035_arc_command.zig

// SPDX-License-Identifier: W3C-20150513

//! Case: Renders arcs with native commands.
//!
//! The pie diagram demonstration has been taken from the SVG spec. It includes
//! material copied from or derived from
//! https://www.w3.org/TR/SVG11/paths.html#PathDataEllipticalArcCommands.
//! Copyright © 2011 World Wide Web Consortium.
//! https://www.w3.org/copyright/software-license-2023/
const std = @import("std");

const z2d = @import("z2d");

pub const filename = "035_arc_command";

pub fn render(io: std.Io, alloc: std.mem.Allocator, aa_mode: z2d.options.AntiAliasMode) !z2d.Surface {
    const width = 400;
    const height = 400;
    var sfc = try z2d.Surface.initPixel(
        .{ .rgb = .{ .r = 0xFF, .g = 0xFF, .b = 0xFF } }, // White
        alloc,
        width,
        height,
    );

    var context = z2d.Context.init(io, alloc, &sfc);
    defer context.deinit();
    context.setSourceToPixel(.{ .rgb = .{ .r = 0xFF, .g = 0x00, .b = 0x00 } });
    context.setAntiAliasingMode(aa_mode);
    context.setLineWidth(5);

    try context.moveTo(200, 200);
    try context.arcNegative(200, 200, 150, std.math.pi, std.math.pi * 1.5);
    try context.closePath();
    try context.fill();
    context.pattern = .{
        .opaque_pattern = .{
            .pixel = .{ .rgb = .{ .r = 0x00, .g = 0x00, .b = 0xFF } }, // Blue for stroke
        },
    };
    try context.stroke();

    context.resetPath();
    try context.moveTo(175, 175);
    try context.arc(175, 175, 150, std.math.pi, std.math.pi * 1.5);
    try context.closePath();
    context.pattern = .{
        .opaque_pattern = .{
            .pixel = .{ .rgb = .{ .r = 0xFF, .g = 0xFF, .b = 0x00 } }, // Yellow for fill
        },
    };
    try context.fill();
    context.pattern = .{
        .opaque_pattern = .{
            .pixel = .{ .rgb = .{ .r = 0x00, .g = 0x00, .b = 0xFF } }, // Blue for stroke
        },
    };
    try context.stroke();

    return sfc;
}