shader_type spatial;
render_mode skip_vertex_transform,unshaded;

uniform vec4 albedo : hint_color;
uniform float voxelSize;
uniform vec2 screen_size;
uniform vec2 viewport_pos;
uniform vec3 camera_pos;

varying vec4 col;

varying mat4 ViewProjectionMatrix;
varying vec4 pos_Box;
varying vec3 radius_Box;
varying vec3 invradius_Box;
varying mat3 rotation_Box;

varying vec3 min_pos_Box;
varying vec3 max_pos_Box;


void vertex() {
    float padding = 1.7f;
    mat4 mvp = PROJECTION_MATRIX * MODELVIEW_MATRIX;
    vec4 gl_Position = mvp * vec4(VERTEX, 1.0);
    ViewProjectionMatrix = mvp;
//  quadricProj(VERTEX,voxelSize,mvp,screen_size/2.0,gl_Position,POINT_SIZE);
    POINT_SIZE = screen_size.y * PROJECTION_MATRIX[1][1] * (voxelSize*padding)/gl_Position.w;





    col = albedo;
    pos_Box = WORLD_MATRIX * vec4(VERTEX,1.0);

    VERTEX = (MODELVIEW_MATRIX * vec4(VERTEX, 1.0)).xyz;
    NORMAL = (MODELVIEW_MATRIX * vec4(NORMAL, 0.0)).xyz;


    radius_Box = vec3(voxelSize);
    invradius_Box = 1.0/radius_Box;
    rotation_Box=mat3(1.0f);

    min_pos_Box = pos_Box.xyz - vec3(voxelSize);
    max_pos_Box = pos_Box.xyz + vec3(voxelSize);
//  PROJECTION_MATRIX = mat4(1.0);
}



vec2 intersectAABB(vec3 rayOrigin, vec3 rayDir, vec3 boxMin, vec3 boxMax) {
    vec3 tMin = (boxMin - rayOrigin) / rayDir;
    vec3 tMax = (boxMax - rayOrigin) / rayDir;
    vec3 t1 = min(tMin, tMax);
    vec3 t2 = max(tMin, tMax);
    float tNear = max(max(t1.x, t1.y), t1.z);
    float tFar = min(min(t2.x, t2.y), t2.z);
    return vec2(tNear, tFar);
}
void fragment() {
    vec2 p = 2.0 * vec2(FRAGCOORD.xy)/(screen_size.xy) - vec2(1.0);
    vec3 ro = camera_pos;//ray origin
    vec4 rdh = (CAMERA_MATRIX * INV_PROJECTION_MATRIX )* vec4(p,-1.0,1.0);
    vec3 rd = rdh.xyz/rdh.w - ro;//ray direction


    vec3 color = col.rgb;

    vec3 boxMin = pos_Box.xyz- radius_Box;
    vec3 boxMax = pos_Box.xyz + radius_Box;


    vec2 result = intersectAABB(ro,rd,boxMin,boxMax);
    bool rayIntersectionTest = result.y > result.x;
    if(rayIntersectionTest == false){
        color = vec3(1.0);
    }
//
        color = sqrt( color );

    ALBEDO =color;


//  ALBEDO = texture(SCREEN_TEXTURE,POINT_COORD).rgb;

}
void light(){

}