add tilesheet.zig

src/app.zig

@@ -3,15 +3,13 @@ const log = std.log.scoped(.app);
 const assert = std.debug.assert;
 const Allocator = std.mem.Allocator;
 
-const Math = @import("math");
-const Vec2 = Math.Vec2;
-
 const STBImage = @import("stb_image");
 const STBTrueType = @import("stb_truetype");
 const Tiled = @import("tiled");
 
 const Platform = @import("platform/root.zig");
 const Gfx = Platform.Gfx;
+const Vec2 = Platform.Vec2;
 const Audio = Platform.Audio;
 const ImGUI = Platform.ImGUI;
 const Rect = Platform.Rect;
@@ -19,6 +17,7 @@ const Color = Platform.Color;
 
 const CanvasScaler = @import("./canvas_scaler.zig");
 const Font = @import("./font.zig");
+const Tilesheet = @import("./tilesheet.zig");
 
 const App = @This();
 
@@ -115,55 +114,6 @@ footstep_sound: Audio.SoundId = .nil,
 
 sfx_bus: Audio.BusId,
 
-const Tilesheet = struct {
-    image: Gfx.ImageData,
-    sprites: []Gfx.Sprite.Id,
-    tile_size: Vec2,
-    width: u32,
-    height: u32,
-
-    pub fn init(gpa: Allocator, image: Gfx.ImageData, tile_width: u32, tile_height: u32) !Tilesheet {
-        const width = image.width / tile_width;
-        const height = image.height / tile_height;
-        const sprites = try gpa.alloc(Gfx.Sprite.Id, width * height);
-        errdefer gpa.free(sprites);
-        @memset(sprites, .nil);
-
-        return Tilesheet{
-            .sprites = sprites,
-            .image = image,
-            .width = width,
-            .height = height,
-            .tile_size = .initFromInt(u32, tile_width, tile_height)
-        };
-    }
-
-    pub fn deinit(self: Tilesheet) void {
-        for (self.sprites) |sprite| {
-            Gfx.deinitSprite(sprite);
-        }
-    }
-
-    pub fn get(self: Tilesheet, x: usize, y: usize) Gfx.Sprite.Id {
-        if (x >= self.width or y >= self.height) {
-            log.warn("Attempt to get tile which is out of bounds", .{});
-            return .nil;
-        }
-
-        const sprite_index = y * self.width + x;
-        if (self.sprites[sprite_index] == Gfx.Sprite.Id.nil) {
-            const sprite = Gfx.initSprite(.{ .padding = 1 });
-            Gfx.setSprite(sprite, .{
-                .image = self.image,
-                .rect = Rect.init(@floatFromInt(x), @floatFromInt(y), 1, 1).multiply(self.tile_size)
-            });
-            self.sprites[sprite_index] = sprite;
-        }
-
-        return self.sprites[sprite_index];
-    }
-};
-
 pub fn init(self: *App, plt: Platform.Init) !?u8 {
     const roboto_font = try Font.init(plt.gpa, .{
         .spritesheet = Gfx.initSpritesheet(.{ .format = .r8 }),
@@ -178,7 +128,7 @@ pub fn init(self: *App, plt: Platform.Init) !?u8 {
             .height = tilesheet_png.height,
             .pixels = .{ .rgba8 = tilesheet_png.rgba8_pixels }
         },
-        64, 64,
+        .init(64, 64)
     );
 
     var player_sprites: PlayerSprites = undefined;

src/tilesheet.zig

@@ -0,0 +1,57 @@
+const std = @import("std");
+const log = std.log.scoped(.app);
+const Allocator = std.mem.Allocator;
+
+const Platform = @import("platform/root.zig");
+const Gfx = Platform.Gfx;
+const Vec2 = Platform.Vec2;
+const Rect = Platform.Rect;
+
+const Tilesheet = @This();
+
+image: Gfx.ImageData,
+sprites: []Gfx.Sprite.Id,
+tile_size: Vec2,
+width: u32,
+height: u32,
+
+pub fn init(gpa: Allocator, image: Gfx.ImageData, tile_size: Vec2) !Tilesheet {
+    const width = @divFloor(image.width, @as(u32, @intFromFloat(tile_size.x)));
+    const height = @divFloor(image.height, @as(u32, @intFromFloat(tile_size.y)));
+    const sprites = try gpa.alloc(Gfx.Sprite.Id, width * height);
+    errdefer gpa.free(sprites);
+    @memset(sprites, .nil);
+
+    return Tilesheet{
+        .sprites = sprites,
+        .image = image, 
+        .width = width,
+        .height = height,
+        .tile_size = tile_size
+    };
+}
+
+pub fn deinit(self: Tilesheet) void {
+    for (self.sprites) |sprite| {
+        Gfx.deinitSprite(sprite);
+    }
+}
+
+pub fn get(self: Tilesheet, x: usize, y: usize) Gfx.Sprite.Id {
+    if (x >= self.width or y >= self.height) {
+        log.warn("Attempt to get tile which is out of bounds", .{});
+        return .nil;
+    }
+
+    const sprite_index = y * self.width + x;
+    if (self.sprites[sprite_index] == Gfx.Sprite.Id.nil) {
+        const sprite = Gfx.initSprite(.{ .padding = 1 });
+        Gfx.setSprite(sprite, .{
+            .image = self.image,
+            .rect = Rect.init(@floatFromInt(x), @floatFromInt(y), 1, 1).multiply(self.tile_size)
+        });
+        self.sprites[sprite_index] = sprite;
+    }
+
+    return self.sprites[sprite_index];
+}