Add documentation for camera-based raycasting selection

[Copilot]

Documents the existing raycasting implementation for shooting rays from the camera to select 3D objects.

Changes

• File-level docs: Added overview of the raycasting pipeline (screen coords → NDC → eye space → world space → triangle intersection)
• calculateRayDirection: Step-by-step documentation of the unprojection math
• rayIntersectsTriangle: Documented Möller–Trumbore algorithm with mathematical basis
• Header file: Added Doxygen-style docs for MouseSelector class and all public methods
• Cleanup: Replaced verbose debug logging with conditional DEBUG_SELECTION macro

Usage

MouseSelector selector(camera);
ID id = selector.addSelectable(model, transform);

// Each frame:
selector.handleSelection(input, screenSize);
if (auto selected = selector.getSelection()) {
    // Handle selection
}

The raycasting pipeline:

1. Screen coords → NDC via (2x/width - 1, 1 - 2y/height)
2. Clip space → Eye space via inverse projection
3. Eye space → World space via inverse view
4. Ray-triangle intersection via Möller–Trumbore

Original prompt

how would i shoot rays from the camera to get a selection

The user has attached the following files from their workspace:

• Rubiks/mouse_selector.cpp

[Chronological Review: The conversation began with the user requesting ideas on implementing pivot points for a Rubik's Cube simulation. The discussion evolved into specific functionalities such as cube rotation based on user input, updating colors and textures during rotation, and addressing issues with control inversions. The user expressed a desire to rethink the rotation mechanics based on camera position and pivot points, leading to a request for code comments to be made more professional. The latest request involved shooting rays from the camera for selection purposes.]

[Intent Mapping:

1. "give me an idea on hw to make pivot points for the rubiks cube" - User seeks guidance on implementing pivot points.
2. "please help me complete it" - User requests assistance in completing the implementation.
3. "is this okay?" - User seeks validation on their current implementation.
4. "yeah lets do 1 and 2" - User agrees to proceed with specific tasks.
5. "okay lets use the arrow keys to roate the cube..." - User specifies control mechanics for cube rotation.
6. "the colors should update after a rotation" - User wants dynamic color updates.
7. "the texture should also be updating while rotating..." - User requests texture updates during rotation.
8. "this happens while roatating..." - User describes a specific issue with color representation during rotation.
9. "it still doing that..." - User continues to report issues with the rotation mechanics.
10. "okay lets rethink the rotation..." - User suggests a complete re-evaluation of rotation logic.
11. "remove comments on code that are self descriptive..." - User requests code comment refinement.
12. "how would i shoot rays from the camera to get a selection" - User inquires about raycasting for selection.]

[Technical Inventory:

• Technologies: OpenGL for rendering the Rubik's Cube.
• Concepts: Pivot points, camera position, raycasting, dynamic texture updates, control inversion.
• Tools: User is working within a C++ environment, specifically modifying files related to the Rubik's Cube simulation.]

[Code Archaeology:

• Files Discussed:
  • window.cpp: Main file for cube rendering and interaction.
  • RubiksCube.cpp and RubiksCube.h: Likely contain the logic for cube mechanics.
  • mouse_selector.cpp: Possibly handles mouse interactions for selection.
• Recent changes were made to these files, indicating ongoing development and refinement.]

[Progress Assessment:

• Completed Tasks: Basic rotation mechanics and color updates have been discussed.
• Partially Complete Work: Issues with control inversions and dynamic updates during rotation remain unresolved.
• Validated Outcomes: User has confirmed some functionalities but continues to face challenges.]

[Context Validation: All critical information regarding the user's goals for the Rubik's Cube simulation, including rotation mechanics, color updates, and raycasting for selection, is captured.]

[Recent Commands Analysis:

• Last Agent Commands: User requested to "remove comments on code that are self descriptive and make the comments more professional" and "how would i shoot rays from the camera to get a selection."
• Tool Results Summary: No specific tool results were returned as the user was focused on code refinement and conceptual inquiries.
• Pre-Summary State: The agent was actively discussing raycasting for selection when the token budget was exceeded.
• Operation Context: These commands relate to the user's goal of improving the usability and functionality of the Rubik's Cube simulation.]

1. Conversation Overview: - Primary Objectives: User aims to implement a Rubik's Cube simulation with dynamic rotation, color updates, and raycasting for selection. - Session Context: The conversation has progressed from initial ideas on pivot points to detailed discussions on rotation mechanics and user controls. - User Intent Evolution: The user has shifted from seeking general advice to addressing specific implementation issues and refining code quality.

2. Technical Foundation:

• OpenGL: Used for rendering the Rubik's Cube and handling graphics.
• C++: The programming language for the simulation's implementation.

3. Codebase Status:

• window.cpp:
  • Purpose: Main file for rendering and interaction.
  • Current State: Ongoing modifications to implement rotation and selection features.
  • Key Code Segments: Functions related to cube rotation and user input handling.
• RubiksCube.cpp and RubiksCube.h: Contain logic for cube mechanics and state management.
• mouse_selector.cpp: Likely manages selection logic based on user input.

4. Problem Resolution:

• Issues Encountered: Control inversions during rotation and dynamic updates not functioning as expected.
• Solutions Implemented: Basic rotation mechanics disc...

Created from VS Code via the GitHub Pull Request extension.

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