%% Build Ego Body Paths and Check for Collisions with Obstacles
% Build an ego body path and maintain obstacle states using the dynamicCapsuleList object. Visualize the states of all objects in the environment at different timestamps. Validate the path of the ego body by checking for collisions with obstacles in the environment.
% Create the dynamicCapsuleList object. Extract the maximum number of steps to use as the number of time stamps for your object paths.

obsList = dynamicCapsuleList;
numSteps = obsList.MaxNumSteps;

%% Add Ego Body
% Define an ego body by specifying the ID, geometry, and state together in a structure. The capsule geometry has a length of 3 m and radius of 1 m. Specify the state as a linear path from x = 0m to x = 100m.

egoID1 = 1;
geom = struct("Length",3,"Radius",1,"FixedTransform",eye(3));
states = linspace(0,1,obsList.MaxNumSteps)'.*[100 0 0];

egoCapsule1 = struct('ID',egoID1,'States',states,'Geometry',geom);
addEgo(obsList,egoCapsule1);

show(obsList,"TimeStep",[1:numSteps]);
ylim([-20 20])

%% Add Obstacles
% Specify states for two obstacles that are separated from the ego body by 5 m in opposite directions on the y-axis.. Assume the obstacles have the same geometry geom as the ego body.

obsState1 = states + [0 5 0];
obsState2 = states + [0 -5 0];

obsCapsule1 = struct('ID',1,'States',obsState1,'Geometry',geom);
obsCapsule2 = struct('ID',2,'States',obsState2,'Geometry',geom);

addObstacle(obsList,obsCapsule1);
addObstacle(obsList,obsCapsule2);

show(obsList,"TimeStep",[1:numSteps]);
ylim([-20 20])

%
%% Update Obstacles
% Alter your obstacle locations and geometry dimensions over time. Use the previously generated structure, modify the fields, and update the obstacles using the updateObstacleGeometry and updateObstaclePose object functions. Reduces the radius of the first obstacle to 0.5 m, and change the path to move it towards the ego body.

obsCapsule1.Geometry.Radius = 0.5;

obsCapsule1.States = ...
    [linspace(0,100,numSteps)' ... % x
     linspace(5,-4,numSteps)' ... % y 
     zeros(numSteps,1)]; % theta

updateObstacleGeometry(obsList,1,obsCapsule1);
updateObstaclePose(obsList,1,obsCapsule1);

%
%% Check for Collisions
% Visualize the new paths. Show where collisions between the ego body and an obstacle, which the display highlights in red. Notice that collisions between the obstacles are not checked.

show(obsList,"TimeStep",[1:numSteps],"ShowCollisions",1);
ylim([-20 20])
xlabel("X (m)")
ylabel("Y (m)")

%
% Programmatically check for collisions by using the checkCollision object function. The function returns a vector of logical values that indicates the status of each time step. The vector is transposed for display purposes.

collisions = checkCollision(obsList)'

% To validate paths with a large number of steps, use the any function on the vector of collision values.

if any(collisions)
    disp("Collision detected.")
end

%
%% Update Ego Path
% Specify a new path for the ego body. Visualize the paths again, displaying collisions.

egoCapsule1.States = ...
    [linspace(0,100,numSteps)' ... % x
    3*sin(linspace(0,2*pi,numSteps))' ... % y
    zeros(numSteps,1)]; % theta

updateEgoPose(obsList,1,egoCapsule1);

show(obsList,"TimeStep",[1:numSteps],"ShowCollisions",1);
ylim([-20 20])

% Copyright 2020 The MathWorks, Inc.