Sparrow Forum

1. 

   dprijadi
   Member

   hi friends

   im simulating a scrolling list of selection in a big SPSprite.
   the selection contains 50+ with 1 SPTextfield and 1 SPIMage for each selection..

   the screen would look like this

   Enter your level :

   (level image) Level 1 text description
   (level image) Level 2 text description
   .
   .
   .
   ((level image) Level 50 tezt description

   each selection textfield is 300x30 and each image is 30x30. all image is using SPtexture in a texture atlas and the sptextfield uses a bitmapped font.

   my questions are:
   - how much is the memory requirement of the SPSprite container? am i correct to assume that since i use atlas and bitmapfont then even if i put many image and text based from that atlas, imy memory requirement will be minimal? even with 100 or even 300 selection lines?
   - which saves mor RAM? using built innfont in SPtextfield or using a Bitmapped font? assuming speed and performance is not a factor

   regards

   Posted 8 months ago #
2. 

   dprijadi
   Member

   note: when i implement the inertial scrolling code from Sparrow WIKI, the direction of scroll is backwards, the screen sxrolls up when i move down and vice versa. otherwise it works perfectly

   Posted 8 months ago #
3. 

   Jugibur
   Moderator

   In *principe* memory consumption is both the same: if using a texture altas or directly load an image.
   BUT: Internally each loaded image must have dimensions with a power of 2.
   So if you load a single image have in some cases unused space if the bitmap inside exactly fits the dimensions with a power of 2.
   In an huge texture atlas you can place more bitmaps efficiently.
   So *practically* a texture atlas most of the time saves more or less RAM.
   One more thing is, that using a texture atlas speed up rendering, because more bitmaps can be drawn in one cycle.

   Second question: Internally the SPTextField creates also a bitmap of the font you directly loaded from your iDevice. So the memory consumption might not be a big difference to a separately created bitmap font (exceptionally the wasted space problematic of using a single image I mentioned above).

   Tip: If you want to save RAM use the variations of PVRs, this is very informative:
   http://wiki.sparrow-framework.org/tutorials/pvr_textures

   Posted 8 months ago #
4. 

   dprijadi
   Member

   hello jugibur

   so a single texture used in many SPImages wont require lots of memory right ?

   Assuming i have 1 SPTexture showing an Apple Picture, i use that SPTexture on 100xSPImages , then the memory consumption is the same using 1xSPImage and 100xSPImage when both use the same SPTexture ?

   #define kMaxApple 1000
   SPTexture *t = [SPTexture TextureWithContentsOfFile:@"applepic.png");
   for (int i=0 , i<=kMaxApple , i++) {
   SPImage *i = [SPImage ImageWithTexture:t];
   [self addchild:i]; //self is an SPSprite Container
   }

   the code snippet above required the same memory whether kMaxApple is 10 or 100 or 1000 ? (i mean the graphic memory requirement)

   Posted 8 months ago #
5. 

   Jugibur
   Moderator

   Yes dprijadi, the images have only a pointer of one loaded texture in RAM,
   so it's very efficient. To manage this in an easier way you can save each texture and atlas to a kind of media manager. So in every level of your game you simply ask the media manager for the texture of a given key. And you could bundle the loading of a bunch of textures in one section.

   You could also color each image in a different way,
   i.e. You have one gray scale texture of an ball and you need 5 different colors of balls, you just need to tint the texture to that colors you need. See here:
   http://wiki.sparrow-framework.org/tutorials/modifying_the_color_of_an_image

   I have used that for different colors of the buttons in my game.

   Posted 8 months ago #

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