Zig 0.16.0 Raylib 6.0 Box3D

README.md

Information:

Sample test physics box3d and raylib zig.

https://github.com/erincatto/box3d

zig fetch --save=box3d git+https://github.com/erincatto/box3d.git

build.zig

const std = @import("std");

pub fn build(b: *std.Build) void {
    const target = b.standardTargetOptions(.{});
    const optimize = b.standardOptimizeOption(.{});

    const raylib_dep = b.dependency("raylib_zig", .{
        .target = target,
        .optimize = optimize,
    });

    const raylib = raylib_dep.module("raylib"); // main raylib module
    const raygui = raylib_dep.module("raygui"); // raygui module
    const raylib_artifact = raylib_dep.artifact("raylib"); // raylib C library

    const box3d_dep = b.dependency("box3d", .{
        .target = target,
        .optimize = optimize,
    });

    const exe = b.addExecutable(.{
        .name = "zig_raylib_box3d",
        .root_module = b.createModule(.{
            .root_source_file = b.path("src/main.zig"),
            .target = target,
            .optimize = optimize,
            .link_libc = true,
        }),
    });

    exe.root_module.linkLibrary(raylib_artifact);
    exe.root_module.addImport("raylib", raylib);
    exe.root_module.addImport("raygui", raygui);

    exe.root_module.addIncludePath(box3d_dep.path("include"));
    exe.root_module.addIncludePath(box3d_dep.path("include/box3d"));
    exe.root_module.addIncludePath(box3d_dep.path("src")); // Some engines require internal src headers
    // exe.root_module.linkLibrary(box3d_dep.artifact("box3d"));

    const box3d_srcs = &[_][]const u8{
        "src/aabb.c",
        "src/arena_allocator.c", // Added
        "src/bitset.c",
        "src/block_allocator.c",
        "src/body.c",
        "src/broad_phase.c",
        "src/capsule.c",
        "src/compound.c",
        "src/constraint_graph.c",
        "src/contact.c",
        "src/contact_solver.c",
        "src/convex_manifold.c",
        "src/core.c",
        "src/distance.c",
        "src/distance_joint.c",
        "src/dynamic_tree.c",
        "src/height_field.c",
        "src/hull.c",
        "src/id_pool.c",
        "src/island.c",
        "src/joint.c",
        "src/manifold.c",
        "src/math_functions.c",
        "src/mesh.c",
        "src/mesh_contact.c",
        "src/motor_joint.c", // Added
        "src/mover.c",
        "src/name_cache.c",
        "src/parallel_for.c",
        "src/parallel_joint.c",
        "src/physics_world.c",
        "src/prismatic_joint.c",
        "src/recording.c",
        "src/recording_replay.c",
        "src/revolute_joint.c", // Added
        "src/scheduler.c",
        "src/sensor.c",
        "src/shape.c",
        "src/simd.c",
        "src/solver.c",
        "src/solver_set.c",
        "src/sphere.c",
        "src/spherical_joint.c",
        // "src/stack_allocator.c", // nope
        "src/table.c",
        "src/timer.c",
        "src/triangle_manifold.c",
        "src/types.c",
        "src/weld_joint.c",
        "src/wheel_joint.c",
        "src/world_snapshot.c",
    };

    inline for (box3d_srcs) |src| {
        exe.root_module.addCSourceFile(.{
            .file = box3d_dep.path(src),
            // Box3D is portable C17 code
            .flags = &.{ "-std=c17", "-O3" },
        });
    }

    b.installArtifact(exe);

    const run_step = b.step("run", "Run the app");
    const run_cmd = b.addRunArtifact(exe);
    run_step.dependOn(&run_cmd.step);

    run_cmd.step.dependOn(b.getInstallStep());

    if (b.args) |args| {
        run_cmd.addArgs(args);
    }
}

build.zig.zon

.{
    // This is the default name used by packages depending on this one. For
    // example, when a user runs `zig fetch --save <url>`, this field is used
    // as the key in the `dependencies` table. Although the user can choose a
    // different name, most users will stick with this provided value.
    //
    // It is redundant to include "zig" in this name because it is already
    // within the Zig package namespace.
    .name = .zig_raylib_box3d,
    // This is a [Semantic Version](https://semver.org/).
    // In a future version of Zig it will be used for package deduplication.
    .version = "0.0.0",
    // Together with name, this represents a globally unique package
    // identifier. This field is generated by the Zig toolchain when the
    // package is first created, and then *never changes*. This allows
    // unambiguous detection of one package being an updated version of
    // another.
    //
    // When forking a Zig project, this id should be regenerated (delete the
    // field and run `zig build`) if the upstream project is still maintained.
    // Otherwise, the fork is *hostile*, attempting to take control over the
    // original project's identity. Thus it is recommended to leave the comment
    // on the following line intact, so that it shows up in code reviews that
    // modify the field.
    .fingerprint = 0x975c3bafb37097c7, // Changing this has security and trust implications.
    // Tracks the earliest Zig version that the package considers to be a
    // supported use case.
    .minimum_zig_version = "0.16.0",
    // This field is optional.
    // Each dependency must either provide a `url` and `hash`, or a `path`.
    // `zig build --fetch` can be used to fetch all dependencies of a package, recursively.
    // Once all dependencies are fetched, `zig build` no longer requires
    // internet connectivity.
    .dependencies = .{
        .raylib_zig = .{
            .url = "git+https://github.com/raylib-zig/raylib-zig.git#8758f4cd3a5ae0df6941c4715257223d34c5ad3e",
            .hash = "raylib_zig-6.0.0-KE8RECZ8BQDm-txuospkpZHbJ6DNpacUF7D88RWQ_qAe",
        },
        .box3d = .{
            .url = "git+https://github.com/erincatto/box3d.git#f42be210a21023e55881afa4c8daba159a60ef47",
            .hash = "N-V-__8AALYluQDdWuYuhnaYTP6Ppmc1i1RZQAxX9i8QRu2n",
        },
    },
    .paths = .{
        "build.zig",
        "build.zig.zon",
        "src",
        // For example...
        //"LICENSE",
        //"README.md",
    },
}

main.zig

const std = @import("std");
const rl = @import("raylib");

// Import Box3D headers mapped via your build.zig layout
const c = @cImport({
    @cInclude("box3d/box3d.h");
});

/// Helper utility to convert a Box3D vector into a Raylib Vector3 structure
fn toRlVec3(v: c.b3Vec3) rl.Vector3 {
    return rl.Vector3.init(v.x, v.y, v.z);
}

pub fn main() !void {
    // 1. Initialize Raylib 3D Application Window Context
    const screen_width = 1280;
    const screen_height = 720;
    rl.initWindow(screen_width, screen_height, "Zig + Box3D Physics Simulation Workspace");
    defer rl.closeWindow();

    // Configure camera positioning in 3D dimensional space
    var camera = rl.Camera3D{
        .position = rl.Vector3.init(0.0, 12.0, 18.0), // Elevated overview position
        .target = rl.Vector3.init(0.0, 2.0, 0.0), // Tracking target center point
        .up = rl.Vector3.init(0.0, 1.0, 0.0), // Standard vertical orientation axis
        .fovy = 45.0, // Field of view angle degree
        .projection = .perspective,
    };

    rl.setTargetFPS(60);

    // 2. Configure and Instatiate Box3D Physics Simulation Environment
    var world_def = c.b3DefaultWorldDef();
    world_def.gravity = c.b3Vec3{ .x = 0.0, .y = -9.81, .z = 0.0 }; // Standard Earth downward gravity acceleration

    const world_id = c.b3CreateWorld(&world_def);
    if (c.b3World_IsValid(world_id) == false) {
        std.debug.print("Failed to initialize Box3D physics world context.\n", .{});
        return error.PhysicsInitializationFailed;
    }
    defer c.b3DestroyWorld(world_id);

    // 3. Create Static Ground Plane Platform Body
    var ground_body_def = c.b3DefaultBodyDef();
    ground_body_def.type = c.b3_staticBody;
    ground_body_def.position = c.b3Vec3{ .x = 0.0, .y = 0.0, .z = 0.0 };
    const ground_body_id = c.b3CreateBody(world_id, &ground_body_def);

    var ground_shape_def = c.b3DefaultShapeDef();
    // Define half-extents parameters for a flat platform using the correct box hull helper
    var ground_box = c.b3MakeBoxHull(8.0, 0.5, 8.0);
    _ = c.b3CreateHullShape(ground_body_id, &ground_shape_def, &ground_box.base);

    // 4. Create Dynamic Falling Sphere Body
    var sphere_body_def = c.b3DefaultBodyDef();
    sphere_body_def.type = c.b3_dynamicBody;
    sphere_body_def.position = c.b3Vec3{ .x = -1.5, .y = 8.0, .z = 0.0 }; // Left side high offset
    const sphere_body_id = c.b3CreateBody(world_id, &sphere_body_def);

    var sphere_shape_def = c.b3DefaultShapeDef();
    sphere_shape_def.density = 1.0;
    sphere_shape_def.baseMaterial.restitution = 0.4; // Set restitution via baseMaterial nested field

    var sphere = c.b3Sphere{ .radius = 0.6 };
    _ = c.b3CreateSphereShape(sphere_body_id, &sphere_shape_def, &sphere);

    // 5. Create Dynamic Dropping Box Cube Body
    var box_body_def = c.b3DefaultBodyDef();
    box_body_def.type = c.b3_dynamicBody;
    box_body_def.position = c.b3Vec3{ .x = 1.5, .y = 10.0, .z = 0.5 }; // Right side higher offset
    const box_body_id = c.b3CreateBody(world_id, &box_body_def);

    var box_shape_def = c.b3DefaultShapeDef();
    box_shape_def.density = 1.2;
    box_shape_def.baseMaterial.friction = 0.3; // Set friction via baseMaterial nested field

    // Define half-extents parameters for a box: 0.75m x 0.75m x 0.75m (Translates into a 1.5m solid cube)
    var box_hull = c.b3MakeBoxHull(0.75, 0.75, 0.75);
    _ = c.b3CreateHullShape(box_body_id, &box_shape_def, &box_hull.base);

    // Real-Time Frame Update Logic & Graphics Rendering Loop
    const time_step: f32 = 1.0 / 60.0; // Fixed update time step mapping 60Hz
    const sub_step_count: i32 = 4; // Constraint sub-stepping engine iteration accuracy pass

    while (!rl.windowShouldClose()) {
        // Handle simulation state reset commands
        if (rl.isKeyPressed(.r)) {
            // Reset Sphere body to its launch configuration definition properties
            c.b3Body_SetTransform(sphere_body_id, sphere_body_def.position, sphere_body_def.rotation);
            c.b3Body_SetLinearVelocity(sphere_body_id, c.b3Vec3{ .x = 0.0, .y = 0.0, .z = 0.0 });
            c.b3Body_SetAngularVelocity(sphere_body_id, c.b3Vec3{ .x = 0.0, .y = 0.0, .z = 0.0 });

            // Reset Box body to its launch configuration definition properties
            c.b3Body_SetTransform(box_body_id, box_body_def.position, box_body_def.rotation);
            c.b3Body_SetLinearVelocity(box_body_id, c.b3Vec3{ .x = 0.0, .y = 0.0, .z = 0.0 });
            c.b3Body_SetAngularVelocity(box_body_id, c.b3Vec3{ .x = 0.0, .y = 0.0, .z = 0.0 });
        }

        // Step the internal physics world forward in time matching target update frames
        c.b3World_Step(world_id, time_step, sub_step_count);

        // Allow orbital camera manipulation directly via mouse mechanics
        rl.updateCamera(&camera, .orbital);

        // Graphics Render Phase Execution
        rl.beginDrawing();
        defer rl.endDrawing();

        rl.clearBackground(rl.Color.ray_white);

        {
            camera.begin();
            defer camera.end();

            // Draw a base layout configuration grid for measurement comparisons
            rl.drawGrid(20, 1.0);

            // Render Static Ground Platform (Dimensions convert half-extents to full sizing dimensions)
            const ground_pos = toRlVec3(c.b3Body_GetPosition(ground_body_id));
            rl.drawCube(ground_pos, 16.0, 1.0, 16.0, rl.Color.gray);
            rl.drawCubeWires(ground_pos, 16.0, 1.0, 16.0, rl.Color.dark_gray);

            // Render Dynamic Falling Sphere
            const sphere_pos = toRlVec3(c.b3Body_GetPosition(sphere_body_id));
            rl.drawSphere(sphere_pos, 0.6, rl.Color.red);
            rl.drawSphereWires(sphere_pos, 0.6, 16, 16, rl.Color.maroon);

            // Render Dynamic Dropping Box Cube
            const box_pos = toRlVec3(c.b3Body_GetPosition(box_body_id));
            rl.drawCube(box_pos, 1.5, 1.5, 1.5, rl.Color.blue);
            rl.drawCubeWires(box_pos, 1.5, 1.5, 1.5, rl.Color.dark_blue);
        }

        // Display Real-Time Overlay Diagnostics Text HUD Information
        rl.drawFPS(10, 10);
        rl.drawText("Box3D Physics + Raylib-Zig Render Workspace", 10, 35, 20, rl.Color.dark_gray);
        rl.drawText("Use Mouse to Rotate Camera Perspective", 10, 60, 16, rl.Color.gray);
        rl.drawText("Red Entity: Sphere | Blue Entity: Box/Hull Cube | Gray: Static Platform Ground", 10, 85, 16, rl.Color.dark_gray);
        rl.drawText("Press [R] to Reset Objects to Spawn State", 10, 110, 16, rl.Color.red);
    }
}