How to dim the current scene by certain percentage?

cocos2d-x C++
1

Hi,

How can I dim the screen by percentage? I need to dim the screen little by little until it reach a certain percentage. Is there a way using this just by Scene? If not, how?

Here is what I am trying to achieve

Your guidance will be appreicated.

2

How about make a DrawNode which draws a black rectangle that covers the whole screen, then set the opacity to the level of dimming that you need?

3

@SteveB

I just got an idea from you! Fantastic! Brilliant! Let me try that out.

4

Or you could just use a png image 1x1 black pixels and stretch it across the screen with opacity.

5

I usually go the LayerColor route, but they all lead to the same effect.

6

Yeah

Here is how i do it:

auto tint = cocos2d::LayerColor::create(cocos2d::Color4B(0, 0, 0, 200));
this->addChild(tint);
7

A lot of approaches, this is what I need. Very brilliant. I also like the 1x1 png image and stretch it to the sign of the screen. Very good!

Here is how i do it:

auto tint = cocos2d::LayerColor::create(cocos2d::Color4B(0, 0, 0, 200));
this->addChild(tint);

This cool as well! Thanks!

8

could you tell us what you have used @neonwarge04 ??

we would like to know what have you used… :smile:

9

@neonwarge04
I just made my own implementation on dimming as suggested by milos1290.

What I did is to create layer. I set the max opacity to 200. And then when game over occurs. I raised the flag that is time to dim the screen.

Here is what my code looks like on the update function:

void MainGameScene::update(float elapsed)

{
mTimeElapsed += elapsed;

if (!mMineField->isGameOver() && mTimeElapsed >= 1.0f)
{
	mTime--;
	ostringstream ss; ss << mTime;
	mTimerLabel->setString(ss.str().c_str());
	mTimeElapsed = 0.0f;
}

if (mMineField->isGameOver() || (mTime <= 0 && mBombCount <= 0))
{
	if (mScreenOpacity <= 200)
	{
		mScreenOpacity+= 20;
		mLayerColor->setOpacity(mScreenOpacity);
	}

	if (mGameOverSprite->getPositionX() <= mGameOverStopPoint.x)
	{
		mGameOverSpriteCurrentWidth += 1100.0f * elapsed;
		mGameOverSprite->setPosition(cocos2d::Vec2(mGameOverSpriteCurrentWidth , mGameOverSprite->getPositionY()));
	}
}

}

Here’s how I did the layer:

	mLayerColor = cocos2d::LayerColor::create(cocos2d::Color4B(0 , 0 , 0 , 0));

Then just add it:

this->addChild(mLayerColor);

Hope this helps.

10

yes, thanks for sharing… :smile:

11

I’m seeing a huge drop in performance when adding a dim layer or draw node on top.
From 60FPS I’m getting about 30-40 FPS when adding a semi transparent layer.
Any ideas how to improve it or it is a fill rate limitation of the GPU?