voxel-test/src/world/chunk.zig

const std = @import("std");
const rh = @import("../util/raylib_helper.zig");
const raylib = rh.raylib;
const A7r = std.mem.Allocator;

pub const Chunk = struct {
    tiles: []i32,
    a7r: A7r,

    pub fn init(a7r: A7r) !Chunk {
        return Chunk{
            .a7r = a7r,
            .tiles = try a7r.alloc(i32, 32 * 32 * 32),
        };
    }

    pub fn deinit(self: Chunk) void {
        self.a7r.free(self.tiles);
    }

    pub fn getTile(self: Chunk, x: u5, y: u5, z: u5) i32 {
        return self.tiles[@as(u15, x) << 10 | @as(u15, y) << 5 | @as(u15, z)];
    }

    pub fn setTile(self: Chunk, x: u5, y: u5, z: u5, tile: i32) void {
        self.tiles[@as(u15, x) << 10 | @as(u15, y) << 5 | @as(u15, z)] = tile;
    }

    pub fn createMesh(_: Chunk) raylib.Mesh {
        const triangle_count: u32 = 1;

        const arr_size: c_uint = triangle_count * 3 * @sizeOf(f32);

        const vertices: [*]f32 = @ptrCast(@alignCast(raylib.MemAlloc(arr_size * 3)));
        const texcoords: [*]f32 = @ptrCast(@alignCast(raylib.MemAlloc(arr_size * 2)));
        const normals: [*]f32 = @ptrCast(@alignCast(raylib.MemAlloc(arr_size * 3)));

        vertices[0] = 0.0;
        vertices[1] = 0.0;
        vertices[2] = 0.0;
        normals[0] = 0.0;
        normals[1] = 1.0;
        normals[2] = 0.0;
        texcoords[0] = 0.0;
        texcoords[1] = 0.0;

        vertices[3] = 1.0;
        vertices[4] = 0.0;
        vertices[5] = 2.0;
        normals[3] = 0.0;
        normals[4] = 1.0;
        normals[5] = 0.0;
        texcoords[2] = 0.5;
        texcoords[3] = 1.0;

        vertices[6] = 2.0;
        vertices[7] = 0.0;
        vertices[8] = 0.0;
        normals[6] = 0.0;
        normals[7] = 1.0;
        normals[8] = 0.0;
        texcoords[4] = 1.0;
        texcoords[5] = 0.0;

        var mesh = raylib.Mesh{
            .triangleCount = triangle_count,
            .vertexCount = triangle_count * 3,

            .vertices = vertices,
            .texcoords = texcoords,
            .texcoords2 = null,
            .normals = normals,
            .tangents = null,
            .colors = null,
            .indices = null,
            .animVertices = null,
            .animNormals = null,
            .boneIds = null,
            .boneWeights = null,
            .vaoId = 0,
            .vboId = null,
        };

        raylib.UploadMesh(@ptrCast(&mesh), false);

        return mesh;
    }
};