Scale non-retina cocos2d-iphone game to fit on an retina iPad screen

Question

My cocos2d-iphone 1.0.1 game is supposed to be universal.

Currently, it already works fine on non-retina iPad. That is, there is no "2x" button that scales my app or anything. The non-retina iPad uses the -hd graphics from the retina iPhone, so I didn't have to make graphics specifically for the non-retina iPad. I just had to reposition my sprites, but the point is that non-retina iPad is good.

Now comes the iPad Retina.

First of all, I don't have iPad Retina graphics, only -hd iPhone retina ones.

My intention is to have the retina iPad display the game as if it was a non-retina iPad - that is, simply scale the game (the graphics still look good).

The first thing that came to my mind was to modify the director. When you replace or push a scene, the scene will get a scale of 2.0.

Although this indeed scales all the game graphics, it has position issues. Basically, if you have a sprite at the bottom of the screen, with the scene scaled it would not appear in the screen at all, because the scale pushed it further to the bottom.

I am pretty much trying to simulate the functionality of the "2x" button that appears when an iPad runs an iPhone app. In this case, technically I want the retina iPad to look exactly like a non retina iPad.

How may I achieve this?

Answer 1

whichever way you do it you will have the problem of scaling (offsets and fonts), but it works for me. I dont enable retina on retina ipads :) and use my -hd textures. Also For backgrounds textures , i systematically use 1136x768 pics ... they work for all devices (cropped on 3.5 iPhones and iPads). The only catch is if you want a background texture that has a 'border' feature, you would need one per device type, and have some 'if' statements at runtime to pick the appropriate texture.

here is my AppController startup

if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
    [director_ enableRetinaDisplay:NO];
    MPLOG(@"iPad device detected : forcing non-retina !");
    [constants setAsIpad];
    isIpadDevice = YES;
}
else {
    isIpadDevice = NO;
    if (![director_ enableRetinaDisplay:YES]) {
        MPLOG(@"Retina Display Not supported");
    }
    else {
        CGSize portrait  = [CCDirector sharedDirector].winSize;
        CGSize landscape = CGSizeMake(portrait.height, portrait.width);
        if (landscape.width >= 568.) {
            [constants setAsIphoneIpodTall];
        } else {
            [constants setAsIphoneIpodSmall];
        }
    }
}

MPLOG(@"Retina display   : %@", NSStringFromBool(kIsRetina));
MPLOG(@"Scale factor     : %.0f", director_.contentScaleFactor);
MPLOG(@"Screen size      : {%.0f, %.0f}", kScreenWidth, kScreenHeight);
MPLOG(@"Tile size        : {%.0f, %.0f}", kTileWidth, kTileHeight);
MPLOG(@"Battle mid point : %@", NSStringFromCGPoint(kBattleMidPoint));
MPLOG(@"Menu width       : %4i", kMapRightMenuWidth);

// Enables High Res mode (Retina Display) on iPhone 4 and maintains low res on all other devices


// Default texture format for PNG/BMP/TIFF/JPEG/GIF images
// It can be RGBA8888, RGBA4444, RGB5_A1, RGB565
// You can change anytime.


[CCTexture2D setDefaultAlphaPixelFormat:kCCTexture2DPixelFormat_RGBA8888];

if (deviceTypeIpodTall == kDeviceType) {

    [GESprite setDefaultPixelFormat:kCCTexture2DPixelFormat_RGBA8888];
    MPLOG(@"Pixel resolution : RGBA8888") ;

}
else {
    if (isIpadDevice) {
        [GESprite setDefaultPixelFormat:kCCTexture2DPixelFormat_RGBA8888];
        MPLOG(@"Pixel resolution : RGBA8888") ;
    }
    else {
        [GESprite setDefaultPixelFormat:kCCTexture2DPixelFormat_RGBA4444];
        MPLOG(@"Pixel resolution : RGBA4444") ;
    }

}
[GESprite defaultPixelFormat];

// If the 1st suffix is not found and if fallback is enabled then fallback suffixes are going to searched. If none is found, it will try with the name without suffix.
// On iPad HD  : "-ipadhd", "-ipad",  "-hd"
// On iPad     : "-ipad", "-hd"
// On iPhone HD: "-hd"
CCFileUtils *sharedFileUtils = [CCFileUtils sharedFileUtils];
[sharedFileUtils setEnableFallbackSuffixes:NO];             // Default: NO. No fallback suffixes are going to be used
[sharedFileUtils setiPhoneRetinaDisplaySuffix:@"-hd"];      // Default on iPhone RetinaDisplay is "-hd"
[sharedFileUtils setiPadSuffix:@"-hd"];                     // Default on iPad is "ipad"
[sharedFileUtils setiPadRetinaDisplaySuffix:@"-hd"];        // Default on iPad RetinaDisplay is "-ipadhd"

// Assume that PVR images have premultiplied alpha

[CCTexture2D PVRImagesHavePremultipliedAlpha:NO];

and in "constants" (hahaha)

+(void)setAsIpad {

kDeviceType          = deviceTypeIpadNormal;
kIsIpad              = YES;
kIsIphoneIpod        = NO;
kIsIphoneIpodTall    = NO;
kMapRightMenuWidth   = 0;
kMapBottomMenuHeight = 0;
kTileHeight          = 80.;
kTileWidth           = 80.;
kScreenWidth         = 1024;
kScreenHeight        = 768;
kIsRetina            = NO;
kScreenSize          = CGSizeMake(kScreenWidth, kScreenHeight);
kScreenMidPoint      = ccp(kScreenWidth / 2, kScreenHeight / 2);
kMidScreen           = kScreenMidPoint;
kBattleMidPoint      = ccp(kScreenWidth / 2 - kMapRightMenuWidth / 2, kScreenMidPoint.y);
}