tiny.gui.paint.strip

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

1const std = @import("std");23const paint_root = @import("root.zig");45const Allocator = std.mem.Allocator;6const Command = paint_root.command.Command;7const Region = paint_root.cpu.Region;89pub const default_height: u32 = 16;10pub const word_lanes: usize = 7;1112pub const Options = struct {13    height: u32 = default_height,14};1516pub const Lane = enum(usize) {17    command_index = 0,18    order = 1,19    strip = 2,20    x0 = 3,21    y0 = 4,22    x1 = 5,23    y1 = 6,24};2526pub const Record = struct {27    command_index: u32,28    order: u32,29    strip: u32,30    x0: u32,31    y0: u32,32    x1: u32,33    y1: u32,34};3536pub const Records = struct {37    words: []u32,38    count: usize,3940    pub fn lane(self: Records, which: Lane) []const u32 {41        const start = @backingInt(which) * self.count;42        return self.words[start .. start + self.count];43    }4445    pub fn laneMut(self: *Records, which: Lane) []u32 {46        const start = @backingInt(which) * self.count;47        return self.words[start .. start + self.count];48    }4950    pub fn at(self: Records, index: usize) Record {51        return .{52            .command_index = self.lane(.command_index)[index],53            .order = self.lane(.order)[index],54            .strip = self.lane(.strip)[index],55            .x0 = self.lane(.x0)[index],56            .y0 = self.lane(.y0)[index],57            .x1 = self.lane(.x1)[index],58            .y1 = self.lane(.y1)[index],59        };60    }6162    pub fn deinit(self: *Records, allocator: Allocator) void {63        allocator.free(self.words);64        self.* = undefined;65    }66};6768const StripRange = struct {69    first: u32,70    last: u32,7172    fn count(self: StripRange) usize {73        return self.last - self.first + 1;74    }75};7677pub fn recordCount(commands: []const Command, width: u32, height: u32, region: Region, options: Options) !usize {78    if (options.height == 0) return error.InvalidStripHeight;79    const active_region = region.clamped(width, height);80    if (active_region.pixelCount() == 0) return 0;8182    var total: usize = 0;83    for (commands) |paint| {84        const bounds = paint_root.cpu.clippedBounds(width, height, paint, active_region) orelse continue;85        total = std.math.add(usize, total, stripRange(bounds.y0, bounds.y1, options).count()) catch return error.RecordCountTooLarge;86    }87    return total;88}8990pub fn reifyAlloc(allocator: Allocator, commands: []const Command, width: u32, height: u32, region: Region, options: Options) !Records {91    const count = try recordCount(commands, width, height, region, options);92    const word_count = std.math.mul(usize, count, word_lanes) catch return error.RecordCountTooLarge;93    const words = try allocator.alloc(u32, word_count);94    errdefer allocator.free(words);95    var records = Records{ .words = words, .count = count };96    try writeRecords(&records, commands, width, height, region, options);97    return records;98}99100fn writeRecords(records: *Records, commands: []const Command, width: u32, height: u32, region: Region, options: Options) !void {101    if (options.height == 0) return error.InvalidStripHeight;102    const active_region = region.clamped(width, height);103    if (active_region.pixelCount() == 0) return;104105    var cursor: usize = 0;106    for (commands, 0..) |paint, command_index| {107        const command_index_u32 = std.math.cast(u32, command_index) orelse return error.CommandCountTooLarge;108        const bounds = paint_root.cpu.clippedBounds(width, height, paint, active_region) orelse continue;109        const range = stripRange(bounds.y0, bounds.y1, options);110        var strip = range.first;111        while (strip <= range.last) : (strip += 1) {112            const y0 = @max(bounds.y0, stripStart(strip, options.height));113            const y1 = @min(bounds.y1, stripEnd(strip, options.height));114            writeRecord(records, cursor, .{115                .command_index = command_index_u32,116                .order = paint.order,117                .strip = strip,118                .x0 = bounds.x0,119                .y0 = y0,120                .x1 = bounds.x1,121                .y1 = y1,122            });123            cursor += 1;124        }125    }126    std.debug.assert(cursor == records.count);127}128129fn writeRecord(records: *Records, index: usize, record: Record) void {130    records.laneMut(.command_index)[index] = record.command_index;131    records.laneMut(.order)[index] = record.order;132    records.laneMut(.strip)[index] = record.strip;133    records.laneMut(.x0)[index] = record.x0;134    records.laneMut(.y0)[index] = record.y0;135    records.laneMut(.x1)[index] = record.x1;136    records.laneMut(.y1)[index] = record.y1;137}138139fn stripRange(y0: u32, y1: u32, options: Options) StripRange {140    std.debug.assert(y0 < y1);141    return .{142        .first = y0 / options.height,143        .last = (y1 - 1) / options.height,144    };145}146147fn stripStart(strip: u32, height: u32) u32 {148    return @intCast(@as(u64, strip) * height);149}150151fn stripEnd(strip: u32, height: u32) u32 {152    return @intCast(@min(@as(u64, std.math.maxInt(u32)), (@as(u64, strip) + 1) * height));153}154155test "reifyAlloc emits globally aligned strip records" {156    const allocator = std.testing.allocator;157    const commands = [_]Command{158        .{159            .kind = .fill,160            .rect = .{ .x = 2, .y = 0, .width = 12, .height = 40 },161            .clip = .{ .x = 0, .y = 0, .width = 64, .height = 64 },162            .color = .{ .r = 20, .g = 30, .b = 40, .a = 255 },163            .order = 3,164        },165        .{166            .kind = .fill,167            .rect = .{ .x = 8, .y = 10, .width = 18, .height = 10 },168            .clip = .{ .x = 0, .y = 0, .width = 64, .height = 64 },169            .color = .{ .r = 80, .g = 90, .b = 100, .a = 255 },170            .order = 7,171        },172    };173174    var records = try reifyAlloc(allocator, commands[0..], 64, 64, Region.full(64, 64), .{ .height = 16 });175    defer records.deinit(allocator);176177    try std.testing.expectEqual(@as(usize, 5), records.count);178    try std.testing.expectEqualSlices(u32, &.{ 0, 0, 0, 1, 1 }, records.lane(.command_index));179    try std.testing.expectEqualSlices(u32, &.{ 3, 3, 3, 7, 7 }, records.lane(.order));180    try std.testing.expectEqualSlices(u32, &.{ 0, 1, 2, 0, 1 }, records.lane(.strip));181    try std.testing.expectEqualSlices(u32, &.{ 0, 16, 32, 10, 16 }, records.lane(.y0));182    try std.testing.expectEqualSlices(u32, &.{ 16, 32, 40, 16, 20 }, records.lane(.y1));183}184185test "recordCount clips to the active region" {186    const commands = [_]Command{.{187        .kind = .fill,188        .rect = .{ .x = 0, .y = 0, .width = 32, .height = 32 },189        .clip = .{ .x = 0, .y = 0, .width = 32, .height = 32 },190        .color = .{ .r = 20, .g = 30, .b = 40, .a = 255 },191    }};192193    const count = try recordCount(commands[0..], 32, 32, .{ .x = 0, .y = 8, .width = 32, .height = 8 }, .{ .height = 16 });194    try std.testing.expectEqual(@as(usize, 1), count);195}