townengine/include/twn_texture_modes.h

#ifndef TWN_TEXTURES_MODES_H
#define TWN_TEXTURES_MODES_H

/* alpha channel information */
enum texture_mode {
    TEXTURE_MODE_OPAQUE,        /* all pixels are solid */
    TEXTURE_MODE_SEETHROUGH,  	/* some pixels are alpha zero */
    TEXTURE_MODE_GHOSTLY,       /* arbitrary alpha values */
};

#endif