Wolfenstein raycaster · gemini-3.1-pro-preview

**Constructing the Core**

I'm focusing on the foundational structure: `index.html`, Canvas, JavaScript, and CSS. It's going to be a raycasting maze shooter, first-person view, built from scratch, no external resources or API calls. Procedural textures, essential controls (W/A/S/D, space, and left/right), and solid wall collision are next on my list. The goal is a playable prototype, with controls clearly displayed.


**Adding Game Mechanics**

I'm now integrating enemies and player interactions. I'll include a small level with an exit and at least three enemies, with occlusion by walls and shots blocked by walls. Player health and enemy damage rules are essential. A HUD will display health and remaining enemies. Defeating all enemies unlocks the exit for a win condition. Restart will reset everything. First, I'll write the HTML.


**Defining Enemy Behaviors**

I'm working on enemy behavior and game states now. Enemies will have simple AI: check for line of sight, and attack the player if clear and in range. A single ray cast will check for shots and enemy collision. I've defined the game states: Playing, GameOver, and Win. I am drafting the raycaster with screen dimensions of 320x240 and planning to use `ImageData` for pixel drawing, with a 64x64 color array for the wall texture and the enemy texture.


**Optimizing the Renderer**

I'm now focusing on optimizing the rendering process. Instead of using `ImageData` for everything, I'll use `ctx.fillStyle` and `ctx.fillRect` for the walls to keep things simpler. However, I can still use a `ZBuffer[screenWidth]` to check distances, the same way Wolf3D does. I have 64x64 textures, with a brick wall and a simple eye monster, respectively. I've also defined the map and the initial player and enemy positions.


**Refining Interactions and Controls**

I'm now refining the shooting and exit interactions. The exit at (2,2) will only unlock when all enemies are defeated. I'll use spacebar to shoot, casting a ray to determine hits. Enemies will be sorted by distance, and I'll calculate angle differences. If within a threshold and closer than any wall, the enemy takes damage. I'll also implement keydown/keyup listeners and an update loop for controls, with example movement code provided. Collision will check against walls but not the exit.


**Implementing Game Logic**

I've got the win condition sorted out: the exit is now walkable but only triggers a win if unlocked. I've defined enemy attacks; they deal 10 damage every second if they can see the player and are close enough. I've designed the HUD, which is going to be overlayed using divs. Finally, I've decided to render the game on a standard 320x240 canvas and scale it up with CSS, using `image-rendering: pixelated;` for that retro look. I am now writing out the complete game logic!


**Designing the HTML Elements**

I'm now focusing on designing the HTML elements for the game's UI. This includes the `gameContainer` for the canvas and HUD, the HUD with health and enemy counters, and the overlay with messages and a restart button. I'm also styling these with CSS for positioning and appearance.


**Defining Game Variables**

I'm now defining the key game variables in JavaScript: canvas and context, screen dimensions, game state, map, player, enemies, key states, z-buffer, and texture array. I'm also preparing a function to generate the textures: wall and enemy, which will be stored as canvases. The initial wall texture will be gray with black horizontal and vertical bricks.


**Creating the Exit Texture**

I've crafted the exit texture, a green square with "EXIT" in white text, and added it to the `textures` array. I also created the texture for the eye monster sprite. The game map is now defined with the exit. I'm storing the player's initial position and direction, along with health points, within the player object.


**Refining Array Indexing**

I've realized a critical issue: I was using `map[x][y]` instead of `map[y][x]` for the map array. This misinterpretation could lead to errors, so I've updated my code to align with `map[y][x]` indexing. This correction is essential for the raycasting calculations. I also decided to call it a "standard" way of accessing the map by row and column, y and x, instead of the opposite.


**Clarifying Exit Logic**

I'm refining the exit interaction logic and clarifying how it will work within the map. I've decided the exit will be a solid block (value 3), rendering with the exit texture. If the exit is encountered and all enemies are defeated, then the game will initiate the win sequence. I'm now writing the movement collision and win condition trigger into the code.


**Implementing Player Controls**

I'm now implementing player movement, strafing, and rotation. Movement uses W/A/S/D keys, with collision against walls implemented and the exit checked for. Strafing utilizes orthogonal direction vectors. Turning uses rotation matrices with `sin` and `cos` functions to update the player's direction and camera plane. The rotation speed is now defined as a constant, and the correct sign for rotation is now set. I'm testing the controls extensively.


**Refining Key Rotations**

I've refined the rotation logic to align with the standard coordinate system and implemented the `rotate` function for key presses. I've corrected the direction with the `cos` and `sin` functions to ensure accurate left and right turns based on the arrow keys. Now that the correct direction is set, I'll be implementing shooting next.



**Implementing Shooting Mechanics**

I'm now implementing the shooting mechanics, including a visual flash effect and damage calculation. The `shoot()` function will find the closest enemy within the player's crosshair and check for wall occlusion. It will check if the line of sight is clear, then apply damage to the enemy. Enemy health will be decreased on a hit, updating the HUD and marking enemies as dead when health reaches zero. I'm focusing on ensuring accuracy in raycasting to determine successful hits.


**Refining Enemy Interactions**

I'm now integrating enemy interactions, specifically their line of sight and attack mechanics. The `updateEnemies()` function now includes line-of-sight checks, enemy attack timers, and player health updates. I've used a simplified DDA algorithm to check for wall occlusion between the enemy and the player, and this determines whether an attack is executed. I've refined the enemy attack logic.


**Refining Raycasting Logic**

I'm now refining the core raycasting loop, optimizing the wall drawing process. I'm focusing on calculating wall distances accurately using the DDA algorithm. I've also implemented the initial setup for the Z-buffer. The aim is to draw the visible walls with correct height and position, before adding textures.

```javascript
// Example of the starting point of the raycasting code to be added
// in the render function. This will be added to the previous code.
      if (sideDistX < sideDistY) {
        sideDistX += deltaDistX;
        mapX += stepX;
        side = 0;
      } else {
        sideDistY += deltaDistY;
        mapY += stepY;
        side = 1;
      }

      if (map[mapY][mapX] > 0) hit = 1;
    }

    if(side == 0) perpWallDist = (mapX - player.x + (1 - stepX) / 2) / rayDirX;
    else           perpWallDist = (mapY - player.y + (1 - stepY) / 2) / rayDirY;

    if (perpWallDist <= 0) perpWallDist = 0.0001;
    zBuffer[x] = perpWallDist;

    let lineHeight = Math.floor(H / perpWallDist);

    let drawStart = -lineHeight / 2 + H / 2;
    if(drawStart < 0) drawStart = 0;
    let drawEnd = lineHeight / 2 + H / 2;
    if(drawEnd >= H) drawEnd = H - 1;

    let texNum = map[mapY][mapX] - 1; // 1 indexed
    let wallX;
    if(side == 0) wallX = player.y + perpWallDist * rayDirY;
    else          wallX = player.x + perpWallDist * rayDirX;
    wallX -= Math.floor(wallX);

    let texX = Math.floor(wallX * texWidth);
    if(side == 0 && rayDirX > 0) texX = texWidth - texX - 1;
    if(side == 1 && rayDirY < 0) texX = texWidth - texX - 1;

    let step = 1.0 * texHeight / lineHeight;
    let texPos = (drawStart - H / 2 + lineHeight / 2) * step;

    for(let y = drawStart; y < drawEnd; y++) {
      let texY = Math.floor(texPos) & (texHeight - 1);
      texPos += step;

      let color;
      if (texNum == 0) color = wallTexture[texWidth * texY + texX]; //Wall
      if (texNum == 2) color = exitTexture[texWidth * texY + texX]; //Exit
      if (texNum == 1) color = enemyTexture[texWidth * texY + texX]; //Enemy

      if (side == 1) color = color / 2;

      ctx.fillStyle = '#' + color.toString(16).padStart(6, '0');
      ctx.fillRect(x, y, 1, 1);
    }
  }
}
```


**Refining Raycasting Loop**

I'm now refining the raycasting logic, focusing on calculating wall distances and optimizing texture mapping. I've updated the raycasting loop, including distance calculation using DDA. I can now draw walls and implement texture mapping. I'm using an `drawImage` and canvas textures for efficiency and a simpler wall drawing process. I'm working to make the lighting correct and have also added simple shading.


**Implementing Sprite Rendering**

I'm now integrating sprite rendering for enemies, calculating their distances, and sorting them for proper layering. I've added code to correctly position enemy sprites on the screen. The code calculates sprite coordinates, projects them onto the screen using inverse determinant calculations and sorts enemies. Then, I draw enemy sprites from a sorted list, accounting for distance to ensure correct occlusion, but I'm having difficulty.


**Finalizing Sprite Rendering**

I've fixed the sprite rendering, and the enemy is properly positioned with correct occlusion. I'm now testing the enemy sprite rendering and making sure the z-buffer works correctly for visual fidelity, and the muzzle flash is in the right place. I also added a simple weapon to the screen, which appears when not shooting.

\n\n
I've successfully integrated sprite rendering for the enemies. I fixed the code which was not properly rendering enemies. The player can now shoot the enemy, and the enemy sprite correctly renders with appropriate depth perception and is properly occluded by walls. I'm working on the muzzle flash right now.


**Separating Flash Variables**

I'm now separating the muzzle flash from damage flash. I'll use `player.flash` for the muzzle effect during shots and `player.damageFlash` for screen flashes when taking damage. I've updated the rendering code to use separate flash variables with their respective colors. Now I will change it in the main loop.


**Implementing Game Loop**

I'm now integrating the main game loop with `requestAnimationFrame`. I am now handling delta time for smooth movement and updating game elements based on elapsed time. I'm also managing player flashes. The loop now calls `update` and `render` functions to process game logic and visual display, and I'm updating game state variables appropriately. I'm updating the HUD.


**Finalizing Game Functionality**

I'm now implementing the win sequence and refining the restart functionality, focusing on resetting game variables and states appropriately. I'm finishing the Win and Game Over sequences, including the victory screen and restart button functionality. The `win()` function now correctly displays a message and stops game updates. I have finished adding the main game function.


**Verifying Coordinate Systems**

I'm verifying the coordinate systems for map array indexing, confirming `map[y][x]` for row-column access. I've re-examined the `drawImage` usage for sprite rendering, ensuring transparency is handled correctly during updates, checking all texture mapping logic. I'm double-checking the code.


**Validating the Code**

I'm now validating all the logic and rendering, particularly focusing on transparency in sprite rendering. I've confirmed that using `fillRect` for the exit texture works as intended because it's opaque. The HUD updates function properly, including displaying game over and win messages. The key input handling ensures keys are tracked correctly, including the spacebar for shooting and 'r' for restart.


**Improving Enemy and Shot Logic**

I'm now refining the enemy's line of sight and shooting mechanics, adding a margin to the range check to fix edge cases. There was an issue with the map layout, which I've fixed, but I'm checking it again. I am not seeing any issues, and I have just clarified the player's starting position and direction. I should also check the shooting.


**Confirming FOV and Direction**

I'm verifying the initial player direction and FOV calculations. I've double-checked the player's initial direction vector and camera plane values, ensuring they accurately define a positive X-axis orientation with a 66-degree field of view, which is the desired outcome. I'll integrate the HTML string.


**Integrating HTML String**

I'm now integrating the provided HTML code into the game, focusing on structural elements and UI components. This includes the `gameContainer`, canvas, HUD, overlay, and control display. I am now adding the corresponding styling to ensure correct positioning and display. Next, I'll review JavaScript integration.


**Finalizing HTML Integration**

I'm now concluding the HTML and CSS integration. I've successfully incorporated the provided HTML structure, which includes game container, canvas, HUD, overlay, and control display. CSS styles have been added for correct positioning and appearance. I've verified the HTML structure and CSS formatting to ensure all elements are correctly structured and visually appealing, and I'm checking their proper functionality.


**Initializing Game Data**

I'm now initializing the map, player data, enemy data, and game states, including key variables and HUD. The exit is properly rendered, along with all the enemies. I'm making sure everything is loaded and set to the initial values.


**Finalizing Game States**

I'm now implementing game state changes in response to the Win and Game Over conditions. The HUD updates function to show "Exit Unlocked" when all enemies are defeated and now shows the restart button on the end screen. I'm now integrating the logic for game restart and ending sequences.


**Refining Shot and Enemy Interactions**

I'm now refining the accuracy of enemy shots, and fixing an edge case by checking the line of sight calculations, ensuring shots are only considered valid when they hit enemies. I'm also now going to work on improving enemy line-of-sight and AI, updating the render loop.


**Improving Enemy AI**

I'm now refining the enemy AI and attack logic further, clarifying the conditions for enemy attacks. The enemy AI is updated to handle cases where enemies may be blocked by obstacles. I'm focusing on ensuring accurate line-of-sight checks and attack triggers to ensure fair gameplay. The game's state updates are also being verified.


**Refining Collision Detection**

I'm now refining the collision detection logic for movement, handling both X and Y axis separately. I'm focusing on the condition where the exit unlocks only if all enemies are defeated. Movement code now uses a two-step check, using `moveX` and `moveY`, and calling the `win()` function. The same is done for `arrowright` key presses.


**Implementing Rotation**

I'm now integrating rotation logic for player movement using key presses, specifically arrow keys, with the correct `cos` and `sin` calculations. The player's direction and camera plane now accurately rotate. I am finalizing the `rotate` function for all directional inputs.


**Finalizing Movement Logic**

I'm now putting the finishing touches on movement. I've integrated collision detection in the `update` function and movement with separate X and Y collisions. I'm focusing on ensuring smooth movement and preventing any player getting stuck on walls.


**Refining Sprite Rendering**

The enemy sprite rendering is improved, with correct positions and occlusion now working as expected. I've successfully incorporated Z-buffer depth perception and the muzzle flash effect, which helps with the user experience. The weapon is rendered. I am now checking it.


**Optimizing Sprite Sorting**

I'm now optimizing the sprite rendering and sorting logic. I've focused on calculating distances for proper layering and occlusion with the Z-buffer. I've updated the enemy sprite code with an optimized calculation for screen coordinates, handling sprite height, width, and drawing boundaries. The sorting of enemies has been improved for better visual depth.


**Refining UI Elements**

I'm now focusing on refining the HUD, muzzle flash, and damage flash for better visual feedback. The weapon is now added. I've separated muzzle flash effects for shooting and damage feedback. I'm focusing on ensuring smooth integration into the main loop, optimizing their rendering to appear correctly.