#version 450 core
struct PosTex { vec4 pospos; vec4 texang; };
layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
layout (std430, binding = 2) readonly buffer Pos { PosTex data[]; };
int indices[6] = {0,1,3,0,3,2};
void main()
{
    vec4 pp = data[gl_VertexID / 6].pospos;
    int j = indices[gl_VertexID % 6];
    float z = (j / 2 > 0.5 ? 5000 : 100);
    vec2 xy = (j % 2 > 0 ? pp.xy : pp.zw);
    gl_Position = theMat * vec4(xy,z,1);
}