Revision Release 2022.3683 Keywords iOS, Solar2D Native, C, CoronaGraphics.h, CoronaExternalBitmapFormat See also CoronaGraphics.h Corona C Functions
Enumerated type describing the pixel format of the bitmap. Bitmap channels are
RGBA format uses premultiplied alpha. This means that if the "raw" values of the channels are r, g, b, and a, the red channel will be r*(a/255).
This enum provides the following constants:
kExternalBitmapFormat_Undefined — Defaults to kExternalBitmapFormat_RGBA.kExternalBitmapFormat_Mask — Alpha; 1 byte per pixel. Textures with bitmaps of this format can be used only as masks.kExternalBitmapFormat_RGB — RGB; 3 bytes per pixel.kExternalBitmapFormat_RGBA — RGBA; 4 bytes per pixel. RGB channels must be premultiplied with alpha.The width of kExternalBitmapFormat_Mask and kExternalBitmapFormat_RGB bitmaps must be a multiple of 4. If the width is not a multiple of 4, the mask will create visual artifacts, and RGB will be treated as RGBA on Windows.
When using kExternalBitmapFormat_RGBA, the red, green, and blue channels must have premultiplied alpha.