#include "math/sdf_shapes"
#include "math/sdf_utils" // For aabb_sdf helper

fn get_dist(p: vec3<f32>, obj_type: f32) -> f32 {
    if (obj_type == 1.0) { return length(p) - 1.0; } // Unit Sphere
    if (obj_type == 2.0) { return sdBox(p, vec3<f32>(1.0)); } // Unit Box
    if (obj_type == 3.0) { return sdTorus(p, vec2<f32>(1.0, 0.4)); } // Unit Torus
    if (obj_type == 4.0) { return sdPlane(p, vec3<f32>(0.0, 1.0, 0.0), 0.0); }
    return 100.0;
}

fn map_scene(p: vec3<f32>, skip_idx: u32) -> f32 {
    var d = 1000.0;
    let use_bvh = (globals.params.y > 0.5);

    if (use_bvh) {
        var stack: array<i32, 32>;
        var stack_ptr = 0;
        
        if (arrayLength(&bvh_nodes) > 0u) {
            stack[stack_ptr] = 0;
            stack_ptr++;
        }

        while (stack_ptr > 0) {
            stack_ptr--;
            let node_idx = stack[stack_ptr];
            let node = bvh_nodes[node_idx];

            if (aabb_sdf(p, node.min, node.max) < d) {
                if (node.left_idx < 0) { // Leaf
                    let obj_idx = u32(node.obj_idx_or_right);
                    if (obj_idx == skip_idx) { continue; }
                    let obj = object_data.objects[obj_idx];
                    let q = (obj.inv_model * vec4<f32>(p, 1.0)).xyz;
                    let s = min(length(obj.model[0].xyz), min(length(obj.model[1].xyz), length(obj.model[2].xyz)));
                    d = min(d, get_dist(q, obj.params.x) * s);
                } else { // Internal
                    if (stack_ptr < 31) {
                        stack[stack_ptr] = node.left_idx;
                        stack_ptr++;
                        stack[stack_ptr] = node.obj_idx_or_right;
                        stack_ptr++;
                    }
                }
            }
        }
    } else { // Fallback to linear scan
        let count = u32(globals.params.x);
        for (var i = 0u; i < count; i = i + 1u) {
            if (i == skip_idx) { continue; }
            let obj = object_data.objects[i];
            if (obj.params.x <= 0.0) { continue; } // Skip raster objects
            let q = (obj.inv_model * vec4<f32>(p, 1.0)).xyz;
            let s = min(length(obj.model[0].xyz), min(length(obj.model[1].xyz), length(obj.model[2].xyz)));
            d = min(d, get_dist(q, obj.params.x) * s);
        }
    }

    return d;
}