font atlas creates glyph records

This commit is contained in:
Mitchell Hashimoto
2022-04-05 19:21:49 -07:00
parent 876d316cda
commit d51ed2536c

View File

@ -103,17 +103,25 @@ pub fn loadFaceFromMemory(self: *FontAtlas, source: [:0]const u8, size: u32) !vo
return error.FaceLoadFailed;
}
/// Get the glyph for the given codepoint.
pub fn getGlyph(self: *FontAtlas, v: anytype) ?*Glyph {
const utf32 = codepoint(v);
const entry = self.glyphs.getEntry(utf32) orelse return null;
return entry.value_ptr;
}
/// Add a glyph to the font atlas. The codepoint can be either a u8 or
/// []const u8 depending on if you know it is ASCII or must be UTF-8 decoded.
pub fn addGlyph(self: *FontAtlas, alloc: Allocator, codepoint: anytype) !void {
pub fn addGlyph(self: *FontAtlas, alloc: Allocator, v: anytype) !void {
assert(self.ft_face != null);
// We need a UTF32 codepoint for freetype
const utf32 = switch (@TypeOf(codepoint)) {
comptime_int, u8 => @intCast(u32, codepoint),
[]const u8 => @intCast(u32, try std.unicode.utfDecode(codepoint)),
else => @compileError("invalid codepoint type"),
};
const utf32 = codepoint(v);
// If we have this glyph loaded already then we're done.
const gop = try self.glyphs.getOrPut(alloc, utf32);
if (gop.found_existing) return;
errdefer _ = self.glyphs.remove(utf32);
const glyph_index = ftc.FT_Get_Char_Index(self.ft_face, utf32);
@ -153,7 +161,6 @@ pub fn addGlyph(self: *FontAtlas, alloc: Allocator, codepoint: anytype) !void {
assert(region.height == tgt_h);
self.atlas.set(region, buffer);
const gop = try self.glyphs.getOrPut(alloc, utf32);
gop.value_ptr.* = .{
.width = tgt_w,
.height = tgt_h,
@ -167,6 +174,16 @@ pub fn addGlyph(self: *FontAtlas, alloc: Allocator, codepoint: anytype) !void {
};
}
/// Returns the UTF-32 codepoint for the given value.
fn codepoint(v: anytype) u32 {
// We need a UTF32 codepoint for freetype
return switch (@TypeOf(v)) {
comptime_int, u8 => @intCast(u32, v),
[]const u8 => @intCast(u32, try std.unicode.utfDecode(v)),
else => @compileError("invalid codepoint type"),
};
}
test {
const alloc = testing.allocator;
var font = try init(try Atlas.init(alloc, 512));
@ -180,6 +197,11 @@ test {
while (i < 127) : (i += 1) {
try font.addGlyph(alloc, i);
}
i = 32;
while (i < 127) : (i += 1) {
try testing.expect(font.getGlyph(i) != null);
}
}
const testFont = @embedFile("../fonts/Inconsolata-Regular.ttf");