[SOLVED] TouchGFX 4.12.3 vu-meter with plot line bug ?

[Ciuffoly www.audiodesignguide]

I am developping a vu-meter with STM32F476G-DISCO + TouchGFX 4.12.3.

The line is plotted but there are some strange effect in some positions probably a bug of the line function or graphic environment.

Also in the simulation the same effect.

https://youtu.be/ZtPSxc7IfpM

here some better result with the optional code

https://youtu.be/BvWxYT_OiOU

I can share the complete project if necessary for the debug.

void  Screen2View::handleTickEvent()
{
    if (count < 2)
    {
        count++;
        return;
    }
    // optional code to get a better result
    //left.setLineWidth(0);
    //left.invalidate();
 
    count = 0;
 
    if (value < 1024) value += 10;
    else value = 0;
 
    float value1 = (value * 68 / 1022) + 56;
    
    plot((float)value1, 179.0, 350.0, 128.0, 313.0);
 
    left.setLineWidth(2);
    left.invalidate();
}
 
void Screen2View::plot(float level, float x0, float y0, float ymax, float r)
{
#define C 3.141592/180.0
 
    char buf[30];
    float s, c, r2, x1, x2, y1, y2;
 
 
    s = sin(level * C);
    c = cos(level * C);
 
    x1 = x0 + (r * c);
    y1 = y0 - (r * s);
 
    r2 = (y0 - ymax) / s;
 
    y2 = ymax;
    x2 = x0 + (r2 * c);
 
#ifdef SIMULATOR
    sprintf(buf, "line %d,%d,%d,%d", (int)x1, (int)y1, (int)x2, (int)y2);
    
    touchgfx_printf("%s \n", buf);
#endif
 
    left.setLine((int)x1, (int)y1, (int)x2, (int)y2);
}
 

[Ciuffoly www.audiodesignguide]

I don't know why but this solve the problem

https://youtu.be/8fbZI_9ptCc

void  Screen2View::handleTickEvent()
{
    left.invalidate();
 
    if (value < 1024) value += 10;
    else value = 0;
 
    float value1 = (value * 68 / 1022) + 56;
    
    plot((float)value1, 179.0, 350.0, 128.0, 313.0);
 
    left.invalidate();
}
 
 
void Screen2View::plot(float level, float x0, float y0, float ymax, float r)
{
#define C 3.141592/180.0
 
    char buf[30];
    float s, c, r2, x1, x2, y1, y2;
 
    s = sin(level * C);
    c = cos(level * C);
 
    x1 = x0 + (r * c);
    y1 = y0 - (r * s);
 
    r2 = (y0 - ymax) / s;
 
    y2 = ymax;
    x2 = x0 + (r2 * c);
 
    left.setLine((int)x1, (int)y1, (int)x2, (int)y2);
}