void App::read_write_pixel_buffer(clan::Canvas &canvas, clan::PixelBuffer &pbuff)
{
clan::ubyte64 time_now = clan::System::get_time();
pbuff.lock(canvas, clan::access_read_write);
if (pbuff.get_format() != clan::tf_rgba8)
throw clan::Exception("Expected the format to be RGBA8");
unsigned char *dptr = (unsigned char *) pbuff.get_data();
// Only write to a portion of the pixel buffer - To keep up the example speed
const int write_fraction = 2;
const int box_width = pbuff.get_width() / write_fraction;
const int box_height = pbuff.get_height() / write_fraction;
int next_line = (pbuff.get_width() - box_width) * pbuff.get_bytes_per_pixel();
dptr += pbuff.get_bytes_per_pixel() * pbuff.get_width() * ( (pbuff.get_height() - box_height) / 2);
dptr += pbuff.get_bytes_per_pixel() * (pbuff.get_width() - box_width) / 2;
for (int ycnt = 0; ycnt < box_height; ycnt++)
{
for (int xcnt = 0; xcnt < box_width; xcnt++)
{
unsigned char blue = dptr[0];
unsigned char red = dptr[1];
unsigned char green = dptr[2];
blue = red + xcnt + (time_now / 10);
green = red + xcnt*ycnt/512 + (time_now / 20);
*(dptr++) = blue;
*(dptr++) = red;
*(dptr++) = green;
*(dptr++) = 0xFF;
}
dptr += next_line;
}
pbuff.unlock();
}
void App::upload_pixel_buffer(clan::Canvas &canvas, clan::PixelBuffer &pbuff_source, clan::PixelBuffer &pbuff_dest)
{
pbuff_source.lock(canvas, clan::access_read_only);
pbuff_dest.upload_data(canvas, clan::Rect(0,0, pbuff_source.get_size()), pbuff_source.get_data());
pbuff_source.unlock();
}