layout(location = 0) in vec3 inPosition;

layout(location = 0) out vec3 ViewDirection;

out gl_PerVertex {
    vec4 gl_Position;
};

layout(std140, binding = 0) uniform UniformMatrixData {
    mat4 proj, view;
} umd;

void main()
{
    gl_Position = vec4(inPosition.xy, 1.0, 1.0);

    mat4 rotMatrix = mat4(1, 0, 0, 0,
                          0, cos(-1.57f), -sin(-1.57f), 0,
                          0, sin(-1.57f), cos(-1.57f), 0,
                          0, 0, 0, 1);

    mat4 invp = inverse(umd.proj);
    mat3 invm = transpose(mat3(umd.view));
    vec3 unpr = (invp * gl_Position).xyz;

    ViewDirection = invm * unpr;
}