Paint Type

While standard X InputOutput windows and other drawables (such as pixmaps) accept only opaque paint, transparent overlay windows permit pixels to be rendered with transparent paint. Valid pixel values painted opaquely obscure pixels in underlying windows. Such pixels have associated color values that are displayed. Pixels rendered transparently have no intrinsic color; they derive their displayed color from the pixels that lie beneath.

Valid pixel values for pixels painted opaquely are obtained via XAllocColor() or another standard pixel allocation mechanism. Painting opaquely with a non-valid pixel value, for example a value that falls outside the valid colormap entries for a visual, produces undefined results for both transparent overlay windows and standard X InputOutput windows.

Paint type is defined with the data structure XSolarisOvlPaintType. By default, the paint type of a GC is opaque. The XSolarisOvlPaintType data structure is defined as:

typedef

enum { 	XSolarisOvlPaintTransparent, 	XSolarisOvlPaintOpaque, }

XSolarisOvlPaintType;