abstracting to engine package

engine/character_data.odin

@@ -0,0 +1,108 @@
+package engine
+
+import "core:encoding/json"
+import "core:fmt"
+import "core:os"
+import "core:path/filepath"
+import "core:strings"
+import sdl "vendor:sdl3"
+
+Frame_Def :: struct {
+	rect:        [4]int,
+	source_size: [2]int,
+	trim_offset: [2]int,
+}
+
+Clip_Def :: struct {
+	loop:   bool,
+	fps:    f32,
+	frames: []Frame_Def,
+}
+
+Char_Def :: struct {
+	version:         int,
+	id:              string,
+	atlas:           string,
+	pixels_per_unit: f32,
+	pivot:           [2]f32,
+	clips:           map[string]Clip_Def,
+}
+
+Character_Data :: struct {
+	def:     Char_Def,
+	texture: ^sdl.Texture,
+}
+
+load_character_data :: proc(
+	renderer: ^sdl.Renderer,
+	character_json_path: string,
+) -> (
+	Character_Data,
+	bool,
+) {
+	file_data, read_err := os.read_entire_file(character_json_path, context.allocator)
+	if read_err != nil {
+		fmt.eprintfln("failed to read %s: %v", character_json_path, read_err)
+		return {}, false
+	}
+
+	defer delete(file_data)
+
+	out: Character_Data
+	if err := json.unmarshal(file_data, &out.def); err != nil {
+		fmt.eprintfln("json unmarshal failed: %v", err)
+		return {}, false
+	}
+
+	// filepath.dir returns a substring of the path — do NOT delete it
+	dir := filepath.dir(character_json_path)
+
+	atlas_path, join_err := filepath.join({dir, out.def.atlas})
+	if join_err != nil {
+		fmt.eprintfln("atlas join failed: %v", join_err)
+		return {}, false
+	}
+
+	defer delete(atlas_path)
+
+	c_path := strings.clone_to_cstring(atlas_path)
+	defer delete(c_path)
+
+	surface := sdl.LoadPNG(c_path)
+	if surface == nil {
+		fmt.eprintfln("LoadPNG failed: %s", sdl.GetError())
+		return {}, false
+	}
+	defer sdl.DestroySurface(surface)
+
+	out.texture = sdl.CreateTextureFromSurface(renderer, surface)
+	if out.texture == nil {
+		fmt.eprintfln("CreateTextureFromSurface failed: %s", sdl.GetError())
+		return {}, false
+	}
+	sdl.SetTextureScaleMode(out.texture, .NEAREST)
+	return out, true
+}
+
+destroy_character_data :: proc(data: ^Character_Data) {
+	if data.texture != nil {
+		sdl.DestroyTexture(data.texture)
+	}
+	data^ = {}
+}
+
+character_frame_rect :: proc(
+	data: ^Character_Data,
+	clip_name: string,
+	frame_index: int,
+) -> (
+	rect: [4]int,
+	ok: bool,
+) {
+	clip, found := data.def.clips[clip_name]
+	if !found || frame_index < 0 || frame_index >= len(clip.frames) {
+		return {}, false
+	}
+
+	return clip.frames[frame_index].rect, true
+}