Why do I need this?
Basically I need to turn a color image into gray-scale. Including a gray-scale version of the image could be a solution, but space is tight in my situation - I don't want my APK to be too big. Besides, I would like to work on the pixels for some effects too. Again, this is to make the APK smaller.
I have found getPixel setPixel from CCTexture2D and Getting image's pixel RGBA, but I would like something more simple.
Any help is appreciated.
Thank you!
Here is my solution for you :
1.First make a CCImage version of your image:
I) from File :
CCImage *img= new CCImage();
img->initWithImageFile("colors.png");
II) From Sprite :
II.1) CCSprite -> RenderTexture2D
II.2) RenderTexture2D -> CCImage (CCImage *testImage = RenderText2D->newCCImage();
)
2.Then You can do what you need :
CCImage *img= ... // make CCImage from CCSprite
int x=3;
if(img->hasAlpha())
x=4;
unsigned char *data = new unsigned char[img->getDataLen()*x];
data = img->getData();
// [0][0] => Left-Top Pixel !
// But cocos2d Location Y-axis is Bottom(0) to Top(max)
for(int i=0;i<img->getWidth();i++)
{
for(int j=0;j<img->getHeight();j++)
{
unsigned char *pixel = data + (i + j * img->getWidth()) * x;
// You can see/change pixels' RGBA value(0-255) here !
unsigned char r = *pixel;
unsigned char g = *(pixel + 1);
unsigned char b = *(pixel + 2) ;
unsigned char a = *(pixel + 3);
}
}
3.Then, convert it to texture_2D
//CCImage -> Texture2d
texture_2D= new CCTexture2D();
texture_2D->initWithImage(img);
4.And Finally back to CCSprite
CCSprite *result= CCSprite::createWithTexture(texture_2D);