refactor(behavior_velocity_occlusion_spot_module): reduce cppcheck warning

[veqcc]

Description

This is based on CppCheck warnings.

1. remove unnecessary if branch
   30b90a3

planning/behavior_velocity_occlusion_spot_module/src/grid_utils.cpp:91:9: style: Condition 'polys' is always true [knownConditionTrueFalse]
    if (polys) {
        ^
planning/behavior_velocity_occlusion_spot_module/src/grid_utils.cpp:89:16: note: Assignment 'polys=true', assigned value is 1
  bool polys = true;
               ^
planning/behavior_velocity_occlusion_spot_module/src/grid_utils.cpp:91:9: note: Condition 'polys' is always true
    if (polys) {
        ^
planning/behavior_velocity_occlusion_spot_module/src/grid_utils.cpp:89:8: style: The scope of the variable 'polys' can be reduced. [variableScope]
  bool polys = true;
       ^

2. add const for const variable
   b9fcb38

planning/behavior_velocity_occlusion_spot_module/src/debug.cpp:121:10: style: Variable 'possible_collisions' can be declared as reference to const [constVariableReference]
  auto & possible_collisions = debug_data.possible_collisions;
         ^

3. remove redundant assignment
   06acd45

planning/behavior_velocity_occlusion_spot_module/src/grid_utils.cpp:327:19: style: Assignment 'intensity=grid_utils::occlusion_cost_value::FREE_SPACE' is redundant with condition 'intensity==grid_utils::occlusion_cost_value::FREE_SPACE'. [duplicateConditionalAssign]
        intensity = grid_utils::occlusion_cost_value::FREE_SPACE;
                  ^
planning/behavior_velocity_occlusion_spot_module/src/grid_utils.cpp:326:21: note: Condition 'intensity==grid_utils::occlusion_cost_value::FREE_SPACE'
      if (intensity == grid_utils::occlusion_cost_value::FREE_SPACE) {
                    ^
planning/behavior_velocity_occlusion_spot_module/src/grid_utils.cpp:327:19: note: Assignment 'intensity=grid_utils::occlusion_cost_value::FREE_SPACE' is redundant
        intensity = grid_utils::occlusion_cost_value::FREE_SPACE;
                  ^

4. remove redundant if branch
   d740ae0

planning/behavior_velocity_occlusion_spot_module/src/grid_utils.cpp:351:39: style: Condition 'param.free_space_max<intensity' is always true [knownConditionTrueFalse]
      } else if (param.free_space_max < intensity && intensity < param.occupied_min) {
                                      ^
planning/behavior_velocity_occlusion_spot_module/src/grid_utils.cpp:349:21: note: Assuming that condition 'intensity<=param.free_space_max' is not redundant
      if (intensity <= param.free_space_max) {
                    ^
planning/behavior_velocity_occlusion_spot_module/src/grid_utils.cpp:351:39: note: Condition 'param.free_space_max<intensity' is always true
      } else if (param.free_space_max < intensity && intensity < param.occupied_min) {
                                      ^
planning/behavior_velocity_occlusion_spot_module/src/grid_utils.cpp:89:8: style: The scope of the variable 'polys' can be reduced. [variableScope]
  bool polys = true;
       ^

5. underflow check
   da77325

6. use const for const parameter
   eca35cd

planning/behavior_velocity_occlusion_spot_module/src/occlusion_spot_utils.cpp:429:87: style: Parameter 'debug_data' can be declared as reference to const [constParameterReference]
  const lanelet::ConstLanelet & path_lanelet, const PlannerParam & param, DebugData & debug_data)
                                                                                      ^

Question

If the first commit (about polys) is acceptable, then the function pointsToRays seems unnecessary anymore.
Do you think I should delete it too?

autoware.universe/planning/behavior_velocity_occlusion_spot_module/src/grid_utils.cpp

Line 108 in fd6306d

pointsToRays(p1, p2, radius);

planning/behavior_velocity_occlusion_spot_module/src/grid_utils.cpp:46:0: style: The function 'pointsToRays' is never used. [unusedFunction]
std::vector<std::pair<grid_map::Position, grid_map::Position>> pointsToRays(
^

Tests performed

No

Effects on system behavior

Interface changes

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[shmpwk]

@veqcc
Thank you for OSS contribution in holiday!
I agree to delete unnecessary if (polys) .
So could you delete pointsToRays you questioned?

[veqcc]

Could anyone give it an approve?

[shmpwk]

Thank you so much!