tiny.zen.diagram.category

1const std = @import("std");23const model = @import("model.zig");4const root = @import("root.zig");56const spec = root.spec;7const Bounds = model.Bounds;89pub const label_buffer_bytes: usize = 512;1011pub fn appendAssumeCapacity(bounds: *Bounds, label_value: []const u8) void {12    for (bounds.categories.items) |item| {13        if (std.mem.eql(u8, item, label_value)) return;14    }15    bounds.categories.appendAssumeCapacity(label_value);16}1718pub fn label(buffer: *[label_buffer_bytes]u8, value: spec.XValue) []const u8 {19    return switch (value) {20        .number => |number| std.fmt.bufPrint(buffer, "{d:.3}", .{number}) catch unreachable,21        .text => |text| text,22    };23}2425pub fn coordinate(label_value: []const u8, bounds: Bounds, left: f64, right: f64) f64 {26    const count = @max(bounds.categories.items.len, 1);27    const slot = (right - left) / @as(f64, @floatFromInt(count));28    for (bounds.categories.items, 0..) |item, index| {29        if (std.mem.eql(u8, item, label_value)) return left + slot * (@as(f64, @floatFromInt(index)) + 0.5);30    }31    return left + slot * 0.5;32}3334test "category labels fit every finite f64 without allocation" {35    var buffer: [label_buffer_bytes]u8 = undefined;36    try std.testing.expect(label(&buffer, .{ .number = std.math.floatMax(f64) }).len < buffer.len);37    try std.testing.expect(label(&buffer, .{ .number = -std.math.floatMax(f64) }).len < buffer.len);38    try std.testing.expectEqualStrings("borrowed", label(&buffer, .{ .text = @constCast("borrowed") }));39}

1pub const category = @import("category.zig");