAttributes object maintains color and grayscale settings for five adjustment categories: default, bitmap, brush, pen, and text. For example, you can specify a color-remap table for the default category, a different color-remap table for the bitmap category, and still a different color-remap table for the pen category.

When you call ImageAttributes::GetAdjustedPalette, you can specify the adjustment category that is used to adjust the palette colors. For example, if you pass ColorAdjustTypeBitmap to the ImageAttributes::GetAdjustedPalette method, then the adjustment settings of the bitmap category are used to adjust the palette colors.

Examples

The following example initializes a ColorPalette structure with four colors: aqua, black, red, and green. The code also creates an ImageAttributes object and sets its bitmap remap table so that green will be converted to blue. Then the code adjusts the palette colors by passing the address of the palette to the ImageAttributes::GetAdjustedPalette method of the ImageAttributes object. The code displays the four palette colors twice: once before the adjustment and once after the adjustment.


VOID Example_GetAdjustedPalette(HDC hdc)
{
   Graphics graphics(hdc);
   INT j;

   // Create a palette that has four entries.
   ColorPalette* palette = 
      (ColorPalette*)malloc(sizeof(ColorPalette) + 3 * sizeof(ARGB));
   palette->Flags = 0;
   palette->Count = 4;

   palette->Entries[0] = 0xFF00FFFF;   // aqua
   palette->Entries[1] = 0xFF000000;   // black
   palette->Entries[2] = 0xFFFF0000;   // red
   palette->Entries[3] = 0xFF00FF00;   // green
  
   // Display the four palette colors with no adjustment.
   SolidBrush brush(Color());
   for(j = 0; j < 4; ++j)
   {
      brush.SetColor(palette->Entries[j]);
      graphics.FillRectangle(&brush, 30*j, 0, 20, 20);
   }

   // Create a remap table that converts green to blue.
   ColorMap map;
      map.oldColor = Color(255, 0, 255, 0);  // green
      map.newColor = Color(255, 0, 0, 255);  // blue

   // Create an ImageAttributes object, and set its bitmap remap table.
   ImageAttributes imAtt;
   imAtt.SetRemapTable(1, &map, ColorAdjustTypeBitmap);

   // Adjust the palette.
   imAtt.GetAdjustedPalette(palette, ColorAdjustTypeBitmap);

   // Display the four palette colors after the adjustment.
   for(j = 0; j < 4; ++j)
   {
      brush.SetColor(palette->Entries[j]);
      graphics.FillRectangle(&brush, 30*j, 30, 20, 20);
   }
}

The following illustration shows the output of the preceding code. Note that the green in the original palette was changed to blue.

Illustration with two rows of colored rectangles; the last of which is green in Row 1, blue in Row 2

Requirements

Requirement	Value
Minimum supported client	Windows XP, Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	gdiplusimageattributes.h (include Gdiplus.h)
Library	Gdiplus.lib
DLL	Gdiplus.dll