Standalone rendering function

Winio · March 23, 2020, 10:00pm

Hi. I need a rather small (code size) function / library to render a 64x64 multidimensional array (informations for every pixel) to a 64x64 hub75e led matrix. No graphical functions, like shapes or text needed, only the renderer, with full collor support. I scanned the smartmatrix code alot, but I couldnt extract my needed code.

I would appreciate some help.

Sebastian

Louis · March 25, 2020, 12:35pm

Take a look at the FastLED_Functions example, which efficiently writes RGB data to the background layer.

marcmerlin · March 25, 2020, 10:05pm

SmartMatrix::GFX will give you a 2D array in which you just write your 24bpp pixels and do matrix->show() when done.
http://marc.merlins.org/perso/arduino/post_2019-04-01_SmartMatrix_-SmartMatrix-Shield-v4-for-Teensy_-ESP32-shield-with-level-shifter_-and-SmartMatrix_GFX.html

or more specifically

github.com

marcmerlin/SmartMatrix_GFX/blob/master/examples/MatrixGFXDemo/MatrixGFXDemo.ino#L317


    }
    matrix->drawRGBBitmap(x, y, RGB_bmp_fixed, w, h);
}


// In a case of a tile of neomatrices, this test is helpful to make sure that the
// pixels are all in sequence (to check your wiring order and the tile options you
// gave to the constructor).
// This also counts as another speed test that measures how fast matrix->show, is.
// 4096 pixels, 55 seconds, 74 frames per second.
// without the pixel copies, it takes 54 seconds, almost as fast.
void count_pixels() {
    matrix->clear();
    for (uint16_t i=0; i<mh; i++) {
	for (uint16_t j=0; j<mw; j++) {
	    matrix->drawPixel(j, i, i%3==0?(uint16_t)LED_BLUE_HIGH:i%3==1?(uint16_t)LED_RED_HIGH:(uint16_t)LED_GREEN_HIGH);
	    matrix->show();
	}
	Serial.print("Row done: ");
	Serial.println(i);
    }
}

or simpler even, you can simply write to
matrixleds[matrix->XY(x,y)] = 0xFFAA55