media: add stbtt binding

packages/media/build.zig

@@ -17,8 +17,11 @@ pub fn build(b: *std.Build) void {
         },
     });
 
-    mod.addCSourceFile(.{
-        .file = b.path("src/stbi/stb_image.c"),
+    mod.addCSourceFiles(.{
+        .files = &.{
+            "src/stbi/stb_image.c",
+            "src/stbtt/stb_truetype.c",
+        },
         .flags = &.{
             "-std=c17",
             "-Wall",

packages/media/src/root.zig

@@ -9,6 +9,7 @@ pub const png = @import("png.zig");
 pub const qoa = @import("qoa.zig");
 pub const qoi = @import("qoi.zig");
 pub const stbi = @import("stbi.zig");
+pub const stbtt = @import("stbtt.zig");
 
 test "refAllDecls" {
     std.testing.refAllDecls(@This());

packages/media/src/stbtt.zig

@@ -0,0 +1,227 @@
+const std = @import("std");
+const Self = @This();
+
+allocator: std.mem.Allocator,
+io: std.Io,
+
+mutex: std.Io.Mutex = .init,
+allocations: std.AutoHashMapUnmanaged(*anyopaque, usize) = .empty,
+allocated_bytes: usize = 0,
+
+const alignment: std.mem.Alignment = .@"16";
+const VoidPtr = ?*align(alignment.toByteUnits()) anyopaque;
+const log = std.log.scoped(.stbi);
+
+pub fn init(allocator: std.mem.Allocator, io: std.Io) Self {
+    return .{
+        .allocator = allocator,
+        .io = io,
+    };
+}
+
+pub fn deinit(self: *Self) void {
+    std.log.scoped(.deinit).debug("Deinitializing {*}", .{self});
+    if (self.allocated_bytes > 0) {
+        log.warn("{d} byte(s) still allocated while deinitializing", .{self.allocated_bytes});
+    }
+    if (self.allocations.size > 0) {
+        log.warn("{d} allocation(s) still tracked while deinitializing", .{self.allocations.size});
+        var it = self.allocations.iterator();
+        var index: usize = 0;
+        while (it.next()) |entry| : (index += 1) {
+            log.warn("Leaked allocation ({d}/{d}) at 0x{x} of {d} byte(s)", .{
+                index + 1,
+                self.allocations.size,
+                @intFromPtr(entry.key_ptr.*),
+                entry.value_ptr.*,
+            });
+            const memory = @as([*]align(alignment.toByteUnits()) u8, @ptrCast(@alignCast(entry.key_ptr.*)))[0..entry.value_ptr.*];
+            self.allocator.free(memory);
+        }
+    }
+
+    self.allocations.deinit(self.allocator);
+}
+
+const import = struct {
+    const stbtt__buf = extern struct {
+        data: ?[*]const u8,
+        cursor: c_int,
+        size: c_int,
+    };
+
+    const stbtt_fontinfo = extern struct {
+        userdata: ?*anyopaque,
+        data: [*]const u8,
+        fonstart: c_int,
+
+        numGlyphs: c_int,
+
+        loca: c_int,
+        head: c_int,
+        glyf: c_int,
+        hhea: c_int,
+        hmtx: c_int,
+        kern: c_int,
+        gpos: c_int,
+        svg: c_int,
+        index_map: c_int,
+        indexToLocFormat: c_int,
+
+        cff: stbtt__buf,
+        charstrings: stbtt__buf,
+        gsubrs: stbtt__buf,
+        subrs: stbtt__buf,
+        fontdicts: stbtt__buf,
+        fdselect: stbtt__buf,
+    };
+
+    const stbtt_kerningentry = extern struct {
+        glyph1: c_int,
+        glyph2: c_int,
+        advance: c_int,
+    };
+
+    const STBTT_vmove = enum(u8) {
+        STBTT_vmove = 1,
+        STBTT_vline,
+        STBTT_vcurve,
+        STBTT_vcubic,
+    };
+
+    const stbtt_vertex = extern struct {
+        x: i16,
+        y: i16,
+        cx: i16,
+        cy: i16,
+        cx1: i16,
+        cy1: i16,
+        type: STBTT_vmove,
+        padding: u8,
+    };
+
+    extern fn stbtt_GetNumberOfFonts(data: [*]const u8) c_int;
+    extern fn stbtt_GetFontOffsetForIndex(index: c_int, data: [*]const u8) c_int;
+    extern fn stbtt_InitFont(info: *stbtt_fontinfo, data: [*]const u8, offset: c_int) c_int;
+    extern fn stbtt_FindGlyphIndex(info: *const stbtt_fontinfo, unicode_codepoint: c_int) c_int;
+    extern fn stbtt_GetFontVMetrics(info: *const stbtt_fontinfo, ascent: ?*c_int, descent: ?*c_int, lineGap: ?*c_int) void;
+    extern fn stbtt_GetFontVMetricsOS2(info: *const stbtt_fontinfo, typoAscent: ?*c_int, typoDescent: ?*c_int, typoLineGap: ?*c_int) c_int;
+    extern fn stbtt_GetGlyphHMetrics(info: *const stbtt_fontinfo, glyph_index: c_int, advanceWidth: *c_int, leftSideBearing: *c_int) void;
+    extern fn stbtt_GetGlyphKernAdvance(info: *const stbtt_fontinfo, glyph1: c_int, glyph2: c_int) c_int;
+    extern fn stbtt_GetGlyphBox(info: *const stbtt_fontinfo, glyph_index: c_int, x0: *c_int, y0: *c_int, x1: *c_int, y1: *c_int) c_int;
+    extern fn stbtt_GetKerningTableLength(info: *const stbtt_fontinfo) c_int;
+    extern fn stbtt_GetKerningTable(info: *const stbtt_fontinfo, table: [*]stbtt_kerningentry, table_length: c_int) c_int;
+    extern fn stbtt_IsGlyphEmpty(info: *const stbtt_fontinfo, glyph_index: c_int) c_int;
+    extern fn stbtt_GetGlyphShape(info: *const stbtt_fontinfo, glyph_index: c_int, vertices: *[*]stbtt_vertex) c_int;
+    extern fn stbtt_FreeShape(info: *const stbtt_fontinfo, vertices: [*]stbtt_vertex) void;
+
+    extern fn stbtt_UnitsPerEm(info: *const stbtt_fontinfo) c_int;
+    extern fn stbtt_GetFontCapHeight(info: *const stbtt_fontinfo, capHeight: ?*c_int) c_int;
+};
+
+pub fn initFont(self: *Self, data: []const u8) !*Font {
+    const info = try self.allocator.create(import.stbtt_fontinfo);
+    errdefer self.allocator.destroy(info);
+
+    info.userdata = self;
+    const res = import.stbtt_InitFont(info, data.ptr, 0);
+    if (res == 0) return error.StbttError;
+
+    return @ptrCast(info);
+}
+
+pub const Font = opaque {
+    pub fn deinit(self: *Font) void {
+        const info = @as(*import.stbtt_fontinfo, @ptrCast(@alignCast(self)));
+        const stbtt = @as(*Self, @ptrCast(@alignCast(info.userdata.?)));
+        stbtt.allocator.destroy(info);
+    }
+
+    pub fn findGlyphIndex(self: *const Font, codepoint: u21) ?u32 {
+        const info = @as(*const import.stbtt_fontinfo, @ptrCast(@alignCast(self)));
+        const res = import.stbtt_FindGlyphIndex(info, codepoint);
+        return if (res != 0) @intCast(res) else null;
+    }
+
+    pub fn getGlyphBox(self: *const Font, glyph: u32) ?GlyphBox {
+        const info = @as(*const import.stbtt_fontinfo, @ptrCast(@alignCast(self)));
+        var x0: c_int = undefined;
+        var y0: c_int = undefined;
+        var x1: c_int = undefined;
+        var y1: c_int = undefined;
+        const res = import.stbtt_GetGlyphBox(info, @intCast(glyph), &x0, &y0, &x1, &y1);
+        return if (res != 0) .{
+            .x_min = @intCast(x0),
+            .y_min = @intCast(y0),
+            .x_max = @intCast(x1),
+            .y_max = @intCast(y1),
+        } else null;
+    }
+
+    pub fn unitsPerEm(self: *const Font) u16 {
+        const info = @as(*const import.stbtt_fontinfo, @ptrCast(@alignCast(self)));
+        const res = import.stbtt_UnitsPerEm(info);
+        return @intCast(res);
+    }
+
+    pub fn getCapHeight(self: *const Font) ?i16 {
+        const info = @as(*const import.stbtt_fontinfo, @ptrCast(@alignCast(self)));
+
+        var cap_height: c_int = undefined;
+        if (import.stbtt_GetFontCapHeight(info, &cap_height) != 0) {
+            return @intCast(cap_height);
+        }
+
+        if (self.findGlyphIndex('H')) |glyph| {
+            if (self.getGlyphBox(glyph)) |box| {
+                return box.y_max;
+            }
+        }
+
+        return null;
+    }
+
+    test "refAllDecls" {
+        std.testing.refAllDecls(@This());
+    }
+};
+
+pub const GlyphBox = struct {
+    x_min: i16,
+    y_min: i16,
+    x_max: i16,
+    y_max: i16,
+};
+
+// --- MALLOC INTERFACE --------------------------------------------------------
+
+export fn castle_media_stbtt_malloc(self: *Self, size: usize) callconv(.c) VoidPtr {
+    self.mutex.lock(self.io) catch return null;
+    defer self.mutex.unlock(self.io);
+
+    self.allocations.ensureUnusedCapacity(self.allocator, 1) catch return null;
+    const memory = self.allocator.alignedAlloc(u8, alignment, size) catch return null;
+
+    self.allocations.putAssumeCapacityNoClobber(memory.ptr, size);
+    self.allocated_bytes += size;
+    //log.debug("Allocated {d} bytes(s) at 0x{x}", .{ size, @intFromPtr(memory.ptr) });
+
+    return memory.ptr;
+}
+
+export fn castle_media_stbtt_free(self: *Self, maybe_ptr: VoidPtr) callconv(.c) void {
+    if (maybe_ptr) |ptr| {
+        self.mutex.lockUncancelable(self.io);
+        defer self.mutex.unlock(self.io);
+
+        const size = self.allocations.fetchRemove(ptr).?.value;
+        self.allocated_bytes -= size;
+        const memory = @as([*]align(alignment.toByteUnits()) u8, @ptrCast(ptr))[0..size];
+
+        self.allocator.free(memory);
+    }
+}
+
+test "refAllDecls" {
+    std.testing.refAllDecls(@This());
+}

packages/media/src/stbtt/stb_truetype.c

@@ -0,0 +1,24 @@
+#include <stddef.h>
+
+void *castle_media_stbtt_malloc(void *self, size_t size);
+void castle_media_stbtt_free(void *self, void *ptr);
+
+#define STBTT_malloc(size, self) castle_media_stbtt_malloc(self, size)
+#define STBTT_free(ptr, self) castle_media_stbtt_free(self, ptr)
+
+#define STB_TRUETYPE_IMPLEMENTATION
+#include "stb_truetype.h"
+
+STBTT_DEF int stbtt_UnitsPerEm(const stbtt_fontinfo *info)
+{
+   return ttUSHORT(info->data + info->head + 18);
+}
+
+STBTT_DEF int stbtt_GetFontCapHeight(const stbtt_fontinfo *info, int *capHeight)
+{
+   int tab = stbtt__find_table(info->data, info->fontstart, "OS/2");
+   if (!tab || ttUSHORT(info->data+tab) < 2)
+      return 0;
+   if (capHeight) *capHeight = ttSHORT(info->data+tab + 88);
+   return 1;
+}