match sketch() {

Ok(_) => {

eprintln!("Sketch completed successfully");

exit(0).unwrap();

}

Err(e) => {

eprintln!("Sketch error: {:?}", e);

exit(1).unwrap();

}

};

let width = 800;

let height = 600;

let mut glfw_ctx = GlfwContext::new(width, height, false)?;

init(Config::default())?;

let surface = glfw_ctx.create_surface(width, height, false)?;

let graphics = graphics_create(surface, width, height, TextureFormat::Rgba16Float)?;

let sphere = geometry_sphere(30.0, 32, 18)?;

graphics_mode_3d(graphics)?;

transform_set_position(graphics, Vec3::new(0.0, 0.0, 600.0))?;

transform_look_at(graphics, Vec3::new(0.0, 0.0, 0.0))?;

let dir_light =

light_create_directional(graphics, bevy::color::Color::srgb(1.0, 0.98, 0.95), 1_500.0)?;

transform_set_position(dir_light, Vec3::new(300.0, 400.0, 300.0))?;

transform_look_at(dir_light, Vec3::new(0.0, 0.0, 0.0))?;

let point_light =

light_create_point(graphics, bevy::color::Color::WHITE, 100_000.0, 800.0, 0.0)?;

transform_set_position(point_light, Vec3::new(200.0, 200.0, 400.0))?;

// Grid of materials varying roughness (x) and metallic (y)

let cols = 11;

let rows = 5;

let mut materials = Vec::new();

for row in 0..rows {

for col in 0..cols {

let mat = material_create_pbr()?;

let roughness = col as f32 / (cols - 1) as f32;

let metallic = row as f32 / (rows - 1) as f32;

material_set(

mat,

"roughness",

shader_value::ShaderValue::Float(roughness),

)?;

material_set(mat, "metallic", shader_value::ShaderValue::Float(metallic))?;

materials.push(mat);

}

}

let base_color = bevy::color::Color::srgb(1.0, 0.85, 0.57);

let spacing = 70.0;

let offset_x = (cols - 1) as f32 * spacing / 2.0;

let offset_y = (rows - 1) as f32 * spacing / 2.0;

while glfw_ctx.poll_events() {

graphics_begin_draw(graphics)?;

graphics_record_command(

graphics,

DrawCommand::BackgroundColor(bevy::color::Color::srgb(0.05, 0.05, 0.07)),

)?;

graphics_record_command(graphics, DrawCommand::Fill(base_color))?;

for row in 0..rows {

for col in 0..cols {

let mat = materials[row * cols + col];

graphics_record_command(graphics, DrawCommand::PushMatrix)?;

graphics_record_command(

graphics,

DrawCommand::Translate(

Vec2::new(

col as f32 * spacing - offset_x,

row as f32 * spacing - offset_y,

)

.extend(0.0),

),

)?;

graphics_record_command(graphics, DrawCommand::Material(mat))?;

graphics_record_command(graphics, DrawCommand::Geometry(sphere))?;

graphics_record_command(graphics, DrawCommand::PopMatrix)?;

}

}

graphics_end_draw(graphics)?;

}

for mat in materials {

material_destroy(mat)?;

}

Ok(())