Hello @bear2023R ,
If your images take up a whole screen you can just use the block transition which does basically what you want but with bigger blocks than just a single pixel.
Another solution would be to use a dynamic bitmap and copy each pixel value individually (but it takes long to read from external ram).
The solution I went for is to set the second image visible on top of the first image and then invalidating each pixel individually. (It was taking too long so I added a RECTANGLESIZE define to invalidate multiple pixels at once.)
To be able to access each pixel and delete them once I already invalidated them I use a map that is declared globally :
std::map<int, int> pixels;
Then I initialize it :
void Screen1View::setupScreen()
{
for(int i = 0; i<WIDTH*HEIGHT/RECTANGLESIZE/RECTANGLESIZE; i++) pixels[i] = i;
pixelToInvalidate.height = RECTANGLESIZE;
pixelToInvalidate.width = RECTANGLESIZE;
}
Finally, I update one pixel (or one rectangle to be faster) each tick (60 ticks per second) in the handle tick event function :
void Screen1View::handleTickEvent()
{
//Set the image visible after the first frame
if(false == imageKitten.isVisible())
{
imageKitten.setVisible(true);
touchgfx_printf("\nImage set visible\nStarting transition");
if (HAL::USE_DOUBLE_BUFFERING) Application::getInstance()->copyInvalidatedAreasFromTFTToClientBuffer(); // Synchronize framebuffers if using double framebuffer
}
if(pixels.size() > 0) //Running transition
{
auto random_it = std::next(std::begin(pixels), rand()%pixels.size()); //Get random pixel from the ones available
pixelToInvalidate.x = (random_it->second)%(WIDTH/RECTANGLESIZE)*RECTANGLESIZE; //Translate pixel number to x position
pixelToInvalidate.y = (random_it->second)/(WIDTH/RECTANGLESIZE)*RECTANGLESIZE; //Translate pixel number to y position
imageKitten.invalidateRect(pixelToInvalidate); //Invalidate pixel
pixels.erase(random_it->first); //Remove invalidated pixel from list of pixels
touchgfx_printf("Remaining pixels : %05d\n", pixels.size());
}
else if(!transitionFinished)
{
touchgfx_printf("Transition finished.\n");
transitionFinished = true;
}
}
Note that if you want true random behavior you should set a seed.
Please find attached a working project running on the simulator (I also tested on a board).
If this post answers your question, make sure to set it as "Best answer" so I can close the ticket.
Regards,
