tiny.gui.paint.synth

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

1const std = @import("std");23const gui = @import("../root.zig");45const Color = gui.model.UiColor;6const Rect = gui.layout.Rect;78pub fn covered(codepoint: u21) bool {9    return switch (codepoint) {10        0x2500...0x257F => boxSegments(codepoint) != null,11        0x2580...0x259F => true,12        0x2800...0x28FF => true,13        0x2295...0x2299 => true,14        0x22EF, 0x276F, 0x2726 => true,15        else => false,16    };17}1819pub fn draw(writer: anytype, codepoint: u21, cell: Rect, color: Color) bool {20    switch (codepoint) {21        0x2500...0x257F => {22            const segments = boxSegments(codepoint) orelse return false;23            drawBox(writer, segments, cell, color);24            return true;25        },26        0x2580...0x259F => {27            drawBlock(writer, codepoint, cell, color);28            return true;29        },30        0x2800...0x28FF => {31            drawBraille(writer, codepoint, cell, color);32            return true;33        },34        0x2295...0x2299 => {35            drawCircled(writer, codepoint, cell, color);36            return true;37        },38        0x22EF => {39            drawMidlineEllipsis(writer, cell, color);40            return true;41        },42        0x276F => {43            drawChevron(writer, cell, color);44            return true;45        },46        0x2726 => {47            drawStar(writer, cell, color);48            return true;49        },50        else => return false,51    }52}5354pub fn drawNotdef(writer: anytype, cell: Rect, color: Color) void {55    const thickness = strokeThickness(cell);56    const x = snap(cell.x + thickness);57    const y = snap(cell.y + thickness);58    const width = @max(thickness, snap(cell.width - thickness * 2));59    const height = @max(thickness, snap(cell.height - thickness * 2));60    fill(writer, .{ .x = x, .y = y, .width = width, .height = thickness }, color);61    fill(writer, .{ .x = x, .y = y + height - thickness, .width = width, .height = thickness }, color);62    fill(writer, .{ .x = x, .y = y, .width = thickness, .height = height }, color);63    fill(writer, .{ .x = x + width - thickness, .y = y, .width = thickness, .height = height }, color);64}6566fn drawCircled(writer: anytype, codepoint: u21, cell: Rect, color: Color) void {67    const t = strokeThickness(cell);68    const side = @min(cell.width, cell.height * 0.72);69    const x0 = snap(cell.x + (cell.width - side) / 2);70    const y0 = snap(cell.y + (cell.height - side) / 2);71    const x1 = x0 + side;72    const y1 = y0 + side;73    const corner = side / 4;74    fill(writer, .{ .x = x0 + corner, .y = y0, .width = side - corner * 2, .height = t }, color);75    fill(writer, .{ .x = x0 + corner, .y = y1 - t, .width = side - corner * 2, .height = t }, color);76    fill(writer, .{ .x = x0, .y = y0 + corner, .width = t, .height = side - corner * 2 }, color);77    fill(writer, .{ .x = x1 - t, .y = y0 + corner, .width = t, .height = side - corner * 2 }, color);78    fill(writer, .{ .x = x0 + corner / 2, .y = y0 + corner / 2, .width = t, .height = t }, color);79    fill(writer, .{ .x = x1 - corner / 2 - t, .y = y0 + corner / 2, .width = t, .height = t }, color);80    fill(writer, .{ .x = x0 + corner / 2, .y = y1 - corner / 2 - t, .width = t, .height = t }, color);81    fill(writer, .{ .x = x1 - corner / 2 - t, .y = y1 - corner / 2 - t, .width = t, .height = t }, color);8283    const cx = x0 + side / 2;84    const cy = y0 + side / 2;85    const reach = side / 2 - corner / 2 - t;86    switch (codepoint) {87        0x2295 => {88            fill(writer, .{ .x = cx - reach, .y = cy - t / 2, .width = reach * 2, .height = t }, color);89            fill(writer, .{ .x = cx - t / 2, .y = cy - reach, .width = t, .height = reach * 2 }, color);90        },91        0x2296 => fill(writer, .{ .x = cx - reach, .y = cy - t / 2, .width = reach * 2, .height = t }, color),92        0x2297 => {93            drawDiagonal(writer, cx, cy, reach, t, color, .both);94        },95        0x2298 => drawDiagonal(writer, cx, cy, reach, t, color, .rising),96        0x2299 => fill(writer, .{ .x = cx - t, .y = cy - t, .width = t * 2, .height = t * 2 }, color),97        else => unreachable,98    }99}100101const DiagonalArms = enum { rising, both };102103fn drawDiagonal(writer: anytype, cx: f32, cy: f32, reach: f32, t: f32, color: Color, arms: DiagonalArms) void {104    const steps: usize = 3;105    const step = reach / @as(f32, @floatFromInt(steps));106    for (0..steps) |index| {107        const offset = step * @as(f32, @floatFromInt(index)) + step / 2;108        fill(writer, .{ .x = cx + offset - t / 2, .y = cy - offset - t / 2, .width = t, .height = t }, color);109        fill(writer, .{ .x = cx - offset - t / 2, .y = cy + offset - t / 2, .width = t, .height = t }, color);110        if (arms == .both) {111            fill(writer, .{ .x = cx - offset - t / 2, .y = cy - offset - t / 2, .width = t, .height = t }, color);112            fill(writer, .{ .x = cx + offset - t / 2, .y = cy + offset - t / 2, .width = t, .height = t }, color);113        }114    }115}116117fn drawMidlineEllipsis(writer: anytype, cell: Rect, color: Color) void {118    const t = strokeThickness(cell);119    const cy = cell.y + (cell.height - t) / 2;120    const spacing = cell.width / 4;121    for (0..3) |index| {122        const offset: f32 = @floatFromInt(index + 1);123        fill(writer, .{ .x = cell.x + spacing * offset - t / 2, .y = cy, .width = t, .height = t }, color);124    }125}126127const BoxSegments = struct {128    left: bool = false,129    right: bool = false,130    up: bool = false,131    down: bool = false,132};133134fn boxSegments(codepoint: u21) ?BoxSegments {135    return switch (codepoint) {136        0x2500, 0x2501 => .{ .left = true, .right = true },137        0x2502, 0x2503 => .{ .up = true, .down = true },138        0x250C, 0x250F, 0x256D => .{ .right = true, .down = true },139        0x2510, 0x2513, 0x256E => .{ .left = true, .down = true },140        0x2514, 0x2517, 0x2570 => .{ .right = true, .up = true },141        0x2518, 0x251B, 0x256F => .{ .left = true, .up = true },142        0x251C => .{ .up = true, .down = true, .right = true },143        0x2524 => .{ .up = true, .down = true, .left = true },144        0x252C => .{ .left = true, .right = true, .down = true },145        0x2534 => .{ .left = true, .right = true, .up = true },146        0x253C => .{ .left = true, .right = true, .up = true, .down = true },147        0x2574 => .{ .left = true },148        0x2575 => .{ .up = true },149        0x2576 => .{ .right = true },150        0x2577 => .{ .down = true },151        else => null,152    };153}154155fn drawBox(writer: anytype, segments: BoxSegments, cell: Rect, color: Color) void {156    const t = strokeThickness(cell);157    const cx = snap(cell.x + (cell.width - t) / 2);158    const cy = snap(cell.y + (cell.height - t) / 2);159    if (segments.left) fill(writer, .{ .x = cell.x, .y = cy, .width = cx - cell.x + t, .height = t }, color);160    if (segments.right) fill(writer, .{ .x = cx, .y = cy, .width = cell.x + cell.width - cx, .height = t }, color);161    if (segments.up) fill(writer, .{ .x = cx, .y = cell.y, .width = t, .height = cy - cell.y + t }, color);162    if (segments.down) fill(writer, .{ .x = cx, .y = cy, .width = t, .height = cell.y + cell.height - cy }, color);163}164165fn drawBlock(writer: anytype, codepoint: u21, cell: Rect, color: Color) void {166    switch (codepoint) {167        0x2580 => fillFraction(writer, cell, color, 0, 0, 8, 4),168        0x2581...0x2588 => {169            const eighths: f32 = @floatFromInt(codepoint - 0x2580);170            const height = cell.height * eighths / 8;171            fill(writer, .{ .x = cell.x, .y = cell.y + cell.height - height, .width = cell.width, .height = height }, color);172        },173        0x2589...0x258F => {174            const eighths: f32 = @floatFromInt(8 - (codepoint - 0x2588));175            fill(writer, .{ .x = cell.x, .y = cell.y, .width = cell.width * eighths / 8, .height = cell.height }, color);176        },177        0x2590 => fillFraction(writer, cell, color, 4, 0, 8, 8),178        0x2591 => fill(writer, cell, shaded(color, 64)),179        0x2592 => fill(writer, cell, shaded(color, 128)),180        0x2593 => fill(writer, cell, shaded(color, 192)),181        0x2594 => fill(writer, .{ .x = cell.x, .y = cell.y, .width = cell.width, .height = cell.height / 8 }, color),182        0x2595 => fill(writer, .{ .x = cell.x + cell.width * 7 / 8, .y = cell.y, .width = cell.width / 8, .height = cell.height }, color),183        0x2596...0x259F => {184            const quads = quadrants(codepoint);185            if (quads.upper_left) fillFraction(writer, cell, color, 0, 0, 4, 4);186            if (quads.upper_right) fillFraction(writer, cell, color, 4, 0, 8, 4);187            if (quads.lower_left) fillFraction(writer, cell, color, 0, 4, 4, 8);188            if (quads.lower_right) fillFraction(writer, cell, color, 4, 4, 8, 8);189        },190        else => unreachable,191    }192}193194const Quadrants = struct {195    upper_left: bool = false,196    upper_right: bool = false,197    lower_left: bool = false,198    lower_right: bool = false,199};200201fn quadrants(codepoint: u21) Quadrants {202    return switch (codepoint) {203        0x2596 => .{ .lower_left = true },204        0x2597 => .{ .lower_right = true },205        0x2598 => .{ .upper_left = true },206        0x2599 => .{ .upper_left = true, .lower_left = true, .lower_right = true },207        0x259A => .{ .upper_left = true, .lower_right = true },208        0x259B => .{ .upper_left = true, .upper_right = true, .lower_left = true },209        0x259C => .{ .upper_left = true, .upper_right = true, .lower_right = true },210        0x259D => .{ .upper_right = true },211        0x259E => .{ .upper_right = true, .lower_left = true },212        0x259F => .{ .upper_right = true, .lower_left = true, .lower_right = true },213        else => .{},214    };215}216217fn drawBraille(writer: anytype, codepoint: u21, cell: Rect, color: Color) void {218    const bits: u8 = @intCast(codepoint - 0x2800);219    const dot_width = @max(1, snap(cell.width / 4));220    const dot_height = @max(1, snap(cell.height / 8));221    const columns = [2]f32{ cell.x + cell.width * 0.18, cell.x + cell.width * 0.58 };222    const rows = [4]f32{223        cell.y + cell.height * 0.12,224        cell.y + cell.height * 0.34,225        cell.y + cell.height * 0.56,226        cell.y + cell.height * 0.78,227    };228    const dots = [8]struct { column: usize, row: usize }{229        .{ .column = 0, .row = 0 },230        .{ .column = 0, .row = 1 },231        .{ .column = 0, .row = 2 },232        .{ .column = 1, .row = 0 },233        .{ .column = 1, .row = 1 },234        .{ .column = 1, .row = 2 },235        .{ .column = 0, .row = 3 },236        .{ .column = 1, .row = 3 },237    };238    for (dots, 0..) |dot, bit| {239        if ((bits >> @intCast(bit)) & 1 == 0) continue;240        fill(writer, .{241            .x = snap(columns[dot.column]),242            .y = snap(rows[dot.row]),243            .width = dot_width,244            .height = dot_height,245        }, color);246    }247}248249fn drawChevron(writer: anytype, cell: Rect, color: Color) void {250    const steps: usize = 4;251    const inset_x = cell.width * 0.2;252    const inset_y = cell.height * 0.22;253    const span_x = cell.width - inset_x * 2;254    const half_y = cell.height / 2 - inset_y;255    const step_x = span_x / @as(f32, @floatFromInt(steps));256    const step_y = half_y / @as(f32, @floatFromInt(steps));257    const thickness = @max(step_y, strokeThickness(cell));258    for (0..steps) |index| {259        const offset: f32 = @floatFromInt(index);260        fill(writer, .{261            .x = snap(cell.x + inset_x + step_x * offset),262            .y = snap(cell.y + inset_y + step_y * offset),263            .width = @max(1, snap(step_x + 1)),264            .height = @max(1, snap(thickness)),265        }, color);266        fill(writer, .{267            .x = snap(cell.x + inset_x + step_x * offset),268            .y = snap(cell.y + cell.height - inset_y - step_y * (offset + 1)),269            .width = @max(1, snap(step_x + 1)),270            .height = @max(1, snap(thickness)),271        }, color);272    }273}274275fn drawStar(writer: anytype, cell: Rect, color: Color) void {276    const rows = [5]f32{ 1, 3, 5, 3, 1 };277    const unit_height = cell.height / 7;278    const unit_width = cell.width / 6;279    for (rows, 0..) |width_units, index| {280        const row_width = unit_width * width_units;281        const row_index: f32 = @floatFromInt(index);282        fill(writer, .{283            .x = snap(cell.x + (cell.width - row_width) / 2),284            .y = snap(cell.y + unit_height * (row_index + 1)),285            .width = @max(1, snap(row_width)),286            .height = @max(1, snap(unit_height)),287        }, color);288    }289}290291fn fillFraction(writer: anytype, cell: Rect, color: Color, x0: f32, y0: f32, x1: f32, y1: f32) void {292    fill(writer, .{293        .x = cell.x + cell.width * x0 / 8,294        .y = cell.y + cell.height * y0 / 8,295        .width = cell.width * (x1 - x0) / 8,296        .height = cell.height * (y1 - y0) / 8,297    }, color);298}299300fn fill(writer: anytype, rect: Rect, color: Color) void {301    writer.fillRect(.{302        .x = snap(rect.x),303        .y = snap(rect.y),304        .width = @max(1, snap(rect.width)),305        .height = @max(1, snap(rect.height)),306    }, color);307}308309fn shaded(color: Color, alpha: u8) Color {310    return .{ .r = color.r, .g = color.g, .b = color.b, .a = @intCast(@as(u16, color.a) * alpha / 255) };311}312313fn strokeThickness(cell: Rect) f32 {314    return @max(1, snap(cell.height / 12));315}316317fn snap(value: f32) f32 {318    return @round(value);319}320321const RecordingWriter = struct {322    rects: std.ArrayListUnmanaged(Rect) = .empty,323    colors: std.ArrayListUnmanaged(Color) = .empty,324    allocator: std.mem.Allocator,325326    fn fillRect(self: *RecordingWriter, rect: Rect, color: Color) void {327        self.rects.append(self.allocator, rect) catch @panic("synth test allocation failed");328        self.colors.append(self.allocator, color) catch @panic("synth test allocation failed");329    }330331    fn deinit(self: *RecordingWriter) void {332        self.rects.deinit(self.allocator);333        self.colors.deinit(self.allocator);334    }335};336337const test_cell = Rect{ .x = 10, .y = 20, .width = 10, .height = 24 };338const test_color = Color{ .r = 200, .g = 100, .b = 50, .a = 255 };339340test "covered spans the terminal vocabulary and rejects letters" {341    try std.testing.expect(covered(0x2502));342    try std.testing.expect(covered(0x258F));343    try std.testing.expect(covered(0x280B));344    try std.testing.expect(covered(0x276F));345    try std.testing.expect(covered(0x2726));346    try std.testing.expect(covered(0x2297));347    try std.testing.expect(covered(0x22EF));348    try std.testing.expect(!covered('a'));349    try std.testing.expect(!covered(0x2560));350}351352test "notdef draws a closed box without a font glyph" {353    var writer = RecordingWriter{ .allocator = std.testing.allocator };354    defer writer.deinit();355    drawNotdef(&writer, test_cell, test_color);356    try std.testing.expectEqual(@as(usize, 4), writer.rects.items.len);357    try std.testing.expectEqual(writer.rects.items[0].y, writer.rects.items[2].y);358    try std.testing.expectEqual(writer.rects.items[1].y + writer.rects.items[1].height, writer.rects.items[2].y + writer.rects.items[2].height);359}360361test "circled operators draw a ring with an inner mark" {362    var ring_only = RecordingWriter{ .allocator = std.testing.allocator };363    defer ring_only.deinit();364    try std.testing.expect(draw(&ring_only, 0x2299, test_cell, test_color));365    const dot_rects = ring_only.rects.items.len;366    try std.testing.expectEqual(@as(usize, 9), dot_rects);367368    var crossed = RecordingWriter{ .allocator = std.testing.allocator };369    defer crossed.deinit();370    try std.testing.expect(draw(&crossed, 0x2297, test_cell, test_color));371    try std.testing.expect(crossed.rects.items.len > dot_rects);372}373374test "midline ellipsis draws three centered dots" {375    var writer = RecordingWriter{ .allocator = std.testing.allocator };376    defer writer.deinit();377    try std.testing.expect(draw(&writer, 0x22EF, test_cell, test_color));378    try std.testing.expectEqual(@as(usize, 3), writer.rects.items.len);379    for (writer.rects.items) |rect| {380        try std.testing.expect(rect.y > test_cell.y + test_cell.height / 4);381        try std.testing.expect(rect.y < test_cell.y + test_cell.height * 3 / 4);382    }383}384385test "left one eighth block fills a narrow left bar" {386    var writer = RecordingWriter{ .allocator = std.testing.allocator };387    defer writer.deinit();388    try std.testing.expect(draw(&writer, 0x258F, test_cell, test_color));389    try std.testing.expectEqual(@as(usize, 1), writer.rects.items.len);390    const rect = writer.rects.items[0];391    try std.testing.expectEqual(test_cell.x, rect.x);392    try std.testing.expectEqual(test_cell.y, rect.y);393    try std.testing.expectApproxEqAbs(test_cell.width / 8, rect.width, 1.0);394    try std.testing.expectEqual(test_cell.height, rect.height);395}396397test "full block covers the cell and shades keep the hue at reduced alpha" {398    var writer = RecordingWriter{ .allocator = std.testing.allocator };399    defer writer.deinit();400    try std.testing.expect(draw(&writer, 0x2588, test_cell, test_color));401    try std.testing.expectEqual(test_cell.width, writer.rects.items[0].width);402    try std.testing.expectEqual(test_cell.height, writer.rects.items[0].height);403404    try std.testing.expect(draw(&writer, 0x2592, test_cell, test_color));405    try std.testing.expectEqual(@as(u8, 128), writer.colors.items[1].a);406    try std.testing.expectEqual(test_color.r, writer.colors.items[1].r);407}408409test "braille dot count follows the bit pattern" {410    var writer = RecordingWriter{ .allocator = std.testing.allocator };411    defer writer.deinit();412    try std.testing.expect(draw(&writer, 0x280B, test_cell, test_color));413    try std.testing.expectEqual(@as(usize, 3), writer.rects.items.len);414415    var full = RecordingWriter{ .allocator = std.testing.allocator };416    defer full.deinit();417    try std.testing.expect(draw(&full, 0x28FF, test_cell, test_color));418    try std.testing.expectEqual(@as(usize, 8), full.rects.items.len);419}420421test "box drawing tee composes three segments" {422    var writer = RecordingWriter{ .allocator = std.testing.allocator };423    defer writer.deinit();424    try std.testing.expect(draw(&writer, 0x251C, test_cell, test_color));425    try std.testing.expectEqual(@as(usize, 3), writer.rects.items.len);426}427428test "chevron and star emit stepped fills inside the cell" {429    var writer = RecordingWriter{ .allocator = std.testing.allocator };430    defer writer.deinit();431    try std.testing.expect(draw(&writer, 0x276F, test_cell, test_color));432    try std.testing.expect(draw(&writer, 0x2726, test_cell, test_color));433    for (writer.rects.items) |rect| {434        try std.testing.expect(rect.x >= test_cell.x - 1);435        try std.testing.expect(rect.x + rect.width <= test_cell.x + test_cell.width + 2);436        try std.testing.expect(rect.y >= test_cell.y - 1);437        try std.testing.expect(rect.y + rect.height <= test_cell.y + test_cell.height + 2);438    }439}