TIEBitmap.MergeWithAlpha
Declaration
procedure MergeWithAlpha(Bitmap: TIEBitmap; DstX: integer = 0; DstY: integer = 0; DstWidth: integer = -1; DstHeight: integer = -1; Transparency: integer = 255;ResampleFilter: TResampleFilter = rfNone; Operation: TIERenderOperation = ielNormal; Resample: boolean = true;
SrcX: integer = 0; SrcY: integer = 0; Opacity: double = 1.0);
Description
Merges the color and alpha channels of Bitmap (source) with the current image.The Bitmap PixelFormat must be ie24RGB or ie32RGB.
If AlphaLocation is iaRGBA, the A channel of 32bit RGBA will be used (rather than the AlphaChannel).
| Parameter | Description |
|---|---|
| Bitmap | Source image with alpha channel to merge with the current image |
| DstX | Horizontal destination position |
| DstY | Vertical destination position |
| DstWidth | Destination width (Bitmap will be resampled/cropped to this value). -1 = the same width of source bitmap |
| DstHeight | Destination height (Bitmap will be resampled/cropped to this value). -1 = the same height of source bitmap |
| Transparency | Transparency of source bitmap. 0 = fully transparent, 255 = fully opaque |
| ResampleFilter | Interpolation filter used when source bitmap needs to be resampled |
| Operation | Blender operation to perform |
| Resample | If true Bitmap is resampled, otherwise it is cropped |
| SrcX | Source bitmap left position |
| SrcY | Source bitmap top position |
| Opacity | Specifies the opacity (0 to 1.0), which can be used as an alternative to setting transparency |
Opacity vs Transparency
Both the Opacity and Transparency parameters provide the same functionality. Transparency is the traditional ImageEn value, whereas Opacity provides easier PSD compatibility.While they can be used in combination, generally only one will be used, i.e. leave Opacity=1 and make use of transparency, or alternatively, leave Transparency=255 and make use of Opacity. For example, for 50% opacity: Transparency = 255 and Opacity = 0.5, or Transparency = 128 and Opacity = 1.0
TIEBitmap Assignment and Drawing Methods
| Method | Mode | Purpose |
|---|---|---|
| Assign | From TIEBitmap/TBitmap/TGraphic/TIcon | Copy whole image |
| AssignImage | From TIEBitmap | Like assign, but does not copy the alpha channel |
| AssignRect | From TIEBitmap/TBitmap | Copy a specified rect |
| CopyAndConvertFormat | From TIEBitmap | Copy whole image |
| CopyRectTo | To TIEBitmap | Copy rect to another image (without scaling) |
| CopyWithMask1 | To TIEBitmap | Copy image using a mask to specify what is copied from the source |
| CopyWithMask2 | To TIEBitmap | Copy image using a mask to specify what is replaced in the destintation |
| DrawToTIEBitmap | To TIEBitmap | Copies all or part of the image to a specified position and/or size |
| JoinBitmaps | From two TIEBitmaps | Draws two bitmaps to a single bitmap |
| MergeAlphaRectTo | With TIEBitmap | Merges the alpha channels of two TIEBitmaps using merge rules |
| MergeWithAlpha | With TIEBitmap | Merges all or part of two TIEBitmaps with alpha channels to a specified position |
| RenderToTIEBitmapEx | To TIEBitmap | Extended drawing of content to a TIEBitmap |
| StretchRectTo | To TIEBitmap | Copy rect to dest rect in another image (with scaling) |
| SwitchTo | To TIEBitmap | Move content from one TIEBitmap to another |
TBitmap Methods
| Method | Mode | Purpose |
|---|---|---|
| Assign | From TIEBitmap/TBitmap/TGraphic/TIcon | Copy whole image |
| AssignTo | To TIEBitmap/TBitmap | Copy whole image with optional scaling |
| AssignRect | From TIEBitmap/TBitmap | Copy a specified rect |
| CopyFromTBitmap | From TBitmap | Copy whole image |
| CopyToTBitmap | To TBitmap | Copy whole image |
| RenderToTBitmapEx | To TBitmap | Extended drawing of content to a TBitmap |
TCanvas Methods
| Method | Mode | Purpose |
|---|---|---|
| DrawToCanvas | To TCanvas | Copies whole image to canvas at specified position (ignoring the alpha channel) |
| DrawToCanvasWithAlpha | To TCanvas | Copies whole image to canvas at specified position (honoring the alpha channel) |
| RenderToCanvas | To TCanvas | Extended drawing of content to a TCanvas (ignoring the alpha channel) |
| RenderToCanvasWithAlpha | To TCanvas | Extended drawing of content to a TCanvas (honoring the alpha channel) |
Example
// Merge uplayer.png over background.pngImageEnView1.IO.LoadFromFile('background.png');
ImageEnView2.IO.LoadFromFile('uplayer.png');
ImageEnView1.IEBitmap.MergeWithAlpha(ImageEnView2.IEBitmap);
ImageEnView1.Update();
ImageEnView1.IO.SaveToFile('output.png');