Default project loading

project.odin

@@ -2,6 +2,7 @@ package main
 
 import "core:os"
 import "core:io"
+import "core:mem"
 
 PROJECT_DATA_HEADER :: "WOWOWOW THIS IS HEADER WOWOWOW"
 PROJECT_DATA_VERSION :: 1
@@ -22,11 +23,48 @@ WriteProjectErrorType :: enum {
 
 project_write :: proc(project: ^ProjectData, path: string) -> os.Error {
 	f := os.open(path, {.Create, .Trunc, .Write}) or_return
+	defer os.close(f)
 	w := io.to_writer(os.to_stream(f))
 	version: u32 = PROJECT_DATA_VERSION
+	header := PROJECT_DATA_HEADER
+
+	io.write_full(w, transmute([]u8)header)
 	io.write_ptr(w, &version, size_of(version))
 	io.write_ptr(w, &project.matrix_count, size_of(project.matrix_count))
 	io.write_ptr(w, raw_data(project.matrices), int(project.matrix_count) * 9 * size_of(f32))
 	os.close(f)
 	return nil
 }
+
+ProjectReadError :: union {
+	os.Error,
+	io.Error,
+	ProjectReadErrorType,
+}
+
+ProjectReadErrorType :: enum {
+	FailedReadingHeader,
+	BadHeader,
+	VersionNeedsUpgrade,
+}
+
+project_read :: proc(project: ^ProjectData, path: string) -> ProjectReadError {
+	f := os.open(path, {.Read}) or_return
+	defer os.close(f)
+	r := io.to_reader(os.to_stream(f))
+	header := PROJECT_DATA_HEADER
+	header_buffer: [len(PROJECT_DATA_HEADER)]byte
+	if num, err := io.read_full(r, header_buffer[:]); err != nil {
+		return ProjectReadErrorType.FailedReadingHeader
+	}
+	if mem.compare(transmute([]byte)header[:], header_buffer[:]) != 0 {
+		return ProjectReadErrorType.BadHeader
+	}
+	version: u32
+	_ = io.read_ptr(r, &version, size_of(u32)) or_return
+	if version != PROJECT_DATA_VERSION {
+		return ProjectReadErrorType.VersionNeedsUpgrade
+	}
+	project.version = version
+	return nil
+}