Sprites and Animations

src/sprite.odin

@@ -0,0 +1,134 @@
+package main
+
+import "vendor:raylib"
+
+Sprite :: struct {
+	texture: raylib.Texture2D,
+	width:   i32,
+	height:  i32,
+	framesX: i32,
+	framesY: i32,
+}
+
+SpriteAnimation :: struct {
+	start_frame: i32,
+	end_frame:   i32,
+	fps:         i32,
+	loop:        bool,
+}
+
+SpriteAnimator :: struct {
+	anim:          ^SpriteAnimation,
+	current_frame: i32,
+	timer:         f32,
+}
+
+load_sprite :: proc(image_path: cstring, w: i32, h: i32) -> Sprite {
+	new_texture: raylib.Texture2D = raylib.LoadTexture(image_path)
+
+	new_sprite: Sprite = {
+		texture = new_texture,
+		width   = w,
+		height  = h,
+		framesX = new_texture.width / w,
+		framesY = new_texture.height / h,
+	}
+
+	return new_sprite
+}
+
+draw_sprite_frame :: proc(
+	sprite: ^Sprite,
+	frame_pos: raylib.Vector2,
+	draw_pos: raylib.Vector2,
+	flipX: bool,
+	flipY: bool,
+	color: raylib.Color,
+) {
+	widthf := f32(sprite.width)
+	heightf := f32(sprite.height)
+
+	src_width := widthf
+	src_height := heightf
+	src_x := frame_pos.x * widthf
+	src_y := frame_pos.y * heightf
+
+	if flipX {
+		src_width = -src_width
+		src_x += widthf
+	}
+
+	if flipY {
+		src_height = -src_height
+		src_y += heightf
+	}
+
+	source_rect := raylib.Rectangle {
+		x      = src_x,
+		y      = src_y,
+		width  = src_width,
+		height = src_height,
+	}
+
+	dest_rect := raylib.Rectangle {
+		x      = draw_pos.x,
+		y      = draw_pos.y,
+		width  = widthf,
+		height = heightf,
+	}
+
+	// origin := raylib.Vector2{widthf * 0.5, heightf * 0.5}
+	// dest_rect.x = draw_pos.x + widthf * 0.5
+	// dest_rect.y = draw_pos.y + heightf * 0.5
+
+	origin := raylib.Vector2{0, 0}
+
+	raylib.DrawTexturePro(sprite.texture, source_rect, dest_rect, origin, 0.0, color)
+}
+
+set_sprite_animation :: proc(animator: ^SpriteAnimator, new_anim: ^SpriteAnimation) {
+	if (animator.anim == new_anim) do return
+
+	animator.anim = new_anim
+	animator.timer = 0
+	animator.current_frame = new_anim.start_frame
+}
+
+draw_sprite_animated :: proc(
+	sprite: ^Sprite,
+	animator: ^SpriteAnimator,
+	draw_pos: raylib.Vector2,
+	flipX: bool,
+	flipY: bool,
+	color: raylib.Color,
+) {
+	frame_pos := frame_to_xy(sprite, animator.current_frame)
+	draw_sprite_frame(sprite, frame_pos, draw_pos, flipX, flipY, color)
+}
+
+update_animator :: proc(a: ^SpriteAnimator, delta: f32) {
+	if a.anim == nil do return
+
+	frame_time := 1.0 / f32(a.anim.fps)
+	a.timer += delta
+
+	if (a.timer >= frame_time) {
+		a.timer -= frame_time
+		a.current_frame += 1
+
+		if (a.current_frame > a.anim.end_frame) {
+			if (a.anim.loop) {
+				a.current_frame = a.anim.start_frame
+			} else {
+				a.current_frame = a.anim.end_frame
+			}
+		}
+	}
+}
+
+frame_to_xy :: proc(sprite: ^Sprite, frame: i32) -> raylib.Vector2 {
+	x := frame % sprite.framesX
+	y := frame / sprite.framesX
+	return raylib.Vector2{f32(x), f32(y)}
+}
+