在GLSL中快速排序？

#version 330 core
out vec4 FragColor;

in vec2 TexCoords;

uniform sampler2D image;
uniform int imageSize;

void quickSort(inout int arr[9], int left, int right)
{
    int i = left, j = right;
    int tmp;
    int pivot = arr[(left + right) / 2];

    while (i <= j) {
        while (arr[i]< pivot) i++;
        while (arr[j] > pivot) j--;
        if (i <= j) {
            tmp = arr[i];
            arr[i] = arr[j];
            arr[j] = tmp;
            i++;
            j--;
        }
    }

    if (left < j)
        quickSort(arr, left, j);
    if (i< right)
        quickSort(arr, i, right);
}

void main()
{
    int arr[9] = int[9](5, 2, 8, 4, 7, 1, 6, 3, 9);
    quickSort(arr, 0, 8);

    FragColor = vec4(float(arr[0]) / 10.0, float(arr[1]) / 10.0, float(arr[2]) / 10.0, 1.0);
}