diff options
Diffstat (limited to 'src/image.zig')
| -rw-r--r-- | src/image.zig | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/src/image.zig b/src/image.zig index 071a2e2a..7b081ec6 100644 --- a/src/image.zig +++ b/src/image.zig @@ -732,11 +732,28 @@ test "native geometry is total at extreme accepted aspect ratios" { /// call once at startup / exit (stb_image's allocator shim) pub fn start(io: std.Io, gpa: std.mem.Allocator) void { zstbi.init(io, gpa); + started = true; } pub fn stop() void { + started = false; zstbi.deinit(); } +/// stb_image has its allocator (`start`): before, nothing of it may run. +var started = false; + +extern fn stbi_info_from_memory(buffer: [*]const u8, len: c_int, x: *c_int, y: *c_int, comp: *c_int) c_int; + +/// Whether `bytes` are an image `decode` can read, from its header alone. +pub fn readable(bytes: []const u8) bool { + if (bytes.len == 0 or bytes.len > std.math.maxInt(c_int)) return false; + var w: c_int = 0; + var h: c_int = 0; + var c: c_int = 0; + if (!started) return true; // ponytail: no stb_image yet (a unit test), so no judging + return stbi_info_from_memory(bytes.ptr, @intCast(bytes.len), &w, &h, &c) == 1; +} + /// decode + downscale to RGBA, gpa-owned. Returns null on any failure — the /// pane then simply shows a blank body. pub fn decode(gpa: std.mem.Allocator, bytes: []const u8) ?struct { rgba: []u8, w: usize, h: usize } { |