local ZOOM_SPEED = 0.1
local ROTATION_SPEED = 1

function init(self)
    msg.post("@render:", "use_camera_projection")
    msg.post(".", "acquire_input_focus")
    self.yaw            = 0   -- for camera rotation
    self.pitch          = 0   -- for camera rotation
    self.zoom           = 5   -- default zoom
    self.zoom_offset    = 0   -- modification from default zoom
end

function update(self, dt)
    local camera_yaw           = vmath.quat_rotation_y(math.rad(self.yaw))
    local camera_pitch         = vmath.quat_rotation_x(math.rad(self.pitch))
    local camera_rot           = camera_yaw * camera_pitch
    local camera_position      = vmath.rotate(camera_rot, vmath.vector3(0, 0, self.zoom + self.zoom_offset))
    go.set_position(camera_position)
    go.set_rotation(camera_rot)

    local cameraposv4 = vmath.vector4(camera_position.x, camera_position.y, camera_position.z, 1)
    go.set("logo#model", "cameraPosition", cameraposv4)
end

function on_input(self, action_id, action)
    if action_id == hash("touch") then
        self.yaw   = self.yaw   - action.dx * ROTATION_SPEED
        self.pitch = self.pitch + action.dy * ROTATION_SPEED
    elseif action_id == hash("wheel_up") then
        self.zoom_offset = self.zoom_offset - ZOOM_SPEED
    elseif action_id == hash("wheel_down") then
        self.zoom_offset = self.zoom_offset + ZOOM_SPEED
    end
end

varying mediump vec3 vReflect;

uniform samplerCube envMap;

void main() {
    gl_FragColor = textureCube(envMap, vReflect);
}

uniform mediump mat4 view_proj;
uniform mediump mat4 world;
uniform mediump mat4 normal_transform;
uniform mediump mat4 world_view;
uniform mediump vec4 cameraPosition;

attribute mediump vec3 position;
attribute mediump vec3 normal;
attribute mediump vec2 texcoord0;

varying mediump vec3 vReflect;

void main()
{
    vec4 worldP = world * vec4(position, 1.0);
    gl_Position = view_proj * worldP;
    
    vec3 worldNormal = normalize(normal);
    vec3 cameraToVertex = normalize( worldP.xyz - cameraPosition.xyz );
    vReflect = reflect( cameraToVertex, worldNormal );
}