HAVE_WEBP: It is defined in PlatformHave.h for Apple ports #if PLATFORM(COCOA) #define HAVE_WEBP 1 #endif USE_WEBP: It is defined in Source/cmake/OptionsPlayStation.cmake and Source/cmake/OptionsWinCairo.cmake for WinCairo And it is defined in PlatformUse.h for GTK and WPE #if PLATFORM(GTK) || PLATFORM(WPE) #define USE_WEBP 1 #endif HAVE_AVIF: It is defined in PlatformHave.h for Apple ports. See https://github.com/WebKit/WebKit/pull/1717 USE_AVIF: It is defined in Source/cmake/OptionsWPE.cmake for WPE And it is defined Source/cmake/OptionsGTK.cmake for GTK We need a single flag for WebP and another flag for AVIF to control when the image format is enabled.
<rdar://problem/96332088>