Automatic width and height properties on images (#88)

build.zig.zon

@@ -3,8 +3,8 @@
     .version = "0.0.0",
     .dependencies = .{
         .supermd = .{
-            .url = "git+https://github.com/kristoff-it/supermd#a034ec48c8a01b26de50f479090716d3ed2152c9",
-            .hash = "122058e6f4ebd493d1c7f7c1e21549d2b2e5d9a1921dba758f3558d88a34a70384be",
+            .url = "git+https://github.com/kristoff-it/supermd#c47273684d3236881fdc9f90fbf66965389d88bd",
+            .hash = "1220f5265c5f99c621f3b2d822723ba1b79297b4c809fcee98c7d48947002458bf7c",
         },
         .scripty = .{
             .url = "git+https://github.com/kristoff-it/scripty#df8c11380f9e9bec34809f2242fb116d27cf39d6",
@@ -39,6 +39,10 @@
             .hash = "1220f2d8402bb7bbc4786b9c0aad73910929ea209cbd3b063842371d68abfed33c1e",
             .lazy = true,
         },
+        .wuffs = .{
+            .url = "git+https://github.com/allyourcodebase/wuffs#818c8ad6607dd5c1ee571362fdb9813b744ee548",
+            .hash = "1220e4ee09c4fa2d90a9cc7f34f14e04be55a779c84d486696fa9f9ab98ade35409d",
+        },
     },
     .paths = .{"."},
 }

build/tools.zig

@@ -65,6 +65,7 @@ pub fn build(b: *std.Build) !void {
     const syntax = b.dependency("flow-syntax", mode);
     const ts = syntax.builder.dependency("tree-sitter", mode);
     const treez = ts.module("treez");
+    const wuffs = b.dependency("wuffs", mode);
 
     const zine = b.addModule("zine", .{
         .root_source_file = b.path("src/root.zig"),
@@ -97,6 +98,7 @@ pub fn build(b: *std.Build) !void {
     layout.root_module.addImport("zeit", zeit);
     layout.root_module.addImport("syntax", syntax.module("syntax"));
     layout.root_module.addImport("treez", treez);
+    layout.root_module.addImport("wuffs", wuffs.module("wuffs"));
     layout.linkLibrary(ts.artifact("tree-sitter"));
 
     b.installArtifact(layout);

src/exes/layout/cache.zig

@@ -6,6 +6,7 @@ const join = zine.join;
 const context = zine.context;
 const Allocator = std.mem.Allocator;
 const DepWriter = zine.DepWriter;
+const wuffs = @import("wuffs");
 
 const log = std.log.scoped(.layout_cache);
 
@@ -957,7 +958,7 @@ fn loadPage(
                 directive.kind.code.src = .{ .url = buf.items };
             },
             inline else => |val, tag| {
-                const res = switch (val.src.?) {
+                const res: context.Value = switch (val.src.?) {
                     .url => continue,
                     .self_page => blk: {
                         if (@hasField(@TypeOf(val), "alternative")) {
@@ -1138,6 +1139,16 @@ fn loadPage(
                             a._meta.kind,
                         );
                         @field(directive.kind, @tagName(tag)).src = .{ .url = url };
+                        if(directive.kind == .image) blk: {
+                            const image_handle = std.fs.cwd().openFile(a._meta.path, .{}) catch break :blk;
+                            defer image_handle.close();
+                            var image_header_buf: [2048]u8 = undefined;
+                            const image_header_len = image_handle.readAll(&image_header_buf) catch break :blk;
+                            const image_header = image_header_buf[0..image_header_len];
+
+                            const img_size = getImageSize(image_header) catch break :blk;
+                            directive.kind.image.size = .{.w = img_size.w, .h = img_size.h};
+                        }
                     },
                 }
             },
@@ -1146,6 +1157,68 @@ fn loadPage(
     return page;
 }
 
+const max_align = @alignOf(std.c.max_align_t);
+fn allocDecoder(
+    comptime name: []const u8,
+) !struct { []align(max_align) u8, *wuffs.wuffs_base__image_decoder } {
+    const size = @field(wuffs, "sizeof__wuffs_" ++ name ++ "__decoder")();
+    const init_fn = @field(wuffs, "wuffs_" ++ name ++ "__decoder__initialize");
+    const upcast_fn = @field(wuffs, "wuffs_" ++ name ++ "__decoder__upcast_as__wuffs_base__image_decoder");
+
+    const decoder_raw = try gpa.alignedAlloc(u8, max_align, size);
+    errdefer gpa.free(decoder_raw);
+    for (decoder_raw) |*byte| byte.* = 0;
+
+    try wrapErr(init_fn(@ptrCast(decoder_raw), size, wuffs.WUFFS_VERSION, wuffs.WUFFS_INITIALIZE__ALREADY_ZEROED));
+
+    const upcasted = upcast_fn(@ptrCast(decoder_raw)).?;
+    return .{ decoder_raw, upcasted };
+}
+fn wrapErr(status: wuffs.wuffs_base__status) !void {
+    if (wuffs.wuffs_base__status__message(&status)) |_| {
+        return error.WuffsError;
+    }
+}
+const Size = struct {w: i64, h: i64};
+fn getImageSize(image_src: []const u8) !Size {
+    var g_src = wuffs.wuffs_base__ptr_u8__reader(@constCast(image_src.ptr), image_src.len, true);
+
+    const g_fourcc = wuffs.wuffs_base__magic_number_guess_fourcc(
+        wuffs.wuffs_base__io_buffer__reader_slice(&g_src),
+        g_src.meta.closed,
+    );
+    if (g_fourcc < 0) return error.CouldNotGuessFileFormat;
+
+    const decoder_raw, const g_image_decoder = switch (g_fourcc) {
+        wuffs.WUFFS_BASE__FOURCC__BMP => try allocDecoder("bmp"),
+        wuffs.WUFFS_BASE__FOURCC__GIF => try allocDecoder("gif"),
+        wuffs.WUFFS_BASE__FOURCC__JPEG => try allocDecoder("jpeg"),
+        wuffs.WUFFS_BASE__FOURCC__NPBM => try allocDecoder("netpbm"),
+        wuffs.WUFFS_BASE__FOURCC__NIE => try allocDecoder("nie"),
+        wuffs.WUFFS_BASE__FOURCC__PNG => try allocDecoder("png"),
+        wuffs.WUFFS_BASE__FOURCC__QOI => try allocDecoder("qoi"),
+        wuffs.WUFFS_BASE__FOURCC__TGA => try allocDecoder("tga"),
+        wuffs.WUFFS_BASE__FOURCC__WBMP => try allocDecoder("wbmp"),
+        wuffs.WUFFS_BASE__FOURCC__WEBP => try allocDecoder("webp"),
+        else => {
+            return error.UnsupportedImageFormat;
+        },
+    };
+    defer gpa.free(decoder_raw);
+
+    var g_image_config = std.mem.zeroes(wuffs.wuffs_base__image_config);
+    try wrapErr(wuffs.wuffs_base__image_decoder__decode_image_config(
+        g_image_decoder,
+        &g_image_config,
+        &g_src,
+    ));
+
+    const g_width = wuffs.wuffs_base__pixel_config__width(&g_image_config.pixcfg);
+    const g_height = wuffs.wuffs_base__pixel_config__height(&g_image_config.pixcfg);
+
+    return .{.w = std.math.cast(i64, g_width) orelse return error.Cast, .h = std.math.cast(i64, g_height) orelse return error.Cast};
+}
+
 pub fn fatal(comptime fmt: []const u8, args: anytype) noreturn {
     std.debug.print(fmt, args);
     std.process.exit(1);

src/render/html.zig

@@ -354,6 +354,7 @@ fn renderDirective(
                 if (directive.title) |t| try w.print(" title=\"{s}\"", .{t});
                 try w.print(" src=\"{s}\"", .{img.src.?.url});
                 if (img.alt) |alt| try w.print(" alt=\"{s}\"", .{alt});
+                if(img.size) |size| try w.print(" width=\"{d}\" height=\"{d}\"", .{size.w, size.h});
                 try w.print(">", .{});
                 if (img.linked) |l| if (l) try w.print("</a>", .{});
                 if (caption != null) try w.print("\n<figcaption>", .{});