RenderTexture Save and Load file doesn't work on Android

cocos2d-x C++
#1

Hi,

I am using RenderTexture to save and load image, it works well ọn iOS but not on Android.

Here is my sample code:

// Create render texture and capture image from spriteA
RenderTexture *render = RenderTexture::create(100,100);
render->begin();
spriteA->visit();
render->end();

//Save image file from Render Texture
render->saveToFile(“SavedFileName”, Image::Format::PNG)

//Load file into Sprite then
std::string fullpath = FileUtils::getInstance()->getWritablePath() + “SavedFileName”;
Sprite *sprite = Sprite::create(fullpath);

The sprite with image the same as spriteA above but it’s quite empty on Android.

Anybody help?

Thank you.

#2

Do you really need save render to image? You can use render->getSprite() to load sprite.
Also, by default saveToFile set bool isRGBA to true, try set it to false like this render->saveToFile("SavedFileName", Image::Format::PNG, false) if it not help try Image::Format::JPG.

#3

Thank you for your feedback.

I need to save file and use it in other place. It works well on iOS but not on Android. By the way, I don’t know what location that the file is stored in Android.

#4

Could you help me to make it works on Android? Thank you.

#5

Ok, i tested you code example. I think i know what you problem. saveToFile need time, so you need check if render finish saving file. Better use callback for this, for example lambda

render->saveToFile("SavedFileName", Image::Format::PNG, true, [] (RenderTexture* texture, const std::string& string) {
 //save file finished
 //some code here
} );

or CC_CALLBACK

render->saveToFile("image.png", Image::Format::PNG, true, CC_CALLBACK_2(YourClass::saveToFileCallback, target));

//somewhere else in your code

YourClass::saveToFileCallback(RenderTexture* texture, const std::string& string)
{
 //save file finished
 //some code here
}

you can create new sprite fom image inside callback or call method that creates sprite.

Tested on Samsung Galaxy Note 3 Android 5.0

1 Like
#6

Thanks you very much ! It works fine !

#7

Here is my example !

auto drawSprite = this->getChildByName("drawSprite "); // this is a sprite , I added this in my code . auto drawSprite = Sprite::create("...") ..v..v.. 

Size pixelSize = Director::getInstance()->getWinSizeInPixels();

auto renderTexture = RenderTexture::create(drawSprite->getBoundingBox().size.width, drawSprite->getBoundingBox().size.height);
renderTexture->retain();
renderTexture->setKeepMatrix(true);
renderTexture->setVirtualViewport(Vec2(162,768-473), Rect(0, 0, 1136,768), Rect(0, 0, pixelSize.width, pixelSize.height));
renderTexture->beginWithClear(0, 0, 0, 0);
drawSprite->visit();
renderTexture->end();

std::string fileName = "avatar.png";

renderTexture->saveToFile(fileName, Image::Format::PNG, true, CC_CALLBACK_2(HelloWorld::saveToFileCallback, this));
//Add this function to avoid crash if we switch to a new scene.
    //On android , I added this line to fix crash at Layer::OnDraw function        
Director::getInstance()->getRenderer()->render();
...........................................................................
...........................................................................
void HelloWorld::saveToFileCallback(cocos2d::RenderTexture * renderTexture, const 
std::string & pathFile)
{
if (m_sprite&& !pathFile.empty())
{
	TextureCache::getInstance()->removeTexture(m_sprite->getTexture());
	m_sprite->setSpriteFrame(Sprite::create(pathFile)->getSpriteFrame());
	m_sprite->setScale(0.555555556f);
	renderTexture->setKeepMatrix(false);
}
}