chore: import upstream snapshot with attribution

pkg/wuffs/src/c.zig

@@ -0,0 +1,18 @@
+pub const c = @cImport({
+    for (defines) |d| @cDefine(d, "1");
+    @cInclude("wuffs-v0.4.c");
+});
+
+/// All the C macros defined so that the header matches the build.
+pub const defines: []const []const u8 = &[_][]const u8{
+    "WUFFS_CONFIG__MODULES",
+    "WUFFS_CONFIG__MODULE__AUX__BASE",
+    "WUFFS_CONFIG__MODULE__AUX__IMAGE",
+    "WUFFS_CONFIG__MODULE__BASE",
+    "WUFFS_CONFIG__MODULE__ADLER32",
+    "WUFFS_CONFIG__MODULE__CRC32",
+    "WUFFS_CONFIG__MODULE__DEFLATE",
+    "WUFFS_CONFIG__MODULE__JPEG",
+    "WUFFS_CONFIG__MODULE__PNG",
+    "WUFFS_CONFIG__MODULE__ZLIB",
+};

pkg/wuffs/src/error.zig

@@ -0,0 +1,13 @@
+const std = @import("std");
+
+const c = @import("c.zig").c;
+
+pub const Error = std.mem.Allocator.Error || error{ WuffsError, Overflow };
+
+pub fn check(log: anytype, status: *const c.struct_wuffs_base__status__struct) error{WuffsError}!void {
+    if (!c.wuffs_base__status__is_ok(status)) {
+        const e = c.wuffs_base__status__message(status);
+        log.warn("decode err={s}", .{e});
+        return error.WuffsError;
+    }
+}

pkg/wuffs/src/jpeg.zig

@@ -0,0 +1,151 @@
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+const c = @import("c.zig").c;
+const Error = @import("error.zig").Error;
+const check = @import("error.zig").check;
+const ImageData = @import("main.zig").ImageData;
+const maximum_image_size = @import("main.zig").maximum_image_size;
+const mul = std.math.mul;
+
+const log = std.log.scoped(.wuffs_jpeg);
+
+/// Decode a JPEG image.
+pub fn decode(alloc: Allocator, data: []const u8) Error!ImageData {
+    // Work around some weirdness in WUFFS/Zig, there are some structs that
+    // are defined as "extern" by the Zig compiler which means that Zig won't
+    // allocate them on the stack at compile time. WUFFS has functions for
+    // dynamically allocating these structs but they use the C malloc/free. This
+    // gets around that by using the Zig allocator to allocate enough memory for
+    // the struct and then casts it to the appropriate pointer.
+
+    const decoder_buf = try alloc.alloc(u8, c.sizeof__wuffs_jpeg__decoder());
+    defer alloc.free(decoder_buf);
+
+    const decoder: ?*c.wuffs_jpeg__decoder = @ptrCast(decoder_buf);
+    {
+        const status = c.wuffs_jpeg__decoder__initialize(
+            decoder,
+            c.sizeof__wuffs_jpeg__decoder(),
+            c.WUFFS_VERSION,
+            0,
+        );
+        try check(log, &status);
+    }
+
+    var source_buffer: c.wuffs_base__io_buffer = .{
+        .data = .{ .ptr = @ptrCast(@constCast(data.ptr)), .len = data.len },
+        .meta = .{
+            .wi = data.len,
+            .ri = 0,
+            .pos = 0,
+            .closed = true,
+        },
+    };
+
+    var image_config: c.wuffs_base__image_config = undefined;
+    {
+        const status = c.wuffs_jpeg__decoder__decode_image_config(
+            decoder,
+            &image_config,
+            &source_buffer,
+        );
+        try check(log, &status);
+    }
+
+    const width = c.wuffs_base__pixel_config__width(&image_config.pixcfg);
+    const height = c.wuffs_base__pixel_config__height(&image_config.pixcfg);
+
+    c.wuffs_base__pixel_config__set(
+        &image_config.pixcfg,
+        c.WUFFS_BASE__PIXEL_FORMAT__RGBA_NONPREMUL,
+        c.WUFFS_BASE__PIXEL_SUBSAMPLING__NONE,
+        width,
+        height,
+    );
+
+    const size: usize = try mul(
+        usize,
+        try mul(usize, width, height),
+        @sizeOf(c.wuffs_base__color_u32_argb_premul),
+    );
+
+    if (size > maximum_image_size) {
+        log.warn("image size {d} is larger than the maximum allowed ({d})", .{ size, maximum_image_size });
+        return error.Overflow;
+    }
+
+    const destination = try alloc.alloc(
+        u8,
+        size,
+    );
+    errdefer alloc.free(destination);
+
+    // temporary buffer for intermediate processing of image
+    const work_buffer = try alloc.alloc(
+        u8,
+
+        // The type of this is a u64 on all systems but our allocator
+        // uses a usize which is a u32 on 32-bit systems.
+        std.math.cast(
+            usize,
+            c.wuffs_jpeg__decoder__workbuf_len(decoder).max_incl,
+        ) orelse return error.OutOfMemory,
+    );
+    defer alloc.free(work_buffer);
+
+    const work_slice = c.wuffs_base__make_slice_u8(
+        work_buffer.ptr,
+        work_buffer.len,
+    );
+
+    var pixel_buffer: c.wuffs_base__pixel_buffer = undefined;
+    {
+        const status = c.wuffs_base__pixel_buffer__set_from_slice(
+            &pixel_buffer,
+            &image_config.pixcfg,
+            c.wuffs_base__make_slice_u8(destination.ptr, destination.len),
+        );
+        try check(log, &status);
+    }
+
+    {
+        const status = c.wuffs_jpeg__decoder__decode_frame(
+            decoder,
+            &pixel_buffer,
+            &source_buffer,
+            c.WUFFS_BASE__PIXEL_BLEND__SRC,
+            work_slice,
+            null,
+        );
+        try check(log, &status);
+    }
+
+    return .{
+        .width = width,
+        .height = height,
+        .data = destination,
+    };
+}
+
+test "jpeg_decode_000000" {
+    const data = try decode(std.testing.allocator, @embedFile("1x1#000000.jpg"));
+    defer std.testing.allocator.free(data.data);
+
+    try std.testing.expectEqual(1, data.width);
+    try std.testing.expectEqual(1, data.height);
+    try std.testing.expectEqualSlices(u8, &.{ 0, 0, 0, 255 }, data.data);
+}
+
+test "jpeg_decode_FFFFFF" {
+    const data = try decode(std.testing.allocator, @embedFile("1x1#FFFFFF.jpg"));
+    defer std.testing.allocator.free(data.data);
+
+    try std.testing.expectEqual(1, data.width);
+    try std.testing.expectEqual(1, data.height);
+    try std.testing.expectEqualSlices(u8, &.{ 255, 255, 255, 255 }, data.data);
+}
+
+test "jpeg: too big" {
+    const data = decode(std.testing.allocator, @embedFile("too_big.jpg"));
+    try std.testing.expectError(error.Overflow, data);
+}

pkg/wuffs/src/main.zig

@@ -0,0 +1,20 @@
+const std = @import("std");
+
+pub const png = @import("png.zig");
+pub const jpeg = @import("jpeg.zig");
+pub const swizzle = @import("swizzle.zig");
+pub const Error = @import("error.zig").Error;
+
+/// The maximum image size, based on the 4G limit of Ghostty's
+/// `image-storage-limit` config.
+pub const maximum_image_size = 4 * 1024 * 1024 * 1024;
+
+pub const ImageData = struct {
+    width: u32,
+    height: u32,
+    data: []u8,
+};
+
+test {
+    std.testing.refAllDeclsRecursive(@This());
+}

pkg/wuffs/src/png.zig

@@ -0,0 +1,151 @@
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+const c = @import("c.zig").c;
+const Error = @import("error.zig").Error;
+const check = @import("error.zig").check;
+const ImageData = @import("main.zig").ImageData;
+const maximum_image_size = @import("main.zig").maximum_image_size;
+const mul = std.math.mul;
+
+const log = std.log.scoped(.wuffs_png);
+
+/// Decode a PNG image.
+pub fn decode(alloc: Allocator, data: []const u8) Error!ImageData {
+    // Work around some weirdness in WUFFS/Zig, there are some structs that
+    // are defined as "extern" by the Zig compiler which means that Zig won't
+    // allocate them on the stack at compile time. WUFFS has functions for
+    // dynamically allocating these structs but they use the C malloc/free. This
+    // gets around that by using the Zig allocator to allocate enough memory for
+    // the struct and then casts it to the appropriate pointer.
+
+    const decoder_buf = try alloc.alloc(u8, c.sizeof__wuffs_png__decoder());
+    defer alloc.free(decoder_buf);
+
+    const decoder: ?*c.wuffs_png__decoder = @ptrCast(decoder_buf);
+    {
+        const status = c.wuffs_png__decoder__initialize(
+            decoder,
+            c.sizeof__wuffs_png__decoder(),
+            c.WUFFS_VERSION,
+            0,
+        );
+        try check(log, &status);
+    }
+
+    var source_buffer: c.wuffs_base__io_buffer = .{
+        .data = .{ .ptr = @ptrCast(@constCast(data.ptr)), .len = data.len },
+        .meta = .{
+            .wi = data.len,
+            .ri = 0,
+            .pos = 0,
+            .closed = true,
+        },
+    };
+
+    var image_config: c.wuffs_base__image_config = undefined;
+    {
+        const status = c.wuffs_png__decoder__decode_image_config(
+            decoder,
+            &image_config,
+            &source_buffer,
+        );
+        try check(log, &status);
+    }
+
+    const width = c.wuffs_base__pixel_config__width(&image_config.pixcfg);
+    const height = c.wuffs_base__pixel_config__height(&image_config.pixcfg);
+
+    c.wuffs_base__pixel_config__set(
+        &image_config.pixcfg,
+        c.WUFFS_BASE__PIXEL_FORMAT__RGBA_NONPREMUL,
+        c.WUFFS_BASE__PIXEL_SUBSAMPLING__NONE,
+        width,
+        height,
+    );
+
+    const size: usize = try mul(
+        usize,
+        try mul(usize, width, height),
+        @sizeOf(c.wuffs_base__color_u32_argb_premul),
+    );
+
+    if (size > maximum_image_size) {
+        log.warn("image size {d} is larger than the maximum allowed ({d})", .{ size, maximum_image_size });
+        return error.Overflow;
+    }
+
+    const destination = try alloc.alloc(
+        u8,
+        size,
+    );
+    errdefer alloc.free(destination);
+
+    // temporary buffer for intermediate processing of image
+    const work_buffer = try alloc.alloc(
+        u8,
+
+        // The type of this is a u64 on all systems but our allocator
+        // uses a usize which is a u32 on 32-bit systems.
+        std.math.cast(
+            usize,
+            c.wuffs_png__decoder__workbuf_len(decoder).max_incl,
+        ) orelse return error.OutOfMemory,
+    );
+    defer alloc.free(work_buffer);
+
+    const work_slice = c.wuffs_base__make_slice_u8(
+        work_buffer.ptr,
+        work_buffer.len,
+    );
+
+    var pixel_buffer: c.wuffs_base__pixel_buffer = undefined;
+    {
+        const status = c.wuffs_base__pixel_buffer__set_from_slice(
+            &pixel_buffer,
+            &image_config.pixcfg,
+            c.wuffs_base__make_slice_u8(destination.ptr, destination.len),
+        );
+        try check(log, &status);
+    }
+
+    {
+        const status = c.wuffs_png__decoder__decode_frame(
+            decoder,
+            &pixel_buffer,
+            &source_buffer,
+            c.WUFFS_BASE__PIXEL_BLEND__SRC,
+            work_slice,
+            null,
+        );
+        try check(log, &status);
+    }
+
+    return .{
+        .width = width,
+        .height = height,
+        .data = destination,
+    };
+}
+
+test "png_decode_000000" {
+    const data = try decode(std.testing.allocator, @embedFile("1x1#000000.png"));
+    defer std.testing.allocator.free(data.data);
+
+    try std.testing.expectEqual(1, data.width);
+    try std.testing.expectEqual(1, data.height);
+    try std.testing.expectEqualSlices(u8, &.{ 0, 0, 0, 255 }, data.data);
+}
+
+test "png_decode_FFFFFF" {
+    const data = try decode(std.testing.allocator, @embedFile("1x1#FFFFFF.png"));
+    defer std.testing.allocator.free(data.data);
+
+    try std.testing.expectEqual(1, data.width);
+    try std.testing.expectEqual(1, data.height);
+    try std.testing.expectEqualSlices(u8, &.{ 255, 255, 255, 255 }, data.data);
+}
+
+test "png: too big" {
+    const data = decode(std.testing.allocator, @embedFile("too_big.png"));
+    try std.testing.expectError(error.Overflow, data);
+}

pkg/wuffs/src/swizzle.zig

@@ -0,0 +1,121 @@
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+const assert = std.debug.assert;
+const c = @import("c.zig").c;
+const Error = @import("error.zig").Error;
+
+const log = std.log.scoped(.wuffs_swizzler);
+
+pub fn gToRgba(alloc: Allocator, src: []const u8) Error![]u8 {
+    return swizzle(
+        alloc,
+        src,
+        c.WUFFS_BASE__PIXEL_FORMAT__Y,
+        c.WUFFS_BASE__PIXEL_FORMAT__RGBA_PREMUL,
+    );
+}
+
+pub fn gaToRgba(alloc: Allocator, src: []const u8) Error![]u8 {
+    return swizzle(
+        alloc,
+        src,
+        c.WUFFS_BASE__PIXEL_FORMAT__YA_PREMUL,
+        c.WUFFS_BASE__PIXEL_FORMAT__RGBA_PREMUL,
+    );
+}
+
+pub fn rgbToRgba(alloc: Allocator, src: []const u8) Error![]u8 {
+    return swizzle(
+        alloc,
+        src,
+        c.WUFFS_BASE__PIXEL_FORMAT__RGB,
+        c.WUFFS_BASE__PIXEL_FORMAT__RGBA_PREMUL,
+    );
+}
+
+pub fn bgrToRgba(alloc: Allocator, src: []const u8) Error![]u8 {
+    return swizzle(
+        alloc,
+        src,
+        c.WUFFS_BASE__PIXEL_FORMAT__BGR,
+        c.WUFFS_BASE__PIXEL_FORMAT__RGBA_PREMUL,
+    );
+}
+
+pub fn bgraToRgba(alloc: Allocator, src: []const u8) Error![]u8 {
+    return swizzle(
+        alloc,
+        src,
+        c.WUFFS_BASE__PIXEL_FORMAT__BGRA_PREMUL,
+        c.WUFFS_BASE__PIXEL_FORMAT__RGBA_PREMUL,
+    );
+}
+
+fn swizzle(
+    alloc: Allocator,
+    src: []const u8,
+    comptime src_pixel_format: u32,
+    comptime dst_pixel_format: u32,
+) Error![]u8 {
+    const src_slice = c.wuffs_base__make_slice_u8(
+        @constCast(src.ptr),
+        src.len,
+    );
+
+    const dst_fmt = c.wuffs_base__make_pixel_format(
+        dst_pixel_format,
+    );
+
+    assert(c.wuffs_base__pixel_format__is_direct(&dst_fmt));
+    assert(c.wuffs_base__pixel_format__is_interleaved(&dst_fmt));
+    assert(c.wuffs_base__pixel_format__bits_per_pixel(&dst_fmt) % 8 == 0);
+
+    const dst_size = c.wuffs_base__pixel_format__bits_per_pixel(&dst_fmt) / 8;
+
+    const src_fmt = c.wuffs_base__make_pixel_format(
+        src_pixel_format,
+    );
+
+    assert(c.wuffs_base__pixel_format__is_direct(&src_fmt));
+    assert(c.wuffs_base__pixel_format__is_interleaved(&src_fmt));
+    assert(c.wuffs_base__pixel_format__bits_per_pixel(&src_fmt) % 8 == 0);
+
+    const src_size = c.wuffs_base__pixel_format__bits_per_pixel(&src_fmt) / 8;
+
+    assert(src.len % src_size == 0);
+
+    const dst = try alloc.alloc(u8, src.len * dst_size / src_size);
+    errdefer alloc.free(dst);
+
+    const dst_slice = c.wuffs_base__make_slice_u8(
+        dst.ptr,
+        dst.len,
+    );
+
+    var swizzler: c.wuffs_base__pixel_swizzler = undefined;
+    {
+        const status = c.wuffs_base__pixel_swizzler__prepare(
+            &swizzler,
+            dst_fmt,
+            c.wuffs_base__empty_slice_u8(),
+            src_fmt,
+            c.wuffs_base__empty_slice_u8(),
+            c.WUFFS_BASE__PIXEL_BLEND__SRC,
+        );
+        if (!c.wuffs_base__status__is_ok(&status)) {
+            const e = c.wuffs_base__status__message(&status);
+            log.warn("{s}", .{e});
+            return error.WuffsError;
+        }
+    }
+    {
+        _ = c.wuffs_base__pixel_swizzler__swizzle_interleaved_from_slice(
+            &swizzler,
+            dst_slice,
+            c.wuffs_base__empty_slice_u8(),
+            src_slice,
+        );
+    }
+
+    return dst;
+}