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Diffstat (limited to 'documentation/drawing.html')
| -rw-r--r-- | documentation/drawing.html | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/documentation/drawing.html b/documentation/drawing.html index 90f9ae6f3..efd8075db 100644 --- a/documentation/drawing.html +++ b/documentation/drawing.html @@ -865,13 +865,19 @@ color. The <TT>draw()</TT> method draws the image using the colors in the file, and masks off any transparent colors automatically. -<P>The <TT>Fl_RGB_Image</TT> class encapsulates a full-color (or -grayscale) image with 1 to 4 color components. Images with an -even number of components are assumed to contain an alpha -channel that is used for transparency. The transparency provided -by the <TT>draw()</TT> method is either a 24-bit blend against -the existing window contents or a "screen door" transparency -mask, depending on the platform and screen color depth. +<P>The <TT>Fl_RGB_Image</TT> class encapsulates a full-color +(or grayscale) image with 1 to 4 color components. Images with +an even number of components are assumed to contain an +alpha channel that is used for transparency. The transparency +provided by the <TT>draw()</TT> method is either a 24-bit +blend against the existing window contents or a "screen door" +transparency mask, depending on the platform and screen color depth. + +<H4><A NAME=fl_can_do_alpha_blending>char fl_can_do_alpha_blending()</A></H4> + +<P><TT>fl_can_do_alpha_blending()</TT> will return 1, if your +platform supports true alpha blending for RGBA images, or 0, +if FLTK will use screen door transparency. <P>FLTK also provides several image classes based on the three standard image types for common file formats: |