injectVertex function
Implementation
void injectVertex(
int i, Float32List list, double l, double t, double r, double b) {
i *= 12;
list[i + 0] = l;
list[i + 1] = t;
list[i + 2] = r;
list[i + 3] = t;
list[i + 4] = l;
list[i + 5] = b;
list[i + 6] = r; // x1 - tr
list[i + 7] = t; // y1
list[i + 8] = r; // x2 - br
list[i + 9] = b; // y2
list[i + 10] = l; // x3 - bl
list[i + 11] = b; // y3
}