Function getDevicePVRPixelFormat

core/platform/Image.cpp:495–534

* Notes: PVR file Specification have many pixel formats, cocos2d-x-v2~v4 and axmol only support pvrtc and etc1 * see: https://cdn.imgtec.com/sdk-documentation/PVR+File+Format.Specification.pdf */

 * see: https://cdn.imgtec.com/sdk-documentation/PVR+File+Format.Specification.pdf
 */
static backend::PixelFormat getDevicePVRPixelFormat(backend::PixelFormat format)
{
    switch (format)
    {
    case backend::PixelFormat::PVRTC4:
    case backend::PixelFormat::PVRTC4A:
    case backend::PixelFormat::PVRTC2:
    case backend::PixelFormat::PVRTC2A:
        if (Configuration::getInstance()->supportsPVRTC())
            return format;
        else
            return backend::PixelFormat::RGBA8;
    case backend::PixelFormat::ETC1:
        if (Configuration::getInstance()->supportsETC1())
            return format;
        else if (Configuration::getInstance()->supportsETC2())
            return backend::PixelFormat::ETC2_RGB;
        else
            return backend::PixelFormat::RGBA8;
            
    case backend::PixelFormat::ASTC4x4:
    case backend::PixelFormat::ASTC5x4:
    case backend::PixelFormat::ASTC5x5:
    case backend::PixelFormat::ASTC6x5:
    case backend::PixelFormat::ASTC6x6:
    case backend::PixelFormat::ASTC8x5:
    case backend::PixelFormat::ASTC8x6:
    case backend::PixelFormat::ASTC8x8:
    case backend::PixelFormat::ASTC10x5:
    case backend::PixelFormat::ASTC10x6:
    case backend::PixelFormat::ASTC10x8:
    case backend::PixelFormat::ASTC10x10:
    case backend::PixelFormat::ASTC12x10:
    case backend::PixelFormat::ASTC12x12:
        return Configuration::getInstance()->supportsASTC() ? format : backend::PixelFormat::RGBA8;

    default:
        return format;
    }
}

namespace
{